DocumentCode :
841699
Title :
Utilization of modified polar coordinates for bearings-only tracking
Author :
Aidala, Vincent J. ; Hammel, Sherry E.
Author_Institution :
U.S. Naval Underwater Systems Center, Newport, RI, USA
Volume :
28
Issue :
3
fYear :
1983
fDate :
3/1/1983 12:00:00 AM
Firstpage :
283
Lastpage :
294
Abstract :
Previous studies have shown that the Cartesian coordinate extended Kalman filter exhibits unstable behavior characteristics when utilized for bearings-only target motion analysis (TMA). In contrast, formulating the TMA estimation problem in modified polar (MP) coordinates leads to an extended Kalman filter which is both stable and asymptotically unbiased. Exact state equations for the MP filter are derived without imposing any restrictions on own-ship motion; thus, prediction accuracy inherent in the traditional Cartesian formulation is completely preserved. In addition, these equations reveal that MP coordinates are well-suited for bearings-only TMA because they automatically decouple observable and unobservable components of the estimated state vector. Such decoupling is shown to prevent covariance matrix ill-conditioning, which is the primary cause of filter instability. Further investigation also confirms that the MP state estimates are asymptotically unbiased. Realistic simulation data are presented to support these findings and to compare algorithm performance with respect to the Cramer-Rao lower bound (ideal) as well as the Cartesian and pseudolinear filters.
Keywords :
Decoupling of systems; Direction-of-arrival estimation; Kalman filtering, nonlinear systems; Matrices; Sonar tracking; Tracking filters; Accuracy; Covariance matrix; Differential equations; Filters; Government; Motion analysis; Nonlinear equations; Sea measurements; State estimation; Target tracking;
fLanguage :
English
Journal_Title :
Automatic Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9286
Type :
jour
DOI :
10.1109/TAC.1983.1103230
Filename :
1103230
Link To Document :
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