
69-1
69.1 Introduction
September 11 has changed the way people think about the airport, aviation, and security in gen-
eral. The threat is expanding interest in more reliable systems to detect presence of people within
th
e
pr
otected
pe
rimeters
. Al
l
se
nsors
th
at
re
spond
to a hu
man
bo
dy
ar
e
di
vided
on th
e
oc
cupancy
an
d
mo
tion
de
tectors
. Th
e
oc
cupancy
de
tectors
de
tect
th
e
pr
esence
of pe
ople
(a
nd
so
metimes
an
i-
mals)
in a mo
nitored
ar
ea
. Th
e
mo
tion detectors
re
spond
on
ly
to mo
ving
ob
jects
. A di
stinction
be
tween
th
e
tw
o
is th
at
th
e
oc
cupancy
de
tectors
pr
oduce
si
gnals
wh
enever
an ob
ject
is st
ationary
or no
t,
wh
ile
th
e
mo
tion
de
tectors
ar
e
se
lective