Home Point altitude

[brandas]

Hi guys,
A few quick questions about RTH and Home Point.
1 - do you have to set the home point manually everytime you fly or does the drone do that automatically?
2 - when a home point is set does it also records the altitude? For example, if I take off from the top of a building, if I activate RTH will it land on the top of the building or will it try to land at the bottom of it? Also, is the RTH altitude you set on settings relative to the altitude where you take off or to altitude 0?
This might be a bit noobie and poor explained... I hope it's clear enough.
Cheers!

 

[JDawg]

It is very important you understand RTH thoroughly or your best intentions will crash it. Page 13
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https://dl.djicdn.com/downloads/Mavic Air/Mavic Air User Manual v1.0.pdf

 

[Meta4]

1 - do you have to set the home point manually everytime you fly or does the drone do that automatically?

Your Mavic will automatically set the home point as soon as it gets a good GPS location fix.
You should hear Ms DJI teling you that the home point has been recorded. Please check it on the map.
Turn up your volume if you don't.

2 - when a home point is set does it also records the altitude? For example, if I take off from the top of a building, if I activate RTH will it land on the top of the building or will it try to land at the bottom of it? Also, is the RTH altitude you set on settings relative to the altitude where you take off or to altitude 0?

The recorded home point has latitude and longitude coordinates but no altitude information.
All heights are relative to home (Home = zero).

If you took off from a tall building and later initiated RTH and allowed RTH to land (you don't have to - you can always cancel RTH and take control yourself), the drone would be aiming for the spot it launched from.
The height of landing spot is irrelevant. You could dig a deep hole or position a big box on the home point without causing a problem.
The drone would return to above the home point at the RTH height you set and commence descending until it can't descend any more.

 

[brandas]

It is very important you understand RTH thoroughly or your best intentions will crash it. Page 13
-
https://dl.djicdn.com/downloads/Mavic Air/Mavic Air User Manual v1.0.pdf

Hi JDawg,
Thanks for the pdf. I had a read at that and I couldn't find an answer for the following answer: when Smart RTH is initiated I understand that the AC will ascend to the RTH pre-set altitude and then flies directly to the Home Point (provided there's no obstacles). However what happens if the AC altitude when you activate Smart RTH is higher than the RTH pre-set altitude? Does the AC perform the RTH at that altitude or does it descend to the RTH pre-set altitude?
It's not that this is very important but I'm just curious and trying to fully understand how RTH works.
Thanks in advance

 

[Meta4]

when Smart RTH is initiated I understand that the AC will ascend to the RTH pre-set altitude and then flies directly to the Home Point (provided there's no obstacles). However what happens if the AC altitude when you activate Smart RTH is higher than the RTH pre-set altitude?

RTH will never descend to come home.
If it already higher than the RTH height, it wil come straight home at whatever height it is at.

 

[brandas]

RTH will never descend to come home.
If it already higher than the RTH height, it wil come straight home at whatever height it is at.

Understood. Thanks

 

[Asgard]

Twice today my Mavic 2 descended when I hit the RTH button, both times it was initiated with the drone about 3 metres from ground so I had to act quick to stop it.
Any ideas what is going on?
my RTH was set at 50 metres I am on latest firmware on drone/controller battery

 

[old man mavic]

there is a minimum hieght and distance from the home point that the mavic has to attain for the RTH to work if you check your info that came with it it will say if you initiate RTH below a certain hieght it will just land just one point why did you press RTH when you were only 3 metres of thr ground

 

[Meta4]

Twice today my Mavic 2 descended when I hit the RTH button, both times it was initiated with the drone about 3 metres from ground so I had to act quick to stop it.
Any ideas what is going on?
my RTH was set at 50 metres I am on latest firmware on drone/controller battery

The most common answer to that question is that you were too close when you initiated RTH.
Read this from p18 in the manual and note particularly 2C:

RTH Procedure
Smart RTH, Low Battery RTH, and Failsafe RTH all follow the RTH procedure:
1. The aircraft adjusts its orientation.
2.a. If the aircraft is further than 20m from the Home Point when the RTH procedure begins, it ascends to the pre-set RTH altitude and then flies to the Home Point at a speed of 12 m/s.
If the current altitude is higher than the RTH altitude, the aircraft flies to the Home Point at the current altitude. Forward and Backward vision systems are enabled.
b. If the aircraft is between 5 m and 20 m from the Home Point when the RTH procedure begins:
i. If the RTH at Current Altitude option is enabled the aircraft flies to the Home Point at the current altitude, unless the current altitude is less than 2 m, in which case the aircraft ascends to 2 m and then flies to the Home Point at a speed of 3 m/s.
ii. If the RTH at Current Altitude option is disabled, the aircraft lands immediately.
c. If the aircraft is less than 5m from the Home Point when the RTH procedure begins, it lands immediately.
3. After reaching the Home Point, the aircraft lands and the motors stop.

Otherwise, if you used the screen button one possibility is that you accudentally pushed teh autoland button?
If you were further away, the recorded flight data, might show what was happening.

 

[highwind]

It is very important you understand RTH thoroughly or your best intentions will crash it. Page 13
-
https://dl.djicdn.com/downloads/Mavic Air/Mavic Air User Manual v1.0.pdf

https://dl.djicdn.com/downloads/Mavic Air/20180525/Mavic Air User Manual v1.2.pdf

Link above to the latest version of the manual (v1.2)