An Efficient Ground Moving Target Imaging Method for Airborne Circular Stripmap SAR

Abstract

This paper studies the imaging of a ground moving target with airborne circular stripmap synthetic aperture radar (CSSAR). First, the range equation of a target moving with accelerations is developed. Then, a new range model of high accuracy is proposed, since the commonly used second-order Taylor-approximated range model is inaccurate when the azimuth resolution is relatively high or the target moves with accelerations. The proposed range model also makes it easy to derive an accurate analytical expression for the target’s 2-D spectrum. Third, based on the proposed range model, the target’s 2-D spectrum is derived and an efficient imaging method is proposed. The proposed imaging method implements focusing via a phase multiplication in the 2-D frequency domain and utilizes the genetic algorithm to accomplish an efficient search of the parameters of the proposed range model. Finally, numerical experiments are conducted to validate the proposed range model and the proposed imaging method.

Curvilinear Flight Synthetic Aperture Radar (CF-SAR): Principles, Methods, Applications, Challenges and Trends

“…Therefore, the research on airborne CF-SAR is significant. Several teams have made important and valuable contributions on airborne CF-SAR, such as [2][3][4]8,16,21,22,[28][29][30][31][32]36,[38][39][40][41]43,50,51,53,54,58,63,67], and the references therein.…”

“…The emergence of curvilinear flight SAR (CF-SAR) is the inevitable result of the comprehensive practicality of SAR. Differing from the non-uniform linear motion of Conv-SAR caused by unintentional motion error [3], CF-SAR realizes the flexible control of the platform and fulfills different application requirements through intentional non-uniform motion, such as accelerated motion and widely concerned circular motion [4], etc. The non-uniform motion makes CF-SAR more suitable for the actual detection environment due to two reasons:…”

“…However, a thorough summary of the current technique status and discussions about future trends is lacking in the existing literature. By providing a comprehensive survey of the CF-SAR technique this paper can serve as a reference for the future development and actual application of Differing from the non-uniform linear motion of Conv-SAR caused by unintentional motion error [3], CF-SAR realizes the flexible control of the platform and fulfills different application requirements through intentional non-uniform motion, such as accelerated motion and widely concerned circular motion [4], etc. The non-uniform motion makes CF-SAR more suitable for the actual detection environment due to two reasons:…”

Circular SAR Incoherent 3D Imaging with a NeRF-Inspired Method

“…In the field of reconnaissance, the primary motivation for adopting a circular trajectory is to achieve continuous and comprehensive observation of complex or dynamic scenes, which can provide valuable information for target identification, classification, and tracking [3]. It is widely acknowledged that, in comparison to conventional narrow-angle linear-trajectory SAR systems, CSAR can capture more comprehensive scattering characteristics of targets [4], leading to improved accuracy in target identification and classification [5][6][7], enhanced detection, velocity measurement, and tracking capabilities of moving targets [8][9][10], as well as reduced radar blind (shadowed) areas [11], among other benefits. In addition to the aforementioned benefits that have been widely recognized, the varying range-Doppler geometry of CSAR data presents a potential for forming high-resolution 3D images in a single-flight pass [12].…”

Improved Dimension-Reduced Structures of 3D-STAP on Nonstationary Clutter Suppression for Space-Based Early Warning Radar

“…However, there will be strong interference of the ground clutter when detecting moving targets. Therefore, clutter suppression plays an important role in moving target detection [1][2][3]. Further, the Earth's rotation [4] makes the clutter nonstationary, which means that the clutter from different range gates have different space-time distributions.…”