COMMISSION V 
SPECIAL APPLICATIONS OF PHOTOGRAMMETRY 
1. Agnard, J.P. 
Canada 
HIGH PRECISION HOLOGRAMMETRY 
After three years of research in hologrammetry, we think that it is time to undertake a critical analysis on what 
has been achieved. 
Except for the challenge of automatic contour-lining, the potential of holography to aerial photography 
treatment is questionable except perhaps for military applications (automatic research of shapes by means of 
spatial filtering). We continue to believe that the application of holography to photogrammetry will be further 
studied in view of new fields of applications, particularly in close-range photogrammetry for recording 
motionless or high speed objects, problems which are difficult to solve by conventional photogrammetry. 
For this purpose, we have designed an apparatus to make precise measurements on the virtual image. Ready 
to be attached to the autograph Wild A7, it includes an hologram support with its six degrees of freedom, a 
20X binocular and a real space mark. 
We hope to reach, with this apparatus, on the virtual holographic image, the same precision as obtained in a 
stereomodel treated by a first order plotter. 
2. Argyris, J.H. 
Germany (F.R.G.) 
MEASUREMENT OF SPATIAL DEFORMATIONS 
BY MEANS OF PHOTOGRAMMETRIC METHODS 
AND ELECTRONIC DATA EVALUATION 
Measuring spatial deformations with photogrammetric methods and electronic data processing. 
Described is a non-contact method developed from close-up photogrammetry to measure position and 
deformation. 
Two commercially available cameras are used as picture carriers. To describe the position of the object to be 
measured, it is marked with special control points whose co-ordinates will be established by measuring them. 
The deformation can then be calculated from the difference of the two positions. The photographs taken will 
be measured in a PSK (Precision stereo comparator). In order to calculate the control point co-ordinates from 
the stereo picture pair, it is necessary to know exactly the optical reproduction principles and specifications 
(that is, inner orientation and lens distortion) and also the position in space (outer orientation). Since the 
orientation data is in physical values it is possible to estimate them. Now, when the object to be measured is 
photographed together with a system of accurately measured control points, their co-ordinates can be 
calculated using the projection laws expressed in simple matrix form which contain the estimated orientation 
data; and they can be transformed into the picture planes where they are compared with their reproductions. 
The differences that occur can be minimized through the systematic variation of the estimated orientation data. 
When the projection laws meet the physical process with sufficient accuracy, the differences between the 
measured and calculated co-ordinates can be reduced down to the plotting accuracy in the PSK. 
The iterative optimization is done through a computer program which should converge with few control points 
even though there is a strong correlation of the orientation data. The orientation data is integrated step by step 
into the calculus of variations, and the computer program can eliminate possible bad measuring values. 
Also described are the experimental technical requirements and the application of this measuring method on 
the static-load test sample. 
55