I want to make sure I fully understand the RTH feature.

ccbiggz

I am new to drones and have flown my brothers a couple of times. Mine will be here Wednesday.

I've been reading a lot of the posts on this excellent forum and wanted to make sure I fully understand the RTH feature.

If I am flying my drone and it goes behind a building, tree, mountain, etc. and it loses the signal from the remote control; this is what will happen.

1. After the drone senses it has lost communication with the remote control, it will wait 3 seconds and then initiate a return to home.

2. If the drone is above the height I have set it for the rth, it will turn toward the home point and begin to go back to that point. If it is not above the rth altitude, it will ascend to that altitude and turn toward home and begin to go back to the home point. If there is anything in the way, it will collide with whatever is in the way. Hopefully I have set the rth altitude to prevent that.

3. It is possible that once the drone ascends to its rth altitude; communications between the drone and the remote control can be reestablished. As long as I don't touch the sticks, the drone will continue to come back to its home point. If I move the sticks, it will stop its rth and will hover awaiting input from the remote control. Unless I see the drone, I shouldn't touch the sticks and let it continue to come home.

4. Once the drone gets inside 20 meters of the home point, it will descend to the ground and hover for 5 seconds and then land. While it is descending, I can move the sticks to stop its descent and move it to exactly where I want it to land. (Assuming communications with the remote control and drone have been reestablished.)

I should never fly without the home point being established and should probably calibrate the compass each time I fly.

Do I have all of this correct?

Thanks for any information!

DJI-Ken

basically yes to all, but when it regains signal you can cancel RTH if you want.

ccbiggz

Ken. Is moving the sticks the only way to cancel RTH or will there be a prompt in the app or some other way?

Thanks!

boxerman

You will learn all the nuances of RTH if you will try different scenarios in the Flight Simulator. Try: initiate RTH with the phantom less than 20m from you (it will simply descend and land). Take it above the RTH altitude and see what it does, then do it with the altitude below the RTH altitude. The simulator will teach you.

RedHotPoker

ccbiggz Posted at 2016-1-4 13:25
Ken. Is moving the sticks the only way to cancel RTH or will there be a prompt in the app or some ot ...

Depress the Return To Home button. You can maneuver the drone, and take back control, depending on battery charge, it also may want to just land.

RedHotPoker

Geebax

Regarding: 'and should probably calibrate the compass each time I fly'

This is not necessary. Unless you move like 100 miles from where you previously performed the compass calibration, it is not necessary to do it again. That is provided it was done correctly the first time. Unnecessary compass calibrations may introduce errors that affect your aircraft.

DJI-Ken

Geebax Posted at 2016-1-5 05:56
Regarding: 'and should probably calibrate the compass each time I fly'

This is not necessary. Unles ...

Agree 100%. I know I have a perfect compass calibration so I only calibrate if I go to a different state (or if I remove my GPS tracker)

DJI-Ken

ccbiggz Posted at 2016-1-5 04:25
Ken. Is moving the sticks the only way to cancel RTH or will there be a prompt in the app or some ot ...

Moving the sticks does not cancel RTH, you can cancel through the app or by pressing the RTH button on the controller

nigelw

ccbiggz Posted at 2016-1-4 20:25
Ken. Is moving the sticks the only way to cancel RTH or will there be a prompt in the app or some ot ...

Moving the throttle stick above 20m AGL, but below RTH height will cause the aircraft to stop ascending & fly to the home point. You will have some control from then on without cancelling RTH. As stated, the best way to appreciate it is to try different scenarios on the simulator.

Geebax

DJI-Ken Posted at 2016-1-5 09:18
Agree 100%. I know I have a perfect compass calibration so I only calibrate if I go to a different ...

I recently went on an expedition 230 miles from home, to the far corner of my state without touching the compass calibration and it was absolutely perfect. Once you get a good calibration, best to leave it alone.

dduncan1978

The RTH altitude, is that based off the take off point? Or the altitude where it lost signal.

ccbiggz

Geebax Posted at 2016-1-5 07:33
I recently went on an expedition 230 miles from home, to the far corner of my state without touchi ...

I'm confused about the compass calibration. I thought DJI recommended calibrating the compass before each flight.

ccbiggz

dduncan1978 Posted at 2016-1-5 08:07
The RTH altitude, is that based off the take off point? Or the altitude where it lost signal.

Good question. Can anybody help with that one?

Northofthe49th

It is based on your take off location, that would technically be your floor/zero point...ie. if you took off raised up to 100' then flew over a canyon and were at that 100' elevation from your take off point and the canyon had a floor of 300' below your take off point, you are technically still only 100' altitude

Geebax

ccbiggz Posted at 2016-1-5 12:16
I'm confused about the compass calibration. I thought DJI recommended calibrating the compass befo ...

DJI do not recommend performing a compass calibration before each flight, they only say to do it if tyou travel a long way from your normal home place. See DJI-Ken's comment above:

'Agree 100%. I know I have a perfect compass calibration so I only calibrate if I go to a different state (or if I remove my GPS tracker)'

That is coming from an official source.

DJI-Ken

dduncan1978 Posted at 2016-1-5 08:07
The RTH altitude, is that based off the take off point? Or the altitude where it lost signal.

