ATTENUATIOIS 1)1 \GKAMS FOR SURFACK DUCTS 



243 



100 



110 



10 



100 

 DUCT THICKNESS IN FEET 



1000 



Figure 4. Horizontal attenuation of first mode and trapping index, 200 mc, standard attenuation (0 M deficit) : 0.498 db 

 per 1,000 yd. 



