@article {1007, title = {Detecting changes in along-path HF propagation during the April 2024 total solar eclipse with radio amateurs and low-cost instrumentation}, journal = {Frontiers in Astronomy and Space Sciences}, year = {2026}, month = {Feb/2026}, abstract = {

The total solar eclipse of April 8, 2024 presented a uniquely favorable circumstance for radio science. The Moon{\textquoteright}s shadow passed near Canadian time standard station CHU, which transmits in the high frequency (HF,\ i.e., 3{\textendash}30 MHz) band. It was therefore possible to observe signal changes due to shifting ionospheric conditions along the path of the eclipse by using CHU as a signal of opportunity. In under 3 months, our undergraduate team developed and deployed low-cost instrumentation to record CHU for timing and amplitude analysis. 18 units were distributed across 6 locations roughly aligned with the eclipse path. Each unit contained a radio recorder which retained time traceability to UTC via GPS time synchronization, allowing capture of the CHU signal with no unbounded error beyond the 50 {\textmu}s sampling interval. Seven units captured changes in the received signal during the eclipse, most notably a tenfold increase in the signal strength at 7.85 MHz for a unit in Little Rock, AR. Its timing suggests a one-hop propagation path reflecting in the ionosphere over Cleveland, OH. The stations were deployed to and maintained by volunteers contacted through the amateur radio and citizen science community. This campaign demonstrates the accessibility and effectiveness of research using low-cost instrumentation and the power of citizen science.

}, doi = {10.3389/fspas.2025.1720301}, url = {https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2025.1720301/full}, author = {Maris Usis and Adam Goodman and Laura Schwartz and David Kazdan and Kristina Collins and John Gibbons and Shashank Sastry and Lucy Ayres and Christopher Brault and Seth Byas and Michael Dimple and Michelle Dowell and Rowan Eggert and Aras Erdag and James Ervin and Dave Goodwin and Scarlett Nelson and Stephen Nichols and Olivia Tulgetske and Christian Zorman} } @proceedings {1018, title = {The Heliophysics Application Programming Interface on the PSWS}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {One of the major enhancements being developed for the Personal Space Weather Network System is our implementation of the Heliophysics Application Programming Interface. This interface is being developed with help from Dr Robert Weigel of George Mason University to make HamSCI data more accessible to researchers. In the first version of the PSWS system, users have been able to download individual files to analysis, but this can be labor intensive and time-consuming if a lot of files are needed. The current NSF-funded effort will make the data more easily accessible to users by leveraging Python libraries that make data access transparent, such as hapiclient, hapiplot, hdpws, And SwarmPAL. This poster gives an overview of what will be included and how you will be able to use it.}, author = {William Engelke and Travis Atkison and Evan Hardt and Christian Hirschey and Gavin Ward and Annika Lee} } @proceedings {1040, title = {Introduction to Baseband Processing}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {Today, much RF digital signal processing is done at baseband, defined here as a signal with frequencies centered around DC or 0 Hz. Baseband processing is somewhat analogous to using an intermediate frequency (IF), as done in a superheterodyne receiver with typical IF frequencies of 455 kHz (AM) or 10.7 MHz (FM), but where the IF is at 0 Hz and where the resulting baseband signal contains both positive and negative frequencies. Just as intermediate frequencies of superheterodyne receivers gave advantages in analog receivers, baseband processing gives certain advantages in digital receivers. Furthermore, most modern Software Defined Radios output in-phase / quadrature (IQ) data streams, containing both amplitude and phase information and centered at baseband. This includes the IQ output of the popular {\textquotedblleft}ka9q-radio{\textquotedblright} software environment used in HamSCI development of the Personal Space Weather Station system. A good understanding of baseband processing and its typical applications is thus useful. In this tutorial, we will introduce a common definition of baseband processing and explore its uses. The presentation will include a reminder of Fourier / frequency domain and complex signal representations. We will discuss the advantages of processing of IQ signals at baseband and will give examples of their use in common tasks. These include signal demodulation and filtering, including asymmetric filtering around 0 Hz. A brief discussion on creating a baseband signal from a non-baseband signal and converting a baseband signal to a non-baseband signal will also be presented. Interactive demonstrations will be provided as well for active learning, easy modification, and experimentation. }, author = {Bill Liles and Philip Erickson and Ethan Miller} } @proceedings {1022, title = {A Low-Cost Low-Power Chirp Ionosonde for Studying the Ionospheric Impacts of Space Weather}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {The ionosphere is a region of the atmosphere characterized by both ions and electrons. It is highly active and experiences changes in parameters such as electron density at different altitudes, based on the energy absorbed from the sun. Ionosondes are a type of radar used to gather data about the height of the ionosphere by transmitting a signal towards the ionosphere. This signal is refracted back to the Earth{\textquoteright}s surface and received in such a manner that return echoes can be timed to calculate the height profile of the bottomside ionosphere. Traditional ionosondes require large antenna systems and high amounts of power. Recent advancements in software defined radio (SDR) technology, advanced digital signal processing, and computational efficiency enable the size, cost, and power demands of an ionosonde system to be reduced. An Ettus N200 Universal Radio Peripheral was used in our system to verify the reliability of our methods, and during the 2024 total solar eclipse, the system was successfully used to sound the ionosphere. It recorded virtual layer height data comparable to multimillion-dollar ionosonde systems. Since then, we have updated the system to use the newer Red Pitaya SDRlab 122-16. This more affordable board is able to sound the ionosphere, using the same methods as the Ettus based system. Additionally, the system is now in a smaller and more portable form. Currently, we are improving its ability to collect data automatically and be controlled remotely. Furthermore, we are continuing to improve our sounding methods to obtain more data using the same hardware.}, author = {Gerard Piccini and Andrew Rodland and Robert McGwier and Robert Spalletta and Nathaniel Frissell and Majid Mokhtari and Philip Erickson} } @proceedings {1014, title = {Multi-Year Climatology of Large-Scale Traveling Ionospheric Disturbances Observed with High Frequency Amateur Radio Receiving Networks Using a Novel Automated Detection Algorithm}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {We present a fully automated, deterministic technique for detecting and characterizing Large Scale Traveling Ionospheric Disturbances (LSTIDs) using 14 MHz amateur (ham) radio data. The method isolates wave periods between 1{\textendash}5 hours and applies sinusoidal curve fitting to the first-hop skip-distance edge of observed communication ranges, yielding quantitative estimates of LSTID amplitude and period. Data from the Weak Signal Propagation Reporting Network (WSPRNet), the Reverse Beacon Network (RBN), and PSKReporter, which is now merged and available on the CEDAR Madrigal database, were used produce a unified multi-year climatology of LSTID activity over the continental United States (2016{\textendash}2023). Results show clear seasonal patterns: enhanced LSTID occurrence during winter, weaker activity in spring and fall, and modest summer increases. These results are consistent with prior studies and suggest modulation by neutral wind filtering, sudden stratospheric warming (SSW), vertical coupling, and solar activity.}, author = {Diego Sanchez and Mary Lou West and Nathaniel Frissell and Gareth Perry and V. Lynn Harve and Bill Engelke and Nicholas Callahan and Philip Erickso and Erich Becker and Sharon Vadas} } @proceedings {1034, title = {The Personal Space Weather Network System and Its Development}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {

This talk gives an overview of the Personal Space Weather Network system : overall architecture, how uploading of data from stations works, how data is visualized and cross-referenced. It explains how to find data based on your research interests, with tips on how to work with digital_rf datasets (a large part of the collection), with examples of analysis work previously done. Finally, it includes an overview of the enhancements that are planned to be implemented over the next 2 to 3 years.

}, author = {Christian Hirschey and Gavin Ward and William Engelke and Evan Hardt and Annika Lee and Travis Atkinson} } @proceedings {1044, title = {A Python data analysis and synthesis toolbox for PSWS Doppler data: A time-of flight case study}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {A prototype Python toolbox is available to aid HamSCI Personal Space Weather Station (PSWS) data interpretation1. The toolbox currently has two themes. First, a set of frequency- (FFT) and time-domain (autocorrelation) scripts for estimating and plotting Doppler frequency, Doppler spread and signal level of PSWS digital_RF data. For bimodal spectra an experimental script estimates Doppler of two peaks, assigns to propagation modes and tries to track even if they cross. Second, a set of scripts invoking PyLap 2D and 3D ray tracing to obtain synthetic spectrograms of one- and two-hop E and F region, low and high ray, propagation modes. Time series of take-off angle, reflection apogee and time of flight (ToF) are derived from automated PyLap simulations. Novel ToF measurements between WWV and KD7EFG, Utah, provide an interpretation challenge case study. Apogee height simulation time series show expected propagation modes, importantly showing periods with two co-propagating modes, and, by omission, suggesting when sporadic E (Es) was present. 5 MHz Es propagation, with minimal vertical height variability, and ToF of 2.12 ms, provided the benchmark to show consistent ToF measurements within 60 us. The more dynamic F region gave rise to commensurate variations in ToF. However, ToF estimates became scattered with two co-propagating modes from WWV (e.g. 5 MHz E and F). 15 MHz Es propagation showed consistent ToF of 2.19 ms from a weak signal 50 dB below one-hop F2. Fascinatingly, an interval with ToF of 14 ms reducing to 8 ms from a weak but strengthening signal was attributed, with certainty, to two-hop sidescatter using 3D PyLap simulation. One-hop via F region only occurred briefly, with correct ToF of 2.81 ms. As the 15 MHz path from WWVH opened, with a strong signal seen in Doppler shift, ToF measurements on the path from WWV, of weak two hop sidescatter, became very scattered. This case study shows the importance of being able to use PSWS Doppler analysis to interpret new ToF measurements. In conclusion, these results herald a significant advance in the HamSCI Community{\textquoteright}s ability to characterize ionospheric propagation channels. }, author = {Gwyn Griffiths and Scott Newell and Paul Elliott and Clint Turner and Brett Anderson and Michael Hauan and Rob Robinett} } @proceedings {1036, title = {Radio Propagation Time Of Flight Measurements:}, year = {2026}, month = {03/2026}, publisher = {HamSCI}, address = {Newington, CT}, abstract = {

Time Of Flight measurements over multiple paths can be a valuable tool when validating and refining radio propagation models. This presentation will discuss current methods in use and several new projects and designs that are being developed for the HamSCI PSWS program. These will include the {\textquotedblleft}Time-Sync Injector{\textquotedblright} and associated software, which is used with an Software Defined Radio such as the RX-888 to allow accurate Time Of Arrival measurement of received signals. Also described will be the {\textquotedblleft}Time-Stamp Transmitter{\textquotedblright}, which generates flexible-format time-stamped signals, and a new receiver design, based on the RX-888, but intended to serve as a platform for future time and frequency measurement projects.

}, author = {Nathaniel Frissell and Scott Newell and Rob Robinett and Clinton Turner and Gwyn Griffiths and Paul Elliott} } @proceedings {931, title = {Analysis by Citizen Scientists of Doppler Radio Observations of the April, 2024 Solar Eclipse}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI community (Ham Radio Science Citizen Investigation) has analyzed high frequency radio observations of the total solar eclipse of April 8, 2024 and found interesting correlations. Nearly fifty ham radio operators recorded over 200 Doppler time series of the national time standard transmitters WWV in Colorado and CHU in Canada using specialized GRAPE (Great Radio Amateur Propagation Experiment) receivers. These observations are archived at the Personal Space Weather Station website, and cover ten frequencies from 0.6 to 25 MHz. There were over sixty different paths from transmitter to receiver at various angles across and along the path of totality from Texas to Maine. For each observation six citizen scientists collected demographic data, found distances and midpoints (where radio signals are reflected from the ionosphere), noted local eclipse information, measured the maximum Doppler shifts, counted multi-path signals, and judged the symmetry of the S-shaped Doppler curves over ingress and egress time periods. We found that the Doppler shifts depend mostly on the Sun{\textquoteright}s obscuration at the midpoint, but also on the carrier frequency and the distance between the transmitter and the receiver. At closer distances a radio wave measured a greater change in the path length as the bottom of the ionosphere retreated skyward and then returned as the Moon uncovered the Sun. \ 

}, author = {Mary Lou West and Nathaniel Frissell and Gary Mikitin and Gregory Popelas and Ronald Wilcox and McKenzie Denton and Robert Spalletta and William Engelke and Gwyn Griffiths and Steve Cerwin} } @proceedings {949, title = {Climatology of Large-Scale Traveling Ionospheric Disturbances Observed with 14 MHz Amateur Radio Using a Novel Automated Detection Technique}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present a multi-year climatology of Large Scale Traveling Ionospheric Disturbance (LSTID) period oscillations observed using 14 MHz amateur (ham) radio data. Traveling ionospheric disturbances (TIDs) are quasi periodic electron density perturbations in the F region ionosphere that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. These are seen, in daytime, as variations in contact ranges in 14 MHz amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet), the Reverse Beacon Network (RBN), and PSKReporter. A new deterministic and fully automated method was developed for identifying and quantifying these disturbances. This technique, which filters for TID wave periods between 1 and 5 hours and curve fits a sinusoidal function to the first hop skip-distance edge of observed communication ranges, provides both TID amplitudes and periods. In this study, we present full year climatologies of LSTID events over the continental United States (CONUS) using RBN, WSPRNet, and PSK observations from 2016- 2021. Results are organized as a function wave period, amplitude, and season. We find that LSTIDs increase in winter and decline during the fall and spring, with slight enhancements in the summer and occasional brief declines in LSTID winter activity. This seasonal pattern shows consistency with previous studies and observations of LSTIDs and medium scale TIDs that suggests this behavior may be associated with neutral wind filtering in the middle atmosphere, sudden stratospheric warming (SSW) events, and multi-step vertical coupling (MSVC) processes. MSVC is a process where gravity waves (GWs) from the lower neutral atmosphere propagate upwards, break, and produce new, higher-order GWs in the thermosphere and TIDs in the ionosphere.

}, author = {Diego Sanchez and Nathaniel Frissell and Mary Lou West and V. Lynn Harvey and Sharon Vadas and Erich Becker and Gareth Perry and William Engelke and Nicholas Callahan and Philip Erickson} } @proceedings {941, title = {Generating and Receiving GPS-Timed Acoustic and Radiofrequency Costas Array Sounding Signals}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Understanding the static and dynamic properties of the ionosphere is of great fundamental and technological importance. This work presents a low-cost, GPS-disciplined transmitter/receiver system that uses Costas arrays similar to those in FT8 to achieve simultaneous time-of-flight and Doppler shift measurements. The sharp correlation peaks in both frequency and time domains of the Costas arrays may allow for the study of difficult-to-measure properties of the HF propagation, such as the number of hops, ionospheric propagation type, etc. The narrow bandwidth and optimal autocorrelation properties also make the Costas array a good signal for the moderate noise of the HF bands and allows for QRP (low-power, under 5W) operation. Our hardware design consists of a microcontroller coupled with an AD9850 direct digital synthesis chip and an external 50 MHz crystal oscillator, as well as an Adafruit GPS module with a 1PPS signal. Our device is designed to interface with standard amateur radio transceivers for both transmission and reception. Its open-source architecture and reliance on readily available off-the-shelf parts make it easily reproducible, and suitable for rapid deployment. Some hams and institutions have already expressed interest in deploying units for coordinated data collection. By offering inexpensive, scalable, and accurate ionospheric sounding capabilities, this project aims to support ongoing research of the ionosphere and HF propagation.

