The geostationary radiation environment

A study of the geostationary radiation environment is presented. The distribution of charged particles is reviewed in terms of population domains, where trapped constituents (energetic electrons and protons) and transients (solar flare protons) have been considered. Synchronous geomagnetic geometry is discussed, and temporal and spatial variations of trapped particles are briefly reviewed. A short description of the current standard environment models is given. Probabilistic solar flare proton predictions are described, including the distinction between ordinary event and anomalously large event fluences and the probability of occurrence of anomalously large events. A special solar proton evaluation approach is suggested for extended manned missions in the synchronous altitude regime. Finally, calculational results are presented for orbital flux integrations and dose and shielding evaluations. The data, given in graphic and tabular form, are explained and discussed.