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Tomographic inversion of gravity gradient field for a synthetic Itokawa model

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number113425
JournalIcarus
Volume336
Early online date3 Sep 2019
DOIs
Publication statusE-pub ahead of print - 3 Sep 2019
Publication typeA1 Journal article-refereed

Abstract

This article investigates reconstructing the internal mass density of a numerical asteroid model using the gradient of a simulated gravity field as synthetic measurement data. Our goal is to advance the mathematical inversion methodology and find feasibility constraints for the resolution, noise and orbit selection for future space missions. We base our model on the shape of the asteroid Itokawa as well as on the recent observations and simulation studies which suggest that the internal density varies, increasing towards the center, and that the asteroid may have a detailed structure. We introduce randomized multiresolution scan algorithm which might provide a robust way to cancel out bias and artifact effects related to the measurement noise and numerical discretization. In this scheme, the inverse algorithm can reconstruct details of various sizes without fixing the exact resolution a priori, and the randomization minimizes the effect of discretization on the solution. We show that the adopted methodology provides an advantageous way to diminish the surface bias of the inverse solution. The results also suggest that a noise level below 80 Eotvos will be sufficient for the detection of internal voids and high density anomalies, if a sparse set of measurements can be obtained from a close-enough distance to the target.

Keywords

  • Asteroid Itokawa, Geophysical techniques, Interiors

Publication forum classification

Field of science, Statistics Finland