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