Feature-Independent Aperture Evaluator for the Curvilinear SAR

Abstract

Curvilinear synthetic aperture radar (SAR), as a more practicable 3-D SAR imaging system, utilizes parametric target feature estimates extracted from the received data to reconstruct the target image. The reconstructed image quality is then impacted by the estimation accuracy of the features. In this letter, through discussing the correlation between the system parameters and the estimation performance of the curvilinear SAR, a conclusion can be drawn on how the overall location accuracy of a target is determined by the correlation between the azimuth and elevation coordinates of the flight path, compactly characterizing the curvilinear aperture. Consequently, a new index, determined only with the aperture parameters, is proposed as an aperture evaluator, which is referred to as the feature-independent aperture evaluator (FAE). FAE can be used for guiding the operational aperture design.

Focusing of Airborne Synthetic Aperture Radar Data From Highly Nonlinear Flight Tracks

“…Most of the simulations are carried out for Ka-band SAR systems; for the image formation, a time-domain correlation algorithm is used. Most recently, Xiangle and Ruliang [7] and Su et al [8], [9] studied the performance of 3-D SAR imaging from nonlinear tracks, mainly in the azimuth-elevation plane, with respect to 3-D target reconstruction using parametric and nonparametric estimation techniques. Vigurs and Wood [10] presented a technique exploiting a nonlinear sensor trajectory to distinguish the Doppler effects of a target's radial velocity from the effect of a cross-range displacement.…”

Fast Bayesian Compressed Sensing Algorithm via Relevance Vector Machine for LASAR 3D Imaging

“…In recent years, scholars have obtained targets' 3D information successfully under different SAR modes such as the tomography SAR (TomoSAR) [6], curvilinear SAR (Cur-SAR) [7], and linear array SAR (LASAR) [8,9]. The TomoSAR obtains the third-dimension imaging resolution by synthesizing the parallel baselines into a virtual aperture along the elevation direction [6].…”

“…The CurSAR usually synthesizes a curved array by controlling Remote Sens. 2021, 13, 1751 2 of 28 the moving trajectory of a single antenna; it combines the pulse compression technology to obtain the 3D imaging resolution [7]. The moving trajectories of both TomoSAR and CurSAR are strictly limited to achieve high-quality imaging, which limits their applications seriously [8].…”

A method for CLSAR 3-D imaging based on backprojection and beamforming

“…The Cartesian co-ordinate is presented using the centre of the investigated area as the origin, the x and directions correspond to range and azimuth directions, and the direction corresponds to height direction. The positions of the signal received by the radar locate at To achieve high-resolution three-dimensional scene reconstruction, curved flight paths should be designed to maximize the dimensions of the frequency space [5,9]. Several common curved apertures used for curvilinear synthetic aperture radar are illustrated in Figure 2 , we can get that the raw data received by curvilinear synthetic aperture radar is sparse in three-dimensional space, for it is restricted by the shape of the flight path.…”