E 
e d. 
REPORT ON THE ACTIVITIES OF WORKING GROUP V/3, 
ANALYTICAL METHODS IN SPECIAL APPLICATIONS 
OF PHOTOGRAMMETRY 
Prof. Dr. Ing, Klaus LINKWITZ 
University of Stuttgart 
After the working group had been established at the Lausanne Congress 1968 a working 
program was formulated during a meeting in Paris in June 1969 in which the problems to be 
especially investigated were decided to be : 
1, - Introduction of calibration data of short range camera - especially with variable focal length - 
into the process of analytical calculation, 
2, - Different analytical solutions for the formation and orientation of the model in short range 
photogrammetry : 
- methods analogue to those of aerial photogrammetry, 
- case in which coordinates of camera positions are known, 
- methods of resection in space and following intersection of object points, 
3. - Precision of object points evaluated by means of analytical short range photogrammetry. Sta- 
tistical study of the influence of varying set-up of photography and of methods for compiling the 
image coordinates, 
| 4, - Practical organization in applying short range photogrammetry in high precision measurement : 
selection and determination of control points, signalisation, stability of cameras, illumination, etc. 
The program was distributed to a number of specialists working in the field and their 
cooperation invited, Due to the fact that the chairman of the working group was heavily engaged 
in the photogrammetric measurements and analytical calculations for the determination of cutting 
pattern of the prestressed cable nets for the Olympic Roofs in Munich no special meeting of the 
members of the working group was held, To cover the above field of interest papers were invited 
by several authors. From these and other publications the following picture emerges on the pre- 
sent situation of analytical close-range photogrammetry. 
In many applications of close-range photogrammetry three dimensional coordinates - 
and hardly any contours - of the photographed object are wanted, Compared with mechanical mea- 
surements of such objects - by 3-dimensional measuring tables - photogrammetry offers the 
following advantages : 
- The momentaneous geometric configuration of the object can be measured by photogrammetry. 
This is important in applications to mechanics and structures where measured objects are subject 
to deformations, 
- Photography of objects is an objective document from which reconstruction can be done indepen- 
dently, : 
- In deformation measurements photogrammetry works free of touching the object physically, 
gives deformations in three directions simultaneously at many points, 
Since still the scope of close-range cameras available on the market is very limited, 
much of the precision photography is done either by amateur -cameras or by self-constructed 
cameras, Lenses used in such cameras are not free of distortion, prohibiting the use of analogue 
plotters, Moreover, radial distortion is a function of object distance, It is therefore necessary 
to employ a distortion function appropriate to the distance between object and camera, Additional- 
ly - McGill 1954 - it is to be supposed that the distortion variates for points distributed throughout 
the photographic field, Only the methods of analytical photogrammetry can overcome these diffi- 
culties and achieve accuracies comparable to mechanical measurements,