20 
"7 
X 
r 
i ? 
Y 
= FT £ 
Y 
.... 4.34 
r=l 
Z 
.Z 
3 
j 
the coordinates of the centroid of sub-block j 
the coordinates of any point r in sub-block j 
total number of points in sub-block j and used in 
the solution 
(2) The best-estimate of the coordinates of a point r is taken as the 
average of its coordinates from the sub-blocks in which it appears. 
Thence: 
. . . . 4.35 
X 
r 
x 
i M 
Y 
= FT 
Y 
i = l 
Z 
_Z_ 
= 1, 2 ... M 
M = the number of sub-blocks containing the point r 
If point r is a ground control point, (X, Y, Z) r will be taken as its 
control coordinates rather than the average. 
(3) The transformation equation used to minimize the discrepancies between 
the coordinates (>T, Y, Z) r , as a best-estimate, and the coordinates 
(X, Y, Z)?, as given for point r in sub-block j, is the following: 
-i r i r 
+ c. 
. .. . 4.36 
b -a 
in which,