Published February 2, 2019 | Version v1

Solar Eclipse 2017 recordings of medium-wave AM broadcast band from western Michigan, U.S.A.

Authors/Creators

Description

recorded by Tim Tromp, KE8JFM

location recorded:   86°09'29" W, 43°11'07" N

These data files are recordings of the entire medium wave broadcast band (535-1705kHz) from  17:57:28UTC to 19:10:23UTC from western Michigan, U.S.A.   Data files are .wav format, but the archived files are .zip, with two or three .wav files packaged together in each .zip file.

Antenna:  DKaz antenna (described at http://www.durenberger.com/documents/DKAZ070314.pdf), 117' long x 22' tall, aimed  @ 180 degrees (no amplification used)

Receiver:  Microtelecom Perseus SDR (http://microtelecom.it/perseus/) with no front end attenuation, center frequency set at 910kHz, recording  1600kHz wide passband, using Perseus software  17:57:28UTC to 18:36:23UTC.  A second session was recorded with center frequency set at 1300kHz, and an 800kHz wide passband, using Perseus software,  18:38:51UTC to 19:10:23UTC.

 

Notes

In the AM broadcast band (535-1705kHz), there are roughly two modes of broadcast station signal coverage, one of which occurs in the daytime, and the other at night. During the day time, signals are propagated by ground wave and and not usually heard well beyond 150km from the transmitter. However, at night, an absorptive region in the ionosphere, the D-layer, disappears, allowing signals to refract off higher regions of the ionosphere, and to be heard hundreds and even thousands, of kilometers away from the transmitter. During the solar eclipse of 21 August 2017, signals were observed changing from daytime to nighttime mode and then back again as the moon's shadow moved across the continental USA. The radio stations in this band use amplitude modulation, which requires a strong stable carrier wave, well suited for observing changes in signal strength over a time period. Please note that there are two small periods of time in these data files when the band was not recorded: 18:13:22 to 18:16:45UTC, and 18:36:23UT to 18:38:51UTC. Included in these files is one provided by Microtelecom ("Perseusv5demo.exe") for playback of the .wav files, plus a help file, "PerseusV5QuickTuningGuide.pdf". As well, there is a reference file to assist in identifying signals ("canusa-Jan2019.pdf"). Finally, there is set of instructions for using the software, including instructions for using "Perseusv5demo.exe" to extract a time series of signal power for an individual radio station's signal ("Using Perseusv5demo to create signal strength time series-KE8JFM.pdf"). Finally, referencing the article archived at http://hamsci.org/sites/default/files/publications/2019_am-eclipse2017_hall-patch.pdf , will give the user of these files an idea of how radio reception datasets from different locations can be used to compare the effects that the solar eclipse had on radio propagation.

Files

canusa-Jan2019.pdf

Files (20.7 GB)

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