GPS NETWORK ADJUSTMENT USING KALMAN FILTER

Abstract

The GPS provides position of a point on the surface of the earth with high degree of speed and accuracy. However, the GPS measurements are also fraught with different types of errors. Among these errors random errors are the most unpredictable. Many applications of GPS data require accurate point position which is possible by reducing the random error in the GPS data. One of the method of reducing the random error is to adjust the network formed by the GPS control points. GPS provides large amount of data continuously at an' interval as low as 0.001 second epoch. Thus huge amount of data may better be processed by an algorithm less complex requiring less memory and computational time. Kalman Filter is a recursive algorithm which requires only the present and the previous observations may be one such algorithm which applied on GPS control network which minimizes the random error. In this study the Kalman Filter algorithm has been applied to adjust a GPS based control network. The results of proposed Kalman filter technique give better accuracy with more consistency and are found superior to the standard one (least square). Keywords: GPS, Network Adjustment, Kalman filter, Recursive Algorithm