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I noticed strange blank line in the middle of completely valid images from VIIRS.

VIIRS Earth image.

This looks like an error in the reception. Would have go unnoticed, unless the same blank line in the middle of Meteor M images!

METEOR-M

Artifacts at the bottom and the top are expected. This could be caused by weak signal.

Any ideas?

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  • $\begingroup$ Good question! I believe that VIIRS data comes from Suomi NPP which operates by scanning. then there is further stitching. This isn't the answer to your question, but it's related: What causes these faint, straight line artifacts in Suomi NPP images of Earth at night? $\endgroup$
    – uhoh
    Sep 28, 2018 at 6:51
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    $\begingroup$ Can you add a link to where you took these images from? It may be useful to understand the exact source as the effect may be due to some post-processing done to create these images (i.e. not due directly to satellite data). For example, the first image you posted seems to me to be a combination of two separate images (not one with a black stripe). If you check this guide to VIIRS, it says that satellite scans come in 3040x12km format, then bundled in "granules" of 3040x570km...so even to make one images, multiple granules have been used. It is important to known who assembled them and how :) $\endgroup$
    – BlueCoder
    Oct 5, 2018 at 7:52
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    $\begingroup$ Here's the guide: rammb.cira.colostate.edu/projects/npp/… It also explains some effects that may produce missing lines of data (althought by a first read they do not seem to me capable to produce that black stripe) $\endgroup$
    – BlueCoder
    Oct 5, 2018 at 7:53

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I found the answer. At least for Meteor-M. Missing lines in the center of image is a satellite defect. According to the link, this could happen every ~6mins due to internal buffer overflow.

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I see this all the time in digital video and usually is not caused by a weak signal but a lag in the processor causing a digital skip or glitch in frames. Other possibilities are physical obstruction in transmission (debris in orbit), some truck drivers use highly modified illegal CB radios that cast interference on all frequencies acting like a jammer on nearby receivers, Electrical surge in the system causing electromagnetic interference, etc.

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  • $\begingroup$ Debris in orbit is much too small to obstruct transmission. Of course satellite receiver antennas are build far away from highways full of trucks. But illegal CB radios don't cast interference on all frequencies especially not on very high frequencies of several gigahertz. CB operates on a very low frequency of 27 MHz, far away from frequencies used for satellite downlink. $\endgroup$
    – Uwe
    Oct 10, 2018 at 8:24
  • $\begingroup$ @Uwe I do know that static from these CB radios can cast static on all frequencies 200 km away or more. Why so they can talk over everyone else on that channel. I will provide link soon $\endgroup$
    – Muze
    Oct 10, 2018 at 15:16
  • $\begingroup$ I don't think it is a static. See the weird lines in Meteor image. If it is a digital signal, then packet might be lost due to noise. And this will cause 2-3-4-10 packet loss. But not several lines. Also notice the form of missing lines. They abruptly start and stop. I guess it might be related to the satellite orientation on orbit. i.e. change in radio signal polarization. But have no clues... $\endgroup$
    – dernasherbrezon
    Oct 11, 2018 at 19:50
  • $\begingroup$ @Aerse depends on the length of transmission that is causing the static. It may also be caused by solar flare activity. $\endgroup$
    – Muze
    Oct 11, 2018 at 20:20
  • $\begingroup$ @Muze: You believe that static from these CB radios can cast static on all frequencies 200 km away or more, but this is not true. $\endgroup$
    – Uwe
    Oct 16, 2018 at 8:29

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