Extrinsic IMU-antenna params clarification

[finnfi]

Hi!

I have a question regarding the extrinsic imu-antenna parameters for hk-deep-urban case.

I have difficulties relating the antenna transform to the picture of the sensor setup. Can you specify in which frame the transform is given? Is the antenna pose in the frame of IMU, resulting in an antenna in front and a bit below the IMU, or is it opposite (the antenna behind the IMU and a bit above? From the picture, I would say that the antenna is both behind and below the IMU, which fits with none of these.

I have pasted the parameters in question below.

Finn

################## Extrinsic parameter from GNSS antennas to IMU ##################

only translation part are measured manually (±0.1), y-axis forward, x-axis right and z-axis up

ANTENNA_T_IMU: !!opencv-matrix
rows: 4
cols: 4
dt: d
data: [ 1, 0, 0, 0,
0, 1, 0, 0.86,
0, 0, 1, -0.31,
0, 0, 0, 1]