It took me somewhat longer this time but i have prepared my traditional yearly report on open data satellite image acquisition numbers – for Sentinel2 and Landsat – for the October 2017 to October 2018 time frame. See last year’s report for reference.
Will make it relatively short this time. Here are the overall recording volume numbers and their development over time:
You can see that the Sentinel-2 acquisition volume was significantly increased in early 2018 (as i already mentioned in my mid year report). This is the result of recording all major land masses at a ten day interval for each satellite now. This can also be seen in the spatial distribution visualizations linked to below.
In the recent months (i.e. the northern hemisphere winter), which are not yet included here but which you can find in the detailed recording patterns per orbital period and the daily recording numbers, the volume went down again because of the sun position recording limit meaning ESA is running Sentinel-2 under capacity so to speak – despite there being many options of making use of the additional free capacity by either:
- recording the Antarctic at higher frequency
- recording otherwise not covered small islands
- relaxing the sun elevation limit in the north during winter.
The Landsat satellites are recording the same way as in previous years – with the reduced Antarctic recording plans for Landsat 8 that were started during the 2016-2017 season leading to the double minimum yearly curve you can observe. You can see this reflected in the spatial distribution visualizations shown below. The USGS has for Landsat 8 extended the night time acquisitions at high latitudes in summer (i.e. evening images) – as i also mentioned before. Off-nadir recording at the latitude limit were also performed similar to the previous year.
|year||day||night||day pixel coverage|
|2016||LS8, LS7||LS8||LS8, S2A|
|2017||LS8, LS7||LS8||LS8, S2A, S2B, S2 (both)|
|2018||LS8, LS7||LS8||LS8, S2A, S2B, S2 (both)|