How To Measure The Range By Using A Vrm - Furuno FAR-3210 Operator's Manual

2.17.1

How to measure the range by using a VRM

There are two VRMs, No. 1 and No. 2, which appear as dashed rings so that you can
distinguish them from the fixed range rings. The two VRMs can be distinguished from
each other by the different lengths of their dashes; the dashes on the No. 2 VRM are
longer.
How to measure the range from the Control Unit
1. Press the VRM 1 or VRM 2 key to display desired VRM.
2. Rotate the VRM rotary control to align the active variable range marker with the
inner edge of the target of interest and read its distance at the bottom-right posi-
tion on the screen. Each VRM remains at the same geographical distance when
you operate the range control. This means that the apparent radius of the VRM
ring changes in proportion to the selected range scale.
To erase a VRM, press the VRM 1 or VRM 2 key to erase corresponding VRM.
How to measure the range from the trackball module
1. Click the title bar on a VRM box to activate the corresponding VRM.
2. Spin the scrollwheel or use the trackball to align the active variable range marker
with the inner edge of the target of interest and read its distance at the bottom-
right position on the screen. Each VRM remains at the same geographical dis-
tance when you operate the range control. This means that the apparent radius of
the VRM ring changes in proportion to the selected range scale set the outer edge
of the VRM on the inner edge of the target.
3. To anchor the VRM, push the left button.
To turn off a VRM, click the arrow in the applicable VRM box. The VRM disappears
and the VRM box is minimized.
000
010
350
340
330
VRM 1
320
310
300
290
280
270
260
250
240
230
220
210
200
190 170
180
2. RADAR, CHART RADAR OPERATION
020
030
Target
040
050
060
070
080
090
100
VRM 2
110
120
130
140
150
160
VRM 1 VRM 2
TTG 45:02 TTG 99:59
0.660 1.180
NM NM
2-21