Title :
GPS estimation algorithm using stochastic modeling
Author :
Nardi, S. ; Pachter, M.
Author_Institution :
Inst. of Technol., Wright-Patterson AFB, OH, USA
Abstract :
The use of direct, or closed-form, solutions of the trilateration equations for obtaining the position fix in the GPS receiver is investigated. A new closed-form position determination algorithm that works in the presence of pseudorange measurement noise and for an arbitrary number of satellites n, where n⩾4, using stochastic modeling is developed. The closed-form algorithm provides an estimate of the GPS solution, viz., user position and user clock bias, as well as the estimation error covariance. The direct algorithm is a two step procedure which, (1) entails the solution of a linear regression problem, and, (2) an update of the solution based on an additional nonlinear measurement equation. Realistic simulation experiments are performed and the direct algorithm´s performance is discussed and compared to the iterative least squares algorithm currently used in GPS
Keywords :
Global Positioning System; covariance analysis; error analysis; noise; radio receivers; stochastic processes; GPS estimation algorithm; GPS receiver; Kalman update algorithm; closed-form algorithm; closed-form position determination algorithm; closed-form solution; direct algorithm; direct solution; estimation error covariance; iterative least squares algorithm; linear regression problem; nonlinear measurement equation; position fix; pseudorange measurement noise; satellites; simulation experiments; stochastic modeling; trilateration equations; two step procedure; user clock bias; user position; Clocks; Equations; Estimation error; Global Positioning System; Iterative algorithms; Noise measurement; Position measurement; Satellites; Stochastic processes; Stochastic resonance;
Conference_Titel :
Decision and Control, 1998. Proceedings of the 37th IEEE Conference on
Conference_Location :
Tampa, FL
Print_ISBN :
0-7803-4394-8
DOI :
10.1109/CDC.1998.762029