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Investigations of the Setting Precision under 
Various Conditions in Photogrammetry 
Kennert Tori egard, Division of Photogrammetry 
R. Inst, of Technology, Stockholm 
Two Investigations of the Influence of Alcohol Upon the Setting 
Precision in Photogrammetric Instruments 
Introduction 
The primary purpose of this project has been to determine the 
effect of alcohol upon stereo vision. The project was divided into two 
groups. 
Investigation 1: The effect of alcohol during measurements. 
Investigation 2: The effect of alcohol taken the previous evening at 
dinner. 
The measurements were performed in instruments with a subjective 
stereomodel. Special attention should be paid to the stereoscopically 
measured horizontal parallaxes. 
Experimental Design 
Four operators took part in the experiments. Readings and record 
ings of measured data were made by four assistants. Alcohol was not 
given to the recordes. In the oriented models of the instruments an 
easily identified point (e. g. a stone in the meadow or a signal) was 
measured in a series of 25 settings every 30 minutes. For operators 1, 
2 and 3 the three coordinates of one point were recorded, while opera 
tor 4 measured the horizontal parallaxes of two different points. Every 
operator measured 15 series a day. 
In investigation 1, alcohol was taken after 3 series. The doses were 
2 ml cognac per kg body weight. Blood sampling was made between 
the series to determine the blood alcohol concentration. 
In investigation 2 the alcohol was taken at dinner and the doses were 
determined according to individual taste. Volumes and times of intake 
were recorded and blood sampling was made during dinner and the 
first hours of the following day. During the measurements in investiga 
tion 2, the time used for every setting was also recorded.