Sperry Marine Visionmaster FT ECDIS, Руководство пользователя

Страница: 213 / 531

ECDIS User Guide Charts
65900012 4-81
Look-Ahead rectangle follows the COG from own ship. The length of the
safety region represents the time, or distance, own ship will travel, based
on current
SOG .
On a multi- node system the look-ahead range is distributed and persisted
across all nodes
WARNING!
PROFILES THAT ADJUST LOOK-AHEAD TIME, BUT NOT LOOK
AHEAD DISTANCE WILL HAVE NO IMMEDIATE EFFECT ON THE
SIZE OF THE SAFETY CHECKING REGION IF LOOK-AHEAD
DISTANCE IS CURRENTLY SELECTED. PROFILES CREATED IN
VERSIONS BEFORE THE LOOK-AHEAD DISTANCE PARAMETER
WAS AVAILABLE MAY BE EDITED SO THAT THE LOOK-AHEAD
DISTANCE PARAMETER IS TAKEN INTO ACCOUNT.
To change Look Ahead values do the following:
1. To change the look-ahead time or distance click on the respective
radio button, the active field toggles depending on the selection
made. To change the time or distance, click in the field and move
the trackball right to increase the value, up to 60 minutes or 10 NM,
or decrease to a minimum of 0 minutes or 0.0NM, see below. As
the look-ahead value is increased or decreased the safety region
lengthens or shortens and the area the system checks for dangers
is adjusted.
In some circumstances it may be desirable for the operator to select a zero
value for Look-Ahead time or distance, for example, when ownship is in a
crowded harbour area. If a zero value is selected a `Minimal Safety Region'
caution is generated. The caution is removed from the Alerts list if the time
is increased to at least 1 minute, or the distance to at least 0.3 NM.
Safety region alerts in the Dangers window are suppressed when
zero Look-Ahead time/distance is selected.
As the safety checking is done periodically there is a delay of a few
minutes for dangers in the dangers list to time out after the look
ahead range has been adjusted. This prevents the same dangers
from being added or removed from the list, and re-alarming due to
fluctuations in the ship's course.
Added Breadth enables a safety region width to be added to either side of
own ship’s beam. The value defines the safety breadth from ship's beam in
metres that the system checks for dangerous objects (for example,