Active Leg Window - Simrad Maris ECDIS900 Operator's Manual

Active leg window

ROT value is calculated from historical values of the heading
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Acceleration of the ROT is calculated from the same set of values
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Acceleration of the speed is calculated from STW values.
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The PP (Pivot point) of the ship is calculated from GPS positions, speed and heading
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values
The future positions are calculated by iteration (every second) as follow:
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 Last position
 Last heading, ROT and speed
 Time interval
The new position of the PP is calculated from the above values, and the ship's orientation
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is displayed according to the new heading (Last heading received + ROT applied for the
time interval within the limit of ROT and time to reach the ROT).
This tool is designed to help the navigator during navigation in narrow waters, where precise
following along the planned route is essential.
The ship's shape is displayed in the middle of the window together with the active leg and
turning curves using a scale from 3500 – 10000 depending on the ship's dimensions.
The picture is leg bearing oriented. In the top left and right corners of the window current leg
bearing and next leg bearing are displayed.
In the bottom part of the tool XTD value is displayed together with indicator of direction to
go to follow exact the route.
In case of ship turning this value is calculated for the end of turn showing how far away from
the leg the ship will end its turn for the next leg.
Moving along the leg
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A
CTIVE LEG WINDOW