NORM on ASBM: Probing the High-Energy Radiation Environment From a Unique Orbit

The first Norwegian Radiation Monitor (NORM) sensor unit, flying aboard the Arctic Satellite Broadband Mission (ASBM), provides critical information on the space radiation environment along its three-apogee (TAP), 16-hour highly elliptical orbit (HEO). This work reviews the first year of NORM measurements, presenting the first detailed evaluation, analysis, and validation of radiation environment measurements along the TAP orbit, specifically focusing on trapped electrons and solar particle radiation. A series of validation studies demonstrate the inter-consistency of NORM measurements relative to the unit’s on-ground and numerical calibration, as well as with measurements from other radiation monitors. In addition, comparisons between NORM flux measurements and electron radiation belt specification models are presented. The results show that NORM provides high-quality and high-resolution measurements of varying electron differential fluxes within the 0.7–5.3 MeV energy range. Furthermore, NORM provides high-quality differential flux measurements of solar energetic protons within the 12–88 MeV energy range. ASBM/NORM datasets are available to EU users and collaborators, providing an invaluable asset for developing and validating space radiation environment models.