radar signal detection in matlab?

Hello,

 I am doing my master thesis in radar signal detection based on  multiple hypothesis testing problem  on the complex measured vector recorded by the radar during the ToT(time on target) , It is made up by a whitening-matched filter (matched to p ,where p is target steering vector of the form p(n)=exp(j2*pi*f*n)).I have a complex Gaussian noise signal with length (5000*1) ,to find covariance matrix from it.also I have radar_received signal with length (5000*1).But I don't know how to implement this matlab, and how to deal with these signals in matlab.
Thanks

[Walter Roberson]

Previous discussion along the same line: http://www.mathworks.com/matlabcentral/answers/24344-covariance-of-noise

[zayed]

It's difficult to deal with matrix 5000*5000 in matlab.So I need an idea to deal with these signals in matlab.As multiple hypothesis testing which is applied using whitening matched filter.

[Walter Roberson]

It isn't difficult to deal with a 5000*5000 matrix, just a bit slow.

Answer 1

[Walter Roberson]

You need a higher dimensional matrix in order to calculate covariance. Covariance is the generalization of variance to higher dimensions, so if you only have a vector all you can get out is a single scalar, the variance.

Are you sure you want to take a covariance of the vector, rather than some kind of autocorrelation? If you are looking for patterns in the noise, then I don't think covariance is the right tool.

[zayed]

The disturbance (e.g., formed by the superposition of thermal noise and correlated clutter) is modeled as complex Gaussian distributed random vector with zero-mean and correlation matrix M=E(d*Hermitian(d)), where Hermitian is the conjugate-transpose operator. .It's assumed that M is full-rank and a

priori known. In realistic radar scenarios,M must be estimated

from secondary data.

[Walter Roberson]

I only had time to survey a couple of papers, but glancing over those and looking at the kind of topics being discussed in other papers, I get the impression that the kind of noise you are discussing is estimated for radar _images_ not for single radar signals. For faster operation over a high resolution image, the radar image can be divided in to blocks of pixels, the mean of each pixel block taken, and the covariance of the pixel block means examined.

[zayed]

I checked the paper “Performance analysis of two covariance

matrix estimators in compound-Gaussian clutter,”, and I didn't notice any thing a bout radar _images,please explain more details.

[Walter Roberson]

I did not happen to encounter that paper. Unfortunately that paper is too complex for me to understand at the moment. I am not sure whether I will be able to understand it later.