Estimation of Integrated Water Vapour from GPS Observations Using Local Models in Hungary

This paper studies the estimation of integrated water vapour (IWV) from the zenith tropospheric delay (ZTD). In order to evaluate the technique, six mathematical models are compared using a stormy summer period and a calm and dry winter period. The mathematical models include locally derived models using more than 10,000 radiosonde observations. The GPS derived IWV values are compared to radiosonde observations and a linear regression prediction of IWV using surface observations, too. Moreover the computations were carried out during a heavy storm in the summer period, when the estimated IWV distribution is compared to radar observations, too.