| OCR Text |
Show 76 Y(uo,vo) can is be the approximated by Zn(u,v) intersection + these two + line of (uO-du,vO-dv) Yvv by Zn=O. maximum. in space u,v 0 the at local This It defined Zn(u,v). + au curves dv2 "2 ellipse aZn du 1 + defined the through Zn(uo,vo) Yuv this curve straight a dv on space pass du Taylor expansion of and (uO+du,vO+dv) Yuu lie U,v to guaranteed by the first order The du2 points intersection with curve -21 + desired two The Yscan - dv aZn av yields two solutions: where. aZn du = dv = aavaZn / a The that .; properties the Y(uo,vo)-Yscan / = -aau-- of Yuu,Yuv,Yvv denominator non-imaginary. This is is at a local nonzero illustrated and in maximum the figure guarantee square root 17. y J ysc.Q. n --------------. Figure 17 - Entering True Local Maximum is |
