Remote sensing of gravity: Feasibility of low orbit local gravimetry with nanosatellites

Radiometry of earth's gravity (gravity gradiometry) and gravimetry have become key tools to perform reconstructions of geological strata in the upper earth's crumble. In several locations, it is being intensely used to locate unknown oil reservoirs by determining the gravity anomalies produced by salt bodies. Nevertheless, in most cases, gradiometric or gravimetric data are obtained by ships or airplanes, both of which are very expensive methods of indirect geophysical exploration. In this paper we propose the possibility to perform gravimetry from a low orbit nanosatellite mission (CubeSat), which might be cheaper than traditional methods. We show that mathematically, it is possible to detect and reconstruct gravitational anomalies with an accuracy similar to that of data taken by airplanes flying up to 10 km above sea level. We discuss the ability of the algorithm to distinguish gravitational anomalies as a function of different orbital altitudes, showing the feasibility of performing satellite gravimetry which provides a first insight of regions of potential interest, so to make further geophysical explorations at sea level just in regions of interest. This method seems to constitute a cheaper alternative than performing the gravimetry on airplanes, particularly in greater extensions of territory.