An Empirical Stochastic Model for GPS

In addition to functional models, stochastic modeling of observations plays an important role in GPS data processing. The stochastic model has influence over several issues of coordinates determination with GPS, such as the covariance matrix of the observations (which leads to weighting scheme) and the estimated covariance matrix of the parameters. In this paper we present an empirical stochastic approach to create observation covariance matrices for GPS. Our approach aims to a more realistic and complete information about the stochastic behavior of GPS observations and an improvement in quality and quality control of estimated coordinates.