Meteorology-Driven Optimum Control of a Multibeam Antenna in Satellite Telecommunications

The paper deals with the problem of controlling the radiation of a telecommunication multispot satellite antenna in which the power can be flexibly routed towards the various spots so as to contrast at best the time variant atmospheric attenuation while keeping at minimum the number of users which do not receive enough signal level. The antenna control is exerted by applying a particular strategy based on the knowledge of the distribution of the weather conditions all over the served region as derived by standard sources like the European Centre for Medium Range Weather Forecasting (ECMWF) or the Meteosat. The paper describes the principles of two types of optimizations: a fixed one based on climatological data, which acts as reference, and an adaptive one based on quasi instantaneous pictures that represent the weather situation across the served region. After an explanation of the basic principles of the optimizations, the paper gives an example of application that, despite the brevity of the trial period we are now able to present, indicates an excellent effectiveness of the system which, in the period observed, allows a reduction of the number of non-served users of the two orders of magnitude in the case of low-margin systems (say 2 to 3 dBs over free space) and a still conspicuous advantage (a reduction of a factor about 5) for greater available margins (say 6 to 7 dBs).