Pulse Compression - MATLAB Simulations for Radar Systems Design - page 248

Symbol Description Units Status

nscat number of point scatterers within the

received window

none input

taup uncompressed pulsewidth seconds input

f0 chirp start frequency Hz input

b chirp bandwidth Hz input

scat_range vector of scatterersÓ range m input

rrec range receive window m input

scat_rcs vector of scatterersÓ RCS input

m 2

win 0 = no window

1 = Hamming
2 = Kaiser with parameter pi
3 = Chebychev - sidelobes at -60dB

none input

y compressed output volts output

The user can access this function either by a MATLAB function call or by exe-
cuting the MATLAB program Ðstretch_gui.mÑ which utilizes MATLAB based
GUI and is shown in Fig. 5.10b . The outputs of this function are the complex
array and plots of the uncompressed and compressed echo signal versus
time. As an example, consider the case where

y

nscat 3

taup 10 ms

f0 5.6 GHz

b 1 GHz

rrec 30 m

scat_range [2 5 10] m

scat_rcs

[1, 1, 2] m 2

win 2 (Kaiser)

Note that the compressed pulse range resolution, without using a window, is
. Figs. 5.11 and 5.12 , respectively, show the uncompressed and
compressed echo signals corresponding to this example. Fig. 5.13 is similar to
Figs. 5.11 and 5.12 except in this case two of the scatterers are less than 15 cm
apart (i.e., unresolved targets at

∆ R = 0.15 m

R relative = [ 33.1 , ] m ).