Approaches to Identifying Medium Wave Signal Enhancements in HamSCI's Solar Eclipse Data

During the solar eclipses of 2023 and 2024,  HamSCI organized 27 volunteers in six countries to record the entire medium wave band (525-1705kHz) using software defined radios (SDRs), both during the eclipse and for the same time period on other days, as well as during dawn and dusk periods.  Well over 20TB of Medium Wave SDR data was submitted to HamSCI as a result. 

For both eclipses, all data has now been preprocessed using visualization software to generate waterfall displays of AM broadcasters’ carriers at 0.1Hz resolution for each of the 117 domestic broadcast channels.  This will allow researchers to quickly pick out signal enhancements during the eclipse periods for further study.  HamSCI is in the process of making the enhanced data available publicly via Zenodo. 

Some participants' data displayed hundreds of these enhancements.   Readable audio from various AM broadcasters was heard for a short time during the eclipse, but many enhancements were of AM broadcasters' carrier waves only.   As hearing a station identification in the enhanced signal's audio is the easiest way to determine the location of a station's transmitter, what can be done to identify those signals that do not contain identification in the audio, or were not strong enough to deliver audio at all?

This presentation will suggest encouraging radio listening hobbyists to "DX the data" available at Zenodo in order to deliver as many station identifications as possible from the audible data.   In addition, ways will be suggested to characterize the carriers of AM broadcasters across data sets in ways to otherwise identify transmitter locations.

This will help provide HamSCI with a higher quality data set, more suitable for assisting in verifying ionospheric models, particularly those that are simulating the effects of solar eclipses.