Program sfimray | 2-D image ray tracing using HWT 
[SYNOPSIS]
sfimray < vel.rsf > dix.rsf nt= dt= order=3
[PARAMETERS]
float   | dt | = |   | 	
int     | nt | = |   | 	
int     | order | =3 |   | 	interpolation order 
[DIRECTORY]
user/fomels
