The Gravity Recovery and Climate Experiment (GRACE) space gravity mission provides a means of estimating changes in mass on the Earth, including hydrological processes, oceanic variations and melting of polar ice sheets.
The raw measurements are actually changes in the distance (accurate to 1/10 of the width of a human hair) between two satellites orbiting at 450 km altitude and separated by ~200 km. To achieve this, we must first compute the orbit of the two satellites, taking into account gravitational effects of the Sun, Moon, ocean tides, atmospheric variations to then be able to identify the signal of the temporal changes in the Earth's gravity field.
The student will be involved in developing software and background models to derive more accurate estimates of the Earth's gravity field. They will then use the estimates to study geophysical processes on Earth.