Some test samples don’t have/show a water surface for a given date (and nearby dates). Example: uid = aabn, date = 2016-08-31, latitude: 36.5597, longitude: -121.51, no water for -30 days.
Now, these samples could be from wells and ponds that are too small to capture on satellite images and we are to overcome this as part of a competition. But also, it is a possible date error since google maps do show some water surface (probably artificial accumulations and controlled) for those coordinates. Maybe there is a need to recheck the competition data (at least the test part of the data).
Any feedback on this will be fine. Thank you.