Program sfpostrtm2d | 2-D exploding-reflector RTM and its adjoint 
[SYNOPSIS]
sfpostrtm2d < in.rsf > out.rsf velocity=vel.rsf wave=wave.rsf adj=y snap=n n0=0 jt=50 nt= dt= padx=nz/2 padz=nz/2
[PARAMETERS]
bool    | adj | =y |  [y/n] | 	adjoint flag, 0: modeling, 1: migration 
float   | dt | = |   | 	
int     | jt | =50 |   | 	time interval of wavefield snapshot 
int     | n0 | =0 |   | 	surface 
int     | nt | = |   | 	
int     | padx | =nz/2 |   | 	
int     | padz | =nz/2 |   | 	
bool    | snap | =n |  [y/n] | 	wavefield snapshot flag 
file    | velocity | = |   | 	auxiliary input file name
file    | wave | = |   | 	auxiliary output file name
[DIRECTORY]
user/zhiguang
