Integration of Earth rotation, geometry and gravity field using space geodetic observations

将地球自转、重力场和几何学综合到一个统一的系统中是国际大地测量协会（IAG）全球大地测量观测系统（GGOS）的主要目标之一。在本项目的框架内，地球自转参数（例如，极点坐标、日长等）将利用空间大地测量观测进行综合平差，对重力场（主要是低阶球谐系数）和地球几何形状（台站位置及其随时间的变化）进行估计。待分析的数据由配备有空间大地测量观测仪器（VLBI; SLR/LLR;GPS;DORIS）的地面站、测高卫星和低地球轨道（LEO）卫星上的GPS接收器（例如，JASON-1、CHAMP和GRACE）。这些观测的严格结合将保证结果真正一致，充分利用补充空间技术，并可将特定技术偏差与真实的地球物理信号区分开来。本项目内设想的研究工作将主要有助于研究地球自转、重力和几何学之间的相互作用以及它们之间的一致性。最后，将把大地测量结果与地球物理数据进行比较。

The integration of Earth rotation, gravity field and geometry into a unified system is one of the major goals of the ¿Global Geodetic Observing System (GGOS)¿ of the International Association of Geodesy (IAG). In the framework of the present project the parameters of Earth rotation (e.g., pole coordinates, length of the day, etc.) of the gravity field (primarily the low-degree spherical harmonic coefficients) and of the Earth¿s geometry (station positions and their temporal variations) will be estimated in a combined adjustment using space geodetic observations. The data to be analyzed is contributed by the ground stations equipped with space geodetic observing instruments (VLBI; SLR/LLR;GPS;DORIS) by altimetry satellites, and by GPS receivers onboard Low Earth Orbiting (LEO) satellites (like, e.g., JASON-1, CHAMP, and GRACE). The rigorous combination of these observations will guarantee, that the results are really consistent, that the complimentary space techniques are fully exploited ant that technique-specific biases may be distinguished from ¿real¿ geophysical signal. The research work envisaged within the present project will primarily contribute to study the interactions between Earth rotation, gravity and geometry and the consistency between them. Finally, the geodetic results will be compared with geophysical data.