Hi,

Few questions about the GPS of the P4-RTK

- where is the GPS-RTK position define ? Is it the GPS antenna position, the "center" of the PH4RTK or the sensor of the camera ?

- If the GPS-RTK position is in the drone (center or antenna), what is the formula to have the relative position of the camera sensor ?

Thanks

From this VERY useful document: P4RwhitePaperV2.pdf
Position compensation between the UAV RTK antenna phase center and camera CMOS center:

36mm in the heading direction, 192mm in the height direction, and 0 perpendiculars to the heading,
as shown below:


The offset from RTK antenna phase center and camera CMOS center in the body system can be
define as below:

∆X = 0.0m
∆Y = 0.036m
∆Z = −0.192m

The Timestamp.MRK file contains the offset of the antenna phase center to camera CMOS center
in the north-east-down coordinate system at the time the photo was taken, and compensation of the
north, east and vertical directions are included in the MRK file for direct compensation to the post-
processed latitude, longitude, and height. In this case, the correction in three directions (x, y, and z)
are all 0, and the acquired position is the position of the antenna phase center. Then the compensation
in the .MRK file are used and the position will be compensated to the camera CMOS center.
The height can be compensated by direct deduction. For compensation in the east and north direction,
it should be noted that the compensation value is in mm while the coordinate value is in degrees.
The user may first perform projection, and then compensate the value of the east/north direction to
that of the projection.

patiam Posted at 2-9 07:29
From this VERY useful document: P4RwhitePaperV2.pdf
Position compensation between the UAV RTK antenna phase center and camera CMOS center:

Thanks ! That's exactly the information we need !

Glad to help.