moveTo altitude


I tried to use the moveTo to return to my take off position, but it moved to the wrong altitude. Both the latitude and the longitude was very precise, but it ended up ~15m above the ground. From the documentation i have understood it as the moveTo function refers to altitude above sea level, same as the GpsLocationChanged returns.

The height I return to is approximately the double of the take off positions altitude above sea level. Have I misunderstood and the frame of reference of the moveTo-function and moveTo refers it’s height to the altitude of the take off position?

A part of the log is displayed below:

09/07/2019 14:48:03.421178	_recv_cmd_cb                    ardrone3.PilotingState.moveToChanged(latitude=59.85470052294315, longitude=10.485001427393343, altitude=14.0, orientation_mode=MoveToChanged_Orientation_mode.NONE, heading=-0.10540332645177841, status=MoveToChanged_Status.DONE)
Current pos after adjusting height: (59.854700602287465, 10.485001046546458, 28.700000762939453) home pos: (59.85470066666673, 10.48500000000046, 14.0)

The Current pos after adjusting height is taken from the GpsLocationChanged right after the first line shows that the moveTo has completed. The home pos is retrieved the same way, but before takeoff. As you can see, the latitude and longitude is rather precise, but the altitude is twice as high as it should be.

Parrot anafi
Ubuntu 18.04
Python 3.6.1
Olympe 1.0.1

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The documentation of the moveTo command seems to be outdated. The altitude parameter is actually the height of the drone from its last take off position.


Dear Nicolas, I want to follow up this question. So the altitude is defined as above the ground, where does the data come from and what is its accuracy range (from the internal barometer or the ultrasonic / optical flow sensors)? Does Olympe provide an interface for this altitude data? Thanks much!

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Hello and sorry to unearth this topic,

Like zqchen, I would like to know how altitude is measured, and, if known, what is the relative accuracy of the received altitude ?
The question lying beneath this is : should I add a barometric sensor to my IoT experimentation or is it relevant to use the data directly available ?

Thank you very much for all your work !

EDIT: As I wandered around this topic on the forum, I found this entry (Jan 2016) that says that on Bebop/Bebop2 drones, altitude data was :

a merge of multiple sensors, sonar sensors if available, barometer, gps…

I am using anafi4k now, can I know if the same policy is applied to my drone for altitude and if possible, could we be provided with the exact scheme of merging these data ?

Again, thank you for your time.