Radar Waveforms - MATLAB Simulations for Radar Systems Design - page 175

ÐMyRadarÑ Design Case Study - Visit 3 177

the matched filter in Eq. (3.116) is identical to that given in Eq. (3.145). This
means that the output of the matched filter exhibits maximum instantaneous
SNR as well as the most achievable range and Doppler resolutions.

3.11. ÐMyRadarÑ Design Case Study - Visit 3

3.11.1. Problem Statement

Assuming a matched filter receiver, select a set of waveforms that can meet
the design requirements as stated in the previous two chapters. Assume linear
frequency modulation. Do not use more than a total of 5 waveforms. Modify the
design so that the range resolution

during the search mode, and ∆ R = 30 m

during tracking. ∆ R = 7.5 m

3.11.2. A Design

The major characteristics of radar waveforms include the waveformÓs
energy, range resolution, and Doppler (or velocity) resolution. The pulse
(waveform) energy is

E t τ = (3.146)

where is the peak transmitted power and is the pulsewidth. Range resolu-
tion is defined in Eq. (3.131), while the velocity resolution is in Eq. (3.140).

P t τ

Close attention should be paid to the selection process of the pulsewidth. In
this design we will assume that the pulse energy is the same as that computed
in Chapter 2 . The radar operating bandwidth during search and track are calcu-
lated from Eq. (3.131) as

3 0 8

B search
B track

× ⁄ ( 2 0 × ) = 5 MHz

   

=

   

(3.147)

3 0 8

   

× ⁄ ( 2 .5 × ) = 20 MHz

Since the design calls for a pulsed radar, then for each pulse transmitted (one
PRI) the radar should not be allowed to receive any signal until that pulse has
been completely transmitted. This limits the radar to a minimum operating
range defined by

c τ
2

R min = -----

(3.148)

In this design choose . It follows that the minimum acceptable R min ≥ 15 Km

pulsewidth is .

τ max ≤ 100µ s