Specifications

38 YEOMAN Sport
RADAR misalignment
Common to manual or YEOMAN plotting. See RADAR
handbook or any book on RADAR for techniques on how to
resolve and rectify this.
Compass misalignment or calibration error
Potentially an area where manual plotting, probably using the
main steering compass, and YEOMAN plotting, based on the
RADAR’s electronic compass, may differ.
A careful check of the electronic compass used for the RADAR
against a properly swung primary compass, taking account of
the deviation card, should be made on all compass headings.
This should be checked from time to time, especially after any
refit, in case the electronic compass sensor should have been
disturbed or any change to its magnetic environment occurred
(e.g. electrical equipment or magnetic material placed nearby).
Navigation system error
Common to either methods and the user should always remain
alert to the fact that the electronic position data may be in error
or may not tie up to the co-ordinates on the chart. Remedies
include:
• a second independent electronic navigation system (i.e.
use both GPS and DECCA or LORAN) and compare
regularly
• regular checking against conventional navigation
including dead reckoning, depth sounder and compass
bearings on known features
• checking against RADAR, for which the YEOMAN
plotting system is particularly convenient.