Program sffftexpa | 2-D FFT-based zero-offset exploding reflector modeling/migration with adjoint  
[SYNOPSIS]
sffftexpa < data.rsf > image.rsf snaps=snaps.rsf left=left.rsf right=right.rsf adj=n cmplx=n pad1=1 nz= dz= nt= dt= t0=0.0f snap=0
[PARAMETERS]
bool    | adj | =n |  [y/n] | 	if n, modeling; if y, migration 
bool    | cmplx | =n |  [y/n] | 	use complex FFT 
float   | dt | = |   | 	time sampling (if modeling) 
float   | dz | = |   | 	time sampling (if migration) 
file    | left | = |   | 	auxiliary input file name
int     | nt | = |   | 	time samples (if modeling) 
int     | nz | = |   | 	time samples (if migration) 
int     | pad1 | =1 |   | 	padding factor on the first axis 
file    | right | = |   | 	auxiliary input file name
int     | snap | =0 |   | 	interval for snapshots 
file    | snaps | = |   | 	auxiliary output file name
float   | t0 | =0.0f |   | 	time origin (if modeling) 
[DIRECTORY]
user/fomels
