DESIGNATING THE ERROR OF VERTICAL COORDINATE OF AIRCRAFT POSITION IN THE GPS SYSTEM

This article presents the results of research concerning the determination of an error of the vertical position of an aircraft during a flight, taking into account, the flight altitude and the values of the ZTD tropospheric product. In particular, this work focuses on the impact of an error in designating the ZTD tropospheric product on the correct determination of a flight altitude. The authors of this work performed a scientific experiment for research data of two flights made by a Cessna 172 around the aerodrome in Dęblin. This article shows the findings of the tropospheric ZTD product specified for the single-frequency SPP positioning method and dual-frequency PPP positioning method. Based on the obtained results, it was discovered that the error of the ZTD tropospheric delay causes an altitude error from 0.08 m at the zenith angle equal to 80o even to 0.79 m at the zenith angle equal to 85o.