CSI Instantaneous Linear Spectrum??

[Dmitry]

What dose they mean (in CSI) by saying: Instantaneous Linear Spectrum (ILS)?
I have time realization of a signal and its ILS accrued by CSI spectrum analyzer 2400. In order to understand what I get as ILS, I've computed: APS, Linear APS, PSD and Linear PSD. They differ from ILS drasticaly! So what is ILS?

Listings for APS, Linear APS, PSD and Linear PSD:

MySignalFFT=fft(MySignal);
% Ns – sampling frequency
% N – lengths of time realisation

% APS
plot((0:N/2-1)*Ns/N,
(conj(OutputFFT(1:N/2))/N*2.* MySignalFFT(1:N/2)/N*2));
% Linear APS
plot((0:N/2-1)*Ns/N,
sqrt(conj(OutputFFT(1:N/2))/N*2.* MySignalFFT(1:N/2)/N*2));
% PSD
plot((0:N/2-1)*Ns/N,
(conj(OutputFFT(1:N/2))/N*2.* MySignalFFT(1:N/2)/N*2)/(Ns/N));
% Linear PSD
plot((0:N/2-1)*Ns/N,
sqrt(conj(OutputFFT(1:N/2))/N*2.*MySignalFFT(1:N/2)/N*2)/(Ns/N));


Regards,
D.Semenov