Surface and Volume Clutter - MATLAB Simulations for Radar Systems Design - page 273

Symbol Description Units Status

sigma0 clutter back scatterer coefficient dB input

thetaE antenna 3dB elevation beamwidth degrees input

thetaA antenna 3dB azimuth beamwidth degrees input

SL antenna sidelobe level dB input

range range; can be a vector or a single value Km input

hr radar height meters input

ht target height meters input

pt radar peak power KW input

f0 radar operating frequency Hz input

b bandwidth Hz input

t0 effective noise temperature Kelvins input

f noise figure dB input

l radar losses dB input

ant_id 1 for (sin(x)/x)^2 pattern

2 for Gaussian pattern

none input

sigmac clutter RCS; can be either vector or sin-

gle value depending on ÐrangeÑ

dB output

CNR clutter to noise ratio; can be either vec-

tor or single value depending on
ÐrangeÑ

dB output

A GUI called Ðclutter_rcs_guiÑ was developed for this function. Executing
this GUI generates plots of the and versus range. Figure 6.8 shows
typical plots produced by this GUI using the antenna pattern defined in Eq.
(6.18). Figure 6.9 is similar to Fig. 6.8 except in this case Eq. (6.19) is used for
the antenna pattern. Note that the dip in the clutter RCS (at very close range)
occurs at the grazing angle corresponding to the null between the main beam
and the first sidelobe. Fig. 6.9c shows the GUI workspace associated with this
function.

σ c CNR

In order to reproduce those two figures use the following MATLAB calls:

[sigmaC,CNR] = clutter_rcs(-20, 2, 1, -20, linspace(2,50,100), 3, 100, 75,
5.6e9, 1e6, 290, 6, 10, 1)

(6.27)

[sigmaC,CNR] = clutter_rcs(-20, 2, 1, -25, linspace(2,50,100), 3, 100, 100,
5.6e9, 1e6, 290, 6, 10, 2)

(6.28)