Advances in Measuring and Modeling the Atmospheric Radiation Environment

New radiation monitors based on solid-state detectors have been developed to perform wide-ranging measurements of the atmospheric environment and provide warnings of sudden increases during solar particle events. Results have been obtained during the current deep solar minimum across the full range of latitudes and from sea level to 13 km altitude. Results for ambient dose equivalent agree very closely with Tissue Equivalent Proportional Counters carried on the same flights. Values of 10 ?Sv/hr are being reached at 12 km altitude and high latitude. Comparisons are made with the QinetiQ Atmospheric Radiation Model and the need to include cosmic-ray heavy ions is demonstrated.