Synopsis
		sfwinscan < cmp.rsf > outf.rsf winsz=200 v0=1000 deltav=20 t0=0.5 n=100

Parameters
		float deltav=20 step lenth for velocity scan   int n=100 numbers of velscan   float t0=0.5 t0 fixed   float v0=1000 init Vel for velocity scan   int winsz=200 for each trace,the width of window. unit:sample point