Amateur Satellites

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Discussion about amateur reception and processing of data from artificial satellites, primarily through radio signals but data from internet resources is welcome too.

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thomasdouwes

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APT image from NOAA-15, currently with AVHRR scanner motor malfunction, plus raw image, waterfall screenshot, audio sample and DSB images as bonus. (i.imgur.com)

submitted 1 year ago by [email protected] to c/amateursatellites

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The main image in post was decoded with WXtoIMG as both noaa-apt and SatDump fail to synchronize it correctly.

Unprocessed image from noaa-apt:

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Waterfall:

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There you can see some breaks, the noticeable horizontal lines.

Which sounds like so (note: the waterfall shown above isn't from the same time as audio):

Compatibility audio link

And the bonus, DSB images:

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Channels 1-20 are left-to-right then bottom.

And also AVHRR scan motor current as of today:

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[–] [email protected] 1 points 1 year ago

Telemetria pochádza s tadiaľto: https://www.star.nesdis.noaa.gov/icvs/status_N15_AVHRR.php
Myslím že je to vysielané v DSB downlinku v rovnakom pásme.

JPEG mohol existovať, ale musela by sa vymeniť existujúca technika. Tieto satelity vysielajú aj HRPT, digitálne vysielanie v pásme L so 4x vyšším rozlíšením než APT v 5 kanáloch namiesto dvoch.
Info o príjme HRPT

JPEG kompresiu v pásme 137MHz využíva LRPT. LRPT aktuálne vysiela len Meteor-M No. 2-3 ktorý má bohužiaľ poškodenú anténu, takže signál je dosť kolísavý.