extrinsic body_T_cam1/cam0 calibration

[FaboNo]

So far I am not able to calibrate these matrices and if I take a look at vins_fusion/imu_propagate I can see a big divergence when I carry the drone around and come back to the start position

Actually what I have is significant difference in the translation part (tx, ty, and tz) of the matrices from one trial to another.
body_T_cam0

0   0  1  Tx
-1  0  0  Ty
 0  1  0  Tz
 0  0  0 1

body_T_cam1

0   0  1  Tx
-1  0  0  -Ty
 0  1  0  Tz
 0  0  0 1

In order to initialize at least the translation part of the two matrices, can you tell me if the origin of the frame is centered on the PixHawk as it is shown below:

Thank you for your support