Determining Actual Radar Range - Raymarine SL72 Owner's Handbook Manual

Chapter 3: Standard Radar Operations
.
Table 3-1:
Maximum Range
(nm)
0.125
0.25
0.5
0.75
1.5
3
6
12
24
The number of range rings shown in the table is the number to the selected
range. Additional range rings are displayed to the edge of the radar picture, at
the standard ring interval for the current range, and are visible when the centre
is offset.

Determining Actual Radar Range

The actual maximum radar range is essentially line-of-sight, and is limited by
the height of the scanner and the height of the target as shown in Figure 3-1.
Table 3-2 lists some range examples:
Figure 3-2:
Table 3-2:
Antenna Height (m)
3
3
5
5
Radar Range Scales
Number of Range
Rings
2
2
4
3
6
6
6
6
6
a
1
Radar
R max = 2.23 (
R max maximum radar range
h radar antenna height
H target height
R max = radar horizon of antenna (
Determining Radar Range
Radar Range
Target Height (m)
3
10
3
10
Range Ring Interval
(nm)
0.0625
0.125
0.125
0.25
0.25
0.5
1
2
4
R max
a
2
Earth
h + H )
in nautical miles
in metres
in metres
a
) + radar horizon of target (
1
Maximum Range (nm)
7.8
10.9
8.9
12.0
3-3
Cliff
a
)
2
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