Nowcasting Astronomical Seeing: A Study of ESO La Silla and Paranal

Weuse extensive seeing and low-atmospheremeteorological data obtained at the European Southern Observatory’s La Silla complex in Chile, and at the proposed site of the Very Large Telescope atCerro Paranal. The differences in seeing between these two locations are studied. A prototype system is set up for predicting seeing values, given knowledge of the meteorological environment. A novel pattern recognition methodology is developed in order to do this. We assess the quality, and quantify the limitations, of such predictions. Broadly speaking, we can carry out predictions in about 80% of cases; and our good seeing nowcasts are about 70% reliable.