
76-6 Environmental
76.3.1 Radar Navigation
e word is derived from radio detection and ranging. It works on the basic principle of reection, which
determines the time required for an RF pulse to travel from a reference source to a target and return as
an ec
ho
. Mo
st
su
rface
se
arch
an
d
na
vigation
ra
dar
hi
gh-frequency
el
ectromagnetic
wa
ves
ar
e
fo
rmed
by a pa
rabolic
an
tenna
in
to
a be
am
fo
rm,
as sh
own
in Fi
gure
76.5. e re
ceiving
an
tenna
is ro
tated
to
sc
an
th
e
en
tire
su
rrounding
ar
ea,
an
d
th
e
be
arings
to th
e
ta
rget
ar
e
de
termined
by th
e
or
ientation
of th
e
an
tenna
at th
e
mo
ment
th
e
ec
ho
re
turns
. e st
andard
ra
dar
is ma
de
up of v
e
co
mponents:
tr