RT_RTK_Slip RTK baseline, slip and squat
RT_RTK_Slip: 140, 33 (0x8C2120 + unit id) (0x321)
Byte 0: Validity
Byte 1: Accuracy
Bytes 2-3: RTK Slip (degrees)
Bytes 4-5: RTK Squat (degrees)
Bytes 6-7: RTK Estimated baseline (mm)
Slip is yaw - heading. Squat is pitch - gradient.
Resolution of slip and squat is degrees/100.
Resolution of estimated baseline is mm.