User's Manual Part 2

Operator Manual
Raytheon Marine GmbH
Germany
R
NSC 18
RADAR
3−15
3748DOC020102Edition: 14.JAN.2005
3.4.1 Sensor Errors
The performance of ARPA depends on the quality of the sensor information
which is processed. The radar is the sensor which measures target range and
bearing relative to own ship. The gyro compass measures the heading of the
own ship ship relative to north. The speed log measures the motion of ship own
relative to the water or bottom.
3.4.1.1 Gyro Compass
A precise Gyro Compass heading is an important condition for accurate target
tracking and ARPA information. The radar user should be aware that Gyro
Compasses may have errors (speed error and acceleration error). These errors
can degrade the accuracy of target results (ARPA INFO).
Raytheon Gyro Compasses have automatic error correction and supply true
heading to radars.
This may not be the case for other Gyro Compass models.
If Gyro Compass heading input is interrupted, the radar will give alarm.
3.4.1.2 Speed Log
A precise speed input from the log is an important condition for accurate target
tracking and ARPA INFO. The radar user should be aware that speed outputs of
logs may be temporarily unstable for various reasons. This may degrade the
accuray tracking results (ARPA INFO).
If speed input is interrupted, the radar will release alarm.