I have been trying to retrieve Sentinel-1 data over a portion of Idaho and Montana, USA via Google Earth Engine. However, I am finding there are gaps in the time series, and sometimes it looks like an end in coverage, particularly in descending paths.
To double, check, I took to the Copernicus hub using the following query: ( footprint:“Intersects(POLYGON((-115.68647533845234 45.207900162515955,-115.68647533845234 43.75639229405459,-112.93798456367267 43.653176231427466,-113.11645799060643 46.15550579339347,-115.57939128229208 46.254320248931634,-115.68647533845234 45.207900162515955,-115.68647533845234 45.207900162515955)))”) AND ( beginPosition:[2018-07-01T00:00:00.000Z TO 2018-09-30T23:59:59.999Z] AND endPosition:[2018-07-01T00:00:00.000Z TO 2018-09-30T23:59:59.999Z] ) AND ( (platformname:Sentinel-1 AND producttype:GRD AND sensoroperationalmode:IW))
The results show that there are very clearly missing images in VV and VH polarizations from the descending paths in central Idaho from July 1 2018 to September 30 2018. Why are these images absent from the IW GRD time series?