Furuno FR-2105-B - Manual (Page 39)

-1.22-
1.18 Collision Assessment by Offset EBL
The origin of the EBL can be placed anywhere with the trackball to enable measurement of
range and bearing between any targets. This function is also useful for assessment of the
potential risk of collision. To assess possibility of collision:
1. Press the EBL ON key to display or activate an EBL (No. 1 or 2).
2. Place the cursor (+) on a target appearing as threatening (A in the illustrated example) by
operating the trackball.
3. Press the EBL OFFSET key on the mode panel, and the origin of the active EBL shifts to
the cursor position. Press the EBL OFFSET key again to anchor the EBL origin.
4. After waiting for a few minutes (at least 3 minutes), operate the EBL control until the EBL
bisects the target at the new position (A'). The EBL readout shows the target ship's course,
which may be true or relative depending on the settings on the RADAR 1 menu.
If relative motion is selected, it is also possible to read CPA (Closest Point of Approach) by
using a VRM as shown below (Figure (a)). If the EBL passes through the sweep origin
(own ship) as illustrated (Figure (b)), the target ship is on a collision course.
5. To return the EBL origin to the own ship's position, press the EBL OFFSET key again.
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A
A 1
VRM
>3.85 NM< EBL
> 150.3
° R<
VRM
> 0.00 NM< EBL
> 150.3
° R<
A
A 1
EBL 1 EBL 1
(a) Evaluating the target ship course in RM (b) Target ship on collision course