This article starts with a brief description of historical observations that have been made concerning the effects of solar eclipses on the strengths of distant medium wave signals. It continues with a description of how medium-wave DXers used software defined radios (SDRs) for the first time during the solar eclipse of August 2017 to record the entire AM broadcast band (535-1705kHz) for later analysis. Although no plan had been made to create a formal experiment, it appears to be possible to use the data collected to analyze the effect of the eclipse on radio propagation. An example is presented, derived from recordings made at four different receiver locations in western North America, describing large variations in the signal strength from Salt Lake City's KSL-1160kHz during the course of the eclipse. The times that peak signal strengths occurred at the four locations are then compared relative to the times of eclipse totality along the signal paths.
HamSCI will again be at the Dayton Hamvention as part of the new Ham Radio 2.0: Innovation and Discovery area sponsored by the Yasme Foundation. Come visit the HamSCI Booth and Forum to learn about projects on the cutting edge of ham radio science and engineering research, including new directions in Sporadic E research, causes of F region ionospheric variability, how propagation works on the new 630 and 2200 m bands, the Personal Space Weather Station, and more. Hamvention will be held May 17-19, 2019 at the Greene County Fairgrounds in Xenia, Ohio.
SEQP logs and data submitted to hamsci.org are now available for download from the Zenodo Data Repository HamSCI Community. This archive contains the locations, logs, and station descriptions submitted by operators to hamsci.org following the SEQP, as well as an aggregated, geolocated archive in CSV format of all Reverse Beacon Network (RBN), WSPRNet, PSKReporter, DXCluster, and SEQP log QSOs. The final rules of the SEQP have also been archived here. More information about the SEQP can be found at http://hamsci.org/seqp, and a published analysis of RBN observations over the United States by Frissell et al. (2018) may be found at https://doi.org/10.1029/2018GL077324.
This week, many HamSCI members are presenting their research at the American Geophysical Union (AGU) Fall Meeting in Washington, D.C. The AGU Fall meeting is one of the largest geoscience meetings in the world, and consists of about 24,000 attendees. The scientific program includes sessions pertaining to all areas of geophysics, including space weather, the solar wind, auroral activity, the ionosphere, and the neutral atmosphere. Below is a list of selected presentations and sessions being given by HamSCI members, or of general interest to ham radio operators. The complete scientific program is available here.
In his recent QEX article, “Ionospheric Disturbances at Dawn, Dusk, and During the 2017 Eclipse,” Steve Cerwin, WA5FRF published his analysis of observations of WWV (5 MHz) and WWVB (60 kHz) transmitters in Ft. Collins, CO as received at his home in San Antonio, TX. Cerwin reports that during the August 21, 2017 eclipse, a definite and measurable enhancement of low frequency (LF) and high frequency (HF) signals from his station. In addition to eclipse observations, Cerwin also examined the dawn and dusk transitions on both frequencies. Notable findings include a propagation null on WWVB that is correlated in time with dusk and dawn, and is consistent with destructive interference from a combination of ionospheric skip and ground-wave multipath propagation. Cerwin also reports on increased frequency jitter at 5 MHz during these times, as well a radical positive frequency swing at dawn and a negative swing at dusk.
The question, “Will anybody participate in the Solar Eclipse QSO Party (SEQP)?” Was answered loud and clear on eclipse day, August 21st. The HF bands were busy from the first minute of the SEQP at 1400 UTC to the closing bell at 2200 UTC. Logs were received from 566 stations. Some operated on all bands, others concentrated on one or two. In total, the SEQP generated over 618,000 RBN spots, 630,000 WSPRNet spots, 1.2 million PSKReporter spots, and 29,000 logged QSOs. The Sun may have taken a lunar nap but the bands were full of life!