Observing the gravity field of different planets and moons by space-borne techniques: Predictions by fast error propagation tools

Abstract

In the first decade of the twenty first century, great strides have been made in observing the Earth’s gravity field by space-borne techniques such as high-low Satellite-to-Satellite tracking by the Global Positioning System (hl-SST, providing 3D information about orbit perturbations), low-low Satellite-to-Satellite tracking (ll-SST) and Satellite Gravity Gradiometry (SGG). In addition, great advances have been made in (preparations for) gravity field recovery for other bodies in the solar system as well, including Mars and the Moon, using tracking from the Deep Space Network (DSN), but also techniques such as hl-SST, ll-SST, Satellite Laser Ranging (SLR) and Delta VLBI. The purpose of the work described in this paper is to gain insight in the possibilities of observing the gravity field of various planetary bodies by space-borne observation techniques. For low-earth orbiting (LEO) satellites, efficient error propagation tools are available that allow an assessment of the gravity field performance as a function of orbital geometry and instrument or observation technique. These tools have been extended for use to other bodies in our solar system, including the Earth’s Moon, Jupiter, Mars, Titan, Enceladus, Europa and Phobos, which are in the scientific spotlight for various reasons. The gravity field performance has been assessed for satellites orbiting these bodies assuming these satellites can make use of DSN tracking or can acquire ll-SST or SGG observations.