Isar Imaging of Non-Uniform Rotation Targets With Limited Pulses via Compressed Sensing

Abstract

Abstract-This research introduces compressed sensing (CS) principle into inverse synthetic aperture radar (ISAR) imaging of nonuniform rotation targets, and high azimuth resolution can be achieved with limited number of pulses. Firstly, the sparsity of the echoed signal of radar targets with non-uniform rotation in certain matching Fourier domain is analyzed. Then the restricted isometry property (RIP) and incoherence of partial matching Fourier matrices are checked, following which an ISAR imaging method based on CS for both random sparse aperture and short aperture cases is proposed. In particular, considering the dependence of the sparse dictionary on the relative rotation parameter, a parameter estimation method by the optimal search in fractional Fourier domain is presented. Simulation experiments verify the effectiveness as well as superiority of the proposed imaging method over traditional methods in terms of imaging performance.

Lasso Based Performance Evaluation for Sparse One-Dimensional Radar Problem Under Random Sub-Sampling and Gaussian Noise

“…Lasso (least absolute shrinkage and selection operator), is used by the statistic community to demonstrate a particular regularization version of least squares (see (9) for its definition). From the Bayesian aspect, Lasso performs a zero-mean Laplace priori on the under-test signal x.…”

“…In [5], Baraniuk and Steeghs suggest to apply CS to radar imaging. After that, the CS based SAR imaging [6,7], ISAR imaging [8,9] and other applications of microwave imaging [10][11][12] are extensively discussed. A more detailed and comprehensive account can be found in [4,13,14].…”

Efficient Classification of Low-Resolution Range Profiles of Automobiles Using a Combination of Useful Features

“…In the test phase, the test feature vector of an unknown target is normalized using (19) and transformed using (22). In classification, we used a simple NNC which utilizes a simple Euclidean distance between two vectors as follows:…”

“…Among several radar signatures, the range profile (RP) shows the unique one dimensional distribution of the radar cross-section [2][3][4][5][6][7][8][9] of the automobile and can be effectively used for classification of automobiles which can contribute to anti-collision, lane-change, and automobile control regardless of weather and day-night conditions [10]. RP can also provide two-dimensional radar image of automobiles if the synthetic aperture radar (SAR) [11][12][13][14][15][16][17][18], the inverse SAR [19] and the jet engine modulation [20] techniques are applied.…”

Coherent Phase Compensation Method Based on Direct if Sampling in Wideband Radar

“…Thus, improving the precision of phase compensation plays an important role in improving the quality of ISAR image. So far, there have been lots of research works focusing on phase compensation, the research directions of which generally fall into two categories: parametric methods and non-parametric methods [9][10][11][12]. Among these numerous methods, Doppler centroid tracking (DCT) [13][14][15] algorithm is one of the state-of-the-art methods.…”