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This is an image of the UK taken by the Suomi NPP satellite's Visible Infrared Imaging Radiometer Suite (VIIRS) in 2012:

Sleepless Britain

There are faint lines emanating from Scotland and northern England, with a negative gradient, about 30° to the horizontal. What are these, airplanes? Or artefacts? Why are they so consistent?

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  • $\begingroup$ They look like an artifact on the image - possibly something on the camera lens. $\endgroup$
    – Phiteros
    Mar 17, 2017 at 20:38
  • $\begingroup$ See this doc. It looks like the artifact might be striping from aggregation, which is hard to get rid of in night time images. $\endgroup$
    – called2voyage ♦
    Mar 17, 2017 at 22:28
  • $\begingroup$ Could you provide a link to the original source of that image? Ideally the Suomi NPP image database itself? It would be nice to see any available technical information about the image, and at least the exact time/date. If you've read so much about asking SXSE questions you'll know that this is important and a reasonable request. Thanks! $\endgroup$
    – uhoh
    Mar 18, 2017 at 9:13
  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage ♦
    Apr 6, 2017 at 17:51

1 Answer 1

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This is the beginnings of an answer. @called2voyage has commented that it looks similar to other striping artifacts from the same satellite. A quick look through there (I'm still trying to read through more carefully) seems to show the striping as horizontal (East-West).

Looking at the image with a bunch of tweaks in color effects shows lines that seem to be tilted at -12 degrees, with a period of about 12 kilometers.

Have to do more reading/searching now to see if there is a 12 degree tilted instrument on board the satellite, or if the satellite's attitude could have been tilted. Suomi NPP does keep busy doing attitude adjustments, although these are carefully coordinated with image acquisitions and are not likely to produce "out-of-whack" images without sufficient documentation. I wish the OP had provided specific information about the date/time of this image or a link to it's source within the database!

If you've ever seen any of the NATS videos on YouTube or Vimeo (downloadable) you can appreciate the OP's comment about air traffic and parallel lines. cf UK 24 or see below. Of course the satellite is in a sun-synchronous LEO and would not be generating long or time-lapse exposures that could produce streaks from aircraft, but the similarity of the appearence is worth noting.

In the mean time if someone more familliar with the satellite can add insight, please feel free to add to this answer or cannibalize it.

Below: From the NPP Fact Sheet - Final.pdf.

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above: from VIIRS Day/Night Band—Correcting Striping and Nonuniformity over a Very Large Dynamic Range.

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Watch: (watch for the military and the civilian "practice exercises")

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