重力卫星数据反演地表质量变化的点质量模型法研究进展
Progress in Point-Mass Modeling Approach for Surface Mass Distribution Derived from Gravity Satellite Data
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摘要: 利用多代重力卫星观测数据监测全球质量变化,使人类对全球物质迁移和环境变化有了更加深刻的认识和理解。由于卫星星载仪器精度和分辨率的限制以及建模误差等多种因素的影响,利用重力卫星数据解算的全球质量变化模型受到条带误差的影响,广泛采用的滤波平滑手段虽然可以对其削弱,但同时会引起更严重的信号泄漏问题。为了克服这些问题,并进一步提高重力卫星数据解算地表质量变化模型的时空分辨率和精度,许多学者基于牛顿万有引力定律发展了点质量模型法,该类方法直接建立地表质量变化参数与卫星受摄运动的关系,并采用约束矩阵处理条带误差和向下延拓产生的不适定问题。综述了点质量模型法的研究进展,详细梳理了不同点质量模型法的基本理论和方法,分析了不同约束矩阵的构建策略和特点,简要总结了点质量模型法的后处理方法,以期能为点质量模型法的后续发展和研究提供参考。Abstract: The successful implementation of multi-generation gravity satellite missions has made significant progress in using gravity satellite observation data to monitor global mass changes. This has improved our understanding of large-scale material migration, global environmental changes in the Earth system, and facilitated research on critical environmental issues such as global sea level change monitoring, glacier melting, and groundwater extraction. Limitations in the accuracy and resolution of satellite instruments, along with factors such as modeling errors, result in global mass changes calculated using gravity satellite data being affected by noise patterns in the form of south-north stripes and signal leakage. While commonly used filtering and smoothing methods effectively mitigate the impact of south-north stripes noise, they exacerbate signal leakage problems. To address these issues and enhance the spatiotemporal resolution and accuracy of surface mass changes in the calculation of gravity satellite data, numerous scholars have developed a point-mass modeling approach based on Newton's law of universal gravitation. These methods establish a direct relationship between surface mass changes and perturbed motion of satellites, employing constraint matrices to tackle strip errors and ill-posed problems arising from downward continuation. This article examines the research progress of the point-mass modeling approach, provides a comprehensive overview of the fundamental theories and various methods employed, analyzes different strategies and characteristics of constraint matrices, and provides a concise summary of the post-processing methods associated with this approach. The comprehensive analysis presented in this article is intended to serve as a valuable reference for the future development and research of the point-mass modeling approach.