Comment by umangrathi

While I was discussing the same with my friends in the industry, came to know about the following facts: 1. Even though resolution is high, drift of min 5m is there for the best of the satellites i.e. relationship between image and gps location. Also given the drift is random, harder to correcct. 2. Indian Surveys require Ground sample distance of around 3mm, drones can get this flying at 50 m height, getting the same from satellites would be too hard and expensive.