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Ties between kinematic and dynamic reference frames (D-VLBI)

运动学和动态参考系之间的联系 (D-VLBI)

基本信息

批准号：
199888442
负责人：
Professor Dr.-Ing. Harald Schuh
金额：
--
依托单位：
Institut für Geodäsie und Geoinformationstechnik
依托单位国家：
德国
项目类别：
Research Units
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/199888442?language=en
关键词：
Ties between kinematic dynamic reference

项目摘要

The goal of project D-VLBI is the realization of frame ties between the dynamic reference frames of space probes like satellites or spacecraft, the Moon and other planetary bodies, the kinematically defined International Celestial Reference Frame (ICRF), and the International Terrestrial Reference Frame (ITRF) realized on Earth. This can be done best by using differential Very Long Baseline Interferometry (D-VLBI), which is a precise method for the determination of relative angles between a calibrator and a target source and is typically applied by the space agencies for spacecraft navigation. D-VLBI data are also extensively incorporated into modern ephemeris calculations and D-VLBI has been proven capable for relative astrometry of faint radio sources and for frame tying of optical and radio catalogues. In the second phase of this project we want to perform proofs of concepts of real differential observations to a variety of satellites to test the astrometric performance of modern D-VLBI techniques and hardware, and to identify limitations and realistic uncertainties in the ultimate frame ties that can currently be achieved, for specific satellite and transmitter configurations. We plan new observations of GNSS satellites, the space VLBI satellite RadioAstron, and the Gaia spacecraft. With our GNSS observations, we aim to demonstrate that differential VLBI observations to a variety of GNSS systems, including Galileo and BeiDou, can be successfully carried out using IVS stations, and that we are able to perform the complete analysis chain to parameter estimation. RadioAstron has a VLBI antenna on board and we want to show how well the satellite positions and frame ties can be made for spacecraft that are themselves simultaneously part of the VLBI observing network. And for Gaia, we aim to determine the optimum observing strategy to tie Gaia's orbit to the ICRF, leading in turn to an improvement in the tie to Gaia's own observational frame. Additionally, we want to share the acquired achievements with the partners in the Research Unit, for example, to improve the planetary and Lunar ephemerides. We will provide D-VLBI analysis results for the Lunar SELENE and Chang'e missions, including the Chang'e-3 lander and rover, to projects PN1 and PN3, to improve the Lunar ephemeris and kinematic-Lunar frame tie. For these same groups we will also provide simulations of differential observations for future missions to investigate possible ephemeris and frame-tying improvements. We will cooperate with project PN2 on core-shift affects in the positions of the VLBI calibrator sources. Core-shift effects limit the accuracy with which all astrometric measurements involving ICRF sources can be made at the level of a substantial fraction of a milliarcsecond. Scheduling and executing our observations will be done in cooperation with project PN7a, which will provide technical and observational assistance.

D-VLBI项目的目标是实现卫星或航天器、月球和其他行星体等空间探测器的动态参照系、运动学定义的国际天文参照系和在地球上实现的国际陆地参照系之间的框架联系。这方面最好的办法是使用差分甚长基线干涉测量(D-VLBI)，这是一种确定校准器和目标源之间相对角度的精确方法，通常由空间机构用于航天器导航。D-VLBI数据也被广泛地纳入现代星历计算中，D-VLBI已被证明能够用于微弱射电源的相对天体测量以及光学和射电星表的框架连接。在该项目的第二阶段，我们希望对各种卫星进行实际差分观测的概念验证，以测试现代D-VLBI技术和硬件的天文测量性能，并确定针对特定卫星和发射器配置目前可以实现的最终框架纽带中的限制和现实不确定性。我们计划对GNSS卫星、空间VLBI卫星RadioAstron和Gaia航天器进行新的观测。通过我们的全球导航卫星系统观测，我们旨在证明，可以使用IVS站成功地对包括伽利略和北斗在内的各种全球导航卫星系统进行VLBI差分观测，并且我们能够执行从参数估计到完整的分析链。RadioAstron上有一个VLBI天线，我们想展示如何很好地为本身也是VLBI观测网络一部分的航天器建立卫星位置和框架纽带。对于盖亚，我们的目标是确定将盖亚的轨道与ICRF联系起来的最佳观测策略，进而改善与盖亚自己的观测框架的联系。此外，我们希望与研究股的合作伙伴分享已取得的成就，例如，改进行星和月球星历。我们将向PN1和PN3项目提供包括嫦娥三号着陆器和月球车在内的月球Selene和嫦娥任务的D-VLBI分析结果，以改进月球星历和运动学-月架关系。对于这些相同的小组，我们还将为未来的飞行任务提供差异观测的模拟，以调查可能的星历和框架捆绑改进。我们将与PN2项目合作，解决VLBI校准源位置上的岩心偏移影响。核心漂移效应限制了所有涉及ICRF源的天体测量的精度，这些测量可以在很大程度上在千分之一秒的水平上进行。我们的观测计划和执行工作将与PN7a项目合作进行，该项目将提供技术和观测援助。