}, author = {Solomon El-Ghannam and Andres Dickson Alarcon and Yaodan Zhang} } @proceedings {929, title = {HamSCI Solar Eclipse QSO Party (SEQP): Observations and Modeling on Ionospheric Effects}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

This study investigates the ionospheric changes during the solar eclipse of April 2024 using data from the HamSCI Solar Eclipse QSO Party (SEQP). SEQP collected radio communication data reported by ham radio operators and global automated receiving networks (e.g., WSPRNet, the Reverse Beacon Network, and PSKReporter). The datasets include radio communications at multiple frequencies in the high frequency (HF) and very high frequency (VHF) bands. Thousands of ham radio operators across the contiguous United States (CONUS) and around the globe contributed to the observations with unprecedented temporal, spatial, and spectral coverage. SEQP datasets are used to infer ionospheric state before, during, and after the solar eclipse. We use the ham radio datasets along with PHaRLAP raytrace modeling to infer the ionospheric response of the solar eclipse and also evaluate the outputs of the physics-based model SAMI3 for the eclipse ionosphere. Our findings suggest that the solar eclipse increased the range of radio communications at lower HF band (3.5, 7, 10 MHz), but decreased the longer range communications at higher HF band (21, 24, 28 MHz). Ham radio datasets from stations continually operated during the eclipse show an earlier opening of radio links between the US and Europe on the eclipse day. We are conducting modeling studies to understand the causes of changes in ham radio observations and to examine the potential combined effect of the sunset terminator and eclipse shadow during the later phase of the eclipse.

}, author = {Kuldeep Pandey and Gareth Perry and Nathaniel Frissell and Travis Atkinson and William Engelke and Joseph Huba and Mary Lou West and Philip Gladstone and Cameron Cushing and McKenzie Denton and Edward Efchak and Gary Mikitin and H. Ward Silver} } @proceedings {957, title = {How Do We Put a HamSCI Personal Space Weather Station in Antarctica?}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present initial ideas on how to place a HamSCI Personal Space Weather Station at United States Antarctic Research Stations.

}, author = {Rebecca Potter and Nina Tormann and Christine Zakzewski and Majid Mokhtari and Nathaniel Frissell and Ken Martin and Jermey McLynch and Hyomin Kim and Gareth Perry and David McGaw and James LaBelle and Tedi Godfrey and Michael Hartje and Gwyn Griffiths and Rob Robinett and Paul Elliott} } @proceedings {926, title = {Interim Findings of the HamSCI DASI2 HF Antenna Project}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

An ad hoc HamSCI DASI2 Antenna Group was tasked in late 2024 with evaluation of antenna options for the DASI2 grant. We present the the materials, methods, and criteria we have so far developed to accomplish this along with preliminary results. \ Antenna systems under consideration include DXE-RSEAV-1FVI, N6GN SAS, LZ1AQ loop dipole, and others. \ The materials include key elements already intended for use in the grant -- the RX888-SDR and software such as the KA9Q-Radio system, the KA9Q-Web spectrum display, WSPRDAEMON, and spot and noise reception reports to wspr.net, wsprdaemon.org, and pskreporter. \ The methods leverage ITU noise figures, known broadcast station locations, significant recent improvements in the spectrum display, and analysis of the local site. \ The criteria so far include antenna performance metrics, site evaluation, ease of deployment, support needs, and cost. This effort will enable us to provide good quality information, some of which we present, for selecting an appropriate antenna for the grant. \ However, the effort to solve this particular task has also demonstrated the general utility of these tools and methods for the amateur radio community. \ A view of the entire HF spectrum enable at-a-glance assessments that can help one more effectively identify and solve problems and optimize reception given the natural limitations of one{\textquoteright}s site. \ One can see recognizable patterns suggesting local and propagated noise, overmodulation, aliasing, inadequate front-end gain, ground loops, and more. \ One can compare two (or more) antennas or one antenna with itself at different sites or orientations, the effects of feed-line placement, interactions with nearby structures or foliage, and more. \ These efforts will inform the choice of an antenna to use for the DASI2 grant but can prove immediately useful for all hams and scientists in understanding and optimizing their receiving systems.

}, author = {Michael Hauan and Glenn Elmore and Rob Robinett and Gwyn Griffiths and Dve Witten and Ulli Grunow and Clint Turner} } @proceedings {961, title = {A Low-Cost Low-Power Chirp Ionosonde for Studying Eclipse Ionospheric Impacts}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The ionosphere is a region of the atmosphere characterized by both ions and electrons. It is highly active and experiences changes in parameters such as electron density at different altitudes, based on the energy absorbed from the sun. Ionosondes are a type of radar used to gather data about the height of the ionosphere by transmitting a signal towards the ionosphere.\  This signal is refracted back to the Earth{\textquoteright}s surface and received in such a manner that return echoes can be timed to calculate the height profile of the bottomside ionosphere. Traditional ionosondes require large antenna systems and high amounts of power. Recent advancements in software defined radio (SDR) technology, advanced digital signal processing (DSP), and computational efficiency enable the size, cost, and power demands of an ionosonde system to be reduced. Two systems are currently used in this project: the Ettus N200 Universal Radio Peripheral (USRP) and the newer Red Pitaya SDRlab 122-16. Using amateur radio fan dipoles and GNU Radio code, the Ettus system was used successfully to sound the ionosphere during the 2024 total solar eclipse. It recorded virtual layer height data comparable to multimillion-dollar ionosonde systems. We are now working to assemble the Red Pitaya system into a smaller form that can be assembled inexpensively and operated with ease. In the following weeks we will improve our sounding methods to be able to obtain more data.

}, author = {Gerard Piccini and Robert McGwier and Robert Spaletta and Nathaniel Frissell and Majid Mokhtari and Philip Erickson} } @proceedings {966, title = {Machine learning applied to the ray tracing model of the OTH radar}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

Over-the-horizon skywave radar (OTHR) uses reflections in the Earth{\textquoteright}s ionosphere to detect targets at very long ranges. To achieve detection, the electromagnetic energy emitted by the radar must follow a specific path with the target as its endpoint. This propagation path is strongly dependent on three factors: the direction of emission, the frequency of the electromagnetic wave and the conditions of the propagation medium, in particular the dynamic and complex characteristics of the ionosphere. From the above, it can be concluded that for this type of radar, the prior determination of the wave propagation path is essential for the correct operation of the system. In this work we are presenting the first results of a computational model based on Machine Learning to predict the propagation path of an electromagnetic wave emitted by an OTHR. A variety of ray tracing models are currently available. These models can range from very simple versions using analytical equations to versions that find the propagation path by solving a system of differential equations using numerical integration methods. The proposed model will provide solutions to the main disadvantages of traditional ray tracing models based on systems of differential equations, such as: Speed of response: once trained, the neural network model is able to respond to new queries almost instantaneously; Adaptive capability: unlike traditional models, neural networks can be retrained or adapted to incorporate new data and scenarios, improving accuracy, and, finally Reduced computing resources: optimised neural network models can run on less demanding hardware than numerical integration methods.

}, author = {Zenon Saavedra and Alexis Vale and Ana Georgina Elias} } @proceedings {925, title = {Software Development for the Grape Personal Space Weather Station v2}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The Grape 2 is a three-channel radio receiver and an integral component of the broader Personal Space Weather Station (PSWS) project. The PSWS network is a distributed array of radio receivers designed to continuously monitor changes in the Earth{\textquoteright}s ionosphere. It achieves this by tracking frequency standard stations, such as WWV, WWVH, and CHU, on a 24/7 basis. The system includes software tools for control and monitoring. Each Grape station transmits daily data to a centralized, publicly accessible database hosted by the University of Alabama, where automated processing generates spectrograms. These visualizations provide researchers with rapid insights into ionospheric conditions and enable long-term studies of space weather phenomena.\ 

}, author = {Cuong Nguyen and Nathaniel Frissell and John Gibbons and Bill Blackwell and Bill Engelke} } @proceedings {879, title = {Automated Methods for Studying Long Scale Ionospheric Disturbances and Climatology}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

During the last year we have been pushing forward with improving our methods for detecting and studying Large Scale Ionospheric Disturbances (LSTIDs) using amateur radio spots from the RBN, WSPR, and PSK databases. We now have automated systems in place to collect and archive these data daily. We developed a way to detect the minimum useful range and extract a curve from that; we can then use a Fast Fourier Transform (FFT) to estimate the period, amplitude, and occurrences of these LSTIDs, leading to an improvement in our capability to study the climatology (long term trends) of these waves in plasma density.

}, author = {William D. Engelke} } @proceedings {820, title = {Citizen Science: Development of a Low-Cost Magnetometer System for a Coordinated Space Weather Monitoring}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of ~3 nT at a 1 Hz sample rate. Crowd-sourced data from the PSWS systems will be collected into a central archive for the purpose of public access and analyzation along with space weather research. Ultimately, data from the PSWS network will combine the magnetometer measurements with high frequency (HF, 3-30 MHz) radio observations to monitor large scale current systems and ionospheric disturbances and events due to drivers from space and the atmosphere alike. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is entirely satisfactory for scientific investigations.

}, author = {Joseph Visone and Hyomin Kim and David Witten and Julius Madey and Nathaniel A. Frissell and John Gibbons and William D. Engelke and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @article {913, title = {Citizen science: Development of a low-cost magnetometer system for a coordinated space weather monitoring}, journal = {HardwareX}, volume = {20}, year = {2024}, month = {Jan-12-2024}, pages = {e00580}, abstract = {
As part of Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project, a low-cost, commercial off-the-shelf magnetometer has been developed to provide quantitative and qualitative measurements of the geospace environment from the ground for both scientific and operational purposes at a cost that will allow for crowd-sourced data contributions. The PSWS magnetometers employ a magneto-inductive sensor technology to record three-axis magnetic field variations with a field resolution of\ 3 nT at a 1 Hz sample rate. The measurement range of the sensor is\ \ nT) and is valid over a temperature range of -40 {\textdegree}C to +85 {\textdegree}C. Data from the PSWS network will combine these magnetometer measurements with high frequency (HF, 3{\textendash}30 MHz) radio observations to monitor large-scale current systems and ionospheric disturbances due to drivers from both space and the atmosphere. A densely-spaced magnetometer array, once established, will demonstrate their space weather monitoring capability to an unprecedented spatial extent. Magnetic field data obtained by the magnetometers installed at various locations in the US are presented and compared with the existing magnetometers nearby, demonstrating that the performance is very adequate for scientific investigations.
}, keywords = {magnetometer}, issn = {24680672}, doi = {10.1016/j.ohx.2024.e00580}, url = {https://www.sciencedirect.com/science/article/pii/S2468067224000749}, author = {Kim, Hyomin and Witten, David and Madey, Julius and Frissell, Nathaniel and Gibbons, John and Engelke, William and Liddle, Anderson and Muscolino, Nicholas and Visone, Joseph and Cao, Zhaoshu} } @proceedings {853, title = {Earth{\textquoteright}s Magnetic Field Migration and Its Effects on HF Propagation}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Propagation of radio waves in Earth{\textquoteright}s ionosphere and atmosphere critically depends on the strength and orientation of Earth{\textquoteright}s background magnetic field, due to the fact that electrons move much more readily along field lines than across them.\  The background magnetic field evolves continuously, driven by currents and other processes inside the planet{\textquoteright}s molten core.\  In particular, since 1990, the north magnetic pole has been migrating at an increased speed relative to its rate over most of the past century, and now moves more than 40 km/year.\  However, the south magnetic pole migration is considerably slower.\  The combination of these two effects has caused the global configuration of the geomagnetic field to change significantly.\  We will describe the sustained drift of magnetic field line locations over the last 40 years, with an emphasis on mid-latitudes where a large number of amateur radio operations take place.\  We will then provide estimates of induced changes in HF propagation over that time, using multiple models, and draw conclusions regarding the general climatology of propagation in various well used bands.

}, author = {Philip J. Erickson and William Liles} } @proceedings {869, title = {High Resolution WSPR Transmissions for Ionospheric Research}, year = {2024}, month = {03/2024}, abstract = {

There are currently over 4000 HAM radio stations worldwide continuously transmitting and receiving beacon signals using the WSPR RF modulation format.\  WSPR is implemented in the open source WSJT-x application program authored by Nobel Laureate Joe Taylor and a large group of contributors. Recent software enhancements to WSJT-x and newly available low-cost transmit and receive hardware using GPS disciplined oscillators permit records of these transmissions (known as {\textquoteleft}spots{\textquoteright}) to be used to study ionospheric events like Travelling Ionospheric Disturbances. Records of those 3 million+ receptions per day are publicly available to all researchers and citizen scientists in a SQL database which ensures access for all. In this presentation we give an introduction to WSPR, the publicly available databases where the {\textquoteleft}spots{\textquoteright} are stored.\  Also included are websites with text, map and graphical outputs which allow easy queries about {\textquoteright}spots{\textquoteright} and examples of low cost research quality transmitters and receivers which are in operation.

}, author = {Rob Robinett and Paul M. Elliott} } @proceedings {816, title = {Personal Space Weather Network, Status Report}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, author = {William D. Engelke} } @proceedings {836, title = {Possible Drivers of Large Scale Traveling Ionospheric Disturbances by Analysis of Aggregated Ham Radio Contacts}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasiperiodic electron density perturbations of the F region ionosphere that have periods of 30 min to over 180 min, wavelengths of over 1000 km, and velocities of 150 to 1000 m/s. These are seen as long slow oscillations in the bottom side of the ionosphere in data from ham radio contacts at 20 meters wavelength on roughly a third of the days in a year. They might be triggered by electromagnetic forces from above, and/or by mechanical pressures from below. The explosion of the Tonga volcano on January 15, 2022 revealed that such a LSTID could be triggered by a violent updraft from the Earth{\textquoteright}s surface into the stratosphere and then detected in the ionosphere over the United States nine hours later. We consider other possible drivers such as the auroral electrojet, the polar vortex, thunderstorms, zonal wind speeds, gravity wave variances, and their time derivatives in 2017.

}, author = {Diego Sanchez and Mary Lou West and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Robert B. Gerzoff and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker and V. Lynn Harvey} } @proceedings {849, title = {On the ray tracing block of a sky wave over-the-horizon radar simulation tool}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

A simulation tool of a sky wave over-the-horizon radar performance and detection process includes many stages based on different models, which creates a synthetic searching scenario as a first step followed by a digital signal processing to detect and locate a potential target. The whole process involves several concatenated physical mechanisms which depend on OTHR specific properties. They can be modeled as quasi-independent blocks to analyze synthetic scenarios in order to define the radar{\textquoteright}s characteristics and range of operation which are essential when selecting radar{\textquoteright}s operating parameters in order to achieve the best performance. In this work a sensitivity analysis of the ray tracing block is performed. This block is implemented as an independent block in the simulation tool and estimates the signal propagation path with an adapted Jones \& Stephenson ray tracing code. This code has options for: (1) the electron density profile, which can be chosen from analytical models or the IRI-2016 model, (2) the Earth{\textquoteright}s magnetic field from the IGRF-12 model, which can be turned on and off, and (3) collision frequencies, which can also be turned on and off. From this ray tracing we obtain the two-way delay of the signal travelling between the transmitter and the target, the ground range distance and azimuth relative to the transmitter. The sensitivity analysis is carried out analyzing this block output{\textquoteright}s\ variation as a consequence of changes in its main input factors. This study is useful to dimension features and elements of a real radar, and also to determine the needs of in-situ ionosphere sounding.

