Synopsis
		sfinterp3 < in.rsf place=place.rsf depth=depth.rsf > out.rsf sx=0. sz=0. dt=2.e-3 nw=4 z=0.5

Parameters
		file depth= auxiliary input file name   float dt=2.e-3 time uncertainty   int nw=4 interpolation accuracy   file place= auxiliary input file name   float sx=0. source x position   float sz=0. source z position   float z=0.5 depth