Accession Number : ADA309774

Title :   Discrete Asynchronous Kalman Filtering of Navigation Data for the Phoenix Autonomous Underwater Vehicle.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : McClarin, David W.

PDF Url : ADA309774

Report Date : MAR 1996

Pagination or Media Count : 140

Abstract : The Phoenix Autonomous Underwater Vehicle must be able to accurately determine its position at all times. This requires: (1) GPS and differential GPS for surface navigation, (2) short baseline sonar ranging system for submerged navigation, and (3) mathematical modeling of position. This thesis describes a method of Kalman filtering to merge the GPS, differential GPS, short baseline sonar ranging, and the mathematical model to produce a single state vector of vehicle position and ocean currents. The filter operates in the extended mode for processing the nonlinear sonar ranges, and in normal mode for the linear GPS/DGPS data. This required installation of a GPS system and the determination of the different variances and errors between these systems. Phoenix now has a real time method of position determination using either position measuring system separately or combined. The results of this work have been validated by real world testing of the vehicle at sea, where position estimates accurate to within several meters were obtained.

Descriptors :   *KALMAN FILTERING, *POSITION FINDING, *AUTONOMOUS NAVIGATION, *UNDERWATER NAVIGATION, MATHEMATICAL MODELS, UNDERWATER VEHICLES, ASYNCHRONOUS SYSTEMS, REAL TIME, THESES, NONLINEAR SYSTEMS, BASE LINES, SELF OPERATION, SONAR, ECHO RANGING, ACOUSTIC RANGES.

Subject Categories : Underwater and Marine Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE