Using Radar To Measure Distances, Ranges, And Bearings - Raymarine a65 Installation And Operation Instructions Manual

13.12 Using radar to measure distances,
ranges, and bearings
When you are using the radar application, you can measure
distances, ranges and bearings in a variety of ways.
These options are detailed in the table below:
Distances
Functions Between Points
Range Rings Yes
(approximate
distance)
Cursor No
Variable Range No
Markers /
Electronic
Bearing Lines
(VRM/EBL)
Floating Yes
VRM/EBL
Measuring using the range rings
Use the range rings to gauge the approximate distances between
points. Range rings are concentric circles displayed on the screen
and centred from your vessel at pre-set distances. The number and
spacing of the rings changes as you range in and out.
Examples:
D12214-1
Range — 1/4 nm Range — 3/4 nm
Range Rings — 760ft Range Rings — 1/4 nm
apart apart
Measuring using the cursor
To measure the bearing and range from your vessel to a specified
target, move the cursor to the appropriate position on the screen
and press Ok, the radar context menu will be displayed which shall
provide:
• Latitude
• Longitude
• Range
• Bearing
1
Item
1.
2.
You can also display the cursor position in the databar, from the
homescreen select: Customize > Databar Set-up > Edit Databar,
now select the data box where you want the cursor position to be
displayed. Select Navigation > Cursor Position.
Measuring using VRM/EBL
Variable Range Markers (VRM)
154
Range From
Your Vessel Bearings
Yes No
(approximate
range)
Yes Yes
Yes Yes
No Yes
D12215-1
Range — 1 1/2 nm
Range Rings — 1/4 nm
apart
2
Description
Cursor
Bearing and range from your vessel to
the cursor position
A Variable Range Marker (VRM) is a circle centred on your vessel's
position and fixed with respect to the heading mode. When this
circle is adjusted to align with a target, its range from your vessel
is measured and displayed on the Radar context menu when you
select the VRM with the cursor.
Electronic Bearing Lines (EBL)
An Electronic Bearing Line (EBL) is a line drawn from your vessel
to the edge of the window. When this line is rotated to align with a
target, its bearing relative to your vessel's heading is measured and
displayed on the Radar context menu when you select the VRM
with the cursor.
The VRM/EBL are combined to measure both the range and the
bearing of the specified target.
Item
1
2
D12216-1
3
4
Measuring using floating VRM/EBL
You can use the VRM/EBL float function to measure the range and
bearing between any two points on the radar screen. This function
allows you to move the VRM/EBL centre away from your vessel's
position and onto a target. You can then change the radius of the
VRM to determine the distance between two points and change the
angle of the EBL, relative to its new origin, to obtain the bearing.
1
0.471nm
55°P
Item
D12217-1
1
2
3
1 2 3 4
0.624nm
56°S
VRM /EBL
Description
VRM
Target
EBL
Range and bearing
Description
Range and bearing
Target 1
Target 2
New a Series / New c Series / New e Series
D12218-1