ИСТИНА

Trapped proton fluxes measured on board three LEO satellites (NPOES- 17, Universitetskiy -Tatiana and Coronas-F) in April 2005 were analysed. Experimental data are summarized using analytical expressions that allow to describe the flux of the trapped protons with energies from 80 keV up to 140 MeV, depending on its pitch angle on the geomagnetic equator. Analytical expressions and the set of their parameters can be used to determine directional proton flux on drift shells L = 1.14 -1.3 under quiet geomagnetic conditions in the period close to the solar minimum.