unknown X, > Y 
The most serious objection against the approach chosen in [2] results 
from the fact that, for the condition of intersection, it is necessary to have 
at least four, and under certain conditions even six plate coordinate measure- 
ments together with their residuals in any single conditional equation. 
Furthermore, in the case of multi-camera triangulation, the same residuals 
appear in more than one conditional equation, making a rigorous least squares 
treatment laborious, or in more complex cases, even impractical. 
The coordinates of the relative and partial control points not given at 
the outset of the computations become known in the solution, as presented in 
[2] , only implicitily as functions of the adjusted plate measurements and 
the orientation elements. The introduction of any additional geometric con- 
ditions as they may exist for any one or all of these coordinates requires 
complex mathematical manipulations, prohibitive from the standpoint of com- 
puting economy. | | 
These difficulties have been avoided in the present solution by including 
the elimination of the unknown coordinates of the model in the process of the 
numerical treatment. In other words, instead of eliminating algebraically the 
, 8nd Z,'s, beforehand, in the system of formulas (12), these 
quantities are carried &s unknowns together with the orientation elements and 
are solved for during the numerical solution. 
ALL of the beneficial consequences of this approach will become evident 
in the least squares solution as described in the next chapter. It suffices 
to mention here the most important features: 
(1) Each point, without regard to its character as absolute, partial or 
relative control point is being treated alike, thus giving rise to two - 
equations, of the form of formulas (12), for each cemers station at which the 
point was recorded. Any given information for example, in the form of spatial 
coordinates, 1s introduced by simply eliminating the corresponding parameter 
corrections from the sequence of unknowns in the least squares solution. 
‚Therefore, all points are treated with only one basic set of equations, 
(formulas. (12)), which are explicit in terms of the measured plate coordinates 
x and y, respectively. | 
16 
MISSAE UG OUO EU