NUMERICAL-METHODS FOR RETRIEVING AEROSOL-SIZE DISTRIBUTIONS FROM OPTICAL MEASUREMENTS OF SOLAR-RADIATION

Retrieving aerosol size distributions from ground measurements is an i ll-posed problem. Several methods have been developed to ''regularize' ' it, giving a stable approximation of its solution. The aim of this p aper is to review the techniques usually adopted and present some new approaches. The case of solutions retrieved both in their parametric a nd non-parametric form is considered. For all the considered methods t he problem of choosing an optimal level of regularization is also disc ussed. Finally, numerical results comparing some inversion techniques in a real case are presented. (C) 1998 Elsevier Science Ltd. All right s reserved.