Graphics Programs Reference
In-Depth Information
C i
=
P c
(7.40)
The clutter power at the output of an MTI is
W () H () 2
C o
=
d
f
(7.41)
–
7.7.1. Two-Pulse MTI Case
In this section we will continue the analysis using a single delay line can-
celer . The frequency response for a single delay line canceler is given by Eq.
(7.6). The single canceler power gain is given in Eq. (7.10), which will be
repeated here, in terms of rather than
f
ω
, as Eq. (7.42),
π f
f r
2
H () 2

---- 
=
4
sin
(7.42)
It follows that
f 2
t 2
P c
2πσ t
2
π f
f r
---- 
C o
=
-------------------
exp
–
---------
4
sin
d
(7.43)
–
Now, since clutter power will only be significant for small , then the ratio
is very small (i.e., ). Consequently, by using the small angle
approximation, Eq. (7.43) is approximated by
f
f
f r
σ t
«
f r
f 2
t 2
P c
2πσ t
 2
π f
f r
-------------------
---------
---- 
C o
exp
–
4
d
(7.44)
–
which can be rewritten as
4 P c π 2
f 2
f 2
t 2
1
f 2
C o
=
---------------
-----------------
exp
–
---------
d
(7.45)
2
2πσ t
–
The integral part in Eq. (7.45) is the second moment of a zero mean Gaussian
distribution with variance
σ t 2
σ t 2
. Replacing the integral in Eq. (7.45) by
yields
4 P c π 2
f 2
2
--------------- σ t
C o
=
(7.46)
Substituting Eqs. (7.46) and (7.40) into Eq. (7.30) produces
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