How To Change The Reference Position - Furuno FAR-2228-BB Operator's Manual

1. OPERATIONAL OVERVIEW
1.50

How to Change the Reference Position

The reference position for measurements (range, bearing, etc.) and markers (heading
line, stern mark, etc.) can be the radar antenna position ([ANT]) or the consistent com-
mon reference point ([CCRP]).
The reference position is a location on own ship to which all horizontal measurements,
for example range, bearing, relative course, relative speed, closest point of approach
(CPA) or time to closest point of approach (TCPA), are normally referenced.
[CCRP] for this series of radars is fixed at the conning position and [ANT] is fixed at
the radar antenna position.
To change the reference position, use the trackball to place the cursor over the "REF
POINT" indication at the top of the screen, then left-click to select [ANT] or [CCRP] as
required. You can also change the reference by spinning the scrollwheel when the cur-
sor is placed over the indication.
The position of the own ship marker changes according to reference position as
shown below. If the CCRP is positioned outside of the effective display area, the bear-
ing scale is indicated with the appropriate reduced detail.
Radar antenna
position is at
center of display
Range and bearing are measured and graphics are drawn according to reference po-
sition as in the table below.
Category
Range and bearing
measurements
Graphics
Bearing cursor
Course, speed
1-96
X
ANT position
Item
EBL
VRM
Cursor
PI line
Range ring
Drop mark
Heading line
Stern mark
Beam line
Own ship vector
Own ship track
Table continued on following page
X
Conning position is at
center of display
CCRP position
Reference point
ANT
Range and bearing Range and bearing
measured from an- measured from
tenna position. CCRP.
Drawn from anten- Drawn from CCRP.
na position.
Drawn with antenna Drawn with CCRP
position at center. at center.
Calculated with an- Calculated with
tenna position at CCRP at center.
center.
CCRP