78 A WORLD ATLAS OF ATMOSPHERIC RADIO REFRACTIVITY 



Figure C-29. Percent of time trapping frequency < 3000 Mc/s: February. 



ISO 150 



180 150 120 90 60 30 



30 60 90 120 150 180 



Figure C-30. Percent of time trapping frequency < 1000 Mc/s: February. 



