x 
Ne 
[x], [x] = 0, Ea are the geocentric coordinates of the local origin given by 
[9], [4], [zu] = 0. The geocentric system is oriented so that its +X axis lies 
* x x 
in the meridian plane of the local origin, The X Y Z coordinates are 
Cartesian coordinates in the local gystem for the point given by a, ^ with H. e 9. 
Tt should be noted that all the coefficients can be computed during the 
. phase of coordinate transformation and consequently enter as constants into the 
least squares solution of the actual photogrammetric triangulation computations. 
(3) A partial control point, given by H: 
Such & point is Situated on an ellipsoid of revolution, the axes of which 
are & = (a + H) and b^ = (b + H). In order to make the approximation values 
y? y? Z2;, as they may be obtained with (57), compatible with this condition, it 
is suggested that first a new Z^ value be computed with: 
70 
  
5 
" 
em rx s enl: b. Aye (50) 
The corresponding conditional equation is then : 
LAX + IT AY + IIT AZ = 0 (51) 
whereby: 
In = Nyt X’ ng - Zn, 
o 
m C (52) 
IIT, = ng +2°n, - Xng 
and | 
ny = cos “141+ Cx Jr ain? [2] 
ng sin“ [61+ C5 S cos "(£1 
nz = [X] cos [#] + G^ Cz] ams [4] (53) 
= Ù 
Ny =r a 
4 Ty 
Vy n sta [6] eon L5] (B - 1) 
56