Synopsis
		sfcos2ang < Fstk.rsf > Fang.rsf velocity=velocity.rsf na=nt da=90/(nt-1) a0=0. extend=4 top=n

Parameters
		float a0=0. angle origin   float da=90/(nt-1) angle sampling   int extend=4 tmp extension   int na=nt number of angles   bool top=n [y/n] velocity scaling option   file velocity= auxiliary input file name