"Also, of course you would use the compass and airspeed sensors to help maintain a direct path as already suggested. It wouldn't be very accurate, but with an IR beacon on the other side, the drone could constantly adjust to maintain it's…"
"I have been thinking of this problem for awhile. And the only solution I can think of is having a completely autonomous drone that does not rely on outside signals. GPS is easy to jam and in fact, you could easily direct a drone anywhere just based…"
"There was a research paper floating around on the net that showed with a ~10% overlap, there was a ~5% increase in efficiency. Don't hold me to those numbers. It was something like that. Unfortunately I don't have the link anymore."
"Why not do some testing with the original prop in the original configuration versus the "up/down" configuration, everything else being the same? Not only will you have your answer, but come back here and let us know what the results were.…"
"If you want cheap and DIY, get a used (i.e. Craigslist) sea kayak and strap on the gear (i.e. batteries, autopilot, motor, etc.). Mikota makes great motors (i.e. made for endurance) for strapping on craft such as this. Also, get one of those kayaks…"