Where is the origin of GPS_POS_X/Y/Z?

[tmk_st (tom)]

Hello everyone,

I have a question about the origin of GPS_POS_X/Y/Z.

The following description says “from the IMU or center of gravity of the vehicle”.
https://ardupilot.org/copter/docs/common-sensor-offset-compensation.html#parameter-details

However, my aircraft has INS_POS_X moved forward, so the IMU position and the center of gravity position are different.Which should I set in this case?

I have seen the same question posted as mine within this forum.
However, I am confused because some answers say offset from IMU and some say offset from center of gravity.

Question on Sensor Position Offset Compensation

Your question makes perfect sense and is a very good one. Both the GPS and INS offsets should be referenced to the same point, so you should set the GPS offsets from the center of gravity, just as you did the INS.

Sensor Position Offset Compensation IMU & GPS

The rules on ArduPilot are : IMU offset are relative to gravity center GPS offset are relative to IMU

Should I set the offset from the IMU or the offset from the center of gravity?

Thanks,

[Mustafa_Gokce]

@Sensor Position Offset Compensation IMU & GPS

The rules on ArduPilot are :

• IMU offset are relative to gravity center
• GPS offset are relative to IMU

Do as suggested in here.

[Yuri_Rage]

As of 4.1.0 and this PR, the origin is frame referenced for both GPS and IMU offsets.

In other words, use the frame origin (typically center of gravity) as the point of reference for all *POS* parameters.

[tmk_st (tom)]

Thanks to both of you for your answers.

Since I’m using 4.1.0, it seems like a good idea to use the frame origin as the reference point for the POS parameter.

Thank you.