Gyro Error Correction - Furuno FCR-2107 Series Operator's Manual

15. Navigation Sensors
15.7

Gyro Error Correction

Typical gyro error sources are installation error, speed/latitude error and dynamic settling error. Typically you detect
gyro error on a user chart superimposed on the TT picture, on Tracked Targets drawn on the chart radar display or
on radar drawn on the chart radar display.
Gyro error correction is used to remove the difference between the chart north and the gyro north.
Gyro error can be corrected totally or partially in the gyro compass system itself. Many gyro compass systems have
automatic speed/latitude corrector, which may use automatic or manual input for speed and latitude. Some
gyrocompass systems also include correction for dynamic settling error.
Automatic gyro error correction based on tabled speed/latitude correction can be used, if the gyrocompass itself does
not make any corresponding correction.
Gyro error compensation can be used to:
•
Correct user chart on Radar screen
•
Correct Tracked Target positions on chart radar display
•
Correct radar drawn on chart radar display
•
Compensate courses used in route monitoring and automatic route steering.
If you have enabled Gyro error correction (see the next
page) and if this correction has modified the value of the
own ship heading, then this condition is always visible
in the information area. Red "(corr)" means the gyro
value has been corrected.
If you have enabled both Gyro error correction from
ship parameters and Gyro error compensation from route
parameters, then Plan and Next in the information area
display show compensated values, as shown in the
example at right. Also, course to steer (used by
automatic route steering) is compensated in this case.
The current value of gyro correction and its method are
displayed in the Other page of the Sensors dialog box as
shown in the example at right. "Table" means
speed/latitude table is the source for gyro correction;
"Manual" indicates manual entry of gyro correction.
15-14
°
HDG 071.0
SPD (WAT) 15.6 kn
SB (POSN) 0.0 kn
°
COG (POSN) 071.0
SOG (POSN) 15.6 kn
59°31.206'N
024°36.731'E
WGS 84
DGPS
kn
POSN
NM
NM