未来卫星重力梯度测量及其时变应用研究

新一代卫星重力测量技术是目前快速测定全球静态/时变重力场的唯一可行手段，已成为全球大地测量观测系统（GGOS）的重要组成部分。本项目面向未来基于冷原子干涉技术的卫星重力梯度测量任务，深入研究卫星轨道优化设计、重力场模型反演、冷原子干涉重力梯度测量原理等基础理论与方法，突破卫星重力梯度观测值仿真、卫星跟踪卫星观测值仿真、卫星姿态观测值仿真、各种观测值噪声模拟、时变重力信号仿真、高阶卫星重力模型解算的并行算法等一系列关键技术，构建重力梯度测量卫星系统闭环仿真平台。进而，探索未来卫星重力梯度测量新模式，设计实施大量针对不同系统级参数的数值仿真实验，深入分析其反演静态和时变重力场的性能，评估探测陆地水储量和大地震同震重力变化的可能性，并给出未来重力梯度测量卫星的系统级指标。成果既可为发展未来卫星重力梯度探测计划提供参考，也可为我国自主研制重力梯度测量卫星提供有力的技术支撑，有重要的科学和现实意义。

Presently, the new generation of satellite gravimetry is the only feasible technique for rapidly determining the global static/temporal gravity field, and has become an important part of the global geodetic observing system (GGOS). This project mainly focus on the future mission of satellite gravity gradiometer based on the technology of cold atom interferometers (CAI). And the optimization design of satellite orbit, the inversion of gravity field model, the basic theory of gravity gradiometer based on cold atom interferometers will be studied in the project. The related key technologies, such as the simulation of satellite gravity gradient, satellite-to-satellite tracking observations, satellite altitude, noise of various observations and temporal gravity signal, will be broken through together with the parallel algorithms of determining the high degree and order geopotential coefficients. The closed-loop simulation platform of satellite gravity gradiometry will be developed. Based on the platform, the project will explores new modes of future satellite gravity gradiometry, and design a number of numerical simulation experiments with different combinations of system-level parameters. The performance of inversing static/temporal gravity field of the future satellite gravity gradiometry will be deeply analyzed, and the possibility of detecting terrestrial water storage and coseismic gravity changes of large-scale earthquakes will be evaluated. The corresponding system-level indexes of future satellite gravity gradiometry will be proposed based on the experiment tests. The result can not only provide references for the development of future satellite gravity gradiometry, but also provide strong technical supports for China's independent development of gravity gradient satellite mission, which have the important scientific and practical significance.