An Improved Full-Aperture ScanSAR Imaging Method Integrating the MIAA Based Aperture Interpolation

Jiaqi Ning,Dacheng Liu,Yingjie Wang,Kaiyu Liu,Heng Zhang

doi:10.1155/2020/8196081

Abstract

In the scanning synthetic aperture radar (ScanSAR) mode, the radar antenna sweeps through different range subswaths to image a wide swath. The full-aperture imaging algorithm for ScanSAR data has been widely used because it can be realized by exploiting the existing standard high-precision Stripmap SAR processor and does not require stitch processing in the azimuth. However, both the focused image and the interferogram achieved by full-aperture processing suffer from spikes. The spikes adversely affect the ScanSAR-related applications, such as target detection and interferometry. To effectively suppress the spikes, an improved algorithm based on the missing-data iterative adaptive approach (MIAA) is proposed in this manuscript. Besides, the proposed method can also improve the azimuth resolution of ScanSAR images. Simulation and experimental results demonstrate that this algorithm has better performance when processing ScanSAR data compared with existing methods.

Highlights

Scanning synthetic aperture radar (ScanSAR) is a kind of operation widely used mode in the modern SAR system [1, 2]
The shape of the building at site A processed by the missing-data iterative adaptive approach (MIAA)-AIT is narrower than that processed by the linear prediction model aperture interpolation technique (LPM-AIT) and more similar to that processed by the Stripmap mode
The outlines of the buildings processed by the MIAA-AIT are clearer than the linear prediction model (LPM)-AIT and more similar to that processed by the Stripmap mode

Summary

Introduction

Scanning synthetic aperture radar (ScanSAR) is a kind of operation widely used mode in the modern SAR system [1, 2]. In the full-aperture approach, gaps between bursts are filled with zeros and all the bursts of a subswath can be coherently processed as Stripmap data. The coherently processed multiple bursts result in strong interference modulations of the azimuth impulse response function, which are called “spikes” [5, 10, 11, 22, 23]. These spikes can contaminate ScanSAR image and influence the interpretation. As the azimuth resolution of the full-aperture result is controlled by the envelope of the spikes [10], the spike suppression can enhance the azimuth resolution at the same time

Azimuth

Problem Statement

Proposed MIAA-AIT Algorithm

Result

Conclusions