《合成孔径雷达成像算法与实现》Figure5.13

clc
clear
close all

距离向参数
R_eta_c_1 = 450;    % 景中心斜距
R_eta_c_2 = 850;    % 景中心斜距
R_eta_c_3 = 1250;   % 景中心斜距

方位向参数
c = 3e8;
f0 = 5.3e6;
Vr = 7100;
Ta = 0.64;      % 目标照射时间
Ka = 2095;      % 方位向调频率
theta_r_c = 0;  % 斜视角

参数计算
lambda = c/f0;
R0_1 = R_eta_c_1*cosd(theta_r_c);       % 最短斜距
R0_2 = R_eta_c_2*cosd(theta_r_c);       % 最短斜距
R0_3 = R_eta_c_3*cosd(theta_r_c);       % 最短斜距
Delta_f_dop = abs(Ka*Ta);               % 多普勒带宽

参数设置
alpha_os = 1;
Fa = alpha_os*Delta_f_dop;      % PRF
Na = 2*ceil(Fa*Ta/2);           % 方位向采样点数
dt = Ta/Na;                     % 采样时间间隔
df = Fa/Na;                     % 采样频率间隔

变量设置
eta = -Ta/8:dt:Ta/8-dt;
f_eta = -Fa/8:df:Fa/8;

信号表达
R_eta_1 = R0_1+Vr^2*eta.^2/(2*R0_1);                % 公式5.1
R_eta_2 = R0_2+Vr^2*eta.^2/(2*R0_2);
R_eta_3 = R0_3+Vr^2*eta.^2/(2*R0_3);
R_rd_1 = R0_1+lambda^2*R0_1*f_eta.^2/(8*Vr^2);      % 公式5.10
R_rd_2 = R0_2+lambda^2*R0_2*f_eta.^2/(8*Vr^2);
R_rd_3 = R0_3+lambda^2*R0_3*f_eta.^2/(8*Vr^2);

绘图
figure
plot(R_eta_1,eta),hold on
plot(R_eta_2,eta),hold on
plot(R_eta_3,eta),set(gca,'ydir','reverse')
figure
plot(R_rd_1,f_eta),hold on
plot(R_rd_2,f_eta),hold on
plot(R_rd_3,f_eta),set(gca,'ydir','reverse')