}, author = {Zenon Saavedra and Ana G. Elias} } @proceedings {848, title = {Sensitivity analysis of ray-tracing techniques to ionospheric electron density profiles}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The Earth{\textquoteright}s ionosphere, a weakly ionized plasma embedded in a magnetic field, constitutes an anisotropic and dispersive medium for the propagation of HF radio waves. Ray-tracing is a powerful and useful technique, included in several radar simulation codes, that allows determining the path of these radio waves through the ionosphere in order, for example, to locate and track a target. Depending on the degree of precision needed, ray-tracing requires more or less precise knowledge of ionospheric conditions along the propagation path. A sensitivity analysis is performed in this work to determine the effect of different electron density height profiles in ray path features considering a fully analytical approach and two ray-tracing algorithms. The analytical approach is based on the quasi-parabolic electron density height distribution which allows for the derivation of exact equations for ray path parameters. The first ray-tracing algorithm consists of Snell-law application to a two-dimensional ionosphere which is layered into thin homogeneous slabs with a constant refractive index. The second algorithm implements the code of Jones and Stephenson, introduced in 1975, and numerically solves Haselgrove ray equations to trace ray paths through an anisotropic medium whose refractive index varies in three dimensions. The three methodologies used to assess an HF signal ray path must assume an electron density height profile which strongly affects any output parameter that depends on the signal traveling path. In particular, the analytical approach, even though it is less accurate, it is considerably faster than any numerical ray-tracing technique. This sensitivity analysis approach allows estimating the percentage variation of ray-tracing outputs which may serve to analyze the errors introduced by ionospheric transient disturbances which cannot be easily included in models considered in ray-tracing algorithms.

}, author = {Ana G. Elias and Mariano Fagre and Zenon Saavedra and Adrian Llanes and Blas F. de Haro Barbas} } @proceedings {850, title = {Trial of applying PHaRLAP raytracing to reproduce Ham spot data}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

HamSCI is one of the NASA{\textquoteright}s official citizen science projects. HamSCI\ spots database, which is from Reverse Beacon Network (RBN) and Weak Signal Propagation Reporter Network (WSPRNet), is of interest. Information of date, time, frequency, latitude, and longitude of transmitter and receiver are used. PHaRLAP is a raytracing tool that can trace the HF radio wave in 2D and 3D. We use the IRI model to generate the required ionospheric information. We employ the PHaRLAP\ to reproduce the ham spots database by launching the HF radio wave from the transmitter, of which its location is obtained from the HamSCI\ spots database. Then, we trace the O-mode propagation of the wave. The wave arrival latitude and longitude are then mapped into a grid based on the Amateur Radio Maidenhead Grid. Finally, we compare the raytracing-based arrival grid with the HamSCI\ arrival grid. The results, under the assumption of 1-hop propagation, show that the PHaRLAP\ raytracing can reproduce the HamSCI\ spots database well.

}, author = {Kornyanat Hozumi and Nathaniel A. Frissell and Min-Yang Chou and Gwyn Griffiths and William D. Engelke and Jia Yue and Shing Fung and Masha Kuznetsova} } @proceedings {818, title = {The Wsprdaemon GRAPE reporting network}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

The recently released Wsprdaemon (WD) Version 3.1.5 added support for WD sites equipped with an RX888 to simultaneously record 16,000 sps IQ files on all WWV and CHU bands.\  After 00:00 UDP WD creates one 10 Hz 24 hour wav file for each of those bands and uploads them in DigitalRF (DRF) format to the HamSCI GRAPE server. This system hardware consists of a RX-888, GPSDO, and a Pi 5.

}, author = {Rob Robinett and Paul Elliott} } @proceedings {692, title = {Analyzing Large Scale Traveling Ionospheric Disturbances using Spot Data and Curve Fitting}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Large Scale Traveling Ionospheric Disturbances can be observed in amateur radio data by plotting and analyzing the propagation of signals from RBN, WSPR and PSK. One of the goals of these analyses is to determine the period and amplitude of these disturbances, which are visible to the human eye in the plotted data, but are challenging to accurately characterize for period and amplitude. (Such data is important for ionospheric climatology studies).\  Earlier research (Frissell, 2016, https://doi.org/10.1002/2015JA022168) has used a spectral approach to this analysis; this presentation shows a curve fitting technique which may prove easier to use for the large volume of analysis necessary for climatology studies.

}, author = {William D. Engelke} } @proceedings {734, title = {Climatology of Large Scale Traveling Ionospheric Disturbances Observed with Amateur Radio Networks}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

A new climatology of Large Scale Traveling Ionospheric Disturbances (LSTIDs) has been observed from ham radio data in 2017. LSTIDs are quasiperiodic electron density perturbations of the F region ionosphere. LSTIDs have periods of 30 min to over 180 min, wavelengths of over 1000 km, and velocities of over 1400 km/hr. In this paper, we show a climatology of observed LSTID events using data from the Reverse Beacon Network (RBN), Weak Signal Propagation Network (WSPRNet), and PSKReporter amateur radio networks. This climatology was performed twice and was cross examined between two members of the research team. Results show that most of the observed LSTIDs occurred during the winter months with a decline towards the summer, with the exception of a spike in June. This paper provides additional insight into the seasonal trends of LSTIDs and provides additional knowledge that will help in the pursuit of what is causing this phenomenon.

}, author = {Diego Sanchez and Mary Lou West and Bob Gerzoff and Gareth W. Perry and Nathaniel A. Frissell and William D. Engelke and Philip J. Erickson} } @article {797, title = {Crowdsourced Doppler measurements of time standard stations demonstrating ionospheric variability}, journal = {Earth System Science Data}, volume = {15}, year = {2023}, month = {Jan-01-2023}, pages = {1403 - 1418}, abstract = {

Ionospheric variability produces measurable effects in Doppler shift of HF (high-frequency, 3{\textendash}30 MHz) skywave signals. These effects are straightforward to measure with low-cost equipment and are conducive to citizen science campaigns. The low-cost Personal Space Weather Station (PSWS) network is a modular network of community-maintained, open-source receivers, which measure Doppler shift in the precise carrier signals of time standard stations. The primary goal of this paper is to explain the types of measurements this instrument can make and some of its use cases, demonstrating its role as the building block for a large-scale ionospheric and HF propagation measurement network which complements existing professional networks. Here, data from the PSWS network are presented for a period of time spanning late 2019 to early 2022. Software tools for the visualization and analysis of this living dataset are also discussed and provided. These tools are robust to data interruptions and to the addition, removal or modification of stations, allowing both short- and long-term visualization at higher density and faster cadence than other methods. These data may be used to supplement observations made with other geospace instruments in event-based analyses, e.g., traveling ionospheric disturbances and solar flares, and to assess the accuracy of the bottomside estimates of ionospheric models by comparing the oblique paths obtained by ionospheric ray tracers with those obtained by these receivers. The data are archived at\ https://doi.org/10.5281/zenodo.6622111(Collins,\ 2022).

}, doi = {10.5194/essd-15-1403-2023}, url = {https://essd.copernicus.org/articles/15/1403/2023/https://essd.copernicus.org/articles/15/1403/2023/essd-15-1403-2023.pdf}, author = {Collins, Kristina and Gibbons, John and Frissell, Nathaniel and Montare, Aidan and Kazdan, David and Kalmbach, Darren and Swartz, David and Benedict, Robert and Romanek, Veronica and Boedicker, Rachel and Liles, William and Engelke, William and McGaw, David G. and Farmer, James and Mikitin, Gary and Hobart, Joseph and Kavanagh, George and Chakraborty, Shibaji} } @proceedings {762, title = {Development of HamSCI PSWS Ground Magnetometer and Data Visualization on the PSWS Central Website}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Hyomin Kim and Nathaniel A. Frissell and David Witten and Julius Madey and William D. Engelke and Tom Holmes and Majid Mokhtari and Scotty Cowling and Anderson Liddle and Nicholas Muscolino and Zhaoshu Cao} } @article {801, title = {Heliophysics and amateur radio: citizen science collaborations for atmospheric, ionospheric, and space physics research and operations}, journal = {Frontiers in Astronomy and Space Sciences}, volume = {10}, year = {2023}, month = {Apr-11-2024}, abstract = {

The amateur radio community is a global, highly engaged, and technical community with an intense interest in space weather, its underlying physics, and how it impacts radio communications. The large-scale observational capabilities of distributed instrumentation fielded by amateur radio operators and radio science enthusiasts offers a tremendous opportunity to advance the fields of heliophysics, radio science, and space weather. Well-established amateur radio networks like the RBN, WSPRNet, and PSKReporter already provide rich, ever-growing, long-term data of bottomside ionospheric observations. Up-and-coming purpose-built citizen science networks, and their associated novel instruments, offer opportunities for citizen scientists, professional researchers, and industry to field networks for specific science questions and operational needs. Here, we discuss the scientific and technical capabilities of the global amateur radio community, review methods of collaboration between the amateur radio and professional scientific community, and review recent peer-reviewed studies that have made use of amateur radio data and methods. Finally, we present recommendations submitted to the U.S. National Academy of Science Decadal Survey for Solar and Space Physics (Heliophysics) 2024{\textendash}2033 for using amateur radio to further advance heliophysics and for fostering deeper collaborations between the professional science and amateur radio communities. Technical recommendations include increasing support for distributed instrumentation fielded by amateur radio operators and citizen scientists, developing novel transmissions of RF signals that can be used in citizen science experiments, developing new amateur radio modes that simultaneously allow for communications and ionospheric sounding, and formally incorporating the amateur radio community and its observational assets into the Space Weather R2O2R framework. Collaborative recommendations include allocating resources for amateur radio citizen science research projects and activities, developing amateur radio research and educational activities in collaboration with leading organizations within the amateur radio community, facilitating communication and collegiality between professional researchers and amateurs, ensuring that proposed projects are of a mutual benefit to both the professional research and amateur radio communities, and working towards diverse, equitable, and inclusive communities.

}, doi = {10.3389/fspas.2023.1184171}, url = {https://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/fullhttps://www.frontiersin.org/articles/10.3389/fspas.2023.1184171/full}, author = {Frissell, Nathaniel A. and Ackermann, John R. and Alexander, Jesse N. and Benedict, Robert L. and Blackwell, William C. and Boedicker, Rachel K. and Cerwin, Stephen A. and Collins, Kristina V. and Cowling, Scott H. and Deacon, Chris and Diehl, Devin M. and Di Mare, Francesca and Duffy, Timothy J. and Edson, Laura Brandt and Engelke, William D. and Farmer, James O. and Frissell, Rachel M. and Gerzoff, Robert B. and Gibbons, John and Griffiths, Gwyn and Holm, Sverre and Howell, Frank M. and Kaeppler, Stephen R. and Kavanagh, George and Kazdan, David and Kim, Hyomin and Larsen, David R. and Ledvina, Vincent E. and Liles, William and Lo, Sam and Lombardi, Michael A. and MacDonald, Elizabeth A. and Madey, Julius and McDermott, Thomas C. and McGaw, David G. and McGwier, Robert W. and Mikitin, Gary A. and Miller, Ethan S. and Mitchell, Cathryn and Montare, Aidan and Nguyen, Cuong D. and Nordberg, Peter N. and Perry, Gareth W. and Piccini, Gerard N. and Pozerski, Stanley W. and Reif, Robert H. and Rizzo, Jonathan D. and Robinett, Robert S. and Romanek, Veronica I. and Sami, Simal and Sanchez, Diego F. and Sarwar, Muhammad Shaaf and Schwartz, Jay A. and Serra, H. Lawrence and Silver, H. Ward and Skov, Tamitha Mulligan and Swartz, David A. and Themens, David R. and Tholley, Francis H. and West, Mary Lou and Wilcox, Ronald C. and Witten, David and Witvliet, Ben A. and Yadav, Nisha} } @proceedings {758, title = {Low-Cost Low-Power Ionosonde}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Ionosondes are a type of radar used to gather data about the height of the ionosphere. Typically, these systems can easily cost thousands of dollars and demand a lot of power. Using newer software defined radio technology, our goal is to develop a low cost, low power ionosonde.

}, author = {Gerard N. Piccini and Robert W. McGwier and Robert A. Spalletta and Majid Mokhtari and Nathaniel A. Frissell and Philip J. Erickson} } @proceedings {694, title = {Measuring Daily Ionospheric Variability and the 2023 and 2024 Solar Eclipse Ionospheric Impacts Using HamSCI HF Doppler Shift Receivers}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

This project will study ionospheric variability across the continental United States (CONUS) generated by dawn/dusk transitions and two solar eclipses occurring in 2023 and 2024. Dawn and dusk produce a complex response in observed ionospheric variability that is still not completely understood. A network of Global Navigation Satellite System (GNSS) stabilized/synchronized high frequency (HF) receivers known as Grapes will be used for the study. Thirty Grape receivers will be deployed throughout North America to optimize the study of the ionospheric impacts simultaneously received from two locations. Additional stations will be funded by the HamSCI amateur radio community. This project will generate observations to answer the scientific questions: (1) How do dawn and dusk ionospheric variability vary with local time, season, latitude, longitude, frequency, distance, and direction from the transmitter? (2) Is eclipse ionospheric response symmetric with regard to the onset and recovery timing? (3) How similar is the eclipse to the daily dawn and dusk terminator passage? (4) Would multipath HF mode-splitting in the post-eclipse interval be similar to dawn events? (5) Would the response be different for two eclipses?

This project is part of the Ham Radio Science Citizen Investigation (HamSCI) program and will be open to volunteers who want to field instruments and contribute to scientific analysis and discussion. This project will also establish a new network of DASI instruments that, due to its low cost and operation by volunteers, has the potential to provide measurements for years to come. This project will support students (undergraduate, MS and Ph.D.).

