Collision Assessment By Offset Ebl; How To Assess Risk Of Collision Using The Offset Ebl - Furuno FAR-2228-BB Operator's Manual

1.34

Collision Assessment by Offset EBL

The origin of the EBL can be placed anywhere to enable measurement of range and
bearing between any two targets. This function is also useful for assessment of the
potential risk of collision. It is possible to read CPA (Closest Point of Approach) by us-
ing the EBL range marker as shown in (a) in the illustration below. If the EBL passes
through the sweep origin (own ship) as shown in (b) in the illustration below, the target
ship is on a collision course.
320
310
A
300
290
280
270
260
250
240
230
No. 1
220
EBL
1.34.1

How to assess risk of collision using the offset EBL

There are two methods for assessing risk collision. You can use the control unit or the
[CURSOR] menu.
Using the control unit (RCU-014)
1. Press the EBL ON key to display or activate an EBL (EBL1 or EBL2).
2. Place the cursor on a target appearing as threatening (indicated as "A" in the ex-
ample figure on the previous page).
3. Press the EBL OFFSET key and the origin of the active EBL shifts to the cursor
position.
4. Press the EBL OFFSET key again to anchor the EBL origin.
5. After waiting for a few minutes (at least 3 minutes), operate the EBL knob until the
EBL bisects the target at the new position (A
ship's course, which can be true or relative depending on the EBL bearing refer-
ence setting.
Note: If relative motion is selected, it is also possible to read CPA by using the
range marker as shown in left-hand figure at the top of the next page. If the EBL
passes through the sweep origin (own ship) as illustrated in the right-hand figure
above, the target ship is on a collision course.
6. To return the EBL origin to the own ship's position, then press the EBL OFFSET
key.
000
350 010
340 020
330 030
040
050
1
A
EBL
range
marker
130
140
210 150
200
160
190
170
180
310
300
060
290
070
280
080
270
090
260
100
250
110
240
120
230
No. 1
EBL
(a)
1
). The EBL readout shows the target
1. OPERATIONAL OVERVIEW
000
350 010
340 020
330 030
320
040
A
EBL
1
A
range
marker
220 140
210 150
200
160
190 170
180
050
060
070
080
090
100
110
120
130
(b)
1-55