simuclutter.m

高频地波雷达的双排线形接受天线阵的海杂波模拟

% function x=SimuClutter(WhichRange,FreqPoint)

%得到模拟的海杂波
clear;

WhichRange=17;
FreqPoint=91;
SweptNum=256;
RadarFreq=7.988; 
WaveLength=300/RadarFreq; 
BraggFreq=0.102*sqrt(RadarFreq); 
CurrentVel=0.5; 
SweptPeriod=0.6528; 
FreqRes=1/SweptNum*SweptPeriod; 
WindDirection=0*pi/180; 
Sector=[-30*pi/180:pi/180:30*pi/180];
SectorNum=length(Sector);

rap=zeros(1,SectorNum);
ran=zeros(1,SectorNum);
t=[0:SweptPeriod:(SweptNum-1)*SweptPeriod]; 
x=zeros(8,SweptNum);

for m=1:SectorNum
    eta=cos((Sector(m)-WindDirection)/2)^4+0.01;
    for i=1:10
        rap(1,m)=rap(1,m)+normrnd(0,eta)+j*normrnd(0,eta);
        ran(1,m)=ran(1,m)+normrnd(0,eta)+j*normrnd(0,eta);
    end
    rap(1,m)=rap(1,m)/10;
    ran(1,m)=ran(1,m)/10;
end 
 
Linex=[0.0,13.3,26.6,39.9,0.0,13.3,26.6,39.9];
Liney=[0.0,0.0,0.0,0.0,-8.0,-8.0,-8.0,-8.0];

for n=1:8
for m=1:SectorNum
    ap=rap(m);
    an=ran(m);
    phi=-2*(pi/WaveLength)*(Linex(n)*sin(Sector(m))+Liney(n)*cos(Sector(m))); 
    vi=CurrentVel*sin(Sector(m));
    FreqShift=2*vi/WaveLength;
    delta=ap*exp(j*2*pi*(BraggFreq+FreqShift)*t)+an*exp(j*2*pi*(-BraggFreq+FreqShift)*t);
    noise=randn(1,SweptNum)+j*randn(1,SweptNum); 
    x(n,:)=exp(j*phi)*delta+x(n,:)+noise; 
end


doat=20*pi/180;
fait=-2*(pi/WaveLength)*(Linex(n)*sin(doat)+Liney(n)*cos(doat));

ft=(30.4/26)*BraggFreq; 
  
% % % % noise=gain*((randn(1,SweptNum)+j*randn(1,SweptNum)));  
xx=10*exp(j*(2*pi*ft*t+fait));
x(n,:)=xx+x(n,:);

bbbb=fftshift(fft(x(1,:)));
figure;
plot(abs(bbbb));  
grid on;