GGOS-SIM-2: Simulation of the Global Geodetic Observing System

ggoes - sim -2的总目标是评估四种主要空间大地测量技术（卫星综合多普勒轨道和无线电定位、全球卫星导航系统、卫星激光测距、甚长基线干涉测量法）在空间中同时定位的潜力，即在一颗或多颗卫星上同时定位。实现全球大地参考系统（TRS）的精度和稳定性，满足国际大地测量协会（IAG）全球大地观测系统（GGOS）的科学驱动要求。目前，这些质量要求尚未达到，但对于可靠地解释全球过程（如全球海平面上升）是非常必要的。在GGOS-SIM项目的第一阶段，所取得的结果表明，四种主要空间大地测量技术的模拟适用于调查全球地面参考框架（TRF）的准确性和稳定性。在第二阶段（GGOS-SIM-2），我们计划通过考虑四种技术在空间上的共存并量化对TRF确定的影响来扩展这些模拟。使用空间连接代替或额外使用通常将各个技术相互连接的地面本地连接，将允许验证这些本地连接，这些本地连接目前在TRS实现方法中没有任何外部控制。在GGOS-SIM-2中，将解决以下问题：•通过类似grip的卫星在空间中应用共定位，可以获得多少精度的后机场及其相关产品，如地球方向参数？•在一颗（或多颗）卫星上实现空间联系的TRS附加价值是什么，以补充地面上的本地联系？•根据最佳轨道选择、地面站数量、观测时间和卫星数量，为了获得满足GGOS要求的TRF，必须满足哪些标准？•在公共POD中特定技术的系统分类对基金会的影响是什么？•对于当地的联系可以得出什么结论？•静态和时变重力场的前景如何？

The overall objective of GGOS-SIM-2 is to assess the potential of co-location in space of the four main space geodetic techniques (Doppler Orbitography and Radiopositioning Integrated by Satellite, Global Navigation Satellite Systems, Satellite Laser Ranging, Very Long Baseline Interferometry), i.e. on board of one or more satellites, to realize a global terrestrial reference system (TRS) with an accuracy and stability meeting the science-driven requirements specified by the Global Geodetic Observing System (GGOS) of the IAG (International Association of Geodesy). Currently, these quality requirements are not achieved but are strongly required to reliably interpret global processes, such as the global sea level rise. Within the first phase of project GGOS-SIM, the achieved results have demonstrated the suitability of simulations of the four main space geodetic techniques for investigating the accuracy and stability of global terrestrial reference frames (TRF). In the second phase (GGOS-SIM-2) we plan extending these simulations by considering co-locations of the four techniques in space and quantifying the effects on the TRF determination. Using space ties instead of or additionally to ground local ties that are customarily interconnecting the individual techniques will allow validating these local ties, which are currently applied without any external control in the TRS realization approaches.Within GGOS-SIM-2 the following questions will be addressed:• Which level of accuracy of the TRF and the related products like Earth orientation parameters can be obtained, applying co-location in space through a GRASP-like satellite?• What is the added value for TRS realization of a space tie on one (or more) satellite(s) complementing the local ties on ground?• Which criteria have to be fulfilled in order to get a TRF meeting the GGOS requirements depending on optimal orbit selection, number of ground stations, observation time, and number of satellites? • What is the impact of technique-specific systematics within the common POD on the TRF?• What can be concluded for the local ties at the ground?• What are the prospects for the static and time-variable gravity field?