engleski

Evaluation of EGNOS Tropospheric Delay Model in South-Eastern Europe

Troposphere affects electromagnetic signal propagation causing signal path bending and the alteration of the electromagnetic wave velocity. Tropospheric delay can introduce a considerable error in satellite positioning, if it is not properly estimated. The GPS signal delay can vary from 2 to 20 m depending on the elevation angles between the receiver and the satellite. Two basic types of delay prediction models exist. The first use surface meteorological parameters to estimate the value of the tropospheric delay, and the other models that do not require real-time meteorological input use average and seasonal variation data related to the receiver’ s latitude and day-of-year. This paper compares performance of both types of models within a period of one year, comprising all seasons, to verify their accuracy over a longer period. The Saastamoinen model known as one of the best performing prediction model was taken as a reference, and the global EGNOS model was used to check how the global estimates of the yearly averages of the meteorological parameters and their related seasonal variations comply with the real-time surface parameters.

Tropospheric delay; Saastamoinen model; Hopfield model; EGNOS model

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