Journal
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
Volume 58, Issue 9, Pages 6020-6038Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/TGRS.2020.2969573
Keywords
Synthetic aperture radar; Satellites; Gratings; Apertures; Spatial resolution; Orbits; Signal resolution; Array spatial ambiguity function (ASAF); grating lobe suppression; multistatic geosynchronous synthetic aperture radar SAR (GEO SAR); resolution analysis
Categories
Funding
- National Natural Science Foundation of China [61960206009, 61971039]
- National Ten-thousand Talents Program Young Top Talent [W03070007]
- Special Fund for Research on National Major Research Instruments (NSFC) [61827901, 31727901]
- Young Elite Scientists Sponsorship Program by China Association for Science and Technology (CAST) [2017QNRC001]
Ask authors/readers for more resources
Multistatic geosynchronous synthetic aperture radar (GEO SAR) utilizes multiple satellites transmitted and received signals simultaneously to generate multiple phase centers (PCs) and to reduce the synthetic aperture time and the power budget. Two key problems of this SAR system are the design of the PC array configuration to satisfy the resolution requirements and the suppression of the grating lobes that are inherently introduced by the PC array. The resolution of the SAR can be analyzed using generalized ambiguity functions (GAFs). However, the current research on the multistatic SAR resolution and grating lobes is mostly based on specified configurations and numerical simulation methods, which cannot establish the relationship between the system parameters and the resolution. This article proposes an analytical analysis method for the multistatic GEO SAR GAF-based on the array spatial ambiguity function (ASAF). First, gradient analysis is used to obtain analytical expressions for ASAF and the multistatic SAR GAF. On this basis, an analytical resolution expression is obtained, and an orbital element design method that considers the Earths rotation is proposed. In addition, the lobe positions are analytically expressed based on the geometry, and the grating lobes are suppressed by designing the optimal integration time such that the null depth of the velocity ambiguity function (VAF) coincides with the grating lobe positions. Finally, simulation results at various positions for various orbit types demonstrate the accuracy of the GAF approximation formula and the satisfactory performance of the optimal time expression in suppressing the grating lobes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available