SFB 1128: Relativistic Geodesy and Gravimetry with Quantum Sensors - Modelling, Geo-Metrology and Future Technology (geo-Q)

地球引力场的空间和时间变化使我们能够以独特的方式探测和量化地球系统的变化过程，并监测与气候变化有关的贡献。重力数据能够直接量化质量变化，如极地冰盖目前的质量损失、海平面上升的质量分量以及大小尺度水循环的变化。然而，从目前的卫星测量获得的引力信号并不具有可靠地识别过程的原因、机制和相互作用的分辨率和准确性。Geo-Q的目标是基于革命性的量子传感器和爱因斯坦广义相对论的建模方法来探索确定引力场的新前沿。Geo-Q将研究综合重力模型的三个核心组成部分，并开发三项全新的大地测量技术：1.以纳米级精度进行卫星间距离的激光干涉测量。未来使用这种传感器的卫星重力测量将通过引力信号实现对质量变化的全球连续监测，其精度将提高十倍，空间分辨率将提高两倍(200公里或更高)。2.用于地面测量活动的快速和紧凑的原子重力传感器，以实现超出卫星技术分辨率极限的质量变化的局部恢复。3.用于根据相对论引力频率红移确定引力势的超精密光学原子钟。由于当今时钟计量的极高精度，这成为可能，它开辟了新的视角，为重力测量和全球统一的高度参考建立未来的基本参考。这三个组件的集成将在全球范围内独一无二。在第一个供资期间，我们奠定了基础，现在我们将把这些基础应用于实地的真正衡量标准。我们将使用我们的原子量子重力仪在德国北部进行测量活动。在2018年初启动GRACE后续任务后，我们现在将分析真实数据，而不是我们在第一阶段练习的模拟数据。新的紧凑型加速计和移动时钟将为移动活动提供便利。经过第一阶段的第一次测试，我们现在将利用时钟网络进行相对论测高活动。

Spatial and temporal variations of the Earth’s gravitational field allow unique ways to detect and quantify processes of change in the Earth system and to monitor contributions related to climate change. Gravitational data enable the direct quantification of mass changes, such as the present mass loss of the polar ice sheets, the mass component of sea level rise, and changes in the large and small-scale water cycle. However, the gravitational signals obtained from current satellite measurements do not have the resolution and accuracy to reliably identify the causes, mechanisms, and interactions of the processes.The goal of geo-Q is to explore new frontiers of the determination of the gravitational field based on revolutionary quantum sensors and modelling methods from Einstein’s theory of General Relativity. geo-Q will investigate three central components of integrated gravity modelling and develop three fundamentally new geodetic measurement techniques:1.Laser interferometry for ranging between satellites at the nanometer level of precision. Future satellite gravimetry with such sensors will achieve – through gravitational signals – a global and continuous monitoring of mass changes with a ten times improved accuracy and two times better spatial resolution (200 km or better).2.Rapid and compact atomic gravity sensors for terrestrial measurement campaigns to achieve a local recovery of mass change beyond the limit of resolution of satellite techniques.3.Ultra-precise optical atomic clocks for the determination of the gravitational potential from relativistic gravitational frequency redshift. This becomes possible due to the extreme accuracy of today’s clock metrology, and it opens new perspectives to establish a future fundamental reference for gravitational measurements and a globally homogeneous height reference.The integration of the three components will be unique worldwide. In the first funding period we have laid the foundations that we will now apply to real measurements in the field. We will employ our atomic quantum gravimeter for measurement campaigns in northern Germany. After the launch of the GRACE Follow-on mission in early 2018, we will now analyse real data instead of the simulated data that we practiced on in the first period. New compact accelerometers and mobile clocks will facilitate mobile campaigns. And after first tests in the first period, we will now conduct relativistic height measurement campaigns with clock networks.