About real time data processing in FMCW RADAR.

Question

AtoZ 2020-2-18

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/506172-about-real-time-data-processing-in-fmcw-radar

回答： Honglei Chen 2020-2-18

clear all;
clear all;
%read the raw data .wav file here
[Y,FS,NBITS]=wavread('Ranging_Radar_Exp');
%constants
c = 3E8; % (m/s) speed of light
%radar parameters
Tp = 20E-3; % (s) pulse time
N = Tp*FS; % # of samples per pulse
fstart = 2405E6; % (Hz) LFM start frequency
fstop = 2495E6; % (Hz) LFM stop frequency
BW = fstop-fstart; % (Hz) transmit bandwidth
f = linspace(fstart, fstop, N/2); %instantaneous transmit frequency
%range resolution
rr = c/(2*BW);
max_range = rr*N/2;
%the input appears to be inverted
trig = -1*Y(:,1);
s = -1*Y(:,2);
clear Y;
%parse the data here by triggering off rising edge of sync pulse
count = 0;
thresh = 0;
start = (trig > thresh);
for ii = 100:(size(start,1)-N)
    if start(ii) == 1 & mean(start(ii-11:ii-1)) == 0
%           start2(ii) =1;
        count = count + 1;
        sif(count,:) = s(ii:ii+N-1);
        time(count) = ii*1/FS;
    end
end
%subtract the average
ave = mean(sif,1);
for ii =1:size(sif,1);
    sif(ii,:) = sif(ii,:)-ave;
end
zpad = 8*N/2;
%2 pulse cancelor RTI plot
figure (20);
sif2 = sif(2:size(sif,1),:)-sif(1:size(sif,1)-1:);
v = ifft(sif2,zpad,2);
S=v;
R = linspace(0,max_range,zpad);
for ii = 1:size(S,1)
    %S(ii,1) = S(ii,:).*R.^(3/2); %Optional: magnitude scale to range
end
S = dbv(S(:,1:size(v,2)/2));
m = max(max(S));
imagesc(R,time,S-m,[-80, 0]);
colorbar;
ylabel('time (s)');
xlabel('range (m)');
title('RTI with 2-pulse cancelor clutter rejection');