Graphics Programs Reference
In-Depth Information
7.8.2. A Design
In earlier chapters we determined that the wavelength is
λ
=
0.1
m
, the PRF
is
f
r
=
1
KHz
, the scan rate is
T
scan
=
2
s
, and the antenna azimuth 3-db
beamwidth is
Θ
a
=
1.3°
. It follows that
2σ
w
λ
2 . 5
×
0.1
σ
v
=
----------
=
-------------------
=
9
Hz
(7.59)
2π
Θ
a
T
scan
2
×
π
σ
s
=
0.265
-------------------
=
0.265
×
-----------------------------------
=
36.136
Hz
(7.60)
π
180
---------
1.32
×
×
2
Thus, the total clutter rms spectrum spread is
σ
2
σ
2
σ
t
=
+
=
81
+
1305.810
=
1386.810
=
37.24
Hz
(7.61)
The expected clutter attenuation using a 2-pulse and a 3-pulse MTI are
respectively given by
f
r
2πσ
t
2
2
1000
36.531
W
------------
--------------------------------
-----
I
2
pulse
=
2
=
2
×
=
⇒
15.63
dB
(7.62)
2
×
π
×
37.24
f
r
2πσ
t
4
4
1000
667.247
W
------------
--------------------------------
-----
I
3
pulse
=
2
=
2
×
=
⇒
28.24
dB
(7.63)
2
×
π 37.24
×
To demonstrate the effect of a 2-pulse and 3-pulse MTI on
ÐMyRadarÑ
design case study, the MATLAB program
Ðmyradar_visit7.mÑ
has been devel-
oped. It is given in Listing 7.6 in Section 7.5. This program utilizes the radar
equation with pulse compression. In this case, the peak power was established
in
Chapter 5
as .
Figs. 7.12
and
7.13
show the desired SNR and the
calculated SIR using a 2-pulse and a 3-pulse MTI filter respectively, for the
missile case.
Figs. 7.14
and
7.15
show similar output for the aircraft case.
P
t
≤
10
KW
One may argue, depending on the tracking scheme adopted by the radar, that
for a tracking radar
σ
t
==
σ
v
9
Hz
(7.64)
since for a radar that employes a monopulse tracking option. In this
design, we will assume a Kalman filter tracker. For more details the reader is
advised to visit
Chapter 9.
σ
s
=
0
Search WWH ::
Custom Search