Institute of Geodesy Research Research Projects
High performance satellite formation flight simulator (CRC 1128, B05)

High performance satellite formation flight simulator (CRC 1128, B05)

Led by:  Dr. Meike List (ZARM), Dr.-Ing. Benny Rievers (ZARM)
Team:  Guy Apelbaum, Dr. Takahiro Kato , Florian Wöske, Dr. Sergiy Svitlov, Dr. rer. nat. Ertan Göklü, Stefanie Bremer
Year:  2014
Funding:  DFG
Is Finished:  yes
Further information

[Translate to English:] The development of high performance sensor systems for geodesy applications demands thorough simulation and adaption processes which are able to realize a level of modeling precision corresponding to the targeted measurement accuracy. This means that a high level of accuracy has to be implemented on both the modeling as well as the numerical approach.

intends to address this problem by developing modular models, tools and methods for the realization of a high precision end-to-end simulation of the geodetic measurement concepts and systems developed in this SFB. With the methods contained in this High Performance Satellite Dynamics Simulator for Satellite Gravimetry (HPS-SG) we will be able to evaluate the performance of measurement systems and sensors, to compare different concepts and to identify means of optimization with a full scale implementation of the system as a numeric model. The focus of the intended works lies on i) a precise modeling of the interaction between sensors and system, ii) a precise modeling of the interaction between the system and the environment (including the influence of the detailed satellite and payload geometry) and iii) the development of a modular modeling approach targeting a fast and flexible assembly of different measurement concepts or mission simulations. In this respect all methods and tools developed in B05 will offer a generic approach which can be adapted to any of the new geodetic measurement concepts developed and researched in this SFB and thus are the foundation for the performance analysis and the optimization.

Besides the general system/sensor analysis questions, B05 also addresses the question of how environmental and system disturbances couple e.g into the gravimetric science signals, how much of the residuals in existing data can be credited to system and environmental influence and how these influences can be identified and extracted from existing data. In this respect the works concentrated in B05 will lead to an improved understanding of the role of environment and system for the resulting residuals in the gravitational field model, and as a long-term goal the reduction of these residuals by a better modeling of the disturbance sources. This is motivated by the experience from current missions, where some effects influencing the sensors performance (such as the twangs for GRACE) cannot be identified and characterized adequately, which may probably be credited to a missing or inaccurate disturbance model. The great benefit of this approach has already been demonstrated for the Pioneer 10 mission, where a missing/imprecise thermal radiation pressure model in the orbit determination codes has led to Doppler residuals which have become known as the Pioneer anomaly. Here a new high precision numerical approach was able to identify this controversially discussed effect as a conventional drag force caused by anisotropic heat radiation (Rievers and L¨ammerzahl, 2011). In this respect, B05 aims at the expansion of the successful philosophy of high-precision perturbation modeling to the area of gravimetric space missions.

In summary B05 delivers the needed numerical foundation for a sensible evaluation and characterization of geodetic measurement concepts, a structured approach for an identification of environmental and system disturbances and thus yields a considerable improvement for the evaluation of already measured data (e.g. GRACE) as well as for the development of new geodetic measurement systems. In this respect, B05 will provide a generic infrastructure for all projects within this SFB. This will be of particular importance for B04, which depends on the use of the HPS-SG end-to-end simulator to generate orbit and system data for the assembly of mock data sets.