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Science china(Information Sciences) 2010年第8期53卷 1628-1640页

作者： zhang lei , li yachao, liu yan, xing mengdao & bao zheng national lab for radar signal processing, xidian university, xi’an 710071, china 1. national lab for radar signal processing Xidian University Xi’an 710071 China

This paper focuses on the motion parameters estimation and inversed synthetic aperture radar (ISAR) imaging for the high-speed spinning targets via the time-frequency characteristics. Assuming that the translational motion is compensated with the available motion compensation techniques, then the residual part of translational motion and the spinning motion are estimated with high precision based on the timefrequency characteristics. Combining with the procedure of the motion estimation, a novel coherent timefrequency spectrum intensity redistribution method, coherent single range Doppler interferometry (CSRDI), is proposed, which provides higher resolution and sustain lower signal to noise rate (SNR) than the current approach. Numerical simulation confirms the validity and high precision of the proposed approaches.

关键词： ISAR time-frequency characteristics CSRDI motion estimation high speed spinning targets

Generating dense and super-resolution ISAR image by combining bandwidth extrapolation and compressive sensing

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Science china(Information Sciences) 2011年第10期54卷 2158-2169页

作者： QUAN YingHui ,zhang lei,GUO Rui,xing mengdao & bao zheng national Key lab for radar signal processing,xidian university,xi’an 710071,china 1. national Key lab for radar signal processing Xidian University Xi’an 710071 China

Recent developing compressive sensing (CS) theory indicates that it is possible to obtain precise recovery of a sparse signal from very limited measurements,which provides a new way for data acquisition and signal processing as nature signals usually involve some degree of *** this paper,we present an algorithm for inversed synthetic aperture radar (ISAR) imaging with super resolution by combining CS and bandwidth extrapolation (BWE) *** ISAR imaging,the backscattering field of target is usually contributed by a few strong scattering centers,whose number is much less than that of image ***,CS is intuitively suitable for constructing super resolution ISAR *** to CS theory,the number of extracted dominating scatterers relies on the signal length,which indicates that if only limited data is available,it is difficult to generate dense ISAR image robustly by CS,and some signal components tend to *** soften this constraint,BWE is combined with CS imaging to increase the degree of freedom of signal while preserving its coherence.A refined CS-based formation for ISAR image-resolution enhancement is then *** real and simulated data experiments are performed to evaluate the proposed approach,and an example of using this technique demonstrates the enhanced image resolution in application of maneuvering target imaging.

关键词： inverse synthetic aperture radar (ISAR) compressive sensing (CS) bandwidth extrapolation (BWE) super resolution

Coherent processing for ISAR imaging with sparse apertures

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Science china(Information Sciences) 2012年第8期55卷 1898-1909页

作者： SHENG Jialian,zhang lei,XU Gang,xing mengdao&bao zheng national Key laboratory of radar signal processing,xidian university,xi’an 710071,china 1. national Key laboratory of radar signal processing Xidian University Xi’an 710071 China

To implement target detection,tracking and imaging in a multifunctional radar system,the wideband measurements for inverse synthetic aperture radar(ISAR)imaging are usually sparsely *** the incoherence problem in such sparse-aperture ISAR(SA-ISAR)systems,we concentrate on the study of a coherent processing method in this *** on an all-pole model,the incoherence parameters between abutting sub-apertures can be effectively *** coherence compensation,an optimization-based SAISAR imaging approach is provided from the view of *** and real data experiments validate the feasibility and effectiveness of the proposals.

关键词： sparse aperture ISAR all-pole model coherent processing

An approach to forward looking FMCW radar imaging based on two-dimensional Chirp-Z transform

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Science china(Information Sciences) 2010年第8期53卷 1653-1665页

作者： liANG Yi 1 , WANG Hongxian 1 , zhang Long 1,2 & bao zheng 1 1 national Key lab of radar signal processing, xidian university, xi’an 710071, china 2 xi’an Polytechnic university, xi’an 710048, china 1. national Key lab of radar signal processing Xidian University Xi’an 710071 China2. Xi’an Polytechnic University Xi’an 710048 China

Airborne forward looking radar imaging, which is an important work mode of imaging radar system, has many advantages combined with frequency modulated continuous wave (FMCW) technology. This paper studies the configuration with one central antenna element for signal transmitting and other antenna elements for signal receiving. According to its imaging geometry, the analytical expression of the received signal for forward looking imaging radar based on FMCW is given. By performing the equivalent phase center principle, the received signal is equalized to the case of system configuration with antenna both for transmitting and receiving signals. The Doppler frequency shift effect, induced by the platform’s continuous motion while radar transmits and receives signals, is analyzed in detail and the approximate compensation method is shown. Based on this, a novel method for forward looking FMCW radar imaging is developed, which adopts two-dimensional Chirp-Z transform to implement scaling operation. Also the complete derivation process of the algorithm and the expression of each compensation factor are presented. The whole algorithm only includes FFT and complex multiplication, with interpolation free, and is easy to implement in reality. Simulation results verify the correctness of the analysis and the validity of the proposed algorithm.

