Satellite image news


Some news on open data satellite images:

I updated the satellite image coverage visualizations. Here is the matching coverage volume plot over time:

Open data satellite image coverage development

There are several important things you can see in that:

  • With Landsat 8 the USGS has for the second southern hemisphere summer season adopted a changed acquisition pattern (indicated by a drop in image volume around December/January) where Antarctic coverage is significantly reduced compared to previous years (see my yearly report for more details)
  • There have been significant fluctuations in the acquisition numbers of the Sentinel-2 satellites. Much of this is related to an inconsistent approach to the Antarctic here as well – with ESA sometimes acquiring Antarctic images with one of the satellites for a few weeks and then dropping it again. A consistent long term plan is not recognizable here.
  • In the last weeks Sentinel-2B acquisitions have been ramped up to full coverage in the nominal 10 day revisit interval (compared to the fairly arbitrary pattern with 10 days for Europe, Africa and Greenland, 20 days for the rest). See the sample of a 10 day coverage below. This is good news.
  • The problems with missing aquisitions and individual tiles are still the same as before as indicated by the orange areas in the visualizations.

Full 10 day coverage by Sentinel-2B in early 2018

Another thing that changed is that ESA seems to have made a smaller change to the Sentinel-2A acquisition pattern including the South Sandwich Islands now. Here an example of a rare nearly cloud free view of Saunders Island:

Saunders Island, South Sandwich Islands by Sentinel-2A

Interestingly this is limited to Sentinel-2A – Sentinel-2B so far has not acquired any South Sandwich Islands images. Like with the Antarctic there does not seem to be a consistent plan behind this which makes this very unrealiable for the data user and kind of another wasted opportunity of establishing Sentinel-2 as a reliable data source.

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