So I am working with Google Earth Engine and I have retrieved all of the viable Sentinel 1 returns over my region of interest. By viable, I mean that I have filtered all sentinel 1 returns spatially over my area, temporally to all available data, filtered to GRD products only, filtered to IW instrument mode only, and the filtered to ascending pass only. Finally, I filtered the returns from that selection and split the returns into sentinel 1a and sentinel 1b. I then take the mean over my region of interest and plot the results. However, I am noticing that the time stamps of the returned data is odd. Here is what I am receiving…
Below is a 10 file sample of my exported file names. They are saved as YYYY-MM-dd T hh:mm:ss My question is this: why are the minute time stamp observations going back and forth between 05 and 21? Should they not all be the same? When plotted, the data is distinctly different. I originally thought it was maybe ascending/descending difference but I filtered for that and the time difference is too small. Then I thought that it was the difference between sentinel 1a and 1b but I filtered for that as well too. Now I’m assuming this is related to the incidence angle or look angle of the acquisition but how do I know what angle corresponds to which set of data? I’m calling the sets the “5” minute return set and the “21” minute return set. Please advise.