Broadband Recordings from Medium Wave DXers Could Support Solar Eclipse Science

Medium wave DXers monitor the AM broadcast band (535-1705kHz) to receive distant radio stations, generally between sunset and sunrise, in order to take advantage of favorable ionospheric conditions then.  Historically, these DXers have been aware of similarly favorable reception conditions that occur during solar eclipses, and during the 2017 solar eclipse, a number of them recorded the entire AM broadcast band using software defined radios (SDRs).  During the upcoming annular and total solar eclipses, it is proposed to suggest to such DXers that their pursuit of distant radio stations be done in such a way as to make their recorded IQ files of optimum use to propagation researchers, both from HamSCI and from elsewhere, by documenting such things as receiver, software  and antenna settings,  and by making sure that timestamps in their data are as accurate as possible.  DXers could also be encouraged  to make additional recordings of sunrise and sunset conditions in order to support HamSCI scientific goals.  Because some DXers use SDRs with system clocks locked to GPS, the data from such SDRs could be useful as a lower frequency adjunct to data gathered from Grape v2, especially if Doppler variation of specific broadcaster’s carriers could be converted to the audio format used by Grape v2, before further processing.  IQ data recorded during the eclipse could be gathered together and archived by HamSCI for future researchers, such as was done for the 2017 eclipse.  The processing of such data to support present HamSCI scientific objectives could require significant volunteer effort, however.