B.L. Malleswari; M. Seetha; I.V. Muralikrishna; and K. Lalkishore

ABSTRACT

This paper focuses on modeling of errors like ionospheric delays, dilution of precision and multipath effects etc., affecting the GPS signals as they travel from satellite to user on Earth. These errors degrade the accuracy of GPS position. An attempt is made to improve the accuracy in locating the GPS receiver by filtering the range measurements. This study emphasizes the coordinate conversion between World Geodetic System (WGS - 84) and Universal Transverse Mercator (UTM) using single frequency ML-250 hand held GPS receiver and smoothening of these coordinates using Kalman filter. A recursive filtering technique, Kalman filter is used for greater accuracy in estimating the position of the user by considering the initial state of the system, statistics of system noise and measurement errors. The results of the proposed Kalman filter technique give better accuracy with more consistency and are found superior to the standard one.

Keywords:Kalman Filter; GPS; data preprocessing; ionospheric; GPS signal; World Geodetic System; WGS; Universal Transverse Mercator; UTM; algorithm; parameters; simulations; data validation