The main focus of this project is to carry out theoretical studies and simulations characterizing the future potential of space gradiometry when applying new (i.e., optical) technology. Gravitational gradiometers provide a high-sensitivity signal that allows the reconstruction of the static gravity field from space with high spatial resolution down to 50 – 80 km. GOCE, for example, used six test masses to measure 2nd derivatives of the gravitational potential using an electrostatic read-out of the test masses. By replacing the electrostatic readout with laser-interferometric techniques, such as have been developed for LISA Pathfinder and LISA, the resolution and noise-level can be significantly improved and even the recovery of temporal variations of the gravity field might become possible. By adding one more test mass in the center, 3rd derivatives could be determined. While a parallel project, A07, aims to develop instrumentation components of such a gradiometer, here the system-level implications will be studied in detail, e.g., the optimal configuration of test masses, processing of raw data, separation of the centrifugal part, drift behavior, measurement bandwidth and dynamic range.

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