RECOMMENDATION ITU-R P.1239 - ITU-R REFERENCE IONOSPHERIC CHARACTERISTICS** ANNEX 1 - Ionospheric characteristics 1 Introduction 2 Mapping functions 3 Prediction of foF2 and M(3000)F2 4 Prediction of foE 5 Prediction of foF1 6 Prediction of foEs and fbEs 7 Prediction of h'F and h'F,F2 8 Prediction of the percentage of occurrence of spread-F 9 Available computer programs and reference data