LEO orbit modeling improvement and application for GNSS and DORIS LEO satellites

该项目旨在开发改进的非保守力模型和相应的软件工具，用于地球卫星轨道的动态建模，根据空间大地测量技术的测量数据确定精确轨道，以及进行相应的测试和验证实验。该项目的一个重要部分是将轨道模型应用于多年解决方案，以调查对大地测量、地球物理和大气参数估计的长时间序列的影响。实际上，估计的地面站坐标、地球自转参数和对流层天顶延迟的准确性与所用轨道的质量直接相关。该项目包括所有主要卫星技术的应用，主要是微波技术GPS（全球定位系统）和DORIS（卫星综合多普勒轨道和无线电定位），但也包括GLONASS（全球导航系统）、GIOVE（伽利略在轨验证元件）和SLR（卫星激光测距）。

The project aims at the development of improved non-conservative force models and corresponding software tools for dynamical modeling of Earth satellite orbits, determination of precise orbits from measured data of space geodetic techniques as well as corresponding tests and validation experiments. An important part of the project is the application of the orbit models on the multi-year solution to investigate the impact on long time-series of estimated geodetic, geophysical and atmospheric parameters. The accuracy of estimated ground station coordinates, Earth rotation parameters and troposphere zenithal delays, in fact,is directly related to the quality of the used orbits. The project includes applications of all the major satellite techniques, mainly the microwave techniques GPS (Global Positioning System) and DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), but also GLONASS (Globalnaja navigacionnaja sputnikovaja sistema), GIOVE (Galileo In-Orbit Validation Element), and SLR (Satellite Laser Ranging).