Figure 2. Iterative Procedure Original Plutonium Data GRID Estimated Grid Matrix Iteration 1 ————____—____—-j»— Estimates (ys) at sample locations. Ty Residuals: R,, il = y, i - y il GRID Iteration 2 —~p»—Estimates (955) at sample locations. 7) + ty Yad = new estimate of concentration surface. 7) Yio Residuals: = new estimate of concentration at sampling locations. nw R,, = y, - (yy, + ¥y) GRID Iteration 3 ——————> Estimates (y;3) at sample locations. + Ty + Ty = final estimate of concentration surface I, Yair * Yun * 43 = final estimate of concentration at sampling locations. ~ Residuals: Ri3 = 97 (Yaa + yo + ¥53) 327