OS.rar_CFAR_OS CFAR radar_cfar clutter_radar_虚警

%%%%%%%%%%相干韦布尔杂波分布%%%%%%%%%% azi_num=1000; fr=1000; %雷达发射信号重频 lamda0=0.05; sigmav=1.0; sigmaf=2*sigmav/lamda0; rand('state',sum(100*clock)); d1=rand(1,azi_num); rand('state',7*sum(100*clock)+3); d2=rand(1,azi_num); xi=1*(sqrt(-2*log(d1)).*cos(2*pi*d2)); coe_num=12; for n=0:coe_num coeff(n+1)=2*sigmaf*sqrt(pi)*exp(-4*sigmaf^2*pi^2*n^2/fr^2)/fr; end for n=1:2*coe_num+1 if n<=coe_num+1 b(n)=1/2*coeff(coe_num+2-n); else b(n)=1/2*coeff(n-coe_num); end end xxi=conv(b,xi); xsigmac=std(xxi); xmuc=mean(xxi); yyi=(xxi-xmuc)/xsigmac; xq=2*(sqrt(-2*log(d1)).*cos(2*pi*d2)); xxq=conv(b,xq); xxi=xxi(coe_num*2+1:azi_num+coe_num*2); xxq=xxq(coe_num*2+1:azi_num+coe_num*2); xisigmac=std(xxi); ximuc=mean(xxi); yyi1=(xxi-ximuc)/xisigmac; xqsigmac=std(xxq); xqmuc=mean(xxq); yyq=(xxq-xqmuc)/xqsigmac; p=1.5; q=2.2; sigmac=sqrt((q.^p)/2); yyi=sigmac*yyi; yyq=sigmac*yyq; xdata_1=(yyi1.*yyi1+yyq.*yyq).^(1/p); %%%%%%%%%%参数设定%%%%%%%%%% fr=1000; %雷达发射信号重频 a=1; fs=4e5; %采样频率 ts=1/fs; RCS=140; k=8.6*10E-5 ; sigma0=10*log10(RCS); %杂波后散射系数 thetaE=2; %天线3db海拔带宽 thetaA=1; %天线3db方位角带宽 SL=-20; %天线旁瓣水平 range_n=200; range_obj1=50; range_obj2=75; range_obj3=100; range=linspace(1,range_n,1000); hr=3; %雷达高度 ht=3; %目标高度 pt=75; %雷达峰值功率 rang_obj1=range_obj1*1000; %目标距离 rang_obj2=range_obj2*1000; rang_obj3=range_obj3*1000; t0=290; %有效噪声温度 l=10; %雷达损耗 ant_id=1; clight=3.e8; %光速 re=6371000; %地球半径 t=1/fr; F=1; B=1e6; %%%%%%%%%%产生杂波回波%%%%%%%%%% lamda=clight/fr; thetaA_deg=thetaA; thetaE_deg=thetaE; thetaA=thetaA_deg*pi/180; thetaE=thetaE_deg*pi/180; rh=sqrt(8.0*hr*re/3.); SLv=10.0^(SL/10); sigma0v=10.0^(sigma0/10); tau=1/B; deltar=clight*tau/2.; range_m=1000.*range; thetar=asin(hr./range_m); thetae=asin((ht-hr)./range_m); propag_atten=1.+((range_m./rh).^4); Rg=range_m.*cos(thetar); deltaRg=deltar.*cos(thetar); theta_sum=thetae+thetar; if(ant_id==0) ant_arg=(2.78*theta_sum)./(pi*thetaE); gain=(sinc(ant_arg)).^2; else gain=exp(-2.776.*(theta_sum./thetaE).^2); end sigmac=(sigma0v.*Rg.*deltaRg).*(pi*SLv*SLv+thetaA.*gain.^2)./propag_atten; sigmac=10*log10(sigmac); %%%%%%%%%%回波幅度计算%%%%%% G=150; A1=sqrt(pt/(4*pi)^3*l)*G^2*lamda*sqrt(RCS)/rang_obj1^2; A2=sqrt(pt/(4*pi)^3*l)*G^2*lamda*sqrt(RCS)/rang_obj2^2; A3=sqrt(pt/(4*pi)^3*l)*G^2*lamda*sqrt(RCS)/rang_obj3^2; %%%%%%%%%%计算目标%%%%%%%%%% s_pc_1=[zeros(1,rang_obj1/range_n),A1,A1,A1,A1,A1,A1,A1,A1,A1,A1,zeros(1,((rang_obj2-rang_obj1)/range_n)-10),A2,A2,A2,A2,A2,A2,A2,A2,A2,A2,zeros(1,((rang_obj3-rang_obj2)/range_n)-10),A3,A3,A3,A3,A3,A3,A3,A3,A3,A3,zeros(1,(1000-rang_obj3/range_n)-10)]; s_pc=xdata_1+s_pc_1+sigmac; Pn=sum(sum((xdata_1).^2)); snr=pt/Pn; % SNR=pt*G^2*lamda^2*RCS/((4*pi)^2*(rang_obj)^4*k*t0*B*F*l); y=log(range_m); c=0.3; logG=c*y+log( s_pc); %figure(1) %plot(s_pc) %grid %figure(2) %plot(logG) %grid N=1000; cfar_os_result=zeros(1,N); cfar_os_result(1,1)=s_pc(1,1)/(sqrt(2)/pi*mean(s_pc(1,2:17))); for i=2:16 noise_mean=sqrt(2)/pi*min(mean(s_pc(1:i-1)),mean(s_pc(1,i+1:i+16))); cfar_os_result(1,i)=s_pc(1,i)/noise_mean; end for i=17:N-16 noise_mean=sqrt(2)/pi*min(mean(s_pc(1,i-16:i-1)),mean(s_pc(1,i+1:i+16))); cfar_os_result(1,i)=s_pc(1,i)/noise_mean; end for i=N-16:N-1 noise_mean=sqrt(2)/pi*min(mean(s_pc(1,i-16:i-1)),mean(s_pc(1,i+1:N))); cfar_os_result(1,i)=s_pc(1,i)/noise_mean; end noise_mean=sqrt(2)/pi*mean(s_pc(1,N-16:N-1)); cfar_os_result(1,N)=s_pc(1,N)/noise_mean; plot(cfar_os_result,'g');grid; xlabel('N'),ylabel('信号幅度'),title('采用OS处理的结果');