Hi,
if you fly in the mountains, f.e. it can happen that you fly up or down 100 meters, and than start RTH.

Does the drone add the RTH-level (f.e. 50 m) to the height level of 1. the start or 2. end point?
Both can be a problem.

If you fly up, 1 is the problem (return level is lower than the end point), if you fly down, 2 would be the problem.

Where you take of is 0m.  RTH alt is added on top of take-off point.  Also, mapping altitude is added on top of take-off point.  If you are mapping for 33m and RTH is at 40M, it will map at 33m then climb to 40m before straight lining to home point.

RTH level is always relative of the point where you took off.  If you took off from a hill of 100m and your RTH was set on 50m, the drone returns on an altitude of 150m.

Remember RTH is always in a strait line. See that you put the RTH altitude high enough to avoid collision with obsticals on it's way, as the MM2 has no obsticle avoidance.

Hi, thbode32. Thanks for reaching out! The RTH altitude is measured from the height where the drone took off. Therefore, the aircraft would ascend depending on the RTH height setting and the height of the home-point where it took off.

DJI Gamora Posted at 12-27 01:27
Hi, thbode32. Thanks for reaching out! The RTH altitude is measured from the height where the drone took off. Therefore, the aircraft would ascend depending on the RTH height setting and the height of the home-point where it took off.

Isn't it logical that there will be a problem?
F.e.:
You set the RTH altidue to 60m and start..
Than you fly 100m upwards a hill and RTH is started for some reason. Now, the drone should try to lower its altitude for 40 m vertically, to reach the 60m altitude. It means it will try to dig a hole in the hill ;-)

AntDX316 Posted at 12-27 00:23
Where you take of is 0m.  RTH alt is added on top of take-off point.  Also, mapping altitude is added on top of take-off point.  If you are mapping for 33m and RTH is at 40M, it will map at 33m then climb to 40m before straight lining to home point.

If you are mapping for 33m and RTH is at 40M, it will map at 33m then climb to 40m before straight lining to home point.
If it's possible to get things wrong, Antman will manage to get it wrong.
The OP never mentioned anything about mapping so your contribution is irrelevant as well as incorrect.

All heights are relative to the launch point.
So RTH height is relative to the launch point - not mapping height + RTH height.

thbode32 Posted at 12-27 01:39
Isn't it logical that there will be a problem?
F.e.:
You set the RTH altidue to 60m and start..

Isn't it logical that there will be a problem?
Not really.
The system is simple and if you understand it, there shouldn't be a problem.
F.e.:
You set the RTH altidue to 60m and start..
Than you fly 100m upwards a hill and RTH is started for some reason. Now, the drone should try to lower its altitude for 40 m vertically, to reach the 60m altitude. It means it will try to dig a hole in the hill ;-)
As it explains in the RTH section of the manual, the drone won't descent to RTH height.
If it is already higher than RTH height it will just come home at the height it is already at.

Labroides Posted at 12-27 01:48
Isn't it logical that there will be a problem?
Not really.
The system is simple and if you understand it, there shouldn't be a problem.

Ok, it will never first descent. That's the point. Thanks.

Labroides Posted at 12-27 01:45
If you are mapping for 33m and RTH is at 40M, it will map at 33m then climb to 40m before straight lining to home point.
If it's possible to get things wrong, Antman will manage to get it wrong.
The OP never mentioned anything about mapping so your contribution is irrelevant as well as incorrect.

You do have a hard time trying to include stuff into presentations that aren't immediately relevant.  Dismissing what I've said as untrue will confuse people who will think you are 100% correct about me being wrong.  Most of the money I've made were from mapping infrastructure successfully.

It can be a struggle conversating with you about certain things but I'm putting the warning out there that if people listen to you over me, they will be further in the dark.  You need to work on stop making things more confusing than they actually are and accept I am right about nearly everything I say so we can tackle other challenges with ease.  I apologize if I somehow offend your self-proclaimed intellectual ego but your level of real-world intellect in this area isn't as high as mine.

I'm working on bringing into question the religion modifier that people have forgotten the purpose of Christmas being made in the first place while all this COVID is happening and people talking about it being fake, how it brings more money into people's pockets, while food bank lines remain and people stop reporting etc.  Just because things aren't in focus doesn't mean the problems don't persist or disappear.  Sidelining or ignoring certain things does not mean they are gone forever.  We would like to engineer our lives to be as controlled as possible but in the real-world, not everyone has such a luxury.

thbode32 Posted at 12-27 01:39
Isn't it logical that there will be a problem?
F.e.:
You set the RTH altidue to 60m and start..

If you are at say 100m, you set RTH at 30M, it won't lower itself.  It will fly back at 100m then land so if you have to fly under a bridge or a tree, if it's directly in between the path from where it is to home position, it could crash into it.

If you want it to descend to RTH height first, there is no option for I think.  Either you have another software that isn't Go4, or just realize to lower your alt before RTH.  Basically just fly manually unless you lose signal of course.

Sometimes / rarely it can be useful to change the RTH altitude during flight. I always have it at 55 meters, but after the start of the flight I noticed that the wind was already a bit strong at 30 meters, which can be bad if RTH is initiated and the drone rises in stronger winds. So I changed the RTH height to 30 meters.

jonny007 Posted at 12-27 08:06
Sometimes / rarely it can be useful to change the RTH altitude during flight. I always have it at 55 meters, but after the start of the flight I noticed that the wind was already a bit strong at 30 meters, which can be bad if RTH is initiated and the drone rises in stronger winds. So I changed the RTH height to 30 meters and then updated the home point. Important: Just changing the RTH height is not enough, you also have to set the home point again, even if the coordinates are the same as at the start, so that the new RTH height is valid

Hi jonny,

Would be nice to screen record this, as my experience is that resetting the RTH height does work without resetting the HP (at the same position).
Ofcourse when not in RTH mode.
Flying in RTH mode you can reset the HP to new position, craft will immediately change heading to the new HP setting, but when in autolanding RTH mode ; you can reset HP to new pos but craft will continue to and at 'old' HP position.

cheers
JJB

JJB* Posted at 12-27 08:56
Hi jonny,

Would be nice to screen record this, as my experience is that resetting the RTH height does work without resetting the HP (at the same position).

Oops, have just checked it, you are right and I removed my remark ;-) But I'm not sure whether that was always the case (with the earlier Fly App versions). Can be, but also can't be. In any case, it currently works (1.2.2) by only setting the RTH and not also the home point. I didn't try whether the RTH height can be changed DURING RTH. Sure, this wouldn't make sense. When connection was lost, the drone can't receive these change and if RTH is running with connection you can let the drone manually rise and/or abort RTH.

AntDX316 Posted at 12-27 06:31
You do have a hard time trying to include stuff into presentations that aren't immediately relevant.  Dismissing what I've said as untrue will confuse people who will think you are 100% correct about me being wrong.  Most of the money I've made were from mapping infrastructure successfully.

It can be a struggle conversating with you about certain things but I'm putting the warning out there that if people listen to you over me, they will be further in the dark.  You need to work on stop making things more confusing than they actually are and accept I am right about nearly everything I say so we can tackle other challenges with ease.  I apologize if I somehow offend your self-proclaimed intellectual ego but your level of real-world intellect in this area isn't as high as mine.

You do have a hard time trying to include stuff into presentations that aren't immediately relevant.  Dismissing what I've said as untrue will confuse people who will think you are 100% correct about me being wrong.

You really are an idiot and most of what you say is complete misinformation, even when it comes to basics like RTH height.
Fortunately, that's obvious to most people that read the nonsense you post.