Gyro Error Correction - Furuno FEA-2107 Operator's Manual

19.9

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 ARPA picture, on ARPA targets drawn on the ECDIS display or on
radar overlay drawn on the ECDIS 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 ARPA radar screen
•
Correct ARPA target positions on ECDIS display
•
Correct radar overlay drawn on ECDIS 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.
°
59 31.206'N
°
024 36.731'E
WGS 84
DGPS
HDG 071.0°
SPD 1.8
(CALC) Kt
SB 1.7
(POSN) Kt
COG 045.1°
(POSN)
SOG 2.0
(POSN) Kt
Posn
19. Navigation Sensors
19-21