NAV 44/7/4
10.3.3 It should be possible to plan an
alternate route in addition to the selected route. The
selected route should be clearly distinguishable from the
other route.
10.3.4 It should be possible for the
mariner to specify a limit of deviation from the planned
route at which activation of an automatic off-track alarm
should occur.
10.3.5 It should be possible for the
mariner to enter points, lines and areas which activate an
automatic alarm. The display of these features should not
degrade the SRNCD information and it should be clearly
distinguishable from the SRNCD information.
l0.4 Route Monitoring
10.4.1 For route monitoring the selected
route and own ship's position should appear whenever the
display covers that area.
10.4.2 It should be possible to display a
sea area that does not have the ship on the display (e.g. for
look ahead, route planning), while route monitoring. If this
is done on the display used for route monitoring, the
automatic route monitoring functions in 10.3.4 and 10.3.5
should be continuous. It should be possible to return to the
route monitoring display covering own ship's position
immediately by single operator action,
10.4.3 An alarm should be given when the
specified limit for deviation from the planned route is
exceeded.
10.4.4 The ship's position should be
derived from a continuous positioning system of an accuracy
consistent with the requirements of safe navigation. Whenever
possible, a second independent positioning method of a
different type should be provided; RCDS should be capable of
identifying discrepancies between the two systems.
10.4.5 RCDS should provide an alarm when
the input from the position fixing system is lost. RCDS
should also repeat, but only as an indication, any alarm or
indication passed to it from a position fixing system.
10.4.6 An alarm should be given by RCDS if
the ship, within a specified time or distance set by the
mariner, will reach critical point on the planned route.
10.4.7 The RCDS should only accept
positional data referenced to the WGS-84 or PE-90 geodetic
datum. RCDS should give an alarm if the positional data is
not referenced to one of these datums.
10.4.8 RCDS should allow the user to
manually align the SRNCD with positional data. This can be
necessary, for example, to compensate for local charting
errors.
10.4.9 It should be possible to display an
alternative route in addition to the selected route. The
selected route should be clearly distinguishable from the
other routes. During the voyage, it should be possible for
the mariner to modify. the selected sailing route or change
to an alternative route.
I:/NAV/44/7-4.WPD
