Last year the RC bug bit me. Bought two planes, batteries, chargers, couple of special tools, wife threatened to throw me out of the house (just kidding - she's incredibly supportive of everything I've ever undertaken). Watched YouTube videos hour after hour after hour learning about 2.4 GHz spread spectrum transmitters and receivers, LiPo batteries, etc.
Then the drone bug hit. My excuse is that I want them for photography. That's my story and I'm sticking to it - but, damn! They're fun to fly too!

One of the first things I learned was about "binding" the transmitter/radio/controller to a receiver. The system works so well you can have quite a few planes in the air at one time (very much unlike the really old days with different frequencies and analog signals) and not be interfering with each other. Then I started hearing and reading a lot about FPV and how it was dangerous to use GoPro WiFi because of GPS interference, blah, blah, blah.

A few months back I attended an "FPV Meet" where a bunch of these drone nuts got together, swapped ideas, lies, raced each other, sold parts, drones, etc. It was about the tightest collection of geek-dom/nerd-dom I've ever been to. It was somewhat like a kid in a candy store!

When my friend got ready to race, the organizers provided him with some sort of tag. Turns out, virtually everyone's using 2.4 GHz systems to control their quads (there was an octo-copter there that was unbelievable!), but the 5.8 GHz signal they're all using for FPV is analog and not everyone can be on the air at the same time. So the organizers were allocating frequencies for the FPV (goggles or displays) and there *was* a limit as to how many could be in the air at the same time. Which brings me to my point - you did know there was going to be a point, didn't you?

Just finished reading a post where a Phantom owner was complaining there was no warning when his signal went out - the signal feeding him video from the Phantom back to his mobile device. Like one of my non-drone-flying friends said one day "...I hate digital. I don't mind watching a snowy picture but with digital, if the signal drops below a certain level, you don't get any picture at all.."

So, if the Lightbridge system is digital, these guys flying several miles away are just asking for trouble, aren't they? It also brought up one more thought.

With the 2.4 GHz spread spectrum system for control permitting dozens of planes in the air at one time, why is DJI recommending you not fly with more than three or four other Phantoms anywhere near you? Is this because of interference potential from Lightbridge or interference from .....???? Do the "channels" you see in the pilot app reflect that this system is or is not fully digital?

And hence autonomous RTH.

mswall@mac.com Posted at 2015-5-27 22:28
And hence autonomous RTH.

Not sure I understand your response.

If someone "steals" your controlling signal, as far as the Phantom is concerned *you're* still in control and it would most likely NOT see a need to come home. Additionally, if someone else suddenly takes control of your bird and it *does* initiate RTH - to whom's home will it go???

I just essentially found it strange that DJI recommended not having very many Phantoms around at the same time. It sort of disputes a lot of what I learned about the 2.4 GHz spread spectrum's ability to easily distinguish between huge multiples of craft also flying.

What I meant was...  in the digital world, you would have to fly the quad into a region where your connection got dropped AND someone else on the same channel using a controller sending valid command codes, and much more importantly was somehow ALSO miraculously digitally "paired" to your quad, then  gained control they could, yes take over.  In the more probable realm, when you lose the digital control link to the Phantom it will (unless it has been disabled by the owner) switch into RTH mode and use primarily GPS and secondarily mag compass to return to its on-board stored last departure point which is currently independent of where any controller resides.

Maybe DJI, thinking of your investment in a photographic platform and not a motocross drone, is helping you see a concern for flying somewhere where there are lots of other "things" flying around.

Update:   DJI just added reset home point to the IOS App 1.1.2.  Going out to try it now.

mswall@mac.com Posted at 2015-5-28 04:24
What I meant was...  in the digital world, you would have to fly the quad into a region where your c ...

That does sound logical. My "doomsday scenario" is probably quite unlikely. Guess we all have enough to worry about already!

mswall@mac.com Posted at 2015-5-28 04:27
Maybe DJI, thinking of your investment in a photographic platform and not a motocross drone, is help ...

Ah! That's good news. Maybe they've done the same thing (or will follow) with the Android version.