Tomographic inversion of gravity gradient field for a small solar system body: Mathematical methodology, resolution, noise and measurement configuration.

In this paper, we investigate gravity gradient field inversion of spacecraft-performed measurements in numerical experiments, in which the asteroid model is based on the shape of the asteroid Itokawa. We base our models on the recent observations and modeling studies which suggest that the internal density varies, increasing towards the center, and that the asteroid may have a detailed structure. Our goal is to advance the mathematical inversion methodology and find feasibility constraints for the resolution, noise and orbit selection for future space missions. The results obtained with simulated data show that the adopted inversion approach has a strong influence on the reconstruction obtained and, furthermore, suggest that the present randomized multiresolution scan algorithm provides a robust way to cancel out bias and artifact effects related to the measurement noise and numerical discretization. It also seems that a noise level below 80 eotvos will be sufficient for the detection of internal voids and high density anomalies, if a limited-angle set of measurements can be obtained from a close-enough distance to the target.