Showing papers by "Mengdao Xing published in 2005"

Radar HRRP target recognition based on higher order spectra

Abstract: Radar high-resolution range profile (HRRP) is very sensitive to time-shift and target-aspect variation; therefore, HRRP-based radar automatic target recognition (RATR) requires efficient time-shift invariant features and robust feature templates. Although higher order spectra are a set of well-known time-shift invariant features, direct use of them (except for power spectrum) is impractical due to their complexity. A method for calculating the Euclidean distance in higher order spectra feature space is proposed in this paper, which avoids calculating the higher order spectra, effectively reducing the computation complexity and storage requirement. Moreover, according to the widely used scattering center model, theoretical analysis and experimental results in this paper show that the feature vector extracted from the average profile in a small target-aspect sector has better generalization performance than the average feature vector in the same sector when both of them are used as feature templates in HRRP-based RATR. The proposed Euclidean distance calculation method and average profile-based template database are applied to two classification algorithms [the template matching method (TMM) and the radial basis function network (RBFN)] to evaluate the recognition performances of higher order spectra features. Experimental results for measured data show that the power spectrum has the best recognition performance among higher order spectra.

High resolution ISAR imaging of high speed moving targets

Abstract: Range-Doppler (RD) algorithms are idely used i inverse synthetic aperture radar (ISAR) imaging. I the standard RD algorithm, envelope alignment and autofocus are first applied to transform the original data into equivalent turntable target data, and the FFT is used for the image formation. Usually, the migratio through resolution cells (MTRCs) due to target rotatio is ignored. ith the improvement of resolutio or the increase of target size, MTRCs cannot be ignored and must be mitigated. For high speed moving targets, the most idely used 'stop-and-go' data model is violated. I this case, the mitigation of MTRCs becomes eve more complicated. I the paper, technical issues associated ith high resolutio ISAR imaging of high speed moving targets are addressed. A preprocessing algorithm is first proposed to convert the non-coherent ra ISAR data into coherent data, the a keystone formatting algorithm developed for the imaging of slo ground moving targets i SAR is applied to mitigate the MTRCs o ing to rotational motion, and, finally, a high resolutio time-frequency analysis based range-instantaneous Doppler (RID) algorithm is used to produce the focused ISAR image. Numerical examples are provided to illustrate the performance of the proposed approach.