Hello,


i have the Groundstation with the Datalink and if i am not mistaken,

the way the drones are designed, they will always potentially crash on the ground because they can not accurately measure their altitude:

Page 16

http://download.dji-innovations. ... _Manual_en_v3.0.pdf

I always read altitude measurements in my groundstation and they vary, eventhough the drone is at the same spot.

It happened to me a couple of times that i could not safely land because the autonavigatoin would try to land the drone inside the earth.

Really i think this is a major design problem.
The ground station needs accurate altitude data, oterhwise this cant work by design. Right or wrong?

Why does DJI not add accurate sensors like many of the small drones have, e.g. Ultrasonic sensors, to measure the height accurately and combine it with what they have.

The way I understand it, the GS and FC awareness of altitude is approximate.
It is primarily based on the FC's barometric sensor.
That's why you see some variation on the GS screen.
In an auto-land situation (& you can observe this easily), the craft descends slowly literally feeling for terra firma.
When downward motion ceases, and the IMU doesn't detect motion, the motors stop...

I experienced something similar today.  GS was reporting ~30ft at Home base gorund altitude.  Then I set 3 way points at 100ft.  The drone took off and went thru the course BUT the GS was showing 70ft altitude numbers NOT 130ft based on what I read in page 16 of the manual mentioned above.

Any one knows why.  Thanks in advance?