Abstract:

The gravity field recovery approach tailored to a twin satellite gravity mission of the GRACE type as presented here, is based on Newton's equation of motion, formulated as a boundary value problem in the form of a Fredholm type integral equation. The basic characteristic of this method is the use of short arcs of the satellite's orbit in order to prevent an increase of mismodelling errors. Furthermore, the presented approach features a unique way of combining range, range-rate as well as range-acceleration observations.

One year of GRACE data is used to simultaneously determine a high resolution static gravity field and monthly variations in the long wavelength part in one recovery step.

The validation of the gravity fields is performed by comparison to existing GRACE gravity field models as well as by external validation based on different criteria. The results reveal the excellent quality of the presented gravity field.