The numbers don’t really line up with my expectation. Using drone imagery, I can get a 1-2 square km area accurate to 5cm accuracy flying at 400ft. That would get me about 2,500 images. If they wanted to do a 1cm accuracy area of a 5 square km area, I would expect 25x the number of photos, or 100,000 images. With enough compute, this could be done in 30 minutes.