This Recommendation provides models and numerical maps of the monthly median characteristics of the ionosphere, and information regarding the statistical variability.
ITU-R P.1239-3-2012 Referenced Document
ITU-R P.1144 Guide to the application of the propagation methods of Radiocommunication Study Group 3*, 2017-12-01 Update
ITU-R P.371 Choice of Indices for Long-Term Ionospheric Predictions