Add Radar simulation

2024-01-27 20:58:23 +08:00
parent c2e23b4fbf
commit ec0f95c639
12 changed files with 336 additions and 0 deletions
@@ -0,0 +1,51 @@
+function doppler = get_doppler(s_T, s_R)
+    global T_r delta_t len f_s c f_c velocity max_t slow_len;
+    
+    freqs = ((0:len-1) * f_s) / len;
+
+    slow_freqs = ((0:slow_len-1) * (1 / T_r)) / slow_len;
+    range_t_slow = 1:slow_len;
+
+    num_slow = max_t / T_r;
+    s_R_slow = zeros(1, slow_len);
+    k = floor(T_r / delta_t);
+
+    init_idx = 1;
+    while abs(s_R(init_idx)) == 0
+        init_idx = init_idx + 1;
+    end
+    init_idx
+
+    for i = 0: num_slow - 1
+        while abs(s_R(init_idx + i * k)) == 0
+            init_idx = init_idx + 1;
+        end
+        s_R_slow(i + 1) = s_R(init_idx + i * k);
+    end
+
+    s_R_fft = fft(s_R_slow);
+    [~, max_index_s_R] = max(s_R_fft);
+    freq_s_R = slow_freqs(max_index_s_R);
+
+    figure(2);
+    subplot(2,1,1);
+    plot(range_t_slow, abs(s_R_slow));
+    title(sprintf('s_R'));
+    subplot(2,1,2);
+    plot(slow_freqs, abs(s_R_fft));
+    title(sprintf('s_R_fft, freq = %E', freq_s_R));
+    xlabel('频率 (Hz)');
+
+    f_d = 1/T_r - freq_s_R;
+
+    fprintf("s_R_freq = %d\n", max_index_s_R);
+    fprintf("doppler_freq = %E\n\n", f_d);
+
+    fprintf("%E\n", 2 * f_c * velocity / c);
+
+    doppler_v = (c * f_d) / (2 * f_c);
+    
+    fprintf("doppler_v: %E\nvelocity: %E\n", doppler_v, velocity);
+
+    doppler = doppler_v;
+end