【作者】 郭金运；

【导师】 胡建国； 黄金维； 李建成；

【作者基本信息】 山东科技大学 ， 大地测量学与测量工程， 2004， 博士

【摘要】 卫星定轨是卫星任务顺利执行的关键，而地球重力场是低轨卫星受力的主要来源，对卫星的跟踪观测提供了更多的地球重力场信息，地球重力场模型精度的改善也提高了卫星定轨的精度。因此，卫星定轨和地球重丈场模型研究是相辅相成的。CHAMP是用于地球科学和大气研究及其应用的德国小卫星，其任务之一就是高精度地确定全球静态地球重力场长波长特征和重力场的时间变化规律。为此，需要由星载GPS数据进行CHAMP卫星的精密定轨。围绕着这些国际地学研究热点，本文的工作和创新点主要有： 1．回顾了重力测量和卫星重力探测技术的发展和应用，阐述了描述低轨卫星状态的直角坐标、Kepler根数、Hill根数和Equinoctial根数之间的相互关系，认为Hill根数和Equinoctial根数能够避免由卫星轨道奇异带来的计算问题，分析了低轨卫星的受摄运动，给出了摄动模型。 2．根据卫星运动微分方程和卫星跟踪观测量，探讨了卫星定轨问题，分析了卫星轨道积分的分析法和数值法，推导了多步CowellⅡ轨道数值积分公式。 3．探讨了星载GPS相位数据钟差改正的多项式拟合法，提出利用宽巷／窄巷法和连续求差法进行模糊度解算以及周跳探测和修复，分析了卫星姿态确定方法、GPS观测量的跟踪点改正模型、GPS天线相位中心改正和偏移改正模型；对CHAMP星载GPS数据和IGS跟踪站实际观测数据进行了处理，认为钟差可达ms级、星载GPS相位观测数据比IGS跟踪站的GPS数据周跳明显增多以及模糊度解算难度增大、GPS相位中心改正和偏移改正可达cm级（甚至更大）。 4．利用IGS跟踪站的GPS数据和星载GPS数据，给出了星载GPS相位观测量、星间相位单差观测量、星地相位双差观测量、星地相位三差观测量，用于卫星精密定轨和地球重力场模型解算。 5．分析了低轨卫星定轨和地球重力场模型解算的参数估计问题，推导了分块Bayes最小二乘参数估计公式，给出了观测方程、变分方程和GPS观测量的导数。 6．根据卫星动力学原理，由星载GPS数据和GS跟踪站的GPS数据构造星地相位双差观测量，对CHAMP卫星进行实际定轨，与德国GFZ的PSO相比，本文定轨径向精度为0.2857m；经过重叠轨道比较和分析，本文重叠轨道径向精度为0.0958m；进行了轨道端点比较，端点轨道径向精度达到0.0666m。 7．根据动力学原理，利用1个月的CHAMP几何定轨结果，采用两步法，解算了一个完全到70阶次的地球重力场模型GGM01S。与EGM96（完全到70阶次）相比，GGM01S的大地水准面起伏精度不超过0.2186m，重力异常精度不超过1.2735mgal。与EIGEN1S（完全到70阶次）相比，GGM01S的大地水准面起伏的精度不超过0.9804m，重力异常精度不超过8.0429mgal。 8．利用1年的CHAMP卫星几何定轨结果，由动力学方法，解算了低阶地球引力位系数时间序列，给出了J₂、J₃，和地心运动的时间变化规律。J₂的变率为山东科技大学博士学位论文摘要jZ二一0.783、10一，’/m onth，J、的年变率为j，=一0.5、10一，，/month，jZ为负说明 地球动力学形状变得越来越圆，人为负说明地球的梨形增强。地心运动的结果为: X方向为8.4mm，变率为X二2.smm/month;Y方向为4.omm，变率为 夕=一l.gmm/month;z方向为5.omm，变率为才=一o.smm/month。更多还原

【Abstract】 The satellite orbit determination is the key to the executive of satellite mission. The earth gravity field is the main force source for the satellite’s motion in its orbit so that the satellite tracking observations can provide more information of the earth gravity filed. Refinement of earth gravity model can improve t ic accuracy of orbit determination of satellite. Therefore, the satellite orbit determir ation and the earth gravity model supplement each other.CHAMP is a German mini-satellite mission used to study on the earth science, atmosphere and their application, one of which is to precisely determine the global static long-wave-length characteristics of earth gravity and its temporal variations. So the precise orbit determination of CHAMP must be made from onboard GPS phase data. Centering on these hot spots of international geo-science studies, the main works and contributions in the dissertation include as follows.1. Development and applications of gravimetry and satellite-borne gravimetry are reviewed. Relations among the rectangle coordinates, Keplerian elements, Hillian elements and Equinoctial elements to describe the motion of low earth orbit satellite are given. The Hillian elements and the Equinoctial elements can solve the calculation problems because of the orbit singular. The perturbed motion of low earth orbit satellite is analyzed and the perturbed models a~e given in the dissertation.2. Based on the differential equations of satellite motion, the satellite orbit determination is discussed from the satellite tracking obseivations. The analytic method and the numerical integration method in the satellite crbit integration are analyzed. Then the multi-step Cowell II numerical integration formulae of satellite orbit integration are concluded.3. The preprocessing of onboard GPS phase data is studied. The polynomial fitting method to correct the clock error of onboard GPS phase data is discussed. The wide-lane and narrow-lane method and the successive difference method are used to solve the ambiguity and to detect and remove the cycle slip. In the meantime, the satellite attitude determination method, the tracking point correction model of GPS observation, the phase center correction and tre phase center offset correction of GPS antenna are analyzed. Soon afterwards, GPS phase data of CHAMP and IGS tracking stations are processed. The clock error is up :o ms level. The cycle slips of onboard GPS phase data of CHAMP are more than these of IGS tracking stations and it is more difficult to solve the ambiguity of onboard GPS phase data than these of IGS tracking stations. The phase center correction and the phase center offset are up to cm level, extremely to dm level.4. To determine the precise orbit of satellite and refine the earth gravity model, onboardGPS phase observations, single difference observation between satellites, air-ground double difference observation and air-ground triple difference observation are constructed from GPS data of IGS tracking stations and CHAMP.5. The problem of parameter estimation to determine the satellite orbit and solve the earth gravity model is analyzed. The partitioned Bayesian least squares parameter estimation is concluded. Then the observation equation, the variation equation and the derivatives of GPS observation are given in the dissertation.6. According to the satellite dynamical theory, the CHAMP orbit is determined from the air-ground double difference observations formed by GPS phase data of CHAMP and IGS tracking stations. Comparing with the PSO of GFZ in Germany, the radial accuracy of the orbit results is 0. 2857m. Comparing and analyzing the overlapping orbits, the radial accuracy is 0.0958m. Comparing the orbit ends, the radial accuracy is 0.0666m.7. Based on the satellite dynamical theory, an earth gravity model up to 70 degree, called as GGMOIS, is solved with the two-step method from one month of geometric orbit data of CHAMP. Comparing with EGM96 up to 70 degree, the geoid undulation accurac更多还原