... (Goodman 19 75)cI(x 1 ,y 1 ; x2,y2) =I(x 1 ,y 1 )I (x2,y2)=I(x 1 ,y 1 )I(x2,y2)+|cu(x 1 ,y 1 ; x2,y2)|2(8.22)Here, I(x,y) =|u(x,y)|2is the intensity andcu(x 1 ,y 1 ; ... W(fx, 0).SPECKLE CORRELATION205cu(x 1 ,y 1 ; x2,y2) = 1 λ2z2∞−∞|P(ξ 1 ,η 1 )|2expi2πλz[ξ 1 (x 1 − x2) + η 1 (y 1 − y2)]dξ 1 dη 1 (8.27)where we have retained the yη-dependence. ... can be found, for example, in Burchand Tokarski (19 68), Dainty (19 75), Erf (19 78), Fourney (19 78), Hung (19 78) and Jonesand Wykes (19 89).8.4 .1 The Fourier Fringe MethodAssume that we image...