}, author = {Rachel Boedicker and Nathaniel Frissell and Kristina Collins and John Gibbons and David Kazdan and Philip J. Erickson} } @proceedings {764, title = {Medium Scale Traveling Ionospheric Disturbances and their Connection to the Lower and Middle Atmosphere}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Nathaniel A. Frissell and Francis Tholley and V. Lynn Harvey and Sophie R. Phillips and Katrina Bossert and Sevag Derghazarian and Larisa Goncharenko and Richard Collins and Mary Lou West and Diego F. Sanchez and Gareth W. Perry and Robert B. Gerzoff and Philip J. Erickson and William D. Engelke and Nicholas Callahan and Lucas Underbakke and Travis Atkison and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {688, title = {Personal Space Weather Station Central Control and Database System}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

As part of the Personal Space Weather Station (PSWS) project, our team has been developing the Central Control System and Central Database System that will be used to collect and store the data generated by the stations. The Central Control System functionality is being developed using Django, a Python based web framework. It is used to define how users will interact with the web server where their collected data will be uploaded, organized, and analyzed. It is also used to define models for the data being collected and how it will be stored in the Central Database System. In the server{\textquoteright}s current state, users can register accounts and stations as well as view lists of uploaded observations. Observation data can also be downloaded individually for analysis. The availability of the PSWS will allow a much larger sample of data to be collected daily. With this data, more accurate models of the ionosphere can be created, granting a better ability to predict how radio waves will be precisely affected by the ionosphere at any given moment and supporting ionospheric science.

}, author = {Anderson B. Liddle and Nicholas Muscalino and William D. Engleke and Travis Atkison} } @article {667, title = {Amateur Radio: An Integral Tool for Atmospheric, Ionospheric, and Space Physics Research and Operations}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.18632d86}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Michael Lombardi and Elizabeth MacDonald and Francesca Di Mare and Ethan S. Miller and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and David R. Themens and Mary Lou West} } @proceedings {628, title = {Climatology of Large Scale Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations of F-region ionospheric electron densities that can affect the range and quality of High Frequency (HF, 3-30 MHz) radio communications. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency radio signals propagating through the ionosphere. TIDs are of great interest scientifically because they are often associated with neutral Atmospheric Gravity Waves (AGWs) and can be used to advance understanding of atmosphere-ionosphere coupling. Large scale TIDs (LSTIDs) have periods of 30-180 min, horizontal phase velocities of 100 - 250 m/s, and horizontal wavelengths of over 1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). Current amateur radio observations are only able to detect LSTIDs. In this study, we present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, author = {Diego S. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and V. Lynn Harvey and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {606, title = {Contrasting effects of the 3-5 November 2021 geomagnetic storm on reception in Colorado of WSPR transmissions from North-Eastern North America with those from Australia}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Solar wind particles from three M-class flares hit the Earth{\textquoteright}s magnetic field around 19:30 UTC on 3 November 2021. The planetary geomagnetic disturbance index (Kp) peaked at 7 that evening and the following morning. At the USGS Boulder Geomagnetic Observatory, Colorado the vertical magnetic field anomaly was below -40 nT between 07:38 UTC and 12:56 UTC on 4 November, dipping briefly to -75 nT. These dramatic space weather events are examined using WSPR spots at N6GN, near Fort Collins, Colorado. Between 10:30 UTC and 11:00 UTC the 7 MHz WSPR spot count showed a ~90\% drop compared with previous days at that time interval. Second, the median distance for remaining spots increased to 7089 km from ~2500 km of previous days. Furthermore, the noise level dropped about 4 dB. At that time of day the noise at N6GN{\textquoteright}s remote receiver is limited by propagated-in noise rather than local or receiver noise. Central to the observed spot count decrease and median distance increase was a 98\% reduction in spots received from grid FN, North Eastern North America: down to 5 spots from a typical 245 on other days in the same interval. But what caused that precipitous drop? We look at signal levels of individual transmissions to try and understand whether received signal levels dropped below the noise or whether Doppler flutter spread the signals beyond the bandwidth of the WSPR decoder. We also seek to understand the increase in spots from Australia compared with previous days. During the storm itself, signal levels from Australia were unchanged; it was not until the following day that levels and the number of spots decreased. We caution and investigate that the very narrow band transmissions may not be decoded more due to spectral distortion and spreading rather than the more usual lack of signal to noise ratio. This analysis provides a valuable use case for WSPR transmissions, reporting via wsprnet.org, augmented with noise estimates and on-line access via the WsprDaemon database with quick-look Grafana and animated Octave visualizations.

}, author = {Gwyn Griffiths and Glenn Elmore} } @proceedings {624, title = {Detecting Large Scale Traveling Ionospheric Disturbances using Feature Recognition and Amateur Radio Data}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

A Large-Scale Transient Ionospheric Disturbance (LSTID) is a traveling perturbation in ionosphere electron density with a horizontal wavelength of approximately 1000 km and a period between 30 to 180 minutes. These can be detected by SuperDARN HF radar and GNSS Total Electron Content measurements. Recently it has been discovered that these can also be detected in amateur (ham) radio signal reports, which are now being generated in vast numbers by operators world-wide. A machine-learning technique was developed to find patterns in these data that indicate the presence of LSTIDs using an object detection technique.

}, author = {William D. Engelke and Nathaniel A. Frissell and Travis Atkison and Philip J. Erickson and Francis Tholley} } @article {670, title = {Fostering Collaborations with the Amateur Radio Community}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.09fe22b4}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and Timothy J. Duffy and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Elizabeth MacDonald and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and Tamitha Mulligan Skov and Mary Lou West} } @proceedings {635, title = {Preliminary Analysis of WWV Experimental Tone Signals}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

NIST Time station WWV and WWVH have recently been broadcasting a set of audio modulation signals designed by the WWV/H Scientific Modulation Group as an initial exploration of possibilities for using these powerful and ubiquitous time distribution HF transmissions as remote sensing diagnostics of the terrestrial ionosphere.\  Included audio modulations include pseudorandom white noise, swept chirps, controlled amplitude sequences, and single pulses.\  The first task in assessing feasibility for remote sensing is to analyze characteristics of the analog WWV transmitters themselves, in order to gauge the transfer function imposed on the original test transmission.\  Using ground wave recordings from a GNSS locked receiver station maintained by Glenn Elmore N6GN, we present preliminary transmitter-centric analysis of WWV experimental tone signals, focusing on amplitude fidelity, transmission delay, cross-ambiguity examination of frequency and amplitude stability, and pseudorandom noise determinations of audio passband shape.

}, author = {Ethan S. Miller and William Liles and Philip J Erickson} } @conference {586, title = {Amateur Radio Communications as a Novel Sensor of Large Scale Traveling Ionospheric Disturbances (Invited)}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Amateur (ham) radio high frequency (HF) communications are routinely observed by automated receiving systems on a quasi-global scale. As these signals are modulated by the ionosphere, it is possible to use these observations to remotely sense ionospheric dynamics and the coupled geospace environment. In this presentation, we demonstrate the use of these data to observe Large Scale Traveling Ionospheric Disturbances (LSTIDs), which are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected simultaneously over the continental United States in observations made by global HF amateur radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and discuss possible reasons why LSTIDs were observed in November but not May.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/822746}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Steven R. and Joshi, Dev Raj and Engelke, William and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {575, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=23773}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth W. and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Harvey, Lynn and Luetzelschwab, R. Carl} } @conference {582, title = {Climatology of Traveling Ionospheric Disturbances Observed by HamSCI Amateur Radio with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

Traveling Ionospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T ≈30-180 min, horizontal phase velocities vH≈ 100- 250 m/s, and horizontal wavelengths H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level. Connections to geospace are explored via SYM-H and Auroral Electrojet indexes, while neutral atmospheric sources are explored using NASA{\textquoteright}s Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2).

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/1000724}, author = {Sanchez, Diego F. and Frissell, Nathaniel A. and Perry, Gareth and Harvey, Lynn and Engelke, William D. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {477, title = {December 2020 Eclipse Festival Analysis}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

A crowdsourced science experiment called the December 2020 Eclipse Festival of Frequency Measurement was carried out for the total solar eclipse across South America on December 14, 2020. Over 80 stations around the world recorded WAV files of 10 MHz time standard stations. We have undertaken to process and visualize this data, and identify geophysical features within it. This poster will summarize our work to date.\ 

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=24-20-1F-16-09-FF-74-70-E0-78-1D-88-6D-21-D5-3F}, author = {Kristina Collins and David Casente and Joanna Elia and Marius Mereckis and David Meshnick} } @conference {550, title = {HamSCI Campaign Co-Design (Panel Discussion)}, booktitle = {HamSCI Workshop 2021}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, organization = {HamSCI}, address = {Virtual}, author = {Kristina V. Collins and Nathaniel A. Frissell and Philip J. Erickson and Laura Brandt and Elizabeth MacDonald and Michael Black and Gareth Perry} } @proceedings {559, title = {HamSCI: Ham Radio Science Citizen Investigation}, year = {2021}, month = {09/2021}, publisher = {International Space Weather Action Team (ISWAT)}, address = {Virtual}, author = {Frissell, Nathaniel A. and Sanchez, Diego and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Gerzoff, Robert} } @conference {544, title = {HamSCI Personal Space Weather: Architecture and Applications to Radio Astronomy}, booktitle = {Annual (Summer) Eastern Conference}, year = {2021}, month = {07/2021}, publisher = {Society of Amateur Radio Astronomers (SARA)}, organization = {Society of Amateur Radio Astronomers (SARA)}, address = {Virtual}, abstract = {

The Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS) project is a citizen science initiative to develop a new modular set of ground-based instrumentation for the purpose of studying the structure and dynamics of the terrestrial ionosphere, as well as the larger, coupled geospace system. PSWS system instrumentation includes radio receivers sensitive to frequencies ranging from the very low frequency (VLF) through very high frequency (VHF) bands, a Global Navigation Satellite System (GNSS) receiver to provide Total Electron Content (TEC) measurements and serve as a precision time and frequency reference, and a ground magnetometer sensitive to ionospheric and geospace currents. Although the PSWS is designed primarily for space weather and space science, its modular and open design in both hardware and software allows for a variety of use cases. The core radio instrument of the PSWS, the TangerineSDR, is a wideband, direct sampling 100~kHz to 60~MHz field programmable gate array (FPGA)-based software defined radio (SDR) receiver with direct applicability to radio astronomy. In this paper, we describe the PSWS and TangerineSDR architecture, show examples of how the TangerineSDR could be used to observe Jovian decametric emission, and discuss the applicability of the TangerineSDR to radio astronomy in general.

}, url = {https://rasdr.org/store/books/books/journals/proceedings-of-annual-conference}, author = {Nathaniel A. Frissell and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Typinski and William D. Engelke and David R. Larsen and David G. McGaw and Hyomin Kim and David M. Witten, II and Julius M. Madey and Kristina V. Collins and John C. Gibbons and David Kazdan and Aidan Montare and Dev Raj Joshi and Veronica I. Romanek and Cuong D. Nguyen and Stephen A. Cerwin and William Liles and Jonathan D. Rizzo and Ethan S. Miller and Juha Vierinen and Philip J. Erickson and Mary Lou West} } @conference {540, title = {HamSCI Personal Space Weather Station (PSWS): Architecture and Current Status}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, author = {Nathaniel A. Frissell and Dev Joshi and Veronica I. Romanek and Kristina V. Collins and Aidan Montare and David Kazdan and John Gibbons and William D. Engelke and Travis Atkison and Hyomin Kim and Scott H. Cowling and Thomas C. McDermott and John Ackermann and David Witten and Julius Madey and H. Ward Silver and William Liles and Steven Cerwin and Philip J. Erickson and Ethan S. Miller and Juha Vierinen} } @proceedings {561, title = {HamSCI Personal Space Weather Station (PSWS): Fall 2021 Update}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=1990}, author = {Frissell, Nathaniel A. and Joshi, Dev Raj and Collins, Kristina and Montare Aidan and Kazdan, David and Engelke, William D. and Atkison, Travis and Kim, Hyomin and Cowling, Scott H. and McDermott, Thomas C. and Ackermann, John and Witten, David and Madey, Jules and Silver, H. Ward and Liles, W. and Cerwin, Stephen A. and Erickson, Phillip J. and Miller, Ethan S, and Vierinen, Juha} } @proceedings {573, title = {Ionospheric Science Motivations and Selected Analysis Techniques for PSWS Grape and Related Data Sets}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=20025}, author = {Erickson, Philip J.} } @proceedings {565, title = {Magnetometer Alignment Techniques Using LocalHost}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=8248}, author = {Engelke, William D.} } @proceedings {566, title = {Magnetometer Board RFI Testing (Proceedings)}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=9172}, author = {Engelke, William D.} } @conference {585, title = {Observations of Mid-latitude Irregularities Using the Oblique Ionosonde Sounding Mode for the HamSCI Personal Space Weather Station}, booktitle = {American Geophysical Union Fall Meeting}, year = {2021}, month = {12}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, abstract = {

The spread in the echoes of high-frequency (HF, 3-30 MHz) radio waves from the F-region of the ionosphere was one of the earliest indications of plasma density irregularities in the mid-latitude F region ionosphere. Although mid-latitude spread F has been widely studied, the plasma instability mechanisms that create these irregularities are still largely unknown. This phenomenon can cause radio wave scintillation effects that degrade the performance of human-made technologies such as satellite communications and Global Navigation Satellite Systems (GNSS). Understanding these irregularities so that they can be anticipated and mitigated are important aspects of space weather research. The occurrence climatology and variability can also be helpful in validating models of these irregularities. Here, we present signatures of mid-latitude irregularities observed in oblique ionograms received near Scranton, PA transmitted by the Relocatable Over-the-Horizon Radar (ROTHR) in Chesapeake, Virginia. These observations are collected with the GNU Chirpsounder2 software, an open source software package capable of creating ionograms from frequency modulated (FM) chirp ionosondes. This ionospheric sounding mode will be implemented in the currently under-development Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS), a ground-based multi-instrument system designed to remote-sense the ionosphere using signals of opportunity. Using the data from the oblique ionograms, we generate the Range Time Intensity (RTI) plots that show ionospheric dynamics through measured path length variations as a function of time. We also compare the RTI plots with Range-Time-Parameter (RTP) plots from the SuperDARN HF radar in Blackstone, Virginia which commonly observes direct backscatter from decameter-scale irregularities within the region of ionosphere traversed by the ROTHR signal.

}, url = {https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/875589}, author = {Joshi, Dev Raj and Frissell, Nathaniel A. and Sarwar, M. Shaaf and Sami, Simal and Ruohoniemi, J. Michael and Baker, Joseph B. H. and Coster, Anthea J. and Erickson, Philip J. and Liles, William and Vierinen, Juha and Groves, Keith} } @conference {537, title = {Observing Large Scale Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Climatology with Connections to Geospace and Neutral Atmospheric Sources}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications. LSTIDs create concavities in the ionospheric electron density profile that move horizontally with the LSTID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. This phenomena manifests as quasi-periodic variations in contact ranges in HF amateur radio communications recorded by automated monitoring systems such as RBN and WSPRNet. In this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a climatology of LSTID activity as well as using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector, season, and geomagnetic activity level. Connections to neutral atmospheric sources are also explored.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {465, title = {Observing Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Validation and Climatology}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Traveling lonospheric Disturbances (TIDs) are propagating variations in ionospheric electron densities that affect radio communications and can help with understanding energy transport throughout the coupled magnetosphere-ionosphere-neutral atmosphere system. Large scale TIDs (LSTIDs) have periods T\ \approx30-180\ min, horizontal phase velocities v_H\approx‍100-‍250 m/s, and horizontal wavelengths \lambda_H\>1000 km and are believed to be generated either by geomagnetic activity or lower atmospheric sources. TIDs create concavities in the ionospheric electron density profile that move horizontally with the TID and cause skip-distance focusing effects for high frequency (HF, 3-30 MHz) radio signals propagating through the ionosphere. The signature of this phenomena is manifest as quasi-periodic variations in contact ranges in HF amateur radio communication reports recorded by automated monitoring systems such as the Weak Signal Propagation Reporting Network (WSPRNet) and the Reverse Beacon Network (RBN). First in this study, members of the Ham Radio Science Citizen Investigation (HamSCI) present a case study showing consistency in LSTID signatures in RBN and WSPRNet are also present in Super Dual Auroral Radar Network (SuperDARN), Global Navigation Satellite System (GNSS), and ionosonde measurements. Then, we present a climatology of LSTID activity as well as\  using RBN and WSPRNet observations on the 1.8, 3.5, 7, 14, 21, and 28 MHz amateur radio bands from 2017. Results will be organized as a function observation frequency, longitudinal sector (North America and Europe), season, and geomagnetic activity level.

