“…Both ways will properly correct the distorted corner region in Fig. 6 : [(x,÷1 -x)2(y1÷1 -y)/ 3 +(x,÷i -)(+i + x1)(y11 +y1)] (5) p = -x1 )(Yj+i -Y)2 /3 + (Yj÷i -Y1)(yt+i +y1)(x÷1 +x)], (6) where N stands for the number of contour points (XN+1 = x1 = x YN÷1 = Yi Ys), S is the area, P is the perimeter and (,j) is the COG ofthe field.…”