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ON THE ORIENTATION PARAMETERS OF NON-METRIC CAMERA 
Prof.Dr. Abdel-latif, M.S.,Dr. A. A-R. Mohamed, and A. El-Sonbaty 
Civil Engineering Department, Assiut University 
Assit, EGYPT 
ABSTRACT 
The accuracy of the parameters of a camera plays an important role 
in photogrammetric messurements. 
In this paper, a direct mathematical method to determine the 
exterior and the interior orientation parameters of a non-metric 
camera is developed. The technique depends on measuring or 
calculating the lengths of lines connecting one image of a control 
point to another and also to the principal point. When compared 
with the collinearity method, the new method has the sdvantages of 
higher accuracy with lower time of computation. 
INTRODUCTION point such as 84 shouid have space 
coordinates (OG Y, 24 2, which can be found 
  
One of the most important items in S . A ; 
photogrammetry is the determination of as the point of intersection of SA. with H. 
the orientation parameters of central 
perspective photographs taken with The method discussed here depends on 
non-metric cameras. Collinearity between deriving the  formulss of the distances 
image point, centre of perspective and joining pairs of images of control points 
object point is often the basic idea in terms of their space coordinates. 
behind the linearized form of the Equating these formulas to their 
mathematical model (AX=L+V). Observations corresponding distances between image 
are usually corrected for systematic points, which can be measured directly or 
deviations (film shrinkage, lens calculated, will give equations in six 
distortion etc.) from the collinearity unknowns : The space coordinates of the 
model before adjustment (Torlegard, 1981). camera station SOL, Y bat and the three 
Wong (1975) states that in close-range the coefficients of the image plane TM(A,B,C). 
photogrammetric solution may. be divided Therefore, at least six independent 
into two major phases : (1) relative equations are required for the solution of 
orientation of individual stereoscopic the problem. 
pair of photos, and (2) model linking and 
absolute orientation to the  object-space The number of line segments joining n 
coordinate system. points is given by :- 
This paper introduces a new mathematical m - n(n-1)/2 (1) 
approach for determining the external From which, only m= (2n - 3) (2) 
orientation parameters for non-metric 
cameras. The system depends mainly on are independent. This means that for six 
using the lengths of lines between the unknowns, at least five control points are 
images of the control points. The ner necessary for the solution of the problem, 
method has been programmed on the which will yield seven independent 
computer and checked mathematically and equations plus three dependent ones. 
practically. When compared with 
collinearity method, the new method has Space Coordinate of an Image Point 
the advantage of higher accuracy with 
lower time of computation. The parametric equations of the straight 
MATHEMATICAL FORMULATION TECHNIQUE line joining S(X_,Y_,Z_J with an object 
oint A.(X.,Y.,Z.) may be represented by:- 
Preliminary Note FE i 15147417 y P y 
X 
X.- (X -X.t 
i sui 
- (33 
Yıt Y Yit (3) 
Z Zu (25 2408 
Let n control points with known space 
1 
coordinates be given as :A,(X,.Y,.Z,)} 
be g 8 TA, (M 11 11 
( Lads Yawn ( : 
2 Aa CX, Yo; 345 AC Ya? 
In Fig.(15, images a, (x, >Y,)> Sox 2:33)» where t is & parameter. 
e 
er Uy) of the ground control Let the equation of the image plane I be: 
points appear in an image positive plane = AR 
H. At the same time, relative to the space AX+ BY + CZ + D = 0 (4) 
eoordinste system QG, X, Y, Z. on image Dividing by one of the coefficients, 
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