Range Rings; Cursor; Heading Line; Measuring The Range - Furuno FMD-1712 Operator's Manual

1.11 Range Rings

The range rings are the concentric circles
around own ship and they provide an
estimate of target range. The selected
range scale automatically determines the
number of rings and their interval is
displayed at the upper-left-hand corner on
the screen.
To turn the range rings on or off, press the
[EBL] and [VRM] keys together.

1.12 Cursor

The cursor is always displayed and
functions to measure the range and bearing
to a target. Operate the Omnipad to place
the cursor on the inside edge of the target
for range measurement or the center of the
target for bearing measurement. The range
and bearing to the cursor appear at the
bottom right-hand corner on the display.
6.0
NM
2.0
045.0
3.35
Figure 1-11 How to measure range and
bearing with the cursor

1.13 Heading Line

The heading line indicates the ship's
heading and it is the solid line which
appears at zero degrees on the bearing
scale.
To temporarily erase the heading line to
look at targets existing dead ahead of own
ship, press the [MENU] and [GUARD] keys
together. Release the keys to display the
heading line.
6
Target
Cursor
Range and
NM
bearing to
cursor

1.14 Measuring the Range

The bearing to a target can be measured by
the range rings, by the cursor (see
paragraph 1.12) and by the VRM (Variable
Range Marker).
Measuring range by the range rings
Count the number of rings between the
center of the display and the target. Check
the range ring interval at the top left-hand
corner of the screen and judge the distance
of the echo from the inner edge of the
nearest ring.
Measuring range by the VRM
1. Press the [VRM] key to turn on the VRM.
2. Within 10 seconds after turning on the
VRM, that is, while "VRM" is highlighted
at the bottom left-hand corner on the
screen, press
(decrease radius) to place the VRM on
the inside edge of the target.
3. Check the VRM readout at the bottom
left-hand corner on the screen.
Note: The VRM becomes stationary when
the [VRM] key is pressed a second
time, or 10 seconds elapses without
pressing or
stationary "VRM" is not highlighted.
6.0
NM
2.0
2.42
VRM NM
VRM
range
Figure 1-12 How to measure range by the
cursor and VRM
To erase the VRM, press the [VRM] key
until the VRM disappears.
(increase radius) or
. When the VRM is
Target
Cursor
VRM
045.0
2.42
NM
Cursor
range