
EXTRACTS FROM OFFICIAL PUBLICATIONS
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(b) The performance of the radar associated with the
ARPA is at its optimum.
(c) The heading and speed inputs to the ARPA are
satisfactory. Correct speed input, where provided
by manual setting of the appropriate ARPA con-
trols) or by an external input, e.g. Doppler log, is
vital for correct processing of ARPA data. Serious
errors of output data can arise if heading and speed
inputs to the ARPA are incorrect. In this context
users should be aware of the possible hazards of
using a ground stabilized mode of ARPA display
when information on the movement of other ships
is being used to assess a potentia