时变引力场对天体测量观测量的相对论影响

With space-borne techniques of measurements, astrometric observation will be able to achieve the accuracy of few microarcsecond or higher. For observations conducted in mutliply epochs, in addition to static gravitational fields, the relativistic effects on astrometry due to time-evolutiosn gravitational fields will reach the thresholds of detection and have to be considered. This research intends to construct the relativistic model of astrometric observations including the effects due to time-evolution gravitational fields in celestial systems, which mainly foucus on two essential issues: (1) Given celestial systems' astrophysical properties, orbital geometry and astrometric parameters, how to describe the effects on the background sources of astrometric observations due to the time-evolution gravitational field; (2) According to observed the time-dependent astriometric quantities of background sources, how to solve the astrophysical properties, orbital geometry and astrometric parameters of the celestial system which causes the light deflection. This framework will provide theoretical foundation for reducing and processing of high-precision space-borne astrometric observations in the future (e.g. Gaia).

以空间探测手段为依托，天体测量的精度将从毫角秒提高到微角秒甚至更高精度水平。对于多历元观测而言，此时除了静态引力场的效应需要考虑以外，天体系统的引力场随时间的变化（即，时变引力场）对天体测量观测量的相对论效应也将达到未来可探测的阈值。本课题旨在建立起天体系统的时变引力场对天体测量观测量的相对论模型，主要围绕着两大核心问题：（1）已知引力系统的物理、轨道几何以及天体测量参数，如何来描述时变引力场对背景源天体测量观测量的影响；（2）根据观测到某天体随时间变化的天体测量量，如何来解读起光线偏折作用的引力系统的物理、几何以及天体测量参数。这一模型将为未来高精度空间天体测量数据（如Gaia）的归算与处理提供理论基础和支撑。

以空间探测手段为依托，天体测量的精度将从毫角秒提高到微角秒甚至更高精度水平。对于多历元观测而言，此时除了静态引力场的效应需要考虑以外，天体系统的引力场随时间的变化（即，时变引力场）对天体测量观测量的相对论效应也将达到未来可探测的阈值。本课题旨在建立起天体系统的时变引力场对天体测量观测量的相对论模型，主要围绕着两大核心问题：（1）已知引力系统的物理、轨道几何以及天体测量参数，如何来描述时变引力场对背景源天体测量观测量的影响；（2）根据观测到某天体随时间变化的天体测量量，如何来反解起光线偏折作用的引力系统的物理、几何以及天体测量参数。针对上述两大核心问题，本项目的主要研究结果包含了：（1）建立时变引力场相关的角度测量模型；（2）解读其中的物理信息；（3）研究这些物理参数的特性。这一模型将为未来高精度空间天体测量数据（如Gaia）的归算与处理提供理论基础和支撑。