@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 {930, title = {The Solar Eclipse Inverse Problem}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI Personal Space Weather Station (PSWS) is a distributed network that includes magnetometers and high frequency receivers. The Great Radio Amateur Propagation Experiment (GRAPE) is a collection of PSWS receivers that record Doppler shift from national time standard signals. The Grape project includes Grape 1 receivers recording Doppler and spectral data as well as the upgraded Grape 2 three channel receivers and the multi-channel WSPR (Weak Signal Propagation Reporter) Grapes. The network collected data during the 2023 and 2024 solar eclipses on frequencies ranging from 2.5 to 20 MHz. The recorded Doppler shift indicates a change in signal path caused when the signal passes through the ionospheric layers in the Earth{\textquoteright}s atmosphere. Due to the scale and variability of the ionosphere, these measurements are sparse and are not accompanied by a known forward model. The reconstruction of eclipse period ionospheric behavior can therefore be viewed as a mathematical inverse problem. We explore various mathematical techniques and algorithms that could be used to solve the inverse problem and model the real time ionospheric behavior.

}, author = {Rachel Boedicker and Nathaniel Frissell and John Gibbons and Kristina Collins and David Kazdan} } @proceedings {871, title = {Signatures of Space Weather in the NJIT V1 Grape Low-IF Receiver}, year = {2024}, month = {03/2024}, abstract = {

The V1 Grape Low Intermediate Frequency (Low-IF; 10 MHz) Receiver is part of a low-cost Personal Space Weather Station (PSWS) developed by the Ham Radio Science Citizen Investigation (HamSCI) Collective. One of the existing deployed Grapes is located at the New Jersey Institute of Technology (NJIT). The Grape measures the WWV 10 MHz signal originating from Fort Collins, Colorado. Variations in WWV{\textquoteright}s signal intensity and frequency, received by the Grape can be used to investigate\  strong space weather events and their effects on the Earth{\textquoteright}s ionosphere. The Grape data is separated into two parameters, Doppler Shift (Hz) which is a change in frequency introduced by the variability of the ionosphere along the WWV to NJIT link, and Relative Power (dB) which can be used as a proxy for the received signal{\textquoteright}s intensity.\  In this presentation, we will explore the possibility of using the Relative Power parameter for studying ionospheric scintillation due to space weather events.\  We will present several examples of data collected on days with known space weather events to assess the Grape{\textquoteright}s ability to detect the event. We will also discuss our analysis techniques, including our strategies to mitigate the local noise environment at NJIT, and future work.

}, author = {Tiago Trigo and Gareth W. Perry and Sebastian Fernandes and John Gibbons and Nathaniel A. Frissell} } @proceedings {478, title = {A Survey of HF Doppler TID Signatures Observed Using a Grape in New Jersey}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=6A-B6-94-74-A1-46-CF-D2-AC-BA-F3-58-2E-71-17-97}, author = {Veronica I. Romanek and Nathaniel A. Frissell and Dev Joshi and William Liles and Kristina Collins and John Gibbons and David Kazdan} }