}, author = {Diego F. Sanchez and Nathaniel A. Frissell and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @conference {542, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2021}, month = {06/2021}, publisher = {CEDAR}, organization = {CEDAR}, address = {Virtual}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in simultaneously over the continental United States in observations made by global High Frequency (HF) amateur (ham) radio observing networks and the Blackstone (BKS) SuperDARN radar. The amateur radio LSTIDs were observed on the 7 and 14 MHz amateur radio bands as changes in average propagation path length with time, while the LSTIDs were observed by SuperDARN as oscillations of average scatter range. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. The amateur radio and BKS SuperDARN radar observations corresponded with Global Navigation Satellite System differential Total Electron Content (GNSS dTEC) measurements. dTEC was used to estimate LSTID parameters: horizontal wavelength 1136 km, phase velocity 1280 km/hr, period 53 min, and propagation azimuth 167{\textdegree}. The LSTID signatures were observed throughout the day following ~400 to 800 nT surges in the Auroral Electrojet (AE) index. As a contrast, 16 May 2017 was identified as a period with significant amateur radio coverage but no LSTID signatures in spite of similar geomagnetic conditions and AE activity as the 3 November event. We hypothesize that atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating are the source of the LSTIDs, and that seasonal neutral atmospheric conditions may play a role in preventing AGW propagation in May but not in November.

}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Gareth W. Perry and Dev Joshi and William D. Engelke and Evan G. Thomas and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @proceedings {555, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {05/2021}, publisher = {SANSA}, address = {Virtual}, url = {https://www.sansa.org.za/events-outreach/superdarn-workshop-2021/}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {574, title = {Sources of Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, year = {2021}, month = {09/2021}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://youtu.be/MHkz7jNynOg?t=22608}, author = {Frissell, Nathaniel A. and Sanchez, Diego F. and Perry, Gareth W. and Kaeppler, Stephen R. and Joshi, Dev Raj and Engelke, William D. and Thomas, Evan G. and Coster, Anthea J. and Erickson, Philip J. and Ruohoniemi, J. Michael and Baker, Joseph B. H.} } @proceedings {505, title = {Survey of ionospheric F2 region variability from the lower atmosphere: drivers and responses - Part 1}, year = {2021}, month = {03/2021}, abstract = {

Carl Luetzelschwab, K9LA, will review the factors that cause the F2 region of the ionosphere to vary in the short-term, on day-to-day and even shorter time scales. These factors can directly affect amateur radio operators through their influence on electron density and therefore on HF propagation. Ionospheric variability drivers will be sorted into three broad categories: 1) solar radiation 2) geomagnetic activity and 3) meteorological sources (neutral atmosphere). Carl will also assess how much F2 ionospheric parameters vary in the short-term during both day and night, and he will also review the contribution of each of the factors to observed F2 region variability.

}, author = {R. Carl Luetzelschwab and Philip J. Erickson} } @proceedings {506, title = {Survey of ionospheric F2 region variability from the lower atmosphere: drivers and responses - Part 2}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

Phil Erickson, W1PJE, will follow with a condensed summary of recent community research on the types of physical processes that produce F2 layer ionospheric variations from waves, heating, and other sources in the lower neutral atmosphere (space weather {\textquotedblleft}from below{\textquotedblright}). Examples will include acoustic waves, gravity waves, planetary waves, TADs (traveling atmospheric disturbances), and their influence on TIDs (travelling ionospheric disturbances). Numerical estimates of the various forcing terms provide a useful gauge of the relative importance and impact of these processes. Phil will close by specifically focusing on estimates of the magnitude of electron density variations in the F2 region of the ionosphere due to earthquake effects. In particular, ionospheric density observations from sources such as the global satellite navigation system (GNSS) allow a quantitative, numerate discussion of earthquake drivers in both time and space dimensions as compared to other known lower atmosphere ionospheric variability drivers.\  Phil will conclude with a discussion of the implications for earthquake associated HF propagation effects in the face of observed day-to-day ionospheric density variability.

}, author = {Philip J. Erickson and R. Carl Luetzelschwab} } @article {548, title = {A Synopsis of the 2021 HamSCI Virtual Workshop}, volume = {105}, year = {2021}, month = {09/2021}, pages = {58-59}, issn = {0033-4812}, url = {https://www.arrl.org/qst}, author = {Erickson, Philip} } @proceedings {503, title = {TangerineSDR Software Demo}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

While doing the hardware engineering for the Tangerine SDR has been in progress, we developed a simulator to act as a Data Engine until the hardware is ready. Using a FlexRadio 6600 to supply the IQ data, we were able to use the simulator to bring the Local Host software to a high level of functionality and readiness for use as part of the Tangerine when the hardware Data Engine is ready. This is a demo of the Tangerine SDR Local Host using the simulator and FlexRadio.

}, author = {William D. Engelke} } @proceedings {464, title = {Traveling ionospheric disturbances tracked through Doppler-shifted AM radio transmissions}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

A comprehensive understanding of the ionosphere is critical for many technologies, particularly those that rely on the propagation of radio waves. This study shows that traveling ionospheric disturbances (TIDs), dawn and dusk signal divergence (terminators), and spread F\ can be tracked and analyzed using clear channel AM radio transmissions and a set of geographically distributed receivers. Early attempts by our research group to track TIDs by AM radio signals reflected from the F region of the ionosphere generated results in conflict with those derived from GPS/TEC mapping methods [Chilcote et al., 2015]. This study seeks to resolve those conflicts with a more sophisticated array of receivers spread throughout the northeastern United States. Specifically, the receivers form a ring around an 810 kHz AM radio station in Schenectady, New York. A minimum of four receivers have been operational from 3/19/20 to the present and Doppler-shifted signals, attributed to TID events, have been consistently visible across several radio channels with frequencies between 800 to 1600kHz. We have focused our study thus far on the terminator signals which appear to be consistent with photochemistry effects and on TID wave characteristic analysis. We have collected a set of exceptional TID events over the past nine months and have correlated our calculated wave characteristics with the data from GNSS TEC, digisonde, and SuperDARN in general finding good agreement between our technique and these established methods. While our study still seeks to clarify discrepancies in our data similar to those seen by Chilcote in the original study, the consistency with which our data typically agrees with other methods supports the validity of using AM radio transmissions to track TIDs in addition to other ionospheric phenomena such as the terminator.\ 

Reference: Chilcote, M., et al. (2015), Detection of traveling ionospheric disturbances by medium-frequency Doppler sounding using AM radio transmissions, Radio Sci., 50, doi:10.1002/2014RS005617.

}, author = {Claire C. Trop and James LaBelle and Philip J. Erickson and Shunrong Zhang and David McGaw and Terrence Kovacs} } @conference {381, title = {Amateur digital mode based remote sensing: FT8 use as a radar signal of opportunity for ionospheric characterization}, booktitle = {HamSCI Workshop}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The K1JT / WSJT suite of digital modes for amateur QSOs, provided to the community by Joe Taylor K1JT and Steve Franke K9AN, has revolutionized the use of weak signal HF propagation to carry short digital messages. Traffic on the FT8 mode has become a large fraction of all digital transmissions by amateurs since its introduction in 2017 near solar minimum. FT8 is a 15 second cadence, 8-tone FSK mode using a sophisticated combination of stacked low-density parity coding (LDPC) and cyclical redundancy check (CRC) codes. Combined with a deep search retrieval algorithm that takes advantage of the sparse information for messages within typical QSOs, the effective FT8 communications detection threshold is considerably lower than other traditional modes such as CW.

FT8 signals undergo changes on reception caused by ionospheric refraction. Observational study of this feature opens up compelling avenues for research into the time and space dependent behavior of ionospheric variations. A technique long known to the passive radio remote sensing community involves intercepting transmissions of opportunity and processing them to yield information on reflecting targets on the transmit-to-receive path. We present initial simulations and studies of the use of FT8 in this manner as an ionospheric range-Doppler passive radar, and will discuss the qualities of these signals for crowdsourced upper atmospheric research, including an explanation and examples of their effective range-Doppler ambiguity in typical QSO exchanges. Also discussed will be the particular effectiveness for radar applications of the three Costas array frequency/time synchronization sequences used by FT8 in the start, middle, and at the end of transmissions.

}, author = {P. J. Erickson and W. Liles and E. S. Miller} } @conference {424, title = {HamSCI Distributed Array of Small Instruments Personal Space Weather Station (DASI-PSWS): Architecture and Current Status (Invited)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. While existing instrument networks provide excellent insight into ionospheric and space science, the system remains undersampled and more observations are needed to advance understanding. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprised of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations (PSWS). These instruments that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers as part of the NSF Distributed Array of Small Instruments (DASI) program. A performance-driven PSWS design (~US$500) will be a modular, multi-instrument device that will consist of a dual-channel phase-locked 0.1-60 MHz software defined radio (SDR) receiver, a ground magnetometer with (~10 nT resolution and 1-sec cadence), and GPS/GNSS receiver to provide precision time stamping and serve as a GPS disciplined oscillator (GPSDO) to provide stability to the SDR receiver. A low-cost PSWS (\< US$100) that measures Doppler shift of HF signals received from standards stations such as WWV (US) and CHU (Canada) and includes a magnetometer is also being developed. HF sounding algorithms making use of signals of opportunity will be developed for the SDR-based PSWS. All measurements will be collected into a central database for coordinated analysis and made available for public access.

}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {N. A. Frissell and D. Joshi and K. Collins and A. Montare and D. Kazdan and J. Gibbons and S. Mandal and W. Engelke and T. Atkison and H. Kim and A. J. Gerrard and J. S. Vega and S. H. Cowling and T. C. McDermott and J. Ackermann and D. Witten and H. W. Silver and W. Liles and S. Cerwin and P. J. Erickson and E. S. Miller} } @conference {359, title = {HamSCI: Space Weather Operational Resources and Needs of the Amateur Radio Community}, booktitle = {American Meteorological Society Annual Meeting}, year = {2020}, month = {01/2020}, publisher = {American Meteorological Society Annual Meeting}, organization = {American Meteorological Society Annual Meeting}, address = {Boston, MA}, abstract = {

The amateur (ham) radio community is a global community of over 3 million people who use and build radio equipment for communications, experimentation, and science. By definition, amateur radio is a volunteer service, with the operators required to hold government-issued licenses that are typically earned by passing knowledge tests covering radio regulations and practices, radio theory, and electromagnetic theory. In the United States, there are about 750,000 licensed hams, ranging in age from very young to very old, and ranging in experience from neophyte to people with advanced degrees in radio engineering and science. Amateur radio operators are licensed to transmit on bands spread across the radio frequency (RF) spectrum, from very low frequency (VLF) up to hundreds of gigahertz. The purpose of these communications range from mission-critical emergency and public service communications to social contacts to highly competitive contests and achievement award programs. Many of these communications rely on trans-ionospheric paths, and therefore are heavily influenced by conditions in near-Earth space, or space weather.
Amateurs today obtain space weather and propagation prediction information from sources such as the NOAA Space Weather Prediction Center (SWPC), spaceweather.com, the Voice of America Coverage Analysis Program (VOACAP), amateur radio propagation columnists (ARRL, RSGB, and CQ Magazine), and spaceweatherwoman.com (Dr. Tamitha Skov). In order to predict success for their communications efforts, hams often use parameters such as smoothed sunspot number, 10.7 cm wavelength solar flux proxy, and the planetary Kp and Ap indices as inputs to predict radio propagation performance. Traditionally, these predictions focus on the driving influence of space conditions and the sun{\textquoteright}s output. However, frontier research in the space sciences community has revealed that for improved predictive success, much more information needs to be provided on neutral atmosphere dynamics from the lower atmosphere and its coupled effects on the ionosphere, and predictions need to be available at higher temporal and spatial resolution. Lower atmospheric influences include atmospheric gravity waves that can couple to traveling ionospheric disturbances that can dramatically alter radio propagation paths. Tropospheric phenomena such as temperature inversions and wind shear also affect VHF and UHF propagation. To be most useful, the ham community needs operational products that provide real time nowcasts and multi-day forecasts which predict how space weather through the whole atmosphere affects radio wave propagation on global scale and at all operational wavelengths.
To help with this effort, hams can provide data with unique spatial and temporal coverage back to the research and forecast community. The amateur radio community has already started this process with the creation of multiple global-scale, real-time propagation reporting systems such as the Weak Signal Propagation Reporting Network (WSPRNet), PSKReporter, and the Reverse Beacon Network (RBN). Studies by the Ham radio Science Citizen Investigation (HamSCI) have shown that data from these systems, if applied correctly, can effectively be used to study ionospheric space weather events. Experienced amateurs keep detailed records of verified point-to-point contacts and have extensive experience operating under a wide variety of geophysical conditions and locations, both of which can provide unique insights when shared with the professional research community. In this presentation, we will describe efforts led by the HamSCI collective to provide this research community feedback through active HamSCI community email lists and annual HamSCI workshops. We will also describe strategies with good initial success at amateur-professional collaboration, including a HamSCI-led amateur radio community - professional research community partnership to create a network of HamSCI Personal Space Weather Stations (PSWS), which will allow citizen scientists to make science-grade space weather observations from their own backyards.

}, url = {https://ams.confex.com/ams/2020Annual/meetingapp.cgi/Paper/370904}, author = {Nathaniel A. Frissell and Philip J. Erickson and Ethan S. Miller and William Liles and H. Ward Silver and R. Carl Luetzelschwab and Tamitha Skov} } @conference {390, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications
and associated Joule heating.

