@proceedings {827,
	title = {Early Results from the 2023 Eclipse Medium Wave Recordings},
	year = {2024},
	month = {03/2024},
	publisher = {HamSCI},
	address = {Cleveland, OH},
	abstract = {<p>During the annular eclipse of 2023, HamSCI organized 13 volunteers in Canada, US, Mexico and Portugal to record the entire medium wave band (525-1705kHz) using software defined radios, both during the eclipse and for the same time period on other days, as well as during dawn and dusk periods. This medium wave data should extend our understanding of the eclipse{\textquoteright}s influence on the ionosphere by using frequencies well below HF. Since the eclipse, all 10 TB of medium wave data has been gathered and archived, followed by preliminary processing using inexpensive commercial software, such that all signal strength data from each participant is now available to 0.1Hz resolution for all broadcast channels.\&nbsp; In addition, for all broadcast channels, and from every participant, useful visualization of signal variations during the eclipse is now available, as well as for all other time periods recorded.\&nbsp;Many participants did see an effect of the eclipse on received signals.\&nbsp; Comparisons of their rates of success compared with percentage of totality at their locations will be discussed. It{\textquoteright}s already possible to support some of the science aims of HamSCI with this gathered and archived data.\&nbsp; Examples will be given of whether signal strength changes observed were symmetric compared with the onset and recovery timing of the eclipse. These changes will likely have been due to ionospheric response as the eclipse progressed. Visual examples will also be given of comparisons between the eclipse{\textquoteright}s effects on target signal characteristics to the effects caused by the passage of the daily dawn and dusk terminator.</p>
},
	author = {Nicholas Hall-Patch}
}
@proceedings {696,
	title = {Broadband Recordings from Medium Wave DXers Could Support Solar Eclipse Science},
	year = {2023},
	month = {03/2023},
	publisher = {HamSCI},
	address = {Scranton, PA},
	abstract = {<p>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.\&nbsp; 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).\&nbsp; 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\&nbsp; and antenna settings,\&nbsp; and by making sure that timestamps in their data are as accurate as possible.\&nbsp; DXers could also be encouraged\&nbsp; to make additional recordings of sunrise and sunset conditions in order to support HamSCI scientific goals.\&nbsp; 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{\textquoteright}s carriers could be converted to the audio format used by Grape v2, before further processing.\&nbsp; 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.\&nbsp; The processing of such data to support present HamSCI scientific objectives could require significant volunteer effort, however.</p>
},
	author = {Nicholas Hall-Patch}
}
