Raymarine Marine GPS System - Manual (Page 156)

Advanced Navigator Functions
5-65
Calibrating to Ensure Data Accuracy
The accuracy of the data generated by your instruments and
performance evaluation systems depends on accurate calibration.
While the following subsection presents an introductory explanation
of instrument calibration, you must refer to the manuals that came with
your instrumentation systems for the specific calibration procedures.
The subsections that follow explain the calibration methodologies for
the following variables:
•
Boat speed
•
Compass
•
Apparent wind angle
•
True wind angle
•
True wind speed
Boat Speed Calibration
Boat speed calibrations are entered directly into your instrumentation
system (refer to your system’s manual for the procedure). While it
may not be practical to check boat speed calibration on a daily basis,
we encourage you to check this variable on a measured mile as often
as possible, as the paddle-wheel impellers that generate boat speed
data can change their physical characteristics markedly over their
lifespan due to the environment in which they operate. When making
a measured mile calibration, perform three consecutive runs over the
known distance, to eliminate any tidal current effects.