title: Engineering tool for trapped proton flux anisotropy evaluation.
abstract: At low altitudes, the high-energy trapped proton fluxes are strongly anisotropic. The proton flux is controlled by the density distribution of the Earth's atmosphere that induces a steep pitch-angle distribution and an East-West effect, the latter caused by the finite size of the proton gyration radius. We have developed a software package, ANISO, to evaluate averaged energy spectra of trapped proton unidirectional fluxes for a given spacecraft orbit and attitude by deducing the angular-dependent proton flux spectra from the AP-8 omnidirectional flux. Included in the model are both the Armstrong et al. (1990) model and a model based on the Badhwar and Konradi (1990) pitch-angle distribution.
authors.affiliation: Belgian Institute for Space Aeronomy, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Kruglanski
mesh_terms: D016880:Anisotropy; D001272:Atmosphere; D018534:Earth, Planet; D008280:Magnetics; D008433:Mathematics; D008962:Models, Theoretical; D011522:Protons; D011835:Radiation Protection; D012984:Software; D013026:Space Flight; D018531:Spacecraft
chemical_list: D011522:Protons