User's Manual

5
12
BASIC RADAR THEORY
■Indirectechoes
Indirect echoes may be returned from either a
passing ship, or returned from a reflecting surface,
such as a mast on your own ship.
An indirect echo from a reflecting surface will appear
on a different bearing from the direct (true) echo, but
the distance will be approximately the same for both.
■Side-lobeechoes
Radiation can escape on each side of the beam
inside the lobes. If a target reflects this radiation, it will
be displayed on the screen as an echo.
Side-lobe echoes usually occur at short ranges and
as a result of large (strongly reflective) targets. They
canbereducedwithproperadjustmentofthe[SEA]
control.
Radarusesaformofelectromagneticradiation,whichlikelight,canbereected.Becauseofthisproperty,some
objects may cause false echoes on the screen where in fact no targets actually exist.
These echoes may appear if a large vessel, bridge, or tank is in proximity. Operators should be familiar with the
effects of these phenomena. In some cases, echoes can be reduced.
Indirect echo
Tr ue echo
Target
Scanner
Mast or
similar obstruction
An echo is reflected at this point.
Own ship
Target
Bridge
Main beam
Side lobes
Tr ue echo
False echo
False
echoes
Tr ue
echo
MXR-5000T / Page 13-2-14