Not another one

  • ChaoticNeutralCzech
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    1 year ago

    Ako dlho trval tento príjam? Stává sa, že je v zorném poli iba vesmier? Môže sa snímač spáliť od slnka?

    • Thomas DouwesOPM
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      1 year ago

      I don’t speak slovak, but I’ll try to respond:
      The satellite transmits constantly, so you are only limited by the time it is above the horizon. The duration of this transmission was about 15 minutes, but the signal was only strong enough for a much shorter time. I can’t remember exactly how long this one was, it was a while ago.

      These russian satellites seem to have a lot of problems with orientation. This is the first and only time so far this satellite has had issues, but the other ones have had a lot of issues before. When it is spinning it usually does send images of space, but I’ve not seen any where it’s only space before.

      Yes, The sensor is sensitive and would be damaged by the sun. One of the old satellites started spinning and the sun burned out the imager.

      preložené:
      Dúfajme, že to prekladateľ príliš nepokazil.

      Ja síce po slovensky neviem, ale pokúsim sa odpovedať:
      Družica vysiela nepretržite, takže ste obmedzený len časom, keď je nad horizontom. Dĺžka tohto vysielania bola asi 15 minút, ale signál bol dostatočne silný len oveľa kratší čas. Nepamätám si presne, aký dlhý bol tento, bolo to už dávno.

      Zdá sa, že tieto ruské satelity majú veľa problémov s orientáciou. Toto je prvý a zatiaľ jediný prípad, keď mal tento satelit problémy, ale ostatné mali veľa problémov už predtým. Keď sa otáča, zvyčajne posiela snímky vesmíru, ale predtým som nevidel žiadne, kde by bol len vesmír.

      Áno, snímač je citlivý a poškodilo by ho slnko. Jeden zo starých satelitov sa začal otáčať a slnko vypálilo snímač.

      • ChaoticNeutralCzech
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        1 year ago

        I am not Slovak either, lol. I thought you were because you have a receiver in Slovakia. However, I am Czech so I understand the similar language and can pretend to speak it. I was hopeful I had someone on the Fediverse to talk to in a language other than English and German. I’ll edit my comments to English so that others can read them. Your translation engine did well.

        Okay so the sensor is just one or more light cells that physically scan lines as the satellite moves across land, with no beginning or end of an image? Very primitive considering they are from the late 1990s.

        • Thomas DouwesOPM
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          1 year ago

          oh, haha. You are probably thinking of @user224@lemmy.sdf.org saying they are in slovakia in this post, not me. I live in the UK.
          This satellite is actually from 2023, I think having one light cell allows for higher resolution and multiple channels. This satellite also has 3 thermal infrared channels that are calibrated so you can see the exact temperature at each pixel, I don’t think that would be possible with a traditional camera system.

          • ChaoticNeutralCzech
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            11 year ago

            Aha. I thought this was a one-person community based on the first few posts so I stopped checking usernames. Sorry.

            Wow, the IR does make the flyover scan technique surprisingly neat. Too bad there is no emergency shutter for when the sensor is about to point at the sun (but that would be another potential point of failure).

            I am confused why they don’t just turn the analogue transmission off to save power or direct more of it to the digital transmitter. The digital data are already received by NOAA’s various receivers and shared with meteorologists online, right? The amateur radio community would complain but they have been unsuccessful in preventing other analog shutdowns.

            • Thomas DouwesOPM
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              1 year ago

              Usually they just don’t start spinning, some of the NOAA ones have been going for 25 years and haven’t ever lost orientation.
              The satellite in this post is a russian one, they don’t have an analog transmission anymore, this image is from digital transmission near the frequency of the NOAA analog one, so still easy enough to recieve.
              But as for the analog NOAA transmission, There really isn’t any reason to shut down the analog transmission, the satellite was built with enough power to run it, so shutting it down would just lead to a surpus of power on satellite. I don’t think the design would even allow pushing more power on the digital signal.
              NOAA will have some huge tracked dishes for this to get a perfect image even with the lowish power level.
              Also, the satellites with analog are not the main ones anymore. NOAA has some new satellites with much higher resolution imagery that are not nearly as easy to receive as these older ones. they only broadcast at 8GHz instead of the 1.7GHz or 137MHz that the current ones do