I am working on radar received signal which is $15000\times 2008$ matrix. Here each row corresponds to one chirp or one signal, this way there are 15000 signals. The difference among them is just the time difference and doppler shift.
If I take the PSD of ten signals, i.e ten signals combined in one row
[C(1,:) C(2,:)...C(10,:)] then take the
psd, the plot is similar the only difference is that the gain increasing, I assume it is the processing gain, also as I increase the number of signals and take the
psd the gain increases even more
I want to know what is the reason of the gain in the plots as the lenth of the signal is increasing, the
fft length is not altered. I Would like to know any mathematics proving this.
fs=1e6; load('Bathymetry_1s_5cm.mat'); C=Chirp; x=[C(1,:) C(2,:) C(3,:) C(4,:) C(5,:) C(6,:) C(7,:) C(8,:) C(9,:) C(10,:)]; Pxx = periodogram(x); hpsd = dspdata.psd(Pxx,'Fs',Fs); % Create a psd data object. plot(hpsd);