Raymarine a67, Инструкция по установке и эксплуатации, Страница: 175 / 330

16.12 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:
Functions
Distances
Between
Points
Range From
Your Vessel
Bearings
Range Rings Yes
(approximate
distance) Yes
(approximate
range) No
Cursor No Yes Yes
Variable Range
Markers /
Electronic
Bearing Lines
(VRM/EBL) No Yes Yes
Floating
VRM/EBL Yes No Yes
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:
D 12214-1 D 12215-1 D 12216-1
Range — 1/4 nm
Range Rings — 760ft
apart Range — 3/4 nm
Range Rings — 1/4
nm apart Range — 1 1/2 nm
Range Rings — 1/4
nm 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 2
D 12217-1
Item Description
1. Cursor
2. Bearing and range from your vessel
to the cursor position
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)
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.
D8403-2
1 3 2
0 .624nm
56°S
4
V RM/EBL
Item Description
1 VRM
2 Target
3 EBL
4 Range and bearing
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.
2 3
V RM/EBL
0 .471nm
55°P
1
D 12218-1
Item Description
1 Range and bearing
2 Target 1
3 Target 2
Radar application
175