Research on ocean surface velocity measurement method for multibaseline interferometric SAR formation system

doi:10.7523/j.ucas.2024.079

Abstract

Abstract: The distributed formation synthetic aperture radar (SAR) can achieve ocean surface velocity measurement through along-track interferometry. However, the existence of cross-track baselines introduces phase influences from flat earth effect, ocean wave height, and sea surface height into the interferometric phase, making it challenging to directly retrieve sea surface velocity accurately from the interferometric phase. This paper proposes a method for measuring ocean surface velocity using a multibaseline interferometric SAR formation system. Firstly, considering the characteristics of wave motion and noise distribution in the scene, a joint suppression method for wave height phase, large-scale wave orbital velocity phase, and noise phase based on spatial averaging is proposed, which effectively suppresses these interferometric phases. Then, to address the coupling issue between the radial velocity phase and sea surface height phase, a method for decoupling the radial velocity phase and height phase based on multibaseline is introduced. By introducing another interference pair to improve the degree of freedom in data processing, the effective separation of these two phase terms is achieved through two sets of coupled interference phases, achieving high-precision measurement of radial flow velocity. Finally, the proposed method was validated using the measured data from the Hongtu-1 satellite, and the results proved the effectiveness of the proposed method.

Key words: distributed synthetic aperture radar (SAR), multibaseline interferometry, along-track interferometric (ATI), ocean surface velocity measurement, phase decoupling

CLC Number:

P731.21

XIE Yuhong, ZHENG Mingjie, WANG Jili, LI Hongxiang, XU Kaijiang, LUO Chao, LIU Jian. Research on ocean surface velocity measurement method for multibaseline interferometric SAR formation system[J]. Journal of University of Chinese Academy of Sciences, DOI: 10.7523/j.ucas.2024.079.

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