CodaOctopus F180R - Remote Lever Arms Configuration

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Hardware

F180R MOTION Sensor User and Reference Guide

3.4.4 Antenna Orientation

The Antenna Orientation has two components — rotation and elevation — that tell the F180R

System what angle the GNSS antenna mounting bar is at relative to the vessel's heading axis,

and what elevation angle the GNSS antenna mounting bar makes relative to the vessel's base

plane.

Rotation is expressed as the angular difference between the vessel's heading and the antenna

mounting bar, using the primary antenna as pivotal point.

Elevation is expressed as height offset of the secondary antenna to the primary antenna, that

is, the difference in altitude between the Secondary and the Primary Antennas.

With the antenna mounting bar aligned port–starboard

with the primary antenna to port, the orientation

rotation is nominally +90°.

Figure 28: GPS Orientation

With the antennas mounted fore–aft (in line with the

vessel) and the secondary antenna aft of the primary

antenna, the orientation rotation is nominally 180°.

With the antennas mounted fore–aft (in line with the

vessel) and the secondary antenna forward of the

primary antenna, the orientation rotation is nominally

0°.

A height offset positive means that the Secondary

Antenna is above or below the Primary Antenna.

NOTE: These nominal GPS orientation rotation and elevation angles must be set

accurately to ensure optimal performance. Following the series of calibration

manoeuvres the system will refine the measurements to more accurate values, and

these are saved with the calibration.

Measure and write down the Antenna orientation rotation and height offset as detailed

above. Later you must type these values into the appropriate fields of the MOTION Control

Settings Wizard.

3.4.5 Remote Lever Arms

The F180R System allows you to set a 'Remote Lever Arm' distances X, Y and Z of the F180R

System so that you may specify the point at which you want the motion outputs to be

computed for. The Remote Lever Arms are configured in Settings Wizard.

With the default zero settings for the X, Y and Z remote lever arm distances, the system

outputs all data referenced to its internal measurement point which is marked on the IMU

enclosure. If you want the system outputs referenced to some other point, for example at a

sonar head, you must enter the lever arm distances between the F180R System IMU and the

desired measurement point.