91 
When determining the shape of columns one can use the same basis: projection rays calculated from each camera 
between the reseau planes which are tangent to the columns. The cylinder can be easily described with a local vector for 
  
ion 
es the field point, a normal vector for the direction of the cylinder in the liquid cell and a radius for the diameter of the cylinder 
ion (see figure 6). For the determination of these parameters a distance function is used as well. The distance between the 
the tangential lines and the rotation axis of the cylinder expressed by the normal vector is the shortest joint between these two 
ns straight lines. So the differences of the distances between the normal vector and the tangential lines and the approximate 
the radius have to be minimized with the method of least squares, and so the parameters of the cylinder.are obtained. 
les | Other columns which are symmetrical with respect to rotation, as spheroids and hyperboloids, can be estimated with 
distance functions, too. Only an additional function for the radius, which depends on the height of the cylinder axis starting 
au from a field point, has to be introduced in the adjustment process when calculating the unknown parameters. 
are To visualize the motion of the liquid bodies a sequence of images is taken during the experiment. In addition to the 
photogrammetric measurements the time is taken to calculate the velocity field of the bodies. 
5. SUMMARY AND OUTLOOK 
In this presentation a concept of a photogrammetric diagnostic tool for the determination of the position and the shape of 
drops and columns in fluid matrices is described. Therefore a model scene and a photogrammetric front end for the 
demonstration breadboard has been realized. The next step will be to prove that the proposed photogrammetric methods 
are suitable to determine the unknown geometry parameters of such experiments with the desired accuracies. 
To be able to compare the experimental results to absolute reference values all test bodies are measured with high 
precision photogrammetrically and with tactile coordinate measurement machines. 
First results and an evaluation of the proposed method will be presented in the near future. 
of 6. LITERATURE 
e. 
a Bósemann, W., Peipe, J., Schneider, C.T. 1994: Zur Anwendung von Still Video Kameras in der digitalen 
jir Nahbereichsphotogrammetrie, Zeitschrift für Photogrammetrie und Fernerkundung, Wichmann Verlag. 
ae ESA, 1991: The Bubble, Drop & Particle Unit BDPU, Microgravity news from esa, Vol. 4, No. 2, December 1991 
2d 
Godding, R. 1993: Ein photogrammetrisches Verfahren zur Überprüfung und Kalibrierung digitaler 
Bildaufnahmesysteme, Zeitschrift fir Photogrammetrie und Fernerkundung, 2/1993. 
Höhle, J. 1971: Zur Theorie und Praxis der Unterwasser Photogrammetrie, Veröff. der DGK, Reihe C, Heft 163. 
Wozniak, ©G. 1986: Experimentelle Untersuchung des Einflusses der Thermokapillarität auf die Bewegung von 
Tropfen und Blasen, Dissertation Universität GH-Essen. 
ACKNOWLEDGEMENT 
The project is sponsored by ESA/ESTEC under the contract no.: 10509/93/NL/PB, Work Order 4 
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop "From Pixels to Sequences", Zurich, March 22-24 1995