12 = 
Symbols used 
surface sound velocity in the ocean 
average vertical velocity of sound in the ocean 
sound velocity at the bottom of the ocean 
velocity of compressional waves in the first 
refraction layer 
velocity of compressional waves in the nth refraction 
layer 
travel time of the first reflected wave 
travel time of the second reflected wave 
travel time of the third reflected wave 
travel time of the mth reflected wave 
travel time of the direct wave 
travel time of refraction arrival 
bottom reflection time from the shot record 
surface-bottom reflection time from the shot record 
topographic correction 
difference in elevation ofthe bottom from the mean 
depth of the ocean 
angle of incidence of R, on bottom 
angle of incidence of G on bottom 
