Program sfcgconst | Test Beam for constant velocity gradient 
[SYNOPSIS]
sfcgconst < in.rsf > out.rsf mask=mask.rsf source=o2 w=0. v0=1. b=0. p=1/v0
[PARAMETERS]
float   | b | =0. |   | 	velocity gradient 
file    | mask | = |   | 	auxiliary output file name
float   | p | =1/v0 |   | 	
float   | source | =o2 |   | 	real source point 
float   | v0 | =1. |   | 	surface velocity 
float   | w | =0. |   | 	beam width 
[DIRECTORY]
user/llisiw
