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Multistage decomposition algorithm for blind source separation

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Progress in Natural Science:Materials International 2002年第5期 60-64页

作者： FENG Dazheng, bao zheng and zhang xianda(Key laboratory for radar signal processing, xidian university, xi’an 710071, china) Key laboratory for radar signal processing Xidian University Xi'an 710071 China

A new algorithm for blind source separation is proposed, which only extracts the single independent component at each stage. The single independent component is acquired by an iterative algorithm for searching for the optimal solution of the defined cost function. Moreover, all the independent components are obtained by systematic multistage decomposition and multistage reconstruction. When there is spatially colored noise, the performance of this algorithm is advantageous over jointly approximated diagonalization of eigen-matrices (JADE) . Simulated results show that if the number of source signals is more than 25, its computational complexity is lower than that of JADE.

关键词： blind source separation multistage decomposition multistage reconstruction criterion iteration algorithm.

Imaging Study of High Squint SAR Based on FMCW

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Imaging Study of High Squint SAR Based on FMCW

2007 Asian and Pacific Conference on Synthetic Aperture radar(APSAR 2007)

作者： liang Yi Wang Hongxian xing mengdao bao zheng national Key lab. of radar signal processing xidian university xi’an P.R.china

This paper establishes the model of high squint FMCW SAR received signal,analyzes its characteristics,and posts the Doppler frequency shift effect induced by the continuous motion in range direction while radar transmitting and receiving signal. Meanwhile,this paper proposes a Modified RD Algorithm （RDA） aimed at high squint FMCW SAR dechirp-on-receive data,which compensates for range walk in the time domain,Doppler frequency shift and range curve in the frequency domain. Point target simulation verifies the analysis and validity of the proposed algorithm. In addition,for the Doppler frequency shift induced by the continuous motion while radar transmitting and receiving signal,this paper also analyses its effect on image.

关键词： high squint FMCW SAR Doppler frequency shift Modified-RDA

An Effective Method for Ship Imaging of Real Data in Helicopter SAR System

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An Effective Method for Ship Imaging of Real Data in Helicop...

2006 CIE International Conference on radar

作者： li Ya-chao ZHOU Feng bao zheng national Key lab of radar signal processing xidian university xi’an china SHAO Si-fei Ya’an university yan’an china

In view of unsteady flying,the helicopter brings about great errors to moving targets imaging,especially the SAR imaging of moving *** an effective method is proposed in this paper and it is based on an idea that uses motion compensation and general second-step keystone transform twice and at the same time,finds an isolated point and estimates Doppler parameters in virtue of WVD transform which are used to remove range walk and ***’s more,the detailed proving course of this method is given in this *** the end,the SAR imaging of moving ship is acquired in azimuth frequency *** this paper also analyzes the echo signals of moving targets under different *** simulation result of three moving point-targets and the imaging result of real ship data have confirmed this method.

关键词： dechirp general keystone transform WVD an isolated point

A New Approach to Improve Coherence in SAR/GMTI processing of Distributed Microsatellites Systems

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A New Approach to Improve Coherence in SAR/GMTI Processing o...

2006 CIE International Conference on radar

作者： Zhenhua zhang Tong Wang Jinshan Ding zheng bao Key lab for radar signal processing xidian university xi’an P.R.china 710071

In order to improve the capability of clutter cancellation in bistatic SAR/GMTI processing,a new method to improve coherence between two sets of echoes from two receivers is developed based on the distributed microsatellites system with the constellation of *** to the idea of equivalent mono-static,the coherence improvement can be achieved by match filter to the spectra of equivalent squint angle,*** bistatic *** this way,the decorrelation component induced by the along-track baseline is *** of Doppler equals to equivalent radial wave multiplied by equivalent squint angle spectra,this method can be realized in two steps,as the first step the compensation of equivalent radial wave number error is achieved through range spectra cut and shift of the narrow band *** the second step,the Doppler spectra not overlapped should be removed,by which the bistatic bisector can be *** results show the decorrelation components introduced by the along-track baseline can be fully eliminated using this method.

关键词： Bistatic SAR GMTI Coherence

A WEIGHTED FEATURE REDUCTION METHOD FOR POWER SPECTRA OF radar HRRPS

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Journal of Electronics(china) 2006年第3期23卷 365-369页

作者： Du Lan liu Hongwei bao zheng zhang Junying national laboratory of radar signal processing Xidian University Xi＇an 710071 China

Feature reduction is a key process in pattern recognition. This paper deals with the feature reduction methods for a time-shift invariant feature, power spectrum, in radar Automatic Target Recognition (RATR) using High-Resolution Range Profiles (HRRPs). Several existing feature reduction methods in pattern recognition are analyzed, and a weighted feature reduction method based on Fisher's Discriminant Ratio (FDR) is proposed in this paper. According to the characteristics of radar HRRP target recognition, this proposed method searches the optimal weight vector for power spectra of HRRPs by means of an iterative algorithm, and thus reduces feature dimensionality. Compared with the method of using raw power spectra and some existing feature reduction methods, the weighted feature reduction method can not only reduce feature dimensionality, but also improve recognition performance with low computation complexity. In the recognition experiments based on measured data, the proposed method is robust to different test data and achieves good recognition results.

