Skip Navigation
Remote View
Amateur Satellites @lemmy.world
u/lukmly013 💾 (lemmy.sdf.org) @lemmy.sdf.org

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

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:


Compatibility image link

Waterfall:


Compatibility image link
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:


Compatibility image link
Channels 1-20 are left-to-right then bottom.

And also AVHRR scan motor current as of today:


Compatibility image link

14 comments

  • Another interesting thing I noticed about these broken APT images is the channel B sync marker is repeated twice instead of the channel A marker. This is why the sync fails, and it makes a "tick tick" sound instead of the "tick tock" sound it normally makes.
    I'd love to know what is causing this, but I think only NOAA knows what is going on with that.

  • Wow, nevedel som, že satelity ešte stále vysielajú analógovo. Miliarda ľudí si musela vymeniť televízny prijímač a tisíce meteorológov stále ladí SSTV...

    A čo sú tie zubaté šikmé hrany v horných rohoch obrazu?

    • Takto vysielajú už len staré satelity NOAA-15 (skener sa stále zasekáva), NOAA-18 a NOAA-19.

      • To je mi jasné, digitální vysílání bude několikanásobně efektivnější. Ale tyhle věci slyším poprvé: ten skener je pohyblivý optický senzor? Ty data o motoru jsi získal jak? Satelit je vysílá jako digitální hodnoty ve stejném pásmu?

        Edit: Holy shit, NOAA-15 je jen 25 let starý. Tou dobou už přece existoval JPEG!

  • You should try satdump for the DSB, it can make some nice HIRS composites.

    The scan motor current seems to be dropping, maybe it will fix itself again.

    • That is from SatDump, I just put it together in JointPics.
      In this case there wasn't anything interesting looking, at least with the pre-set composites. But to be honest, I am not sure how to use that properly. Also what's with the vertical lines with NOAA-15? When I tried NOAA-19 I got OK results

      (Channel 20)

      • That's really strange, I checked my HIRS images from NOAA 15 and I don't have any vertical lines, was there any nearby interference?
        It only works in day, but ch20, ch20, ch20 + ch8 * 0.1 seems to make a nice natural looking colour composite on HIRS. It's a bit hard to see because of how low res the HIRS is, but it makes the land green and the oceans a dark blue.
        My HIRS from that pass (low elevation here):

    • Also, The top right of your APT image is very interesting, some of the actual corupted data seems to be getting into the APT

  • Does the embedded audio work for anyone? I think it’s not even an official Lemmy/Markdown feature.

    • It works in the default Lemmy web UI. I tried it with Opera (Android) and Firefox (Manjaro). It relies on the browser's media player.

      There's still the link below it, for when it doesn't work, which I expect from most Lemmy clients and probably Kbin too.

      • Oh, I didn't check if the compatibility link is any different, I assumed it was the same.

        Of course you cannot embed an external site in a comment but the raw file does seem to work, in browsers at least.

14 comments