Program sfprekirch | 2-D Prestack Kirchhoff time migration with antialiasing. 
[SYNOPSIS]
sfprekirch < inp.rsf vel=vel.rsf > mig.rsf nz=nt dz=dt z0=t0 antialias=1.0
[COMMENTS]
The axes in the input are {time,midpoint,offset}
The axes in the output are {time,midpoint}

[PARAMETERS]
float   | antialias | =1.0 |   | 	antialiasing 
float   | dz | =dt |   | 	
int     | nz | =nt |   | 	
file    | vel | = |   | 	auxiliary input file name
float   | z0 | =t0 |   | 	
[DIRECTORY]
user/chenyk
