Estimation of the Anomalous Gravity Gradient via Precision Angle Tracking.

摘要

A preliminary feasibility study was done on a proposal to estimate the anomalous gravity gradient via precision measurements between two accelerometer triads moving through a gravity field. The state equations to describe the system were developed and an Extended Kalman Filter was designed to exploit the measurement data. A simple, first-order numerical approximation was used in gradient estimation. In addition, a brief conceptualization of the hardware which might be used in an operational system of this type is included. The results indicate that the numerical ill-conditioning in the problem makes the Extended Kalman Filter a poor choice of estimator. Even after scaling variables and employing a U-D Covariance factorization update algorithm, numerical instabilities in the filter were observed. Recommendations for further work on this topic are included. (Author)