Yes, exactly. It's based on magnetic declination and if you look at a map you can see you can go East or West levers hundred miles without much of a deviation at all. And North/South you can go way more.
DJI recommends calibrating way more often, so I'm just explaining what I personally do.

DJI-Ken

dduncan1978 Posted at 2016-1-5 08:07
The RTH altitude, is that based off the take off point? Or the altitude where it lost signal.

The RTH altitude is based on what you set it at (default 30m) and when it goes into RTH mode it will either climb to the set RTH altitude if your under it or stay at whatever altitude your at if you are above the set RTH altitude.

DJI-Ken

Geebax Posted at 2016-1-5 09:44
DJI do not recommend performing a compass calibration before each flight, they only say to do it i ...

No I didn't say that, DJI recommended very often. So what I do is NOT DJI practices, only my opinion.

Geebax

DJI-Ken Posted at 2016-1-5 13:02
No I didn't say that, DJI recommended very often. So what I do is NOT DJI practices, only my opini ...

Sorry, I did not mean to drop you in like that. OK, I will say instead, that experienced flyers suggest not to calibrate frequently.

DJI-Ken

Geebax Posted at 2016-1-5 10:09
Sorry, I did not mean to drop you in like that. OK, I will say instead, that experienced flyers su ...

Exactly, thanks. Myself and everyone I know only calibrate the compass when they travel far away or change something about the aircraft.
What if you go fly from a metal platform and that's the only place to take off from. If you try to calibrate, you will get an error and you just ruined your good calibration and if you try to fly you may crash.
You know yo have a good calibration, take off even though t gives you an error and as soon as you get some altitude your compass is fine. This is only as long as the interference is not strong enough to through the compass out of whack and it would need to be calibrated anyways.
Just my 2 cents.

Geebax

DJI-Ken Posted at 2016-1-5 13:22
Exactly, thanks. Myself and everyone I know only calibrate the compass when they travel far away o ...

Yep, I fly only in rural areas, and never near power lines, metal objects or the like, and I know that having obtained a good compass calibration in the beginning, it is not going to change enough to bother the aircraft.

labroides@yahoo

dduncan1978 Posted at 2016-1-5 11:07
The RTH altitude, is that based off the take off point? Or the altitude where it lost signal.

The only height your Phantom knows is Home = zero.
Everything else is relative to that

dduncan1978

Ok hme it "0". My RTH is "100" feet. I fly over a "rise/high" point. Said "rise/hight" point is 150 feet. Im screwed.....

dduncan1978

Ok my home is "0".........

DJI-Ken

dduncan1978 Posted at 2016-1-5 12:43
Ok hme it "0". My RTH is "100" feet. I fly over a "rise/high" point. Said "rise/hight" point is 150 ...

Your default RTH is set to 30 meters, if you are at 150ft as you say and ina straight line back to you is something taller than 150ft, your Phantom will crash into it if you lose signal and it goes into RTH mode.
ALWAYS, set your RTH altitude if there are are obstructions in your flight area higher then 30 meters.

jpcrown21@aol.c

DJI-Ken Posted at 2016-1-4 21:22
Exactly, thanks. Myself and everyone I know only calibrate the compass when they travel far away o ...

how do you know if your calibration is a good one?

DJI-Ken

jpcrown21@aol.c Posted at 2016-1-6 00:46
how do you know if your calibration is a good one?

I know it's good because when I go into a hover the aircraft sits rock solid and does not drift or oscillate at all.
I can take off and go up straight up a few hundred feet and come down and it lands within a foot of where I took off. And also when in forward flight it flies a perfectly straight line.
That's just what I do, you are recommended to follow DJI's manual.

dduncan1978

DJI-Ken Posted at 2016-1-6 00:03
Your default RTH is set to 30 meters, if you are at 150ft as you say and ina straight line back t ...

Ken, correct me if im wrong, 30 meters is 90 feet, 90 feet is less than the "high" point of 150 feet. So in this case, using the RTH, the drone will raise to the set 90 feet (30 meter) start "home" between "home" and the drone is "said" high point of 150 feet, your 40 low.

crashed and lost drone.

Geebax

dduncan1978 Posted at 2016-1-6 14:58
Ken, correct me if im wrong, 30 meters is 90 feet, 90 feet is less than the "high" point of 150 fe ...

Correct, and he also said:

ALWAYS, set your RTH altitude if there are are obstructions in your flight area higher then 30 meters.

So you should have set the RTH altitude to say 200 feet or 60 Metres in that case.

koine777

I never set my RTH less than 50 meters. Honestly, even if you set it at 100 meters, this is better than an inadvertent crash. If I crash my P3 while flying, as much as it sucks, it's my fault. If I don't set the proper safety settings and this is the reason I crash, I'd beat myself up big time.

Using the simulator is good, but nothing is like experimenting with the aircraft. I went to a very wide area and intentionally flew my aircraft high and away until I intentionally lost signal (screen goes black), multiple times. I made it use RTH. Every time, it worked perfectly. You can overcome RTH by manipulating the controls, but the only way to cancel it is with the app. I have a P3S.

I highly recommend two things. 1. Imagine possible problems during your flight time and prepare for them. 2. Take plenty of time to properly test the safety limits of your particular DJI product.

This forum is replete with people who experience problems, and that is good so we can help each other. However, I must say, I haven't had a single negative experience and am very satisfied with my DJI P3S.