When uploading images to Atlas, a simple overlap calculation is done to determine which of your fields are covered by the uploaded images. This calculation uses the GPS altitude and a rough ground elevation database to estimate how high your images were taken. The calculation assumes the camera was pointed straight down and roughly estimates the area on the ground the images would cover.
Because of these simplifications, the overlap reported in DataHub may be more or less than the actual percentage of the field covered by your captured images. This overlap is a different number than the amount your images overlap for flight planning purposes.
For example, a single image taken from very far above a field boundary may report 100% overlap of that field, but may not overlap any other images uploaded. Accordingly, a line of images that go across a field while the aircraft is travelling to an adjacent field may cause higher than expected overlap estimates.
Errors in the GPS altitude in the image metadata and errors in the ground elevation database may also cause inaccurate overlap estimates.
For these reasons, it's best to check the image locations and altitudes in the MicaSense Uploader tool when uploading images. The uploader allows exclusion of images that are taken outside of defined field boundaries, or images that are taken during aircraft climb, decent, and transit between capture areas. Excluding these images from your uploads will result in more accurate overlap estimates in DataHub, and will save you time by only uploading the images needed to cover your fields.