Target Properties - Furuno 1751 Operator's Manual

Factors Affecting Maximum Range 3. APPLICATION
Figure 3-2 Radar Horizon
Target properties
Generally, larger targets can be seen on the radar display at greater ranges, provided
line-of-sight exists between the scanner and target. However, a large target with poor
reflecting properties may not be detected as easily as a smaller target with better reflecting
properties.
Since one of the main fiinctions of radar is to detect other ships, the composition of a target
ships' huli affects the detection range. A ship whose huli is made of conducting materials,
such as Steel, will return a relatively strong echo.
On the other hånd, hulis made from wood or fiberglass return much weaker echoes,
Vertical surfaces, such as a cliff, are good targets provided they face the radar. Conversely,
horizontal and smooth surfaces such as mudbanks, sandy beaches, and gently sloping hilis
make poor targets because they disperse rather than reflect most of the energy that strikes
them.
The strongest radar echoes known come from built-up areas, docks, etc., because these
targets are less subject to changes in aspect. These types of targets have three flat, smooth
surfaces mutually at right angles. Some radar buoys are arranged this way so as to deliberate-
ly
increase
their detection range.
3-3