Program sffbpwd | omnidirectional plane-wave destruction  
[SYNOPSIS]
sffbpwd < in.rsf > out.rsf dip=fp.rsf radius=1.0
[PARAMETERS]
file    | dip | = |   | 	auxiliary input file name
float   | radius | =1.0 |   | 	interpolating radius for opwd 
[DIRECTORY]
user/chen