}, author = {D. Sanchez and N. A. Frissell and G. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker} } @conference {425, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, GNSS TEC, and Ionosondes}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2020}, month = {06/2020}, address = {Santa Fe, NM (Virtual)}, url = {http://cedarweb.vsp.ucar.edu/wiki/index.php/2020_Workshop:MainVG}, author = {D. F. Sanchez and N. A. Frissell and G. W. Perry and W. D. Engelke and A. Coster and P. J. Erickson and J. M. Ruohoniemi and J. B. H. Baker and R. C. Luetzelschawb} } @conference {383, title = {Observations and Modeling Studies of the Effects of the 2017 Solar Eclipse on SuperDARN HF Propagation}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The total solar eclipses offer a unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. Unique responses may be witnessed during eclipses, including changes in radio frequency (RF) propagation at high frequency (HF). Such changes in RF propagation were observed by the Super Dual Auroral Radar Network (SuperDARN) radars in Christmas Valley, Oregon and in Fort Hayes, Kansas during the 2017 solar eclipse. At each site, the westward looking radar observed an increase in slant range of the backscattered signal during the eclipse onset followed by a decrease after totality. In order to investigate the underlying processes governing the ionospheric response to the eclipse, we employed the HF propagation toolbox (PHaRLAP), created by Dr. Manuel Cervera, to simulate SuperDARN data for different models of the eclipsed ionosphere. By invoking different hypotheses and comparing simulated results to SuperDARN measurements we could study the underlying processes governing the ionosphere and improve our model of the F-Region responses to an eclipse. This method was used in three studies to: identify the cause of the increase in the distance radio waves traveled during the eclipse; evaluate different models of change in eclipse magnitude over time; and investigate the effect of the neutral wind velocity on the simulated eclipse data. This presentation will discuss observations made by SuperDARN during the 2017 eclipse, major results from our raytrace studies, and unanswered questions that may be useful to consider when planning HamSCI{\textquoteright}s campaign and/or similar ionospheric studies for the next eclipse over the United States in 2024.

}, author = {M. Moses and L. Kordella and G. D. Earle and D. Drob and J. Huba and J. M. Ruohoniemi} } @conference {400, title = {Patterns in Received Noise: Methods, Observations and Questions (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

There are valid concerns that local noise, often as common mode, is an increasing problem for radio amateurs. By adding two noise measurement algorithms to a robust Weak Signal Propagation Reporter (WSPR) processing and reporting package\ -\ wsprdaemon\ -\ we now have the capability to record and share noise level measurements from over twenty amateur stations. With locations from Maui to Moscow, and ranging from very quiet rural Northern California, Utah, and Austria to more typical suburban noise environments we have observed a multitude of patterns in received noise on the LF to HF bands (136 kHz to 28 MHz). These patterns show clearly where and when the local noise floor becomes a limiting factor. More intriguingly, we have observed coherent fluctuations in the noise over periods of hours at a pair stations 1000 km apart. Now with observations from a {\textquoteright}diamond{\textquoteright} of four stations we can look in more detail at the timing of these coherent fluctuations. With over six months of observations every two minutes from several stations we can show systematic seasonal variations in the daily noise patterns. We think we understand the root causes of some of the features, such as the local noon minimum and the post-sunset maximum in late spring and summer. However, we have yet to reach a satisfactory understanding for some patterns, including a transition to a daytime noise maximum in autumn. The challenging task of calibration to a field strength in free space will not be ignored, but for this presentation it will be set aside as we concentrate on patterns and not absolute noise levels. This presentation will outline the noise measurement methods, show examples of noise patterns from several stations, introduce the on-line database and its Grafana interface that delegates will be able to explore, and we will seek comments, insights and suggestions as to causes for the patterns and next steps for this collaborative effort.

}, author = {Gwyn Griffiths and Rob Robinett and Glenn Elmore and Clint Turner and Tom Bunch and Dennis Benischek} } @proceedings {436, title = {PSWS Control Software and Database}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Engelke, William D.} } @conference {406, title = {Super Cheap Scintillation Console: Literate-Pancake (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The goal of this project is to make yet another "low cost" console for calculating scintillation caused by ionospheric irregularities. Using some of the cheapest devices that come up in a simple google search for gps receivers and computers we{\textquoteright}ve kept cost below $60 USD. As an exercise in seeing if anything useful can be obtained by bashing the cheapest stuff on the internet together, who knows, they may even be capable of making useful observations to detect ionospheric irregularities. At this low barrier to entry, both in terms of cost and programming experience, this is intended to be an introductory project using GPS that goes beyond location tracking, and involves ionospheric science that Ham Radio operators are already familiar with. Some basic software has been produced to process the NMEA data from the device and process it enough to produce the scintillation data product. Currently under development, this software is public and open source. Although this device is certainly of a lower quality than many more expensive set ups, the end result is at least superficially comparable to some of the other inexpensive devices that are still several times more expensive. Some rudimentary scinillation detection can be performed, obtaining where and when scintillation is occurring. The hard part now, is finding the right combination of data product and online accesss to make historical scintillation data available to future scientists. With mass market parts and completely free and open source software, perhaps this community can even find novel uses for this data beyond the intent of this work.

}, author = {Jonathan M. Smith and Brian Espinal-Juarez} } @conference {375, title = {TangerineSDR Database and Control System Architecture}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

In support of the Personal Space Weather Station Network, a team at the University of Alabama are working on two parallel software efforts. First, an embedded system is being developed for the small board computer that will be a part of the TangerineSDR. This package includes a web interface for user friendliness and a main controller written in C to handle high speed data. Second, a Central Control System will be developed that users can log into and upload data they collect. This central system will be used for aggregating and analyzing data, as well as to coordinate data collection. The embedded system and central control will work together so that science data collection is easy for the user. As an added bonus, the TangerineSDR will give each user tools for observing propagation at their own location, as an aid to their ham radio activities.

}, author = {W. Engelke} } @conference {365, title = {TangerineSDR System Architecture}, booktitle = {HamCation}, year = {2020}, month = {02/2020}, publisher = {Orlando Amateur Radio Club}, organization = {Orlando Amateur Radio Club}, address = {Orlando, FL}, author = {William D. Engelke} } @conference {382, title = {Update on the Golden Ears Project}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The Radio Receiver Instrument (RRI), part of the Enhanced Polar Outflow Probe (e-POP) science payload on the Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE) spacecraft, has recorded continuous wave (CW; Morse code) transmissions during the American Radio Relay League (ARRL) Field Day exercises since 2015. Perry et al. (2018) demonstrated the value of such transmissions to radio science. By identifying a handful of hams in the RRI data collected during the 2015 Field Day and inputting their transmitting locations into a high frequency (HF) ray tracing model, Perry et al. were able to accurately estimate foF2 over a portion of the midwestern United States. They were also able to diagnose the periodic fading in the amplitude of one ham{\textquoteright}s transmission as a multipath propagation effect unique to transionospheric propagation.

One lesson from the Perry et al. analysis was that decoding the transmissions using CW {\textquotedblleft}skimmers{\textquotedblright}, software capable of decoding large bands of CW signal, was not feasible with the RRI data. This is likely due to the fact that the signals disperse and degrade as they transit from the ground, through the ionosphere, and up to the spacecraft. As a result, the Perry et al. transmissions had to be decoded aurally by the article{\textquoteright}s co-authors. Since 2015, RRI has collected several hours of ARRL Field Day transmissions, necessitating a more organized decoding effort, rather that the ad hoc methodology employed thus far.

Accordingly, the {\textquotedblleft}Golden Ears Project{\textquotedblright} was initiated following the RRI operations for the 2019 ARRL Field Day. The goal of the project is straightforward: use members of the ham community with a distinct aptitude for aurally decoding CW signals (i.e., individuals with {\textquotedblleft}Golden Ears{\textquotedblright}) to decode data collected by RRI in thorough and organized way. In this presentation we will disseminate the first project{\textquoteright}s first results from 2019 Field Day operations. We will describe the experimental setup, methodology used to prepare the data from the decoders, discuss their results, and outline the future directions of the project.

Perry, G. W., Frissell, N. A., Miller, E. S., Moses, M., Shovkoplyas, A., Howarth, A. D., \& Yau, A. W. (2018). Citizen Radio Science: An Analysis of Amateur Radio Transmissions With e-POP RRI. Radio Science, 933{\textendash}947. https://doi.org/10.1029/2017RS006496

}, author = {G. Perry and P. J. Erickson and B. D. Blain and R. Reif and N. A. Frissell} } @conference {274, title = {HamSCI Personal Space Weather Station: A New Tool for Citizen Science Geospace Research}, booktitle = {USNC{\textendash}URSI National Radio Science Meeting}, year = {2019}, month = {01/2019}, publisher = {U.S. National Committee for URSI}, organization = {U.S. National Committee for URSI}, address = {Boulder, CO}, abstract = {

Recent advances in geospace remote sensing have shown that large-scale distributed networks of ground-based sensors pay large dividends by providing a big picture view of phenomena that were previously observed only by point-measurements. Notable examples include the improved understanding of traveling ionospheric disturbance (TID) sources based on observations from the high frequency (HF) Super Dual Auroral Radar Network (SuperDARN) radars and GNSS-based total electron content remote sensing networks. While these existing networks provide excellent insight into TID science, the system remains undersampled (especially at HF) and more observations are needed to advance understanding. Additionally, previous measurements have revealed that characteristics of medium scale traveling ionospheric disturbances (MSTIDs) observed on the bottomside ionosphere using oblique HF sounding by SuperDARN differ from integrated ionospheric measurements of MSTIDs made using GNSS-TEC. These differences have yet to be accounted for, and additional observations could aid in understanding the propagation of MSTIDs from the bottom to the top of the ionosphere. In an effort to generate these additional measurements, the Ham Radio Science Citizen Investigation (HamSCI, hamsci.org) is working with the Tucson Amateur Packet Radio Corporation (TAPR, tapr.org), an engineering organization comprising of volunteer amateur radio operators and engineers, to develop a network of Personal Space Weather Stations that will provide scientific-grade observations of signals-of-opportunity across the HF bands from volunteer citizen observers. These measurements will play a key role in the characterization of ionospheric variability across the geographic regions in which these stations are deployed. We will describe concepts, key software patterns for radio science, and proposed timelines for the Personal Space Weather Station project. A particular focus will be assembling the proper metadata for science grade observations, and strategies for lightweight calibration of radio sensors. Initial project efforts concentrate on a wideband receiving station and backing software data distribution system.

}, url = {https://nrsmboulder.org/}, author = {J. S. Vega and N. A. Frissell and P. J. Erickson and A. J. Gerrard} } @article {275, title = {High Frequency Communications Response to Solar Activity in September 2017 as Observed by Amateur Radio Networks}, journal = {Space Weather}, year = {2019}, month = {2019/01/11}, abstract = {

Abstract Numerous solar flares and coronal mass ejection (CME) induced interplanetary shocks associated with solar active region AR12673 caused disturbances to terrestrial high frequency (HF, 3--30 MHz) radio communications from 4-14 September 2017. Simultaneously, Hurricanes Irma and Jose caused significant damage to the Caribbean Islands and parts of Florida. The coincidental timing of both the space weather activity and hurricanes was unfortunate, as HF radio was needed for emergency communications. This paper presents the response of HF amateur radio propagation as observed by the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) to the space weather events of that period. Distributed data coverage from these dense sources provided a unique mix of global and regional coverage of ionospheric response and recovery that revealed several features of storm-time HF propagation dynamics. X-class flares on 6, 7, and 10 September caused acute radio blackouts during the day in the Caribbean with recovery times of tens of minutes to hours, based on the decay time of the flare. A severe geomagnetic storm withKpmax\ =\ 8\ +\ and?SYM\ ?\ Hmin\ =\ \ ?\ 146?nT occurring 7-10 September wiped out ionospheric communications first on 14 MHz and then on 7 MHz starting at~1200 UT 8 September. This storm, combined with affects from additional flare and geomagnetic activity, contributed to a significant suppression of effective HF propagation bands both globally and in the Caribbean for a period of 12 to 15 days.

}, keywords = {Amateur Radio, Geomagnetic Storm, Ham Radio, HF Radio Propagation, Radio Blackout, Solar Flare}, issn = {1542-7390}, doi = {10.1029/2018SW002008}, url = {https://doi.org/10.1029/2018SW002008}, author = {Frissell, Nathaniel A. and Vega, Joshua S. and Markowitz, Evan and Gerrard, Andrew J. and Engelke, William D. and Erickson, Philip J. and Miller, Ethan S. and Luetzelschwab, R. Carl and Bortnik, Jacob} } @conference {295, title = {High Frequency Communications Response to Solar Activity in September 2017 as Observed by Amateur Radio Networks}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Numerous solar flares and coronal mass ejection-induced interplanetary shocks associated with solar active region AR12673 caused disturbances to terrestrial high-frequency (HF, 3{\textendash}30 MHz) radio communications from 4{\textendash}14 September 2017. Simultaneously, Hurricanes Irma and Jose caused significant damage to the Caribbean Islands and parts of Florida. The coincidental timing of both the space weather activity and hurricanes was unfortunate, as HF radio was needed for emergency communications. This paper presents the response of HF amateur radio propagation as observed by the Reverse Beacon Network and the Weak Signal Propagation Reporting Network to the space weather events of that period. Distributed data coverage from these dense sources provided a unique mix of global and regional coverage of ionospheric response and recovery that revealed several features of storm time HF propagation dynamics. X-class flares on 6, 7, and 10 September caused acute radio blackouts during the day in the Caribbean with recovery times of tens of minutes to hours, based on the decay time of the flare. A severe geomagnetic storm with Kpmax = 8+ and SYM-Hmin = -146 nT occurring 7{\textendash}10 September wiped out ionospheric communications first on 14 MHz and then on 7 MHz starting at \~{}1200 UT 8 September. This storm, combined with affects from additional flare and geomagnetic activity, contributed to a significant suppression of effective HF propagation bands both globally and in the Caribbean for a period of 12 to 15 days.

}, author = {Nathaniel A. Frissell and Joshua S. Vega and Evan Markowitz and Andrew J. Gerrard and William D. Engelke and Philip J. Erickson and Ethan S. Miller and R. Carl Luetzelschwab and Jacob Bortnik} } @conference {290, title = {IonTV: Using WWV Timing Reference Signals to Observe Ionospheric Variation}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

For decades, an AM modulated time signal has been broadcast at multiple HF frequencies by the National Institute of Standards and Technology (NIST).\  Shortwave radio stations WWV in Colorado and WWVH in Hawaii use these frequencies for the broad dissemination of accurate coordinated universal time information.\  As the HF signal traverses the ionosphere, propagation effects ensue, and the high temporal precision of the original transmitted signal provides an attractive potential for wide-sense monitoring of ionospheric variations.\  We present the results of an ongoing set of data collections and statistical analysis of the received variation in WWV timing signals aimed at extracting ionospheric propagation effects.\  The work includes design of a software defined receiver (SDR) for processing the amplitude modulated dual sideband (AM-DSB) timing signal. By observing the time shift between consecutive seconds of the 10MHz WWV timing signal, reflected from the ionosphere, the change in the effective height of the ionosphere can be estimated.\  Simultaneous measurements taken from different observation angles allow a more accurate sensing of ionospheric electron density variability as projected into refractive effects.\  The project also has a goal of creating a straightforward and reliable way for hobbyists and citizen scientists to demodulate and process their own NIST timing data. We describe a sample analysis of several blocks of WWV received data, both on remote paths and locally through groundwave propagation near the Colorado transmit array, including simultaneous collects. To process the timing data, several approaches will be described, including a heterodyne SDR with a digital phase-locked-loop (PLL).\  Carrier offset tracking using PLL techniques produce Doppler shifts that are associated with traveling ionospheric disturbances and inherent electron density variability.\  Demodulation and amplitude/phase analysis of the 100 Hz subcarrier of WWV can also provide precise delta-time information on ionospheric propagation through examination of variability in arrival of the leading edge of 1 pulse-per-second ticks.\  Results to date suggest that variation between consecutive second markers is a uniformly distributed Gaussian random variable with at least some of this variation due to ionospheric factors, although systematics must be addressed.

