A Research Of Distributed Collaborative Probing Technology And Experiment

Distributed radar has the advantage of space diversity gain and detection performance over the monostatic radar because of its multi-angle and multi-path probing mode,which means that the same detection range requires less transmission power,with low intercept characteristics,or the same transmission power with a larger detection range.Multi-angle probing can obtain high scattering coefficient echo with higher probability,which means better anti-stealth performance.Therefore,distributed radar has attracted much attention.This thesis mainly studies the following four aspects of distributed cooperative probing technology and experiment:1.The problem of distributed radar Doppler frequency estimation is investigated and a velocity estimation method based on maximum likelihood estimation is proposed.Firstly,the objective function of the maximum likelihood estimation of velocity is obtained according to the signal model with range immigration correction.Then the optimization problem is transformed into the form of weight and input.Next,the center frequency of the filter is changed by interpolation filtering to obtain the doppler frequency estimation and the velocity estimation of the target.2.The research on spatial angle estimation problem.Firstly,the maximum likelihood estimation of angle estimation is given,then the CRLB of angle estimation is derived,and the angle estimation ambiguity problem of subarray level data is analyzed.A multi-carrier ESPRIT algorithm based on the singular value decomposition(SVD)is proposed.Specifically,the idea of multiple spatial sampling frequency is applied to tackle the angle ambiguity problem.Furthermore,the angle estimation accuracy is improved by the multiple estimates obtained from the singular value decomposition of the auto-correlation and cross-correlation matrices.Next,a subspace cancelation method is presented.Firstly,the interference+target eigenvector is obtained through the spectrum decomposition of the covariance matrix of the test data,and the interference eigenvector is obtained through the spectrum decomposition of the covariance matrix of the secondary data.Then the correlation coefficient of the eigenvector is utilized to distinguish and eliminate the interference.Finally,the target subspace and the angle estimation can be obtained.3.The problem of distributed radar data association and location is investigated,and a distributed radar data association and location method based on point clustering is presented.The coordinate of each point in a coordinate system is obtained through point location,then the points are converted to the same coordinate system through coordinate transformation,finally,the point set of each target is obtained by point clustering and the location coordinate of each target is obtained.4.The measured data processing of distributed radar is investigated,and a short time multi-frame joint processing is given,and the processing results of measured multipath echo are also presented.The echo data under transmitting deceptive jamming is processed,and a deceptive jamming discrimination algorithm based on the correction of scattering coefficients within and between paths is introduced.The distribution of correlation coefficients indicates that the algorithm can distinguish deceptive jamming efficiently.