7-3  Section 7 True and False Echoes on Display 
 
 
 
 
 
 
7.2  Intensity Reflected from the Target 
The signal intensity reflected from a target depends not only on the height and size of the target but 
also on its material and shape. The echo intensity from a higher and larger target is not always higher 
in general. 
In particular, the echo from a coast line is affected by the geographic conditions of the coast. If the 
coast has a very gentle slope, the echo from a mountain of the inland like the figure below appears on 
the radar display. Therefore, the distance to the coast line should be measured carefully. 
 
 
 
The next table  shows the relation between the target detection range  and the radar reflection 
cross-sectional area (RCS) with regard to the type and the height of the target in a situation in which 
the weather is good, the sea state is calm and the radio wave propagation is normal. As revealed by 
this table, even on the same sea shore line, detection range greatly differs depending on the height of 
the  target from the surface of the sea. Furthermore, because the target detection range  is greatly 
influenced by the shape and material of the target and environmental conditions, such as the sea state, 
weather, and radio wave propagation, caution should be taken when detecting range of target. 
   
Mountain displayed
on the radar display
Sea shore line not displayed
on the radar display.
HL
Sea Shore Line Not Displayed on the Radar Display