rcs_circ_plate.m
上传用户:szahd2008
上传日期:2020-09-25
资源大小:1275k
文件大小:1k
- function [rcsdb] = rcs_circ_plate (r, freq)
- % This program calculates and plots the backscattered RCS of
- % circular flat plate of radius r.
- eps = 0.000001;
- % Compute aspect angle vector
- % Compute wavelength
- lambda = 3.e+8 / freq; % X-Band
- index = 0;
- for aspect_deg = 0.:.1:180
- index = index +1;
- aspect = (pi /180.) * aspect_deg;
- % Compute RCS using Eq. (2.37)
- if (aspect == 0 | aspect == pi)
- rcs_po(index) = (4.0 * pi^3 * r^4 / lambda^2) + eps;
- rcs_mu(index) = rcs_po(1);
- else
- x = (4. * pi * r / lambda) * sin(aspect);
- val1 = 4. * pi^3 * r^4 / lambda^2;
- val2 = 2. * besselj(1,x) / x;
- rcs_po(index) = val1 * (val2 * cos(aspect))^2 + eps;
- % Compute RCS using Eq. (2.36)
- val1m = lambda * r;
- val2m = 8. * pi * sin(aspect) * (tan(aspect)^2);
- rcs_mu(index) = val1m / val2m + eps;
- end
- end
- % Compute RCS using Eq. (2.35) (theta=0,180)
- rcsdb = 10. * log10(rcs_po);
- rcsdb_mu = 10 * log10(rcs_mu);
- angle = 0:.1:180;
- plot(angle,rcsdb,'k',angle,rcsdb_mu,'k-.')
- grid;
- xlabel ('Aspect angle - degrees');
- ylabel ('RCS - dBsm');
- legend('Using Eq.(13.39)','Using Eq.(13.38)')
- freqGH = num2str(freq*1.e-9);
- title (['Frequency = ',[freqGH],' GHz']);