我国将来更高精度CSGM卫星重力测量计划研究

摘要

基于卫星跟踪模式的优化选取、关键载荷的优化组合、轨道参数的优化设计、仿真模拟的先期启动和反演方法的优化改进，开展了我国将来CSGM（China’s Satellite Gravity Mission）卫星重力测量计划实施的研究论证。由于卫星跟踪卫星高低/低低（SST-HL/LL）模式对地球中长波重力场的探测精度较高、技术要求相对较低，而且可借鉴当前GRACE卫星的成功经验，因此建议将来CSGM卫星重力测量计划采用SST-HL/LL模式；建议开展激光干涉星间测距仪、复合GPS接收机、非保守力补偿系统、卫星体和加速度计质心调节装置等关键载荷的先期研制；建议将来CSGM卫星的轨道高度（300～400km）和星间距离（100±50km）选择在已有重力卫星的测量盲区；建议将仿真技术应用于CSGM卫星的方案论证、系统设计、部件研制、产品检验、空中使用、故障分析等研发和运行的全过程；对比分析了卫星轨道摄动法、动力学法、能量守恒法和加速度法的优缺点，建议寻求新型、高精度、高效率和全频段的卫星重力反演方法；提出将来CSGM卫星重力测量计划的预期科学目标：在300阶处，累计大地水准面精度和累计重力异常精度分别为1～5 cm和1～5 mGal。%The research demonstrations on the implementation of the future CSGMsatellite gravity mission in China were carried out,based on the preferable selection of satellite tracking modes,the optimal combination of key payloads,the preferred design of orbital parameters,the beforehand execution of simulated studies,and the optimum improvement of gravity recovery methods.Firstly,the Satellite-to-Satellite Tracking in the High-Low/Low-Low mode (SST-HL/LL)was used in the future CSGM satellite gravity mission due to the high-accuracy measurement of the Earth's gravitational field,the lower technical requirements and the successful experiences of the current twin GRACE satellites.Secondly,the space-borne instruments consisting of the interferometric laser intersatellite ranging system,the compound GPS receiver,the drag-free system,the center of mass trim assembly,etc.were developed in advance.Thirdly,the orbital altitude of 300~400 km and the intersatellite range of 100 ± 50 km were designed in the unmeasurable area of the existing gravity satellites.Fourthly,the simulation techniques were applied to the holistic processes of the development and operation for CSGM,including scheme demonstration,system design,parts development,production test, practical application and malfunction analysis.Fifthly,the advantages and disadvantages of the satellite orbital perturbation,dynamic,energy conservation and semi-analytic methods were contrastively analyzed,and the new-type,high-precision,high-efficiency and full-frequency satellite gravity recovery methods were investigated.Finally,the expected scientific objectives of the future CSGM satellite gravity mission showed that the cumulative geoid height error is 1 ~5 cm and the cumulative gravity anomaly error is 1 ~5 mGal at degree 300.