Estimation of residual tropospheric delay for high-altitude vehicles: towards precise positioning of a stratospheric airship

Abstract

GPS can play an important role in high-altitude vehicle positioning. In such GPS applications, the residual tropospheric delay in GPS measurements is a major error source. Several strategies for estimating the residual zenith tropospheric delay have been presented in the literature. Generally, such models include the time-varying residual tropospheric errors into the stochastic models, which are then estimated using a Kalman filter. However, these methods have not considered the height difference between GPS receivers. A new functional model for tropospheric delay is proposed in this paper. The error of the meteorological data measured at a ground reference site is estimated by Kalman filtering. Analytical results of a flight experiment indicate that the proposed model is indeed superior to the standard models. The new model can compensate for errors of meteorological data, and is feasible for use in precise positioning of high-altitude receiver platforms.