}, author = {Philip J. Erickson and William Liles and J. Dusenbury and K.C. Kerby-Patel and Ethan Miller and Gary Bust and Cathryn Mitchell} } @conference {329, title = {IonTV: Using WWV Timing Reference Signals to Observe Ionospheric Variation}, booktitle = {Hamvention HamSCI Forum}, year = {2019}, month = {05/2019}, publisher = {Dayton Amateur Radio Association}, organization = {Dayton Amateur Radio Association}, address = {Xenia, OH}, abstract = {

For decades, an AM modulated time signal has been broadcast at multiple HF frequencies by the National Institute of Standards and Technology (NIST).\  Shortwave radio stations WWV in Colorado and WWVH in Hawaii use these frequencies for the broad dissemination of accurate coordinated universal time information.\  As the HF signal traverses the ionosphere, propagation effects ensue, and the high temporal precision of the original transmitted signal provides an attractive potential for wide-sense monitoring of ionospheric variations.\  We present the results of an ongoing set of data collections and statistical analysis of the received variation in WWV timing signals aimed at extracting ionospheric propagation effects.\  The work includes design of a software defined receiver (SDR) for processing the amplitude modulated dual sideband (AM-DSB) timing signal. By observing the time shift between consecutive seconds of the 10MHz WWV timing signal, reflected from the ionosphere, the change in the effective height of the ionosphere can be estimated.\  Simultaneous measurements taken from different observation angles allow a more accurate sensing of ionospheric electron density variability as projected into refractive effects.\  The project also has a goal of creating a straightforward and reliable way for hobbyists and citizen scientists to demodulate and process their own NIST timing data. We describe a sample analysis of several blocks of WWV received data, both on remote paths and locally through groundwave propagation near the Colorado transmit array, including simultaneous collects. To process the timing data, several approaches will be described, including a heterodyne SDR with a digital phase-locked-loop (PLL).\  Carrier offset tracking using PLL techniques produce Doppler shifts that are associated with traveling ionospheric disturbances and inherent electron density variability.\  Demodulation and amplitude/phase analysis of the 100 Hz subcarrier of WWV can also provide precise delta-time information on ionospheric propagation through examination of variability in arrival of the leading edge of 1 pulse-per-second ticks.\  Results to date suggest that variation between consecutive second markers is a uniformly distributed Gaussian random variable with at least some of this variation due to ionospheric factors, although systematics must be addressed.

}, author = {Philip J. Erickson and William Liles and J. Dusenbury and K.C. Kerby-Patel and Ethan Miller and Gary Bust and Cathryn Mitchell} } @conference {361, title = {Large Scale Traveling Ionospheric Disturbances Observed using HamSCI Amateur Radio, SuperDARN, and GNSS TEC}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Large Scale Traveling Ionospheric Disturbances (LSTIDs) are quasi-periodic variations in F region electron density with horizontal wavelengths \> 1000 km and periods between 30 to 180 min. On 3 November 2017, LSTID signatures were detected in observations made by Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) for the first time. The RBN and WSPRNet are two large-scale High Frequency (HF, 3-30 MHz) amateur (ham) radio observing networks that provide data to the Ham Radio Science Citizen Investigation (HamSCI). The LSTIDs were observed on the 7 and 14 MHz amateur radio bands, and are detected by observing changes in average propagation path length with time. LSTID period lengthened from T ~ 1.5 hr at 12 UT to T ~ 2.25 hr by 21 UT. Simultaneous LSTID signatures were present in ham radio observations over the continental United States, the Atlantic Ocean, and Europe. LSTIDs observed with amateur radio were consistent with LSTIDs observed by the Blackstone SuperDARN HF radar and in differential GNSS Total Electron Content (TEC) measurements. GNSS TEC maps were used to estimate LSTID parameters: horizontal wavelength 1100 km, phase velocity 950 km/hr, period 70 min, and propagation azimuth 135{\textdegree}. The LSTID signatures were observed throughout the day following ~800 nT surges in the Auroral Electrojet (AE) index at 00 and 12 UT. We will discuss potential generation hypotheses for the observed LSTIDs, including atmospheric gravity wave (AGW) sources triggered by auroral electrojet intensifications and associated Joule heating.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/581488}, author = {Nathaniel A. Frissell and Diego F. Sanchez and Evan Markowitz and Gareth W. Perry and William D. Engelke and Anthea Coster and Philip J. Erickson and J. Michael Ruohoniemi and Joseph B. H. Baker} } @conference {360, title = {A Low-Cost Citizen Science HF Doppler Receiver for Measuring Ionospheric Variability}, booktitle = {American Geophysical Union Fall Meeting}, year = {2019}, month = {12/2019}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

Advancement in understanding short term and small spatial scale ionospheric variability requires global high time and spatial resolution measurements. Professional ionospheric sounding networks are extensive and capable, yet more measurements are still needed due to the strongly magnetized nature and large extent of the ionosphere. High Frequency (HF, 3-30 MHz) radio signals are refracted by the ionosphere, and therefore are modulated by processes such as traveling ionospheric disturbances (TIDs) and geomagnetic storms. By measuring the amplitude and Doppler shift of trans-ionospheric HF signals, it is possible to detect signatures of ionospheric absorption and changes in propagation path length. We present a design for a low-cost citizen science HF multi-band receiver that measures the amplitude and Doppler shift of reference signals of opportunity from the US National Institute of Standards and Technology station WWV and the Canadian Institute for National Measurement Standards station CHU. The receiver will make 1 s cadence measurements on nine HF beacon frequencies and subsequently upload the results to a central server for scientific analysis. The local user will be able to review data daily, both locally and in aggregate on a web server, and participate in discussion of the ionospheric measurements. This receiver forms one component of the low-cost version of the Ham Radio Science Citizen Investigation (HamSCI) Personal Space Weather Station (PSWS), and is designed with the intention of distribution to hundreds to thousands of citizen science observers. Preliminary results from the prototype receiver will be presented.

}, url = {https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/602677}, author = {Kristina Collins and David Kazdan and John Gibbons and Aidan Montare and Skylar Dannhoff and Philip J. Erickson and Nathaniel A. Frissell} } @conference {292, title = {New Directions in Sporadic-E Research}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

A complete understanding of the causes of Sporadic-E propagation has so far defied analysis. The large number of possible parameters, many of which are non-linear and/or stochastic (random) in nature, has made it very difficult to model the system well enough to tease apart the causes and effects so as to be able to predict this phenomenon. This research effort, spurred in part by Joe Dzekovich{\textquoteright}s (K1YOW) QST article which suggested a possible relationship between Upper Level Lows and Sporadic E on 6 meters, is applying methods of Deep Learning (a branch of Artificial Intelligence) combined with traditional analytics to better understand what make the 6-meter {\textquotedblleft}magic{\textquotedblright} band work. The HamSCI HARC spots database is used along with data from NOAA, NASA, and meteorite monitoring networks. This is a progress briefing on research which is ongoing and not yet complete.

}, author = {William Engelke} } @conference {315, title = {PSWS Science Requirements Panel Discussion (Panel)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

Moderator: Ward Silver, N0AX

  1. Phil Erickson, W1PJE, MIT Haystack Observatory, Radio, Ionospheric, \& Magnetospheric Science
  2. Nathaniel Frissell, W2NAF, NJIT, Radio, Ionospheric, \& Magnetospheric Science
  3. Hyomin Kim, KD2MCR, NJIT, Magnetospheric Physics
  4. Bill Liles, NQ6Z, VLF Science
  5. John Ackermann, N8UR, TAPR, Radio Engineering
  6. Scotty Cowling, WA2DFI, TAPR, Radio Engineering
  7. Tom McDermott, N5EG, TAPR, Radio Engineering
}, author = {John Ackermann and Scotty Cowling and Philip J. Erickson and Nathaniel A. Frissell and Hyomin Kim and William Liles and Thomas McDermott and Ward Silver} } @conference {325, title = {Sounding the Ionosphere with Signals of Opportunity in the High-Frequency (HF) Band}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, abstract = {

The explosion of commercial off-the-shelf (COTS) education- and consumer-grade hardware supporting software-defined radio (SDR) over the past two decades has revolutionized many aspects of radio science, bringing the cost and calibration of traditionally complex receiver hardware within the grasp of even advanced amateur experimenters. Transmission has now become the limiter of access in many cases, particularly through spectrum management and licensing considerations. Fortunately, several classes of signals endemic to the HF band lend themselves to processing for ionospheric characteristics: time and frequency standard broadcasters, surface-wave oceanographic radars, amateur radio transmissions, and ionospheric sounders.

This presentation is a tour of these signals of opportunity and techniques for collecting and processing them into ionospheric characteristics, with emphasis on distributed receivers collecting on a small number (four or fewer) of coherent channels. Receiving techniques will be discussed for near-vertical ({\textquotedblleft}quasi-vertical{\textquotedblright}) incidence skywave (NVIS or QVI), long-distance oblique soundings, and transionospheric sounding. Soundings will be demonstrated from space-based, ground-based, and maritime platforms.

Binary, Doppler, delay, cone angle of arrival, and polarization observations will be exploited, depending on the signal type and capability of the collector. Each of these techniques conveys different, but not always {\textquotedblleft}orthogonal,{\textquotedblright} information about the ionospheric skywave channel. The information content of each datum will be discussed with respect to the implications for inverting the local or regional ionosphere from the observations. More importantly than inverting the full ionosphere, some of these techniques are sensitive indicators of ionospheric irregularities, structures, and instabilities, that might otherwise be difficult to study due to limited geographic coverage with larger, more exquisite instrumentation.

}, author = {Ethan S. Miller and Gary S. Bust and Gareth W. Perry and Stephen R. Kaeppler and Juha Vierinen and Nathaniel A. Frissell and A. A. Knuth and Philip J. Erickson and Romina Nikoukar and Alexander T. Chartier and P. Santos and C. Brum and J. T. Fentzke and T. R. Hanley and Andrew J. Gerrard} } @conference {309, title = {Web-Based Scientific Visualizations of RBN/WSPR Data (Demonstration)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, author = {Nathaniel A. Frissell and Evan Markowitz and Diego Sanchez and William D. Engelke} } @conference {276, title = {High Frequency Communications Response to Solar Activity in September 2017 as Observed by Amateur Radio Networks}, booktitle = {Fall AGU}, year = {2018}, month = {12/2018}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {Washington, DC}, abstract = {

Numerous solar flares and coronal mass ejection (CME) induced interplanetary shocks associated with solar active region AR12673 caused disturbances to terrestrial high frequency (HF, 3{\textendash}30 MHz) radio communications from 4-14 September 2017. Simultaneously, Hurricanes Irma and Jose caused significant damage to the Caribbean Islands and parts of Florida. The coincidental timing of both the space weather activity and hurricanes was unfortunate, as HF radio was needed for emergency communications. This paper presents the response of HF amateur radio propagation as observed by the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) to the space weather events of that period. Distributed data coverage from these dense sources provided a unique mix of global and regional coverage of ionospheric response and recovery that revealed several features of storm-time HF propagation dynamics. X-class flares on 6, 7, and 10 September caused acute radio blackouts during the day in the Caribbean with recovery times of tens of minutes to hours, based on the decay time of the flare. A severe geomagnetic storm withKpmax = 8 + and SYM - Hmin = - 146 nT occurring 7-10 September wiped out ionospheric communications first on 14 MHz and then on 7 MHz starting at\ 1200 UT 8 September. This storm, combined with affects from additional flare and geomagnetic activity, contributed to a significant suppression of effective HF propagation bands both globally and in the Caribbean for a period of 12 to 15 days.

}, keywords = {Amateur Radio, Geomagnetic Storm, Ham Radio, HF Radio Propagation, Radio Blackout, Solar Flare}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/419847}, author = {Frissell, Nathaniel A. and Vega, Joshua S. and Markowitz, Evan and Gerrard, Andrew J. and Engelke, William D. and Erickson, Philip J. and Miller, Ethan S. and Luetzelschwab, R. Carl and Bortnik, Jacob} } @conference {236, title = {Initial Results of HamSCI Ham Radio 21 August 2017 Eclipse Ionospheric Experiments}, booktitle = {American Meteorological Society Annual Meeting}, year = {2018}, month = {01/2018}, publisher = {American Meteorological Society}, organization = {American Meteorological Society}, address = {Austin, TX}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. Despite more than 60 years of research, questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. We present initial results from three amateur radio experiments designed to study the 2017 total solar eclipse: the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT). These experiments are coordinated by HamSCI, the Ham Radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://ams.confex.com/ams/98Annual/webprogram/Paper337094.html}, author = {N. A. Frissell and J. R. Ackermann and D. Bern and F. Ceglia and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. Gerzoff and P. Gladstone and S. W. Gunning and J. D. Huba and J. D. Katz and E. S. Miller and M. L. Moses and S. E. Reyer and S. W. Rose and A. Shovkoplyas and H. W. Silver and P. Smith and J. S. Vega and M. L. West and R. Williams} } @article {248, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, journal = {Geophysical Research Letters}, volume = {45}, year = {2018}, month = {05/2018}, type = {Research Letter}, abstract = {

On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium and high frequency radio propagation by the Solar Eclipse QSO Party (SEQP) citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at\ h >= 125 km altitude with elevation angles\ θ >= 22{\textdegree}, while 14 MHz signals refracted at\ h \< 125 km with elevation angles\ θ \< 10{\textdegree}.

}, issn = {1944-8007}, doi = {https://doi.org/10.1029/2018GL077324}, url = {https://doi.org/10.1029/2018GL077324}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and G. D. Earle and M. L. Moses and M. L. West and J. D. Huba and P. J. Erickson and E. S. Miller and R. B. Gerzoff and W. Liles and H. W. Silver} } @conference {277, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, booktitle = {Fall AGU}, year = {2018}, month = {12/2018}, publisher = {American Geophysical Union Meeting}, organization = {American Geophysical Union Meeting}, address = {Washington, DC}, abstract = {

On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium- and high-frequency radio propagation by the Solar Eclipse QSO Party citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h>=125 km altitude with elevation angles θ>=22{\textdegree}, while 14 MHz signals refracted at h \< 125 km with elevation angles θ \< 10{\textdegree}.

