Focusing Arc-Array Bistatic Synthetic Aperture Radar Data Based on Keystone Transform

Abstract

Arc-array synthetic aperture radar (AA-SAR) has become a novel imaging scheme for full azimuth observation. However, the exiting arc-array monostatic SAR system is placed on a single platform and is easy to detect. Arc-array bistatic SAR (AA-BiSAR) with a stationary transmitter is proposed in this paper, which can obtain high data acquisition efficiency and reduce vulnerability of arc-array monostatic SAR. Furthermore, since the azimuth resolution with full azimuth observation is not related to the location of the stationary transmitter, the transmitter can be placed far away from the receiver. Compared with imaging algorithms for other modes, the key points of AA-BiSAR imaging algorithms are a square root in the bistatic slant range equation and an arc synthetic array in azimuth. According to the imaging geometry of AA-BiSAR, a novel imaging approach for AA-BiSAR based on keystone transform (KT) is proposed, and the KT implements range-cell migration correction (RCMC) in conditions of trigonometric function under square root in the range history and arc synthetic array in azimuth via reformatting the AA-BiSAR raw data. Besides presenting the proposed imaging approach, a complete resolution analysis of AA-BiSAR is given. Results of numerical simulation experiments on point targets validate the proposed imaging approach.

Staring Spotlight SAR with Nonlinear Frequency Modulation Signal and Azimuth Non-Uniform Sampling for Low Sidelobe Imaging

“…After circular shifting and windowing, the linear unbiased minimum variance is used to calculate the phase error gradient after the inverse Fourier transform, and the well focused SAR images are output while the phase error is less than the designed error threshold. The major disadvantage of the BPA is low computational efficiency, while frequency domain algorithms [25][26][27] show more computational efficiency and are widely adopted in recent SAR imaging modes. However, to handle the raw data of the new proposed modes, these algorithms usually need to be modified.…”

“…As shown in Figure 8, the range preprocessing step includes NLFM pulse compression and the first-order MoCo. In airborne SAR imaging, MoCo must be considered to The major disadvantage of the BPA is low computational efficiency, while frequency domain algorithms [25][26][27] show more computational efficiency and are widely adopted in recent SAR imaging modes. However, to handle the raw data of the new proposed modes, these algorithms usually need to be modified.…”

“…where ∆t is the original average azimuth time sampling interval. The major disadvantage of the BPA is low computational efficiency, while frequency domain algorithms [25][26][27] show more computational efficiency and are widely adopted in recent SAR imaging modes. However, to handle the raw data of the new proposed modes, these algorithms usually need to be modified.…”

An Adjusted Frequency-Domain Algorithm for Arc Array Bistatic SAR Data with One-Moving Transmitter

“…Arc array bistatic SAR (AA-BiSAR) [8] is a new type of variant bistatic SAR system, with the transmitter and receiver deployed on different platforms. Compared with AA-SAR, AA-BiSAR can observe the target from different angles and can obtain front-view or backview area imaging.…”

CNN-Based Vehicle Target Recognition with Residual Compensation for Circular SAR Imaging

“…Research based on SAR and CSAR includes time-frequency analysis, 2D/3D imaging, digital elevation model (DEM), target detection and recognition, etc. [1][2][3][4][5][6][7][8][9][10][11].…”