SFB 1464: Relativistic and quantum-based geodesy (TerraQ)

气候变化过程在重力数据中广泛存在。但是，监测相关的质量变化需要更好的时空分辨率和更高的精度，这只能通过采用创新的量子技术概念来实现。TerraQ将大地测量学和物理学的专业知识整合在一个独特的组合中，开发全新的传感器、测量技术和分析方法。在测试质量和卫星之间进行光学测距，原子干涉加速度测量和梯度测量，以及用时钟测量时间是克服经典概念问题的必要方法。有了这些新技术，几乎所有空间和时间尺度上的质量变化都可以以前所未有的精度进行观测，并将作为地球科学中大量应用的输入，从监测当地地下水盆地到观测海洋中复杂的全球质量运输过程。为了推进卫星重力测量，TerraQ研究了激光干涉测量系统，用于测量地球轨道上测试质量之间的距离。在这里，TerraQ基于其pi从以前成功的卫星任务（如GRACE Follow-On）中获得的知识，在分辨率和精度方面迈出了下一步。对于地面重力测量，TerraQ研究和开发量子传感器，用于基于冷原子的物质波干涉测量的快速和非常精确的重力测量。这些发展包括用于野外活动的紧凑型移动设备和用于极高精度的大型固定设备。前者为地方和区域重力调查提供了新的战略，这将在易北-威西沿海地区得到证明，后者将在未来提供新的重力标准。terrraq开创了用于实现物理高度系统和重力场观测的计时水准概念。关键是测量由于分离时钟的引力红移引起的频率差异，以确定大地测量网中的重力位差。为此，我们使用由光纤连接的可移动光学原子钟。这些时钟和概念现在将发展到达到几厘米的精度水平。TerraQ把分析模型，需要表征和应用新的测量概念在一个健全的理论基础。将对各种涉及的重力场量进行专门的大地测量和相对论建模，以牢固地显示新方法与传统方法相比的优越性能。TerraQ将量子物理学和大地测量学的专业知识结合起来，将工程技术和基础研究相结合，为推进重力地球观测的前沿奠定了良好的基础。我们对观测质量变化的新概念的发展和实现将为气候变化研究提供重要的投入，对整个地球科学领域产生巨大影响。

Climate change processes are widely imprinted in gravitational data. But better temporal and spatial resolution and higher accuracy are required to monitor the related mass changes, which can only be achieved by employing innovative quantum technology concepts. TerraQ integrates expertise from geodesy and physics in a unique constellation to develop fundamentally new sensors, measurement techniques and analysis methods. Optical ranging between test masses and satellites, atom-interferometric accelerometry and gradiometry, and chronometric levelling with clocks are the required approaches to overcome the problems of classical concepts. With these novel techniques, mass variations on almost all spatial and temporal scales can be observed with unprecedented accuracy and will serve as input for a multitude of applications in the geosciences, from the monitoring of local groundwater basins to the observation of the complex global mass transport processes in the oceans.To advance satellite gravimetry, TerraQ investigates laser-interferometric systems for ranging between test masses in Earth orbits. Here, TerraQ builds on its PIs’ knowledge from previous successful satellite missions such as GRACE Follow-On to make the next step in resolution and accuracy.For terrestrial gravimetry, TerraQ studies and develops quantum sensors for rapid and very accurate gravity measurements based on matter wave interferometry with cold atoms. These developments include both compact, mobile devices for field campaigns and large-scale stationary devices for extreme precision. While the former enable new strategies for local and regional gravity surveys, which will be demonstrated in the Elbe-Weser coastal region, the latter will provide a new gravity standard in the future.TerraQ pioneers the concept of chronometric levelling for the realisation of physical height systems and gravity field observations. Key is the measurement of frequency differences due to the gravitational redshift of separated clocks to determine gravity potential differences in geodetic networks. For this, we use transportable optical atomic clocks connected by optical fibres. These clocks and concepts will now be developed to achieve the few cm level of accuracy.TerraQ puts the analysis models, needed to characterise and apply the novel measurement concepts on a sound theoretical basis. Dedicated geodetic and relativistic modelling of the various involved gravity field quantities will be performed to firmly show the superior performance of the new approaches compared to the conventional ones.The combination of expertise from quantum physics and geodesy in TerraQ, integrating engineering skills and fundamental research, serves as an excellent basis to advance the frontiers of gravimetric Earth observation. Our development and realisation of new concepts for observing mass variations will provide crucial input for climate change research with an enormous impact on the whole field of geoscience.