User Manual
Reference number: 4111A-RADAR4600-GBD-R1.1
Date: 27 February 2018
Page 120 of 149
Example with different object materials and different angles
7.3
Echo strength in relation to target consistency
The strength of the reflected wave from a target varies depending on not only the distance from the target,
its height or size, but also its material and features. A target with a low degree of reflection or low incident
angle, such as GRP and wooden is not reflected well.
Care shall be taken that a GRP ship, a wooden vessel or an object such as sand, a sandbar and
muddy cay are poor radar targets.
7.3.1
Improved echo strength by radar reflectors
Small boats are often equipped with radar reflectors, which highly improve reflection of radar waves. A small
GRP-sailing boat with an optimum placed reflector often is shown as better target on radar screen, than a
bigger wooden boat without reflector.
7.4
Minimum detectable distance
Due to physical limitations, a shipborne radar is not
able to detect targets with a shorter distance to
radar antenna less than 15m. IMO regulations
demand on a minimum distance of 40m.
Additional the minimum detection range is limited
according to height of antenna installation and
shadowing of ship-structures.
