Azimuth Sources On A Span System; Course Over Ground - Novatel SMART7 Installation And Operation Manual

SMART7 with SPAN Operation
INSCALIBRATE RBV STOP
8. At this point INSCALSTATUS will report a source status of CALIBRATED. Turn the vehicle
around and come to a stop on the finishing point of the previous line.
9. Initiate the second pass of the calibration by issuing the INSCALIBRATE command with the
ADD parameter:
INSCALIBRATE RBV ADD
10. Drive the vehicle back along the original course, until you reach the starting point for the
first pass. Stop the vehicle, and re-issue the INSCALIBRATE command, with the STOP para-
meter. INSCALSTATUS will again indicate a source status of CALIBRATED.
At this point the multi-line calibration can be considered complete, but more iterations can
be repeated until the desired accuracy level is reached.
11. When the calibration is complete, the calibrated offset value can be viewed in either the
INSCALSTATUS log or the INSCONFIG log.
To save a calibrated rotation for subsequent start ups, issue the SAVECONFIG command after
calibration is complete. Each time the IMU is re-mounted this calibration should be performed
again.
After the INSCALIBRATE RBV ENABLE command is entered, there are no body-vehicle
rotation parameters present and a kinematic alignment is NOT possible. Therefore this
command should only be entered after the system has performed a kinematic alignment
and has a valid INS solution.
For information about the logs and commands used in this procedure, refer to the
Commands and Logs Reference

4.6 Azimuth Sources on a SPAN System

The SPAN system use three different methods to calculate the azimuth.

Course Over Ground

l
Inertial Azimuth
l
ALIGN Azimuth
l
4.6.1 Course Over Ground
The course over ground azimuth is determined using the position delta between two position
solutions computed by the OEM7 receiver. This is the simplest way to compute an azimuth and is
done using either the GNSS solution or the INS solution. This method does not work when the
vehicle is stationary as any position difference is due to position error and the computed azi-
muth is meaningless.
Course over ground azimuth is of greatest advantage in aerial or marine environments where
the actual direction of travel may not match the forward axis of the aircraft/boat due to winds or
currents. This effect is known as the crab angle. Course over ground azimuth is a great way to
compute the offset if another means of computing the vehicle azimuth is available.
SMART7 Installation and Operation User Manual 0C
Manual.
OEM7
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