A02 – Gravity Sensing with VLBAI

The research project A02 is focusing on two key aspects:

• The correlation of the very long baseline atom interferometer (VLBAI) with motion sensors on the Seismic Attenuation System (SAS) making it possible to utilise the large scale factors achievable on such distances.
• Detailed investigation of systematic effects at an uncertainty level ≤ 10nm/ s² leading towards the operation of the VLBAI facility as a higher-order reference gravimeter.

With the vibration isolation in work, the instability of our VLBAI could reach ≤ 5nm/ s² at 1 s, equivalent to an order of magnitude improvement over the state of the art and competitive with superconducting gravimeters and will in the long run provide the data for more precise mass transport models. Similarly, this unprecedented sensitivity is key to characterising systematic effects at the targeted level. With the SAS in the work, the VLBAI facility will commence operation as a gravimeter and register gravity time series. This project will allow us to operate the first gravity reference station based on VLBAI and prove its benefits in the first comparison campaign of such a device with transportable secondary gravimeters such as the FG5X-220 and the gravimeter QG-1 in project A01.