Hello yesterday when I was flying I saw that the apparent height of 15 meters on the ODS is actually 3 meters.I  Perform IMU calibration but calibration did not complete even though I ran out of fully charged battery!  Has anyone made thıs experience before or any suggestions?

Yesterday I succeeded the IMU calibration, but the altitude information still seems incorrect in telemetry. There is a difference of 2-5 meters between the actual altitude and the apparent altitude in telemetry.
This is a serious problem and I recommend everyone to check it on their vehicle.

Below around 3 meters the drone uses the vision sensors under the drone to evaluate height above a surface, subject to the actual surface. Above that it then uses a barometer & GPS which is zeroed at take off. The barometer can only ever be an increase or decrease in height based on the take off point. GPS does not give height dynamically I.e it does not have topographic information. Again it’s in ref to the take off point. A combination of GPS altitude and the barometers height are used to give an approximate height above the ground referenced at the take off location.

From your description it suggests that your lower vision sensors may not be working. Hover the drone a few feet off the ground and see what height is shown in the goggles. Increase the drones height and see if the increase/decrease is representative.

Buzzyone Posted at 4-12 04:32
Below around 3 meters the drone uses the vision sensors under the drone to evaluate height above a surface, subject to the actual surface. Above that it then uses a barometer & GPS which is zeroed at take off. The barometer can only ever be an increase or decrease in height based on the take off point. GPS does not give height dynamically I.e it does not have topographic information. Again it’s in ref to the take off point. A combination of GPS altitude and the barometers height are used to give an approximate height above the ground referenced at the take off location.

From your description it suggests that your lower vision sensors may not be working. Hover the drone a few feet off the ground and see what height is shown in the goggles. Increase the drones height and see if the increase/decrease is representative.

He showed the height correctly on the first take-off (maybe a minor difference) but after flying a little, there was a difference of a few meters again. As you go down, the altitude drops normally, but it makes it look like it lost its reference point after flying.
So, if the sensors below are faulty, should I calibrate the sensors? How can I tell if the sensors are working correctly?
Thank you very much

fans21216cdd Posted at 4-12 09:28
He showed the height correctly on the first take-off (maybe a minor difference) but after flying a little, there was a difference of a few meters again. As you go down, the altitude drops normally, but it makes it look like it lost its reference point after flying.
So, if the sensors below are faulty, should I calibrate the sensors? How can I tell if the sensors are working correctly?
Thank you very much

what happens here in my opinion is the drift of the baro sensor caused by speed and the wind. The sensor is not placed in the way that it is not influenced by the rushing wind while flying. Rushing wing make the pressure registered either higher or lower - what gives very inaccurate reading. I don't trust the height being displayed even a bit. I try to use my eyes to guesstimate how hi I am flying ...

fans21216cdd Posted at 4-12 09:28
He showed the height correctly on the first take-off (maybe a minor difference) but after flying a little, there was a difference of a few meters again. As you go down, the altitude drops normally, but it makes it look like it lost its reference point after flying.
So, if the sensors below are faulty, should I calibrate the sensors? How can I tell if the sensors are working correctly?
Thank you very much

If you connect to Assistant 2 and go into calibration & follow the instructions on screen, part of this process will put the
Images from the sensor on screen. If you have a fault you won’t get the images & you won’t be able calibrate.

The height does drift over time, so shouldn’t be relied upon.