Furuno FR-1500 MARK-3, User Manual

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1.19 Measuring Bearing
Use the Electronic Bearing Lines (EBLs) to find bearing of a target. There are two EBLs, No.1 and
No.2, which are toggled by successive presses of the [EBL ON] key. Each EBL is a straight
dashed line extending out from the own ship position up to the circumference of the radar picture.
The fine dashed line is the No.1 EBL and the coarse dashed one is the No.2 EBL.
1. Press the [EBL ON] key to display either of the EBLs. Successive presses of the [EBL ON]
key toggles the active EBL between No.1, No.2 and index lines (if displayed) and the
currently active EBL readout is circumscribed.
2. Rotate the EBL rotary control clockwise or counterclockwise until the active EBL bisects the
target of interest, and read its bearing at the lower-left corner of the screen.
3. Press the [EBL OFF] key to erase each EBL.
The EBL readout is affixed by R (relative) if it is relative to own ship’s heading, or T (true) if it is
referenced to the North, as determined by the item EBL/VRM/+ on the OTHERS menu.
Note 1:
Bearing reference cannot be selected for IMO type (no menu selection). For the IMO
type, relative bearing is selected in the HU mode, and true bearing in HUTB, CU, NU and TM
modes.
Note 2:
The cursor may be returned to OS position by pressing the VRM control (R-type only).
1.20 Collision Assessment by the 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 the No.1 EBL.
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, 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 rotary 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 OTHERS menu.