Chapter 3 SPAN Operation
OEM7 SPAN Installation and Operation User Manual v14
126
Command
Purpose
SETINSROTATION
USER
By default, attitude information output by SPAN is for the vehicle frame. If attitude
output is required to be referenced to another frame (typically the axes of a gimbal-
mounted sensor), the USER offset can be used to rotate the attitude output in general
SPAN logs to this frame.
SETINSROTATION
MARKx
Similar to the user rotation, this rotation can be used to change the attitude output
reference frame for the MARKxPVA logs.
SETINSTRANSLATION
GIMBAL
This command provides the offset from the IMU center of navigation to the gimbal
center of navigation. This is an optional translation used by Inertial Explorer for post-
processing.
3.12 Relative INS
NovAtel's Relative INS technology generates a position, velocity and full attitude vector between two SPAN sys-
tems. One is the Master receiver and the other is the Rover receiver. Once configured, the Master receiver
begins transmitting corrections to the Rover receiver. Relative information is created and the system begins
filling the
RELINSPVA
log and
SYNCRELINSPVA
log on the Rover receiver. The
RELINSPVA
log is then
transmitted back to the Master receiver for output.
The data link required must be able to support [108bits x #obs tracked per second]. The
RELINSPVA
log is requested ONNEW (available from 1Hz-20Hz depending on the setup of the
RELINSAUTOMATION
com-
mand) while the
SYNCRELINSPVA
log can be requested ONTIME at up to 200Hz (at the rover only). Position
and velocity solutions are differenced in the ECEF frame and then rotated into the local level. The Relative offset
vector that is output is dependent on Master/Rover's precise RTK vector and their eccentric offset vectors
(optional offset provided using the
USER
parameter in the
SETINSTRANSLATION
command), shown in
