User Manual
Reference number: 4111A-RADAR4600-GBD-R1.1
Date: 27 February 2018
Page 123 of 149
Small objects are masked by bigger
and higher objects in front of them.
7.8.1
Blind or shadowed areas
Blind areas are sections which can not be detected by radar beam,
whereas shadowed areas are sections, which can be detected partly by
radar beam.
Objects in blind areas are not detectable by radar.
Objects in shadowed areas are detectable if they have well reflecting
surfaces.
7.9
False targets
An object that does actually not exist within the selected radar range
may appear on the display. The phenomena that causes false echoes
are categorized and be described as follows:
Multiple targets by bouncing ship to ship
If there is a big reflective surface nearby and perpendicular at a
close distance,( i.e. when your ship is passing another big ship,
etc.), radio wave bounces between your ship and the other ship.
Therefore, 2 to 4 images may appear at equal range in the
direction of this target. The false image generated by this multi-
path reflection is referred to as “double targets”. In this case, the
closest target is the real one.
You will notice as the distance and bearing between own ship and the
reflective target changes, the duplicate targets will disappear.
Therefore, this false image can be easily distinguished.