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Advances in Earth Science >

2025 , Vol. 40 >Issue 9: 902 - 915

DOI: https://doi.org/10.11867/j.issn.1001-8166.2025.078

Simplified Polarized GNSS-ReSAR Land Surface Remote Sensing Technology

  • Xuerui WU
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  • Center for Astro-geodynamics Research, Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China
WU Xuerui, research areas include GNSS-R/SoOP-R modeling and geophyscial parameters retrieval. E-mail: xrwu@shao.ac.cn

Received date: 2025-06-30

  Revised date: 2025-08-28

  Online published: 2025-10-31

Supported by

the National Key Research and Development Program of China(2024YFB3910001);The National Natural Science Foundation of China(42061057)

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Abstract

Global Navigation Satellite System Reflectometry (GNSS-R) is an effective Earth observation method that analyzes navigation satellite reflection signals to invert surface parameters. Historical research has shown that traditional GNSS-R systems primarily adopt a single-polarization configuration (Right-Handed Circularly Polarized (RHCP) transmission and Left-Handed Circularly Polarized (LHCP) reception, hereinafter referred to as LR polarization). With the advancement of technology, the use of RHCP antennas to receive surface-reflected signals has gained attention. The traditional Delay-Doppler Map (DDM) processing mode of GNSS-R has low efficiency in utilizing scattering features under different observation geometries. In this context, the development of GNSS-based Synthetic Aperture Radar (GNSS-SAR) technology that can effectively receive surface scattering signals across geometric configurations has become a promising research direction. This study focuses on remote sensing exploration of the fusion technology of reduced polarization GNSS-R and synthetic aperture radar (GNSS ReSAR: GNSS Reflectometry and Synthetic Aperture Radar). Based on dual-polarization (LR and RR) data obtained from the Spanish airborne GLORI experiment, soil moisture inversion research was conducted. Dual-polarization GNSS-R data from the Chinese Tianmu (TM) commercial satellite were synchronously used for comparative verification. Both experiments consistently showed that the reflectance of the RR polarization was approximately 10 dB lower than that of the LR polarization, but the accuracy of soil moisture inversion based on the two polarizations was comparable. Because of the limited ability to obtain simplified polarization data, this study used the Land Surface GNSS Reflection Simulator (LAGRS) model, constructed based on radiative transfer theory, to analyze other scattering characteristics of simplified polarization. A systematic analysis of the scattering mechanism and development trend of the GNSS ReSAR mode provides a theoretical reference for the evolution of new-generation GNSS-R technology to a certain extent.

Key words： Global Navigation Satellite System Reflectometry (GNSS-R); Hybrid Compact Polari metry; Delay Doppler Map (DDM); Synthetic Aperture Radar (SAR).

Cite this article

Xuerui WU . Simplified Polarized GNSS-ReSAR Land Surface Remote Sensing Technology[J]. Advances in Earth Science, 2025 , 40(9) : 902 -915 . DOI: 10.11867/j.issn.1001-8166.2025.078

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