GNSS-based navigation and surveillance (degradation) - severe GNSS-based navigation and surveillance (degradation) - severe GNSS_SEV HF communications (propagation, absorption) - moderate HF communications (propagation, absorption) - moderate HF_COM_MOD Radiation at flight levels (increased exposure) - moderate Radiation at flight levels (increased exposure) - moderate RADIATION_MOD The items within this code table are the types of space weather phenomena of significance to aeronautical operations Communications via satellite (propagation, absorption) - moderate Communications via satellite (propagation, absorption) - moderate SATCOM_MOD GNSS-based navigation and surveillance (degradation) - moderate GNSS-based navigation and surveillance (degradation) - moderate GNSS_MOD Communications via satellite (propagation, absorption) - severe Communications via satellite (propagation, absorption) - severe SATCOM_SEV Space Wx Phenomena 1 Radiation at flight levels (increased exposure) - severe Radiation at flight levels (increased exposure) - severe RADIATION_SEV HF communications (propagation, absorption) - severe HF communications (propagation, absorption) - severe HF_COM_SEV 2019-03-20T16:54:58.099Z