Inertial Reference Frame Origin of Pixhawk

I need to estimate the affine transform from the Pixhawk to an onboard camera. The Pixhawk maintains a pose estimate, but where is this origin of this coordinate frame physically on a Pixhawk (this model)? I need to physically estimate this transform in CAD.

Thank you!

I’m not sure your going to get the implied precision you expect from your question…
It looks like the EKF can compensate for GPS and IMU position, make sure you correctly set the

EKF parameters:
EKF2_IMU_POS_X
EKF2_IMU_POS_Y
EKF2_IMU_POS_Z

EKF2_GPS_POS_X
EKF2_GPS_POS_Y
EKF2_GPS_POS_Z

All with respect to the vehicle center of gravity…
Assuming the EKF correctly compensates for this then the correct answer to your question would be the vehicle center of gravity…

YMMV
I’m just learning about the PX4…
chasing these down it looks like:
Parameters are defined in ekf2\ekf2_params.c
then turned into _param_ekf2_gps_pos_x in ekf2\EKF2.hpp…
then put into an array pgs_pos_body in ekf2\EKF2.cpp
then put into a vector pos_offset_body in EKF\control,cpp
and that file also seems to use this…to adjust things…

Thanks @pbreed, I think you are right about the center of mass. It seems like other forums also say the same.