The application of time in closure as a novel strategy towards error-free space geodeticobservations

这个项目是最接近于本研究单元封面应用中给出的时钟镊子概述概念的项目。该项目与研究股的其他几个项目，即P1、P5、P6、P8、P9和P10密切合作。这突出了该项目对整个研究单位的核心作用。它针对不同的重点，通过利用在GOW实现的公共时空参考点来改进空间大地测量技术。该项目的总体目标是查明和尽量减少测量误差，并制定适用于日常业务的校准程序。此外，还设想将观测误差和大气延迟分开。今天这些技术提供的准确性仍然受到未知的系统、仪器和模型误差的影响。在第一步中，重新访问已经存在的SLR和VLBI的闭合测量，以识别、提取和解决隐藏的偏差。之后，我们将与GOW的团队一起设计、进行和分析进一步的测量，以便根据时钟关系提出缓解系统误差的最佳策略。多丽丝不直接依赖于地面时钟，GNSS最终将通过伪卫星进行独立校准。这需要与SLR和VLBI不同的分析策略。基于时钟关系的可变系统误差的可靠识别和提取是关键。最后，向研究单位的其他项目(P9和P10)提供经校正(校准)的观测值，以便进行技术间组合。该项目有力地促进了站点基准标记的技术重新设计，将其作为未来可能满足GGOS核心站点需求的榜样，并验证了其性能。

This project is the closest to the outlined concept of the clock tweezers as given in the cover application of this research unit. The project closely cooperates with several other projects of the research unit, namely P1, P5, P6, P8, P9 and P10. This highlights the central role of the project for the whole research unit. It aims at different foci for the improvement of space-geodetic techniques by exploiting the common space-time reference point, realized at GOW. The overall goal of the project is the identification and minimization of measurement errors and the development of calibration procedures applicable in routine operations. In addition, the separation of observation errors and atmospheric delays is envisaged. The accuracy provided by the techniques today still suffers from a combination of unknown systematic instrumental and model errors. In a first step, the already existing closure measurements for SLR and VLBI are revisited to identify, extract and resolve the hidden biases. Afterwards, together with the team at GOW we will design, conduct and analyse further measurements in order to come up with the best strategy for the mitigation of systematic errors, based on clock ties. DORIS does not directly depend on the ground clock and GNSS will eventually have an independent calibration via a pseudolite. This requires a different analysis strategy compared to SLR and VLBI. The reliable identification and extraction of the variable systematic errors based on clock ties are central. Finally, corrected (calibrated) observations are provided to other projects of the research unit (P9 and P10) for the inter-technique combination. This project strongly contributes to the technical redesign of the station fiducial marker as a role model for a possible future GGOS core station requirement and validates its performance.