THIS STUDY CALLED RADIATION ENVIRONMENT USING ARMAS DATA IN THE NAIRAS MODEL (RADIAN) WILL EXPAND A PHYSICS-BASED MODELING CAPABILITY USING KALMAN FILTER DATA ASSIMILATION. RECENT CURRENT EPOCH AND A FEW HOURS OF FORECAST RADIATION ENVIRONMENT INFORMATION WILL BE AVAILABLE FROM THIS SYSTEM TO SPECIFY THE GLOBAL DOSE RATE ENVIRONMENT FROM THE SURFACE OF THE EARTH INTO LOW EARTH ORBIT. THIS TASK ADDRESSES A PRIMARY GOAL AND MEASURE OF SUCCESS OF THE 3.1.2 CHARACTERIZATION OF THE EARTH S RADIATION ENVIRONMENT FST I.E. DEMONSTRATING THE TEMPORAL SPATIAL AND MAGNITUDE VARIABILITY IN THE RADIATION ENVIRONMENT FROM TROPOSPHERIC ALTITUDES TO THE RADIATION BELTS USING OBSERVATIONS AND EXISTING MODELS REPORTED WITH APPROPRIATE METRICS OF UNCERTAINTY.