@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 {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 {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 and Paul Elliott} } @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} }