Matlab实现旋转体目标的微动特性仿真

clear; close all; clc; f = 10e9; c = 3e8; %in body fixed system P1 = [0, 0, 0]; %first point scatterer P2 = [0.3, 0, 0.6]; P3 = [-0.3, 0, 0.6]; P0 = [0, 0, 0]; Pax = [0, 0, 1]; model = [P1; P2; P3; P0; Pax]; N_sctr = size(model, 1); T = 2.048; dt = 0.001; t = 0:dt:T-dt; nt = length(t); %the origion of the object X0 = 1000; Y0 = 5000; Z0 = 5000; n_radial = [X0;Y0;Z0]/norm([X0, Y0, Z0]); phi = 30*pi/180; theta = 30*pi/180; psi = 20*pi/180; Rz = [cos(phi) sin(phi) 0; -sin(phi) cos(phi) 0; 0 0 1]; Ry = [cos(theta) 0 -sin(theta); 0 1 0; sin(theta) 0 cos(theta)]; Rx = [1 0 0; 0 cos(psi) sin(psi); 0 -sin(psi) cos(psi)]; Rinit = Rx*Ry*Rz; model_ini = model*Rinit; figure(1); plot3(model(1,1), model(1,2), model(1,3),'bo') hold on plot3(model_ini(1,1), model_ini(1,2), model_ini(1,3),'bo') plot3(model_ini(2,1), model_ini(2,2), model_ini(2,3),'go') plot3(model_ini(3,1), model_ini(3,2), model_ini(3,3),'ro') line([model_ini(2,1) model_ini(3,1)],[model_ini(2,2) model_ini(3,2)],... [model_ini(2,3) model_ini(3,3)],... 'color','k','linewidth',2.0,'lineStyle','-') line([model_ini(2,1)/2+model_ini(3,1)/2 model_ini(1,1)],... [model_ini(2,2)/2+model_ini(3,2)/2 model_ini(1,2)],... [model_ini(2,3)/2+model_ini(3,3)/2 model_ini(1,2)],... 'color','k','linewidth',1.5,'linestyle','--') axis image view(-10, 20) axis([-0.8 0.8, -0.8 0.8, -0.4 0.8]) xlabel('x') ylabel('y') zlabel('z') title('Trajectory of Three Spining Sctterers') grid drawnow ux = model_ini(5,1); uy = model_ini(5,2); uz = model_ini(5,3); fs = 8/T; ws_x = 2*pi*fs*ux; ws_y = 2*pi*fs*uy; ws_z = 2*pi*fs*uz; ws = [ws_x; ws_y; ws_z]; Omiga_s = sqrt(ws_x*ws_x+ws_y*ws_y+ws_z*ws_z); ws_unit = ws/Omiga_s; Ws = [0 -ws_unit(3) ws_unit(2);... ws_unit(3) 0 -ws_unit(1);... -ws_unit(2) ws_unit(1) 0 ]; model_new = model_ini; for i=1:100 Rs = eye(3)+Ws*sin(Omiga_s*t(i))+Ws*Ws*(1-cos(Omiga_s*t(i)));%Rodrigues formula model_new = model_new*Rs; figure(1) plot3(model_new(1,1),model_new(1,2),model_new(1,3),'bo') plot3(model_new(2,1),model_new(2,2),model_new(2,3),'go') plot3(model_new(3,1),model_new(3,2),model_new(3,3),'ro') drawnow end grid on for i=1:nt Rs = eye(3)+Ws*sin(Omiga_s*t(i))+Ws*Ws*(1-cos(Omiga_s*t(i))); dRs = Omiga_s*(Ws*(Ws*sin(Omiga_s*t(i))+cos(Omiga_s*t(i)))); for j=1:size(model(1:3,:),1) MicroDoppler(j,i) = 2*(f/c)*(model_ini(j,:)*dRs)*n_radial; end end figure(2) plot(t, MicroDoppler(1,:),'b.'); hold on plot(t, MicroDoppler(2,:),'g.'); plot(t, MicroDoppler(3,:),'r.'); title('Micro-Doppler Signature of a Spining Target'); xlabel('Time (sec)'); ylabel('Doppler Frequency (Hz)'); axis([0 T -800 800]) drawnow