Novatel OM-20000122 user manual Inertial Azimuth, Align Azimuth, Logs with Azimuth data

SPAN-CPT Operation Chapter 3

3.5.2Inertial Azimuth

The inertial azimuth computed by the SPAN inertial navigation filter. It uses the sensors in the IMU to compute the azimuth of the IMU (this can be rotated to another reference if desired). For more information, see the APPLYVEHICLEBODYROATION and VEHICLEBODYROTATION commands in the SPAN on OEM6 Firmware Reference Manual (OM-20000144).

This azimuth is the one provided in the majority of the INS logs available to a SPAN user. See Table 5, Logs with Azimuth data on page 31.

3.5.3ALIGN Azimuth

On SPAN systems with dual antennas, an azimuth is available from the dual antenna baseline. This is the same azimuth that is used as an update to the SPAN solution. It is noisier than the inertial azimuth and is available at a much lower rate, but will have a stable mean. This azimuth is computed from the master antenna to the rover antenna based on how the antennas are oriented on the vehicle.

There is a specific subset of logs that output this azimuth. See Table 5, Logs with Azimuth data on page 31.

Table 5: Logs with Azimuth data

Log	Log	Azimuth Source
	Format
INSPVA / INSPVAS / INSPVAX	NovAtel	Inertial
INSATT / INSATTS / INSATTX	NovAtel	Inertial
PASHR	NMEA	Inertial
INSSPD	NovAtel	Course Over Ground
		Computed using the INS solution only
BESTVEL	NovAtel	Course Over Ground
		From the best system solution which could be either
		GNSS or INS
GPVTG	NMEA	Course Over Ground
		From the best system solution which could be either
		GNSS or INS
HEADING	NovAtel	ALIGN
GPHDT	NMEA	ALIGN

SPAN-CPT User Manual Rev 8 31