固定非差模糊度的重力卫星运动学精密定轨方法

项目名称： 固定非差模糊度的重力卫星运动学精密定轨方法

项目编号： No.41304027

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 张守建

作者单位： 武汉大学

项目金额： 25万元

中文摘要： 卫星精密定轨是本世纪新一代卫星重力任务成功实施的核心技术之一，运动学轨道因不受先验力学模型影响，最适于地球重力场反演。然而，运动学轨道对观测噪声及观测条件非常敏感，轨道整体精度较差且局部存在系统性偏差。为了进一步提高运动学轨道精度及可靠性，本项目围绕非差模糊度固定的关键技术开展深入研究：（1）针对星载GPS数据粗差多、周跳多、受电离层影响大等特点，提出利用原始载波相位观测值探测并修复周跳的有效方法，提高非差模糊度固定成功率；（2）针对低轨卫星弧段短、模糊度多等特点，研究非差模糊度估计、固定及检验方法，确保运动学定轨的精度和可靠性；（3）研究非差精密定轨观测模型增强方法，提高观测卫星数目偏少时的轨道精度。最终实现固定非差模糊度的运动学定轨，并确定精度为2~3 cm的长弧段运动学轨道，为确定更高精度的地球重力场模型奠定基础并提供技术支撑。

中文关键词： SPAR方法；周跳；模糊度固定；小数偏差；运动学定轨

英文摘要： Precise orbit determination is one of the key technologies in the new generation satellite gravity missions, the kinematic orbits, which are independent of the a priori dynamic model, are the most suitable ones for the Earth gravity filed determination. However, then accuracy of the kinematic orbits, which are sensitive to the observation noise and the observation geometry, are poor and there are some systematic errors. In order to improve the accuray and reliability of the kinematic orbits, this proposal will resolove the zero-difference ambiguity fixing technologies, and study: (1) Considering that the space-borne GPS data have more gross errors and cycle slips, we will try to detect and repaire the cycle slips using the raw carrier phase observations; (2) Considering that the continuous arc is very short and there are much more ambiguities in space-borne GPS data, in order to keep the accuracy and the reliability of the kinematic orbits, we will study the zero-difference ambiguity estimation, fixing and validiation method; (3) Study the orbit enhancement method to improve the orbits' precision in case of satellite number less than four. Finally, the kinematic orbits' precision will be improved by fixing the zero-difference ambiguities, and kinematic orbits with accuracy of 2 ~ 3 cm for CHAMP, GRACE and GOCE s

英文关键词： SPAR；Cycle Slip；Ambiguity Resolution；UPD；Kinematic POD