Development of the HARM model for aviation dosimetry

 Primary galactic cosmic-rays (GCRs) and Solar energetic particles (SEPs) enter the Earth's atmosphere in varying amounts. Due to that, the aircrew and passengers are exposed to ionizing radiation in amounts that depend on severable factors. At the top of the atmosphere and beyond, cosmic radiation is modulated by the geomagnetic field and solar activity. Once ionising radiation, albeit from either GCRs or SEPs, crosses the geomagnetic field and enters the atmosphere, it interacts with the atmospheric molecules in the same manner regardless of where it came from. The High Altitude Radiation Monitor (HARM) model has been in development at the North-West University since January 2021, for calculation of doses of ionizing radiation in the atmosphere. Here we introduce this model, discuss its input parameters and output results, and show its initial results during flights compared with other well known models.