title_body: Could a drone collect a river sample? I know very little about drones, but I'm trying to learn if collecting river samples is something that could be done autonomously using commercial drones?
  
  Is it possible to give the drone some coordinates of the river and have it go and collect without further input?
  Is it even legal to do such a thing without someone controlling?
  If it's not possible to do autonomously, how much input would be needed from a controller?
upvoted_answer: Autonomous operation isn't a technical problem.  For example, DJI's drones are capable of flying themselves back to the launch point if the signal from the remote control fails.
  The problem is legality.
  Most drones are required to be flown within the operator's line of sight.  The reason for this isn't because the operator has to be actively controlling the drone -- a fully-autonomous drone is perfectly legal -- but because the operator is responsible for collision avoidance.
  If you've got an operator watching things, ready to take over if a problem arises, a self-piloting drone is perfectly legal.  If, on the other hand, you want something that's completely unattended, you'll need to work with your local regulatory agency to get permission, and that's going to be a difficult thing to do.