EVALUATION OF STATISTICAL-MODELS FOR CLEAR-AIR SCINTILLATION PREDICTION USING OLYMPUS SATELLITE MEASUREMENTS

The objective of this study is to evaluate and to compare some of the statistical models for the monthly prediction of clear-air scintillati on variance and amplitude from ground meteorological measurements. Two new statistical methods, namely the direct and the modelled physical- statistical prediction models, are also introduced and discussed. They are both based on simulated data of received scintillation power deri ved from a large historical radiosounding set, acquired in a mid-latit udue site. The long-term predictions derived from each model are compa red with measurements from the Olympus satellite beacons at the Louvai n-la-Neuve site at 12.5 and 29.7 GHz and at the Milan site at 19.77 GH z during 1992. The model intercomparison is carried out by checking th e assumed best-fitting probability density function for the variance a nd log-amplitude fluctuations and analysing the proposed relationships between scintillation parameters and ground meteorological measuremen ts. Results are discussed in order to understand the potentials and th e limits of each prediction model within this case study. The agreemen t with Olympus measurements is found to be mainly dependent on the pro per parametrization of prediction models to the radiometeorological va riables along the earth-satellite path. (C) 1997 by John Wiley & Sons, Ltd.