Synopsis
		sffrt < in.rsf > out.rsf ref=ref.rsf curv=0 inv=n mtd=0 mu=0.05 eta=0.05 niter=5 np=0 op=0 dp=0 x0=maxoff

Parameters
		int curv=0 0: linear; 1:parabolic   float dp=0 stepout interval   float eta=0.05 eta: for fhrt, fcrt   bool inv=n [y/n] if y, perform inverse operation   int mtd=0 0: fart; 1:firt; 2:fhrt; 3:fcrt   float mu=0.05 mu: for firt, fhrt, fcrt   int niter=5 sparse iterations: for fhrt, fcrt   int np=0 stepout number   float op=0 first stepout (moveout at "ref")   file ref= auxiliary input file name   float x0=maxoff reference offset