soj_req.m
上传用户:szahd2008
上传日期:2020-09-25
资源大小:1275k
文件大小:1k
- function [BR_range] = soj_req (pt, g, sigma, b, freq, loss, range, ...
- pj, bj,gj, lossj, gprime, rangej)
- % This function implements equations for SOJs
- c = 3.0e+8;
- lambda = c / freq;
- lambda_db = 10*log10(lambda^2);
- if (loss == 0.0)
- loss = 0.000001;
- end
- if (lossj == 0.0)
- lossj =0.000001;
- end
- sigmadb = 10*log10(sigma);
- range_db = 10*log10(range * 1000.);
- rangej_db = 10*log10(rangej * 1000.);
- pt_db = 10*log10(pt);
- b_db = 10*log10(b);
- bj_db = 10*log10(bj);
- pj_db = 10*log10(pj);
- factor = 10*log10(4.0 *pi);
- BR_range = ((pt * 10^(2.0*g/10) * sigma * bj * 10^(lossj/10) * ...
- (rangej)^2) / (4.0 * pi * pj * 10^(gj/10) * 10^(gprime/10) * ...
- b * 10^(loss/10)))^.25 / 1000.
- s_at_br = pt_db + 2.0 * g + lambda_db + sigmadb - ...
- 3.0 * factor - 4.0 * 10*log10(BR_range) - loss
- index =0;
- for ran_var = .1:1:1000;
- index = index + 1;
- ran_db = 10*log10(ran_var * 1000.0);
- s(index) = pt_db + 2.0 * g + lambda_db + sigmadb - ...
- 3.0 * factor - 4.0 * ran_db - loss + s_at_br;
- soj(index) = s_at_br - s_at_br;
- end
- ranvar = .1:1:1000;
- %ranvar = ranvar ./BR_range;
- semilogx (ranvar,s,'k',ranvar,soj,'k-.','linewidth',1.5);
- xlabel ('Range normalized to cross-over range');
- legend('Target echo','SOJ')
- ylabel ('Relative signal or jamming amplitude - dB');
-