权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Barycentric Ephemeris

重心星历表

基本信息

批准号：
199886862
负责人：
Professor Dr.-Ing. Jürgen Müller
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/199886862?language=en
关键词：
Barycentric Ephemeris

项目摘要

The goal of this project is to lay the foundations for a new solar system ephemeris. In the first funding phase, the work focused on the identification and acquisition of observational data, the improvement of relevant force models,, and on the corresponding software development. Regarding the force model, the work initially concentrated on the librational motion of the Moon as well as on perturbing effects due to individual asteroids or asteroid populations, in the form of ¿mass rings¿. The implementation of a mass ring is planned by the end of the first phase. Concerning force modeling, updates shall be implemented in the second phase, which includes an improved lunar libration model (PN3). Furthermore, we will investigate the significance of additional mass rings, representing e.g., Trans-Neptunian Objects. The explicit optional use of TCB is planned for future versions of our ephemeris, which requires the introduction of time-scale-consistent initial values and masses. Moreover, a relation with the TT time scale is essential for data reduction. So far, in this step we adopted the series expansion of Hirayama. To enable direct comparisons with other ephemerides, this analytical approach shall be replaced by simultaneous numerical integration of the differential equation for the time-scale difference TT-TDB together with the equations of motion for the solar system bodies. The check of the accuracy of our ephemeris will continue via cross-comparisons with renowned ephemerides (DE, INPOP, EPM). On the other hand, we will exploit new available observations (DVLBI, Gaia). For the first time, these allow a firm tie of the dynamical reference frame (realized by the motion of celestial bodies) w.r.t. the kinematical reference frame (via D-VLBI and Gaia observations of stars and solar system objects). A direct relation between the involved reference frames is given by planned VLBI observations of the Gaia spacecraft (PN4). After inclusion of any available observational data, a re-determination of relevant solar system parameters will be performed. This requires the development of a suitable combination strategy and careful weighting scheme for different observation types, and the selection of an optimal set of parameters for a common adjustment. In addition, the new ephemeris will support tests on fundamental physics parameters. The high computational burden of the ephemeris calculation shall be met by parallel computing techniques. Benefitting from our experiences, efforts in this direction will be intensified in the second funding period. For the software implementation we will request support from highperformance computer centers affiliated with the partner institutions. Users of our new ephemeris within the research group will be the colleagues from the projects PN2, PN3, PN4, and PN5. Further collaborations are planned with external users, such as with the asteroid and comet group at DLR.

该项目的目标是为新的太阳系星历表奠定基础。在第一个供资阶段，工作重点是确定和获取观测数据，改进相关的力模型，以及开发相应的软件。关于力模型，工作最初集中在月球的平动以及由于单个小行星或小行星群的扰动效应，以质量环的形式。计划在第一阶段结束时实施大规模环。关于力模型，将在第二阶段进行更新，其中包括改进的月球天平动模型（PN 3）。此外，我们将研究额外的质量环的意义，例如，外海王星天体TCB的明确可选使用计划为我们的星历，这需要引入时间尺度一致的初始值和质量的未来版本。此外，与TT时间尺度的关系对于数据简化是必不可少的。到目前为止，在这一步中我们采用了平山级数展开。为了能够与其他星历表进行直接比较，这种分析方法将由时间尺度差TT-TDB的微分方程与太阳系天体的运动方程同时进行数值积分来代替。我们将继续通过与著名的星历（DE、INPOP、INP-C）进行交叉比较来检查我们的星历的准确性。另一方面，我们将利用新的可用观测（DVLBI，盖亚）。这是第一次，这些允许一个坚实的纽带的动力学参考系（实现天体的运动）w.r.t.运动学参考系（通过D-VLBI和盖亚对恒星和太阳系天体的观测）。盖亚航天器（PN 4）计划进行的VLBI观测给出了所涉及的参考框架之间的直接关系。在纳入任何现有观测数据之后，将重新确定相关的太阳系参数。这就需要为不同的观测类型制定适当的组合策略和仔细的加权方案，并为共同的平差选择一组最佳参数。此外，新的星历表将支持对基本物理参数的测试。星历表计算的高计算负担将通过并行计算技术来解决。在第二个供资期，将借鉴我们的经验，加强这方面的努力。对于软件的实施，我们将要求与合作机构附属的高性能计算机中心提供支持。研究小组内我们新星历的用户将是项目PN 2、PN 3、PN 4和PN 5的同事。还计划与外部用户开展进一步合作，例如与德国航天中心的小行星和彗星小组合作。