@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 {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} } @proceedings {748, title = {How Do I Talk From Scranton to Pakistan Using​ High Frequency Amateur Radio?​}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

This poster will demonstrate the possible ways to send propagation transmissions from The University of Scranton to Karachi, Pakistan. To do this, VOACAP will be used to map out possible paths and peak times for transmission and then WSRP.rocks will be used to compare the empirical VOACAP model outputs to observed data. A recommendation will then be made for the optimal time and frequency to communicate using high frequency (HF) radio between Scranton, PA and Karachi, Pakistan.

}, author = {Zainab Shah and Gwyn Griffiths and Rob Robinett and Nathaniel Frissell} } @proceedings {698, title = {Low Cost, High Accuracy and Stability FST4W Transmissions Using the QDX Transceiver}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

In his presentation Gwynn Griffiths has shown how the spectral spreading information logged by the WSJT-x FST4W decoder can offer researchers new insights in to HF propagation.\  While there are dozens of wsprdaemon KiwiSDR FST4W receive sites around the world already decoding and logging FST4W spots on all of the HF bands, there are only a few sites transmitting those signals.\  The frequency accuracy and stability required by this use of FST4W means that existing low cost WSPR beacons like the widely deployed QRP Labs U3S and Zacktek cannot be converted to FST4W transmitters, and there are only a few very costly ham transceivers which come with external clock input ports.\  However QRP Labs has recently introduced the US $70 QDX digital mode transceiver kit which, when paired with a Raspberry Pi running WSJT-x and a low cost GPSDO, creates a 80-20M or 20-10M transmitter which meets the requirements of this application.\  It is to be hoped that the easy installation and low cost of such a system will encourage many more hams to deploy such beacons worldwide and thus expand propagation studies beyond North America and Europe.

}, author = {Rob Robinett} } @proceedings {473, title = {Visualising propagation to mid-latitudes from a shipboard WSPR transmitter on a passage from 27oN to 70oS using the WsprDaemon database, and how to access the data}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

WSPR transmitters and or receivers on polar research ships provide opportunities for several interesting propagation studies. Such studies include propagation across the Boreal and Austral Auroral Ovals with the ship working in the Polar Regions, or, as in this case, on mid-latitude propagation with the ship on transit. For RV Polarstern{\textquoteright}s voyage from Gran Canaria (27.5oN) to Neumayer III station, Antarctica (70.5oS) from 27 December 2020 {\textendash} 18 January 2021 a WSPR transmitter (DP0POL) operated on all bands 160{\textendash}10 meters. Heatmaps of the number of spots received in Europe and North America each hour, each day, and on each band have been generated from the WSPR data held on the WsprDaemon server. These spot-count heatmaps, proxies for circuit reliability, clearly delineate the diurnal variation in band opening times and how those diurnal variations vary systematically over a 100o span of latitude on the voyage south. However, quantitative assessment of the spot numbers needs care; the number of reporters receiving spots changes with time and distance. Furthermore, there were far fewer distinct reporters for the MF and upper HF bands (11 for 160 m and 14 for 10 m compared with 447 for 40 m and 473 for 20 m). The heatmaps of SNR show several intriguing features, including steps from no decodes to SNRs some 10 dB above the WSPR decoding threshold as bands open and close. A Grafana dashboard is available for all to explore at http://logs1.wsprdaemon.org:3000/d/QGlNSz-Gk_2\  Other ways to obtain WSPR data from the WsprDaemon database are outlined, including using Octave, KNIME, R, Python, PySpark and Clickhouse. A worked example shows how to use Octave to generate a time sequence of great circle maps, as a movie, of where WSPR spots from DP0POL were received on the voyage from 27.5oN to 70.5oS.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=57-BC-D3-11-D9-50-97-40-0D-F8-D2-C5-AA-73-79-6A}, author = {Gwyn Griffiths and Rob Robinett} } @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} }