Modeling the low-altitude trapped radiation environment

The predictions of models of trapped energetic particle radiation at low altitudes, including the NASA trapped radiation models, are compared with low altitude measurements of energetic protons and electrons. Knowledge of the trapped energetic particle radiation at low altitudes in the vicinity of the south Atlantic magnetic anomaly is considered to be important for the analysis of the space environmental effects on space systems in this region. The long term trends in the observations are generally consistent with the NASA trapped radiation models. The discrepancies between the models and observations are currently being investigated using a 3D diffusive model and realistic atmospheric and magnetic field models. The requirements for future work and development of low altitude trapped radiation environment models are discussed.