Novel sensor concepts for future gravity field satellite missions

The German Aerospace Center (DLR) recently announced the establishment of new institutes dedicated to the development of quantum technologies for a variety of applications. The DLR-Institute for Satellite Geodesy and Inertial Sensing (DLR-SI) will, among others, develop inertial sensors based on quantum optical methods and concepts for their use in Earth observation. DLR-SI is located at Leibniz University of Hannover (LUH) with departments at the Center of Applied Space Technology and Microgravity (ZARM, Bremen) and Physikalisch-Technische Bundesanstalt (PTB, Braunschweig). The department Satellite Geodesy and Geodetic Modelling at LUH focuses on geodetic applications, e. g. for next-generation gravity missions and reference systems. As a first step, the implementation of GRACE-FO and GOCE type satellite gravimetry missions utilising different approaches of integrating a cold atom interferometer (CAI) with classical electrostatic accelerometers is investigated. Even the addition of a single axis CAI, creating a hybrid of the classical and quantum sensor, can improve the derived gravity field solution. This technique can be extended to a gradiometer as well, by simultaneously probing two spatially separated atomic clouds for one axis. In addition to the development of CAI based sensors, the progress of atomic clocks makes a new type of observation available for the low degree gravity field coefficients. This presentation gives an overview of the current and planned work at the newly formed department for Satellite Geodesy and Geodetic Modelling at DLR-SI. We present the first studies on the implementation of CAI-supported sensors and the combination of different sensor types for satellite gravimetry missions