关键词： radar Automatic Target Recognition (RATR) High-Resolution Range Profile (HRRP) Power spectrum Feature reduction Fisher's Discriminant Ratio (FDR)

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Research on indoor experimentation of range SAL imaging system

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Science china(Technological Sciences) 2009年第10期52卷 3098-3104页

作者： GUO liang xing mengdao zhang Long TANG Yu bao zheng State Key laboratory of radar signal processing Xidian UniversityXi’an 710071China xi’an Polytechnic university Xi’an 710048China

By means of advantages of both SAR and lidar, the combination of the techniques of (inverse) synthetic aperture and lidar makes it possible to obtain high resolution 2-D image. In this paper, an indoor experimental system of inverse synthetic aperture lidar imaging is given and a processing approach is presented. The given system is in the mode of lidar system with separated receiver and transmitter, which can effectively eliminate the jamming from the lens or/and the intersection between two optic fibers. Based on the reference channel techniques, a method for the compensation of nonlinear frequency in the time domain is presented, which can solve the problem of nonlinear frequency efficiently. Then, with the mature inverse synthetic aperture algorithm, an image of inverse synthetic aperture lidar can be obtained, which is the first attempt in china. Finally, experimental results confirm the validity of the presented method and the feasibility of the experimental system.

关键词： idar synthetic aperture range profile phase error imaging of rotating objects

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A NOVEL DIRECTION OF ARRIVAL ESTIMATOR

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Journal of Electronics(china) 2004年第2期21卷 97-103页

作者： ShaoChao LuGuangyue baozheng xi＇anInstitutionofPostsandTelecommunications Xi＇an710061 Keylab.forradarsignalprocessing XidianUniversityXi＇an710071

A Direction Of Arrival(DOA) estimator based on the signal separation principle is introduced, and one of representative multidimensional estimators is established by introducing Matrix Operator projection signal steering Vector Excision(MOVE) operation. Thanks to Alternating Separation (AS) technique, the multidimensional problem is transformed into a series of one-dimensional optimal ones. Furthermore, an equivalent simplified implementation of the AS is obtained. Finally the definiteness and uniqueness of the estimator are analyzed.

关键词： Matrix Operator projection signal steering Vector Excision(MOVE) estimator Alternating Separation(AS) algorithm Alternating projection algorithm

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High-speed ground moving target detection research using triangular modulation FMCW

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Frontiers of Electrical and Electronic Engineering in china 2009年第2期4卷 127-133页

作者： Yi liANG Long zhang mengdao xing zheng bao national Key laboratory of radar signal processing Xidian UniversityXi’an 710071China xi’an Polytechnic university Xi’an 710048China

The frequency modulated continuous wave(FMCW)radar has the characteristics of low probability of interception,good hidden property and the ability to counter anti-radiation *** paper proposes a new method for high-speed ground moving target detection(GMTD)using triangular modulation *** to the characteristic of the opposite range shift induced by the upslope and downslope modulation FMCW,the upslope and downslope are imaged,*** compensation of continuous motion of the platform and time difference between upslope and downslope signals for imaging,the moving target can be detected through displaced phase center antenna(DPCA)*** the moving target is detected,the moving target image is extracted,and correlation processing is used to obtain the range shift,which can be used to estimate the target radial velocity,and further to find the real position of the *** effectiveness of this method is verified by the result of computer simulation.

关键词： ground moving target detection(GMTD) triangular modulation frequency modulated continuous wave(FMCW) correlation processing

Parameters Estimation of LFM signals Based on STTFD

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Parameters Estimation of LFM Signals Based on STTFD

2008 9th International Conference on signal processing(ICSP’2008)

作者： Long zhang 1 2 xiao-hui He 2 Ya-chao li 1 Meng-dao xing 1 zheng bao 1 1 the State Key lab for radar signal processing xidian university Shaanxi 710071 P.R.china 2 xi’an Polytechnic university Shaanxi 710048 P.R.china

The accurate estimation of the center frequency and the chirp rate of a linear frequency-modulated（LFM） signal palys an important role in radar signal *** WVD transform can show the characteristic of the center frequency and the chirp rate of a LFM signal,but the cross-terms of signals deteriorates the precision of the estimation of the center frequency and the chirp ***,in order to estimate those parameters of the LFM signals better,this paper proposes a new method based on the scaling transform in time-frequency distribution plane（STTFD） for the parameters estimation of the LFM signals,by which the frequency of each LFM signal in timefrequency plane changes from the linear distribution along the time axis to the constant distribution along the time axis,then the coupling effect between the signal time and the correlation function delay can be removed and the center frequencies and the chirp rates of the LFM signals can be accurately estimated by the peak value locations of accumulated signals realized by the Fourier transform with respect to the time *** the same time,the analysis of the characteristic of STTFD is given in ***,the simulated result shows that the method proposed in this paper can effectively weaken the effect of the cross-terms and accurately estimate the center frequencies and the chirp rates of the LFM signals.

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