}, keywords = {Amateur Radio, Citizen Science, Ham Radio, HF propagation, ionosphere, solar eclipse}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/418915}, author = {Frissell, N. A. and Katz, J. D. and Gunning, S. W. and Vega, J. S. and Gerrard, A. J. and Earle, G. D. and Moses, M. L. and West, M. L. and Huba, J. D. and Erickson, P. J. and Miller, E. S. and Gerzoff, R. B. and Liles, W. and Silver, H. W.} } @conference {172, title = {Analysis of the August 2017 Eclipse{\textquoteright}s Effect on Radio Wave Propagation Employing a Raytrace Algorithm}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, abstract = {

The upcoming total solar eclipse over the continental United States on August 21 offers an unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the west-to-east motion of the eclipse terminator, the duration of the event, the solar zenith angle, and the continued visibility of the corona. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses, as measured by changes in radio frequency (RF) propagation. High Frequency (HF) propagation varies greatly depending on ionospheric conditions. Hence, our analysis will include data collected during the eclipse by several HF systems shown in Figure 1 including SuperDARN, temporary radio transceiver sites, and amateur radio networks such as the Reverse Beacon Network (RBN) and Weak Signal Propagation Reporter Network (WSPRNet). The data analysis will be guided by raytrace models of HF propagation through an eclipsed ionosphere employing the HF propagation toolbox, PHaRLAP (created by Dr. Manuel Cervera).

}, author = {M. L. Moses and S. Burujupali and K. Brosie and S. Dixit and G. D. Earle and L. Kordella and N. A. Frissell and C. Chitale} } @conference {219, title = {Anthropogenic Space Weather}, booktitle = {HamSCI-UK}, year = {2017}, month = {10/2017}, publisher = {HamSCI-UK}, organization = {HamSCI-UK}, address = {Milton Keynes, UK}, author = {P. J. Erickson and T. I. Gombosi and D. N. Baker and A. Balogh and J. D. Huba and L. J. Lanzerotti and J. C. Foster and J. M. Albert and J. F. Fennell and E. V. Mishin and M. J. Starks and A. N. Jaynes and X. Li and S. G. Kanekal and C. Kletzing} } @conference {176, title = {Fitting Ionospheric Models Using Real-Time HF Amateur Radio Observations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {J. D. Katz and N. A. Frissell and J. S. Vega and A. J. Gerrard and R. B. Gerzoff and P. J. Erickson and E. S. Miller and M. L. Moses and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas} } @conference {175, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppller and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {213, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {HamSCI-UK}, year = {2017}, month = {10/2017}, publisher = {HamSCI-UK}, organization = {HamSCI-UK}, address = {Milton Keynes, UK}, author = {N. A. Frissell and W. Engelke and J. D. Katz and J. S. Vega} } @conference {226, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {2017 Annual Meeting of the APS Mid-Atlantic Section}, year = {2017}, month = {11/2017}, publisher = {American Physical Society}, organization = {American Physical Society}, address = {Newark, NJ}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and M. L. West and G. D. Earle and M. L. Moses and H. W. Silver} } @conference {230, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {American Geophysical Union Fall Meeting}, year = {2017}, month = {12/2017}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and M. L. Moses and G. D. Earle and M. L. West and P. J. Erickson and E. S. Miller and R. Gerzoff and H. Ward Silver} } @conference {207, title = {HamSCI and the 2017 Total Solar Eclipse (Experiment Description)}, booktitle = {ARRL and TAPR Digital Communications Conference}, year = {2017}, month = {09/2017}, address = {St. Louis, MO}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. In spite of more than 60 years of research, open questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. This pa- per describes the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT), three amateur radio experiments designed to study the 2017 total solar eclipse. These experi- ments are coordinated by HamSCI, the Ham radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://www.tapr.org/pub_dcc.html}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and S. W. Gunning and A. J. Gerrard and M. L. Moses and G. D. Earle and E. S. Miller and J. D. Huba and M. Hirsch and H. W. Silver and S. E. Reyer and J. R. Ackermann and M. D. Suhar and D. Bern} } @conference {210, title = {HamSCI and the 2017 Total Solar Eclipse (First Results)}, booktitle = {ARRL and TAPR Digital Communications Conference}, year = {2017}, month = {09/2017}, address = {St. Louis, MO}, url = {https://www.tapr.org/pub_dcc.html}, author = {N. A. Frissell and W. Engelke and J. D. Katz and S. W. Gunning and J. S. Vega} } @conference {174, title = {HamSCI: The Ham Radio Science Citizen Investigation (Banquet Presentation)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and J. Dzekevich and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppler and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {208, title = {The H.A.R.C. Database and Visualization Utilities}, booktitle = {ARRL and TAPR Digital Communications Conference}, year = {2017}, month = {09/2017}, address = {St. Louis, MO}, abstract = {

HamSCI{\textquoteright}s goal is to construct a symbiotic relationship between the formal research community and the Amateur Radio community. To facilitate this transfer of knowledge HamSCI must pioneer technologies that allow scientists to easily obtain and understand Amateur Radio data. This task necessitates the creation of warehousing and visualization facilities that allow scientists to easily understand and make use of our data sets. We are currently testing a database and visualization toolkit designed to handle our existing 2 billion-record long QSO log. This data set represents a compiled version of data gathered by the Reverse Beacon Network, WSPRNet, and PSKReporter. Our goal is to build a robust, fast, and queryable front end to the massive, and currently underuti- lized, data sources created by Amateur Radio operators.

}, url = {https://www.tapr.org/pub_dcc.html}, author = {J. D. Katz and W. Engelke and N. A. Frissell} } @conference {163, title = {Ionospheric Impacts of the 2017 Total Solar Eclipse}, booktitle = {Dayton Hamvention}, year = {2017}, address = {Xenia, OH}, author = {Magalina Moses and Gregory Earle and Sushma Burujupalli and Nathaniel A. Frissell and Lee Kordella and Snehal Dixit and Charudatta Chitale and Xiayou Han} } @conference {173, title = {Ionospheric Simulations of the 2017 Solar Eclipse QSO Party}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and M. L. Moses and G. D. Earle and S. W. Gunning and A. J. Gerrard and E. S. Miller and M. L. West and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas and H. W. Silver} } @conference {165, title = {The Solar Eclipse QSO Party: Ionospheric Sounding Using Ham Radio QSOs}, booktitle = {Dayton Hamvention}, year = {2017}, address = {Xenia, OH}, abstract = {

The 2017 Total Solar Eclipse is expected to temporarily induce profound changes on ionospheric structure, dynamics, and radio propagation. The ARRL and HamSCI are sponsoring a Solar Eclipse QSO Party (SEQP) that will be used to generate to assist in imaging ionospheric changes before, during, and after the eclipse. Data will be collected through participant submitted logs and the use of automated tools such as the Reverse Beacon Network (RBN), PSKReporter, and WSPRNet. SEQP rules and a prediction of results will be presented.

}, author = {Nathaniel A. Frissell and Joshua D. Katz and Andrew J. Gerrard and Magdalina Moses and Gregory D. Earle and Robert W. McGwier and Ethan S. Miller and Stephen Kaeppler and H. W. Silver} } @conference {162, title = {Upper Level Lows and Six Meter 50 Mhz Sporadic E}, booktitle = {Dayton Hamvention}, year = {2017}, address = {Xenia, OH}, abstract = {

Amateur radio is used to explore possible correlations between weather storm systems and sporadic E clouds to see if they are collocated. While some of the main causes of sporadic E propagation are wind shear, meteor strikes and upper atmospheric tides (ultimately coming from solar EUV energy inputs), radio operators have noticed that sporadic E propagation is also changed significantly by hurricanes and storms. \ Specific cases where K1YOW used amateur radio to investigate the effects of low pressure weather storms on the formation and/or enhancement of 6 meter sporadic E clouds are presented. DX Maps and earth wide weather model charts combined with operations on 6 meters are used to examine possible correlations between the location of the sporadic E clouds and the low pressure weather storm systems. \ Initial findings show a high degree of correlation when magnetic field strength is taken into consideration.

}, author = {Joseph A. Dzekevich and Philip J. Erickson} } @conference {158, title = {On the use of solar eclipses to study the ionosphere}, booktitle = {15th International Ionospheric Effects Symposium IES2017}, year = {2017}, month = {05/2017}, address = {Alexandria, VA}, abstract = {

Exploring the effects of solar eclipses on radio wave propagation has been an active area of research since the first experiments conducted in 1912. In the first few decades of ionospheric physics, researchers started to explore the natural laboratory of the upper atmosphere. Solar eclipses offered a rare opportunity to undertake an active experiment. The results stimulated much scientific discussion.
Early users of radio noticed that propagation was different during night and day. A solar eclipse provided the opportunity to study this day/night effect with much sharper boundaries than at sunrise and sunset, when gradual changes occur along with temperature changes in the atmosphere and variations in the sun angle.
Plots of amplitude time series were hypothesized to indicate the recombination rates and re- ionization rates of the ionosphere during and after the eclipse, though not all time-amplitude plots showed the same curve shapes. A few studies used multiple receivers paired with one transmitter for one eclipse, with a 5:1 ratio as the upper bound. In these cases, the signal amplitude plots generated for data received from the five receive sites for one transmitter varied greatly in shape.

}, author = {W. Liles and C. Mitchell and M. Cohen and G. Earle and N. Frissell and K. Kirby-Patel and L. Lukes and E. Miller and M. Moses and J. Nelson and J. Rockway} } @conference {144, title = {Characterizing the Ionosphere Using a Commercial Off the Shelf Software Defined Radio System}, booktitle = {Fall 2016 American Geophysical Union}, year = {2016}, month = {12/2016}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francsico}, abstract = {

On August 21, 2017, there will be a total solar eclipse over the continental United States (US). Solar eclipses offer a way to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the east-west motion of the eclipse terminator, the speed of the transition, and the continued visibility of the corona throughout the eclipse interval. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses including variations in the density and altitude of the F2 peak. In order to study these changes, we will establish four temporary field stations along the path of totality to track the maximum usable frequency (MUF) across the US over the course of the eclipse. Each field station shall consist of a commercial off the shelf (COTS) software defined radio (SDR) transceiver, a laptop computer running automatic link establishment (ALE) software, a Global Positioning System (GPS) receiver for timing, and a COTS antenna. Custom ALE software will automate the sites{\textquoteright} operation during the experiment to determine the MUF. As a validation test prior to the eclipse, we established three sites along the east coast to confirm that the SDRs are capable of inferring ionospheric conditions. The preliminary results characterize the effects of the sunrise/sunset terminator on our system{\textquoteright}s measurements as well as the change in foF2 during different seasons and under different geomagnetic conditions.

}, url = {http://hamsci.org/sites/default/files/publications/2016_AGU_Moses.pdf}, author = {Magdalina L. Moses and S. Dixit and Gregory D. Earle and Nathaniel A. Frissell and Lee Kordella and Xiaoyu Han and Charudatta Chitale} } @conference {143, title = {HamSCI: The Ham Radio Science Citizen Investigation}, booktitle = {Fall 2016 American Geophysical Union}, year = {2016}, month = {12/2016}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco}, abstract = {

Amateur (or {\textquotedblleft}ham{\textquotedblright}) radio operators are individuals with a non-pecuniary interest in radio technology, engineering, communications, science, and public service. They are licensed by their national governments to transmit on\ amateur radio frequencies. In many jurisdictions, there is no age requirement for a ham radio license, and operators from diverse backgrounds participate. There are more than 740,000 hams in the US, and over 3 million (estimated)\ worldwide. Many amateur communications are conducted using transionospheric links and thus affected by space weather and ionospheric processes. Recent technological advances have enabled the development of\ automated ham radio observation networks (e.g. the Reverse Beacon Network,\ www.reversebeacon.net) and specialized operating modes for the study of weak-signal propagation. The data from these networks have been\ shown to be useful for the study of ionospheric processes. In order to connect professional researchers with the volunteer-based ham radio community, HamSCI (Ham Radio Science Citizen Investigation,\ www.hamsci.org) has\ been established. HamSCI is a platform for publicizing and promoting projects that are consistent with the following objectives: (1) Advance scientific research and understanding through amateur radio activities. (2) Encourage\ the development of new technologies to support this research. (3) Provide educational opportunities for the amateur community and the general public. HamSCI researchers are working with the American Radio Relay League\ (ARRL,\ www.arrl.org) to publicize these objectives and recruit interested hams. The ARRL is the US national organization for amateur radio with a membership of over 170,000 and a monthly magazine, QST. HamSCI is\ currently preparing to support ionospheric research connected to the 21 Aug 2017 Total Solar Eclipse by expanding coverage of the Reverse Beacon Network and organizing a large-scale ham radio operating event ({\textquotedblleft}QSO\ Party{\textquotedblright}) to generate data during the eclipse.

}, url = {http://hamsci.org/sites/default/files/publications/2016_AGU_Frissell_HamSCI.pdf}, author = {Nathaniel A. Frissell and Magdalina L. Moses and Gregory Earle and Robert W. McGwier and Ethan S. Miller and Steven R. Kaeppler and H. Ward Silver and Felipe Ceglia and David Pascoe and Nicholas Sinanis and Peter Smith and Richard Williams and Alex Shovkoplyas and Andrew J. Gerrard} } @conference {52, title = {Experiment Design to Assess Ionospheric Perturbations During the 2017 Total Solar Eclipse}, booktitle = {Fall AGU - Poster Presentation}, year = {2015}, month = {12/2015}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {San Francisco, CA}, abstract = {

On August 21, 2017, there will be a total solar eclipse over the United States traveling from Oregon to South Carolina. Solar eclipses offer a way to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the east-west motion of the eclipse terminator, the speed of the transition, and the continued visibility of the corona throughout the eclipse interval. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses. These include changes in the ionospheric electric fields, changes in the Total Electron Content (TEC) along paths through the eclipsed region, and variations in the density and altitude of the F2 peak. Several studies over the past century investigated these effects; however, some of the results from these studies are contradictory. These contradictions and the studies{\textquoteright} limited spatial resolution leave many fundamental questions unanswered. The advent of several mid-latitude Global Positioning System (GPS) and radar networks in the past few decades, such as the Continuously Operating Reference Station (CORS) system and the Super Dual Auroral Radar Network (SuperDARN) radar system, have enabled ionospheric observations with hitherto unprecedented spatial resolution. Also, the establishment of several nationwide amateur radio reporting systems, such as the Reverse Beacon Network (RBN) that monitors radio wave propagation on the high frequency (HF) bands, offers the potential for evaluating changes in ionospheric conditions with unprecedented spatial resolution. We propose to study the effects of the total solar eclipse on the ionosphere using a combination of GPS receivers, the SuperDARN radar system, HF band amateur radio, and plasma modeling. The overall objectives of this study are to characterize the changes in F-region plasma morphology during the eclipse over a larger spatial domain than any previous eclipse experiment. In addition, the amateur radio component of our study offers a unique opportunity to further engage the amateur radio community nationwide in a scientific study.

}, author = {Magdalina Moses and Gregory Earle and Nathaniel Frissell and Stephen Kaeppler} } @booklet {668, title = {HamSCI and the 2017 Total Solar Eclipse (HamSCI Founding Document)}, year = {2015}, url = {https://hamsci.org/publications/hamsci-and-2017-total-solar-eclipse-hamsci-founding-document}, author = {Nathaniel A. Frissell and Magdalina L. Moses and Gregory D. Earle and Robert McGwier and H. Ward Silver} }