CONTENTS

Annex 1
 1     Introduction
2 Propagation modes
        2.1 Ground wave mode
        2.2     Sky-wave modes
 3     Multipath time spread
 4     Variability
        4.1     Variations of a signal in daytime
        4.2 Variations of a signal in daytime from place to place
        4.3 Variations of a signal in night-time
 5     Conclusions
Appendix 1  to Annex 1