rate either by deviation in slope or in linearity, changes occur which 

 might prove either favorable or unfavorable for radar propagation. The 

 relation of temperature, partial pressure of water vapor, and atmospheric 



RANGE 



2 4 6 8 10 20 

 IN THOUSANDS OF YARDS 



Figure .'52. — Reflected power expressed in decibels above minimum discernible signal 

 plotted as a function of range for a large iceberg 1 L09 by 'MM) feet ; 19,050 

 sq. feel I whose observation aspect, indicates directivity of reflected 

 radiation. 



74 



