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Estimating Small-Body Gravity Field from Shape Model and Navigation DataThis paper presents a method to model the external gravity field and to estimate the internal density variation of a small-body. We first discuss the modeling problem, where we assume the polyhedral shape and internal density distribution are given, and model the body interior using finite elements definitions, such as cubes and spheres. The gravitational attractions computed from these approaches are compared with the true uniform-density polyhedral attraction and the level of accuracies are presented. We then discuss the inverse problem where we assume the body shape, radiometric measurements, and a priori density constraints are given, and estimate the internal density variation by estimating the density of each finite element. The result shows that the accuracy of the estimated density variation can be significantly improved depending on the orbit altitude, finite-element resolution, and measurement accuracy.


Document ID
20150014786
Document Type
Conference Paper
External Source(s)
Authors
Park, Ryan S. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Werner, Robert A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bhaskaran, Shyam (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 3, 2015
Publication Date
August 18, 2008
Subject Category
Lunar and Planetary Science and Exploration
Report/Patent Number
AIAA Paper 2008-6603
Meeting Information
AIAA/AAS Astrodynamics Specialist Conference(Honolulu, HI)
Distribution Limits
Public
Copyright
Other
Keywords
Covariance Analysis
Estimation
Finite-Element