An empirical model is presented in order to describe the pitch angle distributions
of H+ particles in inner magnetosphere. The data analysis is based on
three-year observations made by the AMPTE/CCE/CHEM instrument in the
energy range 1-300 keV and in the L-shell range 3-9, using the average proton
fluxes with AE < 100 nT. The model consists of a multi-parametric functional
form, that depends on pitch angle, energy, L-shell and a few independent factors.
The factors are determined for every magnetic local time. This is the first model,
able to accurately reproduce the average proton pitch angle distributions in the
whole inner magnetosphere, revealing interesting statistical features. Many of
these features have been already evidenced by previous studies and can be
explained by processes theoretically interpreted. Furthermore, the model outlines
some new features never analyzed before
