60 A WORLD ATLAS OF ATMOSPHERIC RADIO REFRACTIVITY 



180 150 120 90 60 30 



30 60 90 120 150 180 



Figure B-16. Slope of regression line of AN versus N s , b. 



180 

 80 



30 60 90 120 150 BO 



180 150 120 90 60 30 30 60 90 120 150 180 



Figure B-17. Correlation coefficient of AN versus N B . 