关键词： forward looking radar imaging FMCW Chirp-Z transform

radar HRRP RECOGNITION BASED ON THE MINIMUM KULLBACK-leiBLER DISTANCE CRITERION

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Journal of Electronics(china) 2007年第2期24卷 199-203页

作者： Yuan li liu Hongwei bao zheng Key lab for radar signal processing Xidian University Xi＇an 710071 China

To relax the target aspect sensitivity and use more statistical information of the High Range Resolution Profiles (HRRPs), in this paper, the average range profile and the variance range profile are extracted together as the feature vectors for both training data and test data representa-tion. And a decision rule is established for Automatic Target Recognition (ATR) based on the mini-mum Kullback-leibler Distance (KLD) criterion. The recognition performance of the proposed method is comparable with that of Adaptive Gaussian Classifier (AGC) with multiple test HRRPs, but the proposed method is much more computational efficient. Experimental results based on the measured data show that the minimum KLD classifier is effective.

关键词： High Range Resolution Profile (HRRP) Automatic Target Recognition (ATR) Kullback-leibler Distance (KLD) Adaptive Gaussian Classifier (AGC)

A coordinate-transform based FFBP algorithm for high-resolution spotlight SAR imaging

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Science china(Information Sciences) 2015年第2期58卷 31-41页

作者： yanG ZeMin xing mengdao zhang lei bao zheng national Key lab of radar signal processing Xidian University

This paper proposes a coordinate-transform(CT) implementation for the fast factorized backprojection(FFBP) algorithm(CT-FFBP) to process high-resolution spotlight synthetic aperture radar(SAR)data. Unlike the FFBP utilizing two-dimensional image-domain interpolation for sub-aperture fusion, CT-FFBP finishes the image-projection using CT with the accommodation of chirp-z transform and circular shifting. Without interpolation, CT-FFBP yields enhanced efficiency over the interpolation based FFBP, besides maintaining high precision simultaneously. Both simulation and real-data experiments verifies the efficiency and precision superiorities of the CT-FFBP.

关键词： spotlight synthetic aperture radar(SAR) fast factorized back-projection(FFBP) coordinate-transform(CT)

THEORY OF ORTHONORMAL M-BAND WAVELET PACKETS

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Journal of Electronics(china) 1998年第3期15卷 193-198页

作者： zhang Jiankang bao zheng Jiao licheng (Key lab. for radar signal processing, xidian university, xi’an 710071)

In recent years, M-band orthonormal wavelet bases, due to their good characteristics, have attracted much attention. The ability of 2-band wavelet packets to decompose high frequency channels can be employed to improve the performance of wavelets for time-frequency localization, which makes more kinds of signals for analyzing by wavelets. Similar to the notations from the extension of 2-band wavelets to 2-band wavelet packets, the theoretic framework of M-band wavelet packets is developed, a generalization of the notations and properties of 2-band wavelet packets to that of M-band wavelet packets is made and the corresponding proofs are given.

关键词： 2-band wavelets M-band wavelets wavelet packets

An Efficient Kernel Optimization Method for High Range Resolution Profile Recognition

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An Efficient Kernel Optimization Method for High Range Resol...

A STUDY OF REDUCED-RANK STAP

2006 CIE International Conference on radar

作者： Bo Chen Hongwei liu and zheng bao national lab of radar signal processing xidian university xi’an Shaanxi 710071 china

A kernel optimization based on fusion kernel for HRRP is proposed in this *** on the fusion of the 1norm and 2-norm Gaussian kernels,our method combines the different characteristics of them so that not only is the kernel function optimized but also the speckle fluctuations of HRRP are *** on the radar measured data the presented method is employed to the kernel optimization of KPCA and the classification performance of the extracted is evaluated via a SVM ***,experiment results are compared and analyzed,which prove our method effective.

关键词： High-resolution range profile (HRRP) speckle fluctuations kernel machines class separability empirical feature space kernel optimization.

来源： cnki会议评论

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Journal of Electronics(china) 2000年第4期17卷 289-296页

作者： zhang liang bao zheng liao Guisheng (Key lab. for radar signal processing, xidan university, xi’an 710071, china)

This paper starts with the discussion of the principle of Reduced-Rank (RR) Space-Time Adaptive processing (STAP). It is followed by a dedication of the upper bound performance of all eigen-based RR methods provided by Cross Spectral Method (CSM) under the condition of a given processor rank and an identical secondary sample size. A performance comparison between two RR STAP processors with prefixed structure and CSM is performed by the means of simulations. It is shown that the performance of time pre-filtering followed by jointly localized STAP structure (i.e. 3DT-SAP) is very close to the upper bound and thereby it is an effective RR approach.

关键词： Airborne phased array radar Reduced-Rank STAP (RR STAP) Cross Spectral Method (CSM) Clutter suppression Detection performance

Unparallel trajectory bistatic spotlight SAR imaging

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Science in china(Series F) 2009年第1期52卷 91-99页

作者： zhang lei JING Wei xing mengdao bao zheng Key laboratory for radar signal processing Xidian University Xi'an 710071 China

A new approach for unparallel trajectory bistatic spotlight SAR imaging is proposed. The approach utilizes the concept of instantaneous Doppler wavenumber and introduces two variants, the sum-range and subtraction-range, to develop the 2D frequency analytical formula. Based on the assumption of plane wavefront, the transmitting and receiving Doppler are separated and formulated via series reversion. And frequency scaling is applied to focus image. The algorithm is with high computational efficiency, and provides well focus for limited scene imaging. Simulation result confirms the validity of the approach.

关键词： unparallel trajectory bistatic SAR instantaneous Doppler wavenumber series reversion frequency scaling algorithm unparallel trajectory bistatic SAR instantaneous Doppler wavenumber series reversion frequency scaling algorithm