CONTENTS

 1 Introduction
 2 Annual median night-time field strength
        2.1 Reference time
        2.2 Cymomotive force
        2.3 Sea gain
        2.4 Polarization coupling loss
        2.5     Slant propagation distance, p
       2.6 Loss factor incorporating effects of ionospheric absorption and related factors
        2.7 Hourly loss factor
        2.8 Loss factor incorporating effect of solar activity
 3 Day-to-day and short-period variations of night-time field strengths
Appendix 1
List of symbols
 1 Hourly loss factor: L_t
 2 Sunset and sunrise times
Annex 1  Accuracy of method
Annex 2  A discussion on daytime sky-wave propagation
 1 LF cases
 2 MF cases