NAV 44/7/4
8. COLOURS AND SYMBOLS
8.1 The display should use colours to
aid in distinguishing between features
8.2 If the colours and symbols used
differ significantly from the paper chart, a legend of
colours and symbols should be provided.
8.3 Chart features and symbols should
be large and bold enough to be clearly visible. The own-ship
symbol should be immediately visible at a glance.
8.4 Means should be provided to
ensure that the use of the ECS at night will not adversely
affect night vision.
8.5 It should be possible to
unambiguously operate the controls of the ECS at night
9. DISPLAY SCREEN REQUIREMENTS
9.1 A minimum chart display area of
180mm x 180mm should be used.
9.2 The resolution should be such
that the chart features, symbols and characters used are
clearly readable.
9.3 The display should have an
adequate vrewmg angle
10. ROUTE PLANNING AND ROUTE
MONITORING
10.1 The mariner should bear in mind
that the use of an ECS does not relieve him of his
responsibility to plan, monitor and record his voyage on the
paper chart, in accordance with the accepted principles of
safe watchkeeping.
10.2 The ECS should provide tools and
procedures for planning and saving a route, and the route in
use should appear automatically whenever that area is on the
display.
10.3 Means should be provided for
entering and reading off geographic positions and for laying
off and measuring bearings and distances from own-ship.
10.4 During route monitoring the ships
position should be displayed and updated frequently, and the
past track should remain on the display long enough to show
trends.
10.5 The ECS should give an alarm if the
position input is lost. The ECS should repeat, as an
indication only, any alarms originating in the positioning
sensor in use.
10.6 The ECS should give an alarm if the
computer fails (e.g. display freeze).
11. ACCURACY
11.1 The ECS should not degrade the
accuracy of the information from other sources.
12. CONNECTIONS WITH OTHER EQUIPMENT
12.1 The ECS should be connected to a
system providing continuous position fixing.
12.2 The ECS should not degrade the
performance of any equipment to which it is interfaced.
12.3 Interfaces should be in accordance
with an accepted international standard.*
13. DIAGNOSTIC CHECKS
13.1 The ECS should include adequate
diagnostic checks providing meaningful identification of
faults.
14. POWER SUPPLY
14.1 A brief power-break should not
interrupt route monitoring.
*IEC 61162 (series)
I:/NAV/44/7-4.WPD
