Radar Detection - MATLAB Simulations for Radar Systems Design - page 113

1.1. For the ÐMyRadarÑ design case study, use , , and
. Alternatively use and
for the missile case. Note that the selected SNR
values are best estimates or educated guesses, and it may require going
through few iterations before finally selecting an acceptable set.

n P = 1 R 0 = 90 Km

( SNR 0 ) aircraft = 8.5 dB R 0 = 55 Km

( SNR ) missile = 9 dB

The program will then calculate the number of frames and their associated
ranges. The program uses the function Ðfluct_loss.mÑ to calculate the
Swerling V at each frame and the additional SNR required to accom-
plish the same probability of detection when target fluctuation is included.

2.

P D

Depending on the fluctuation type, the program will then use the proper
MATLAB function to calculate the probability of detection for each frame,
.

3.

P D i

3.1. For the ÐMyRadarÑ design case study, these functions are
Ðpd_swerling1.mÑ and Ðpd_swerling 3.mÑ .

Finally, the program uses Eq. (2.99) to compute the cumulative probability
of detection,

4.

P D n .

A Graphical User Interface (GUI) has been developed for this program; Fig.
2.20 shows its associated GUI workspace. To use this GUI, from the MATLAB
command window type Ðmyradar_visit2_2_guiÑ . Executing the program
Ð myradar_visit2_2.mÑ using the input values stated above yields the following
cumulative probabilities of detection for the aircraft and missile cases,

P DC Missile = 0.99872

P DC aircraft = 0.99687

These results clearly satisfy the design requirement of . However,
one must re-validate the peak power requirement for the design. To do that, go
back to Eq.s (1.107) and (1.108), and replace the SNR values used in Chapter 1
by the values adopted in this chapter (i.e., and
). It follows that the corresponding single pulse energy
for the missile and the aircraft cases are respectively given by

P D ≥ 0.995

( SNR 0 ) aircraft = 8.5 dB

( SNR ) missile = 9 dB

10 0.9
10 0.56

-------------

E m = 0.1658 × = 0.36273 Joules

(2.113)

10 0.85
10 0.56

-------------

E a = 0.1487 × = 0.28994 Joules

(2.114)