DOA_compare_amplitude.rar_amplitude_方位估计比幅_比幅 DOA_比幅法测向_比幅测向

%方位估计实验 比幅法 clear all; close all; %导入数据 load('data_831.mat'); x0(1,:) = Data1_AI_0___U'; x0(2,:) = Data1_AI_1___U'; x0(3,:) = Data1_AI_2___U'; x0(4,:) = Data1_AI_3___U'; x0(5,:) = Data1_AI_4___U'; x0(6,:) = Data1_AI_5___U'; x0(7,:) = Data1_AI_6___U'; x0(8,:) = Data1_AI_7___U'; x0(9,:) = Data1_AI_8___U'; x0(10,:) = Data1_AI_9___U'; x0(11,:) = Data1_AI_10___U'; x0(12,:) = Data1_AI_11___U'; %圆弧基阵信息 N = 12; R = 0.24; BETA = 30*pi/180; %上述基阵尺寸近似满足lambda=d/2 %声信号信息 F = 5700; %5.7khz信号 FS = 200000; %200kHz采样 T = 100/F; %100个CYCLE T0 = 1; %1s周期 NS = T*FS; %脉宽内的采样点 C = 1450; %声速 THETA_D = 30; %多波束的波束指向角增量,必须是360的约数 THETA_T = (0:THETA_D:360)*pi/180; %假定信号来得方向 x = [zeros(N,300) x0(:,146000:147000) zeros(N,300)]; M = length(x(1,:)); figure(1); for i=1:N subplot(3,4,i) plot(x(i,:)); axis([0 M-1 -5 5]) title(strcat(num2str(i),'号阵元')); end for t = 1:length(THETA_T)-1 %形成各个波束，波束号 %在假定入射方向THETA_T(t)时，各阵元补时延差，使其同相叠加，提前为正 for i = 0:N-1 %阵元号 delay_T(i+1) = FS*R*cos(THETA_T(t)-i*BETA)/C; %相对相位中心的延迟为-，提前为+ x_d(i+1,:) = interp1(0:M-1,x(i+1,:),(0:M-1)-delay_T(i+1),'cubic');%提前量推迟回去 end w = [1 1 1 1 0 0 0 0 0 1 1 1]; %0°指向角时的加权向量 %调用循环移位子函数 w = CRS(w,t-1); x_d= diag(w)*x_d; y = sum(x_d); D(t) = sum(abs(y)); %在假定入射方向THETA_T(t)时，该波束输出幅度响应 end [Dmax1 Dmax2 t1 t2] = max2(D,1:length(THETA_T)-1); figure(2) stem(1:length(THETA_T)-1,D,'*'); title('波束输出幅度响应'); xlabel('波束号t'); ylabel('各波束幅度响应'); xyz = THETA_T(t1)*180/pi; theta_d = (-30:0.1:30)*pi/180; for j=1:length(theta_d) theta1 = THETA_T(t1)+theta_d(j); theta2 = THETA_T(t2)+theta_d(j); for i = 0:N-1 %阵元号 delay_T(i+1) = FS*R*cos(theta1-i*BETA)/C; %相对相位中心的延迟为-，提前为+ x_d(i+1,:) = interp1(0:M-1,x(i+1,:),(0:M-1)-delay_T(i+1),'cubic');%提前量推迟回去 end w = [1 1 1 1 1 1 1 1 1 1 1 1]; %0°指向角时的加权向量 %调用循环移位子函数 w = CRS(w,t1-1); x_d= diag(w)*x_d; y = sum(x_d); D1(j) = sum(abs(y)); %在假定入射方向THETA_T(t)时，该波束输出幅度响应 for i = 0:N-1 %阵元号 delay_T(i+1) = FS*R*cos(theta2-i*BETA)/C; %相对相位中心的延迟为-，提前为+ x_d(i+1,:) = interp1(0:M-1,x(i+1,:),(0:M-1)-delay_T(i+1),'cubic');%提前量推迟回去 end w = [1 1 1 1 1 1 1 1 1 1 1 1]; %0°指向角时的加权向量 %调用循环移位子函数 w = CRS(w,t2-1); x_d= diag(w)*x_d; y = sum(x_d); D2(j) = sum(abs(y)); %在假定入射方向THETA_T(t)时，该波束输出幅度响应 deta_D(j) = D1(j)-D2(j); end figure(3) plot(theta_d*180/pi,D1,'r',theta_d*180/pi,D2,'b'); xlabel('波束指向角转动量'),ylabel('两波束输出信号幅度') hold on; grid on; figure(4) plot((THETA_T(t1)+THETA_T(t2))/2+theta_d*180/pi,deta_D); xlabel('波束指向角转动量'),ylabel('两波束输出信号幅度差值'),axis([-30 30 -10000 10000]) grid on; for i = 1:length(theta_d) if(deta_D(i)==min(abs(deta_D))) break; end end THETA_T = (THETA_T(t1)+THETA_T(t2))/2+theta_d(i); theta_dircetion = THETA_T*180/pi