REPORT OF WORKING GROUP 2 
COMMISSION VII 
INTERNATIONAL SOCIETY FOR PHOTOGRAMMETRY* 
by 
William A. Fischer 
U. S. Geological Survey 
Washington, D. C. 
Introduction 
Working Group 2, Commission VII, is concerned with interpretation 
techniques and instruments. The present report deals with some developments 
in interpretation techniques and instruments since the last report in 1956 
and discusses trends in development of new instruments and techniques. 
Material for this report was obtained from 31 contributors; the Chairman of 
Working Group 2 wishes to thank each of the contributors. The material 
received was so voluminous that it could not all be included. 
This report is divided into four parts as follows: 1) a summary of 
information received, 2) a listing of selected instruments and techniques 
(where feasible, instruments or techniques are identified with the 
contributor), 3) national reports, 4) other contributions. 
Summary 
"Less use is being made of paper prints than heretofore [consequently 
more use of film positives”. This is undoubtedly due to the fact that the 
resolving power of films and taking lenses now exceeds the resolving power 
of papers." (R. Coakley, written communication, 1959). New stereoscopes 
have been developed for field use (fig. 1), for viewing roll film (Eig. 2), 
and for viewing with high magnification. New plotting instruments for 
aiding in the cartographic aspects of photointerpretation have been developed 
that are particularly applicable to natural resource studies and terrain 
analyses. 
Many new developments, however, imply that a revolution in both 
technique and equipment is in the offing. These developments include: 
1) Measurement of recognition elements other than size for purposes 
of identification or description. (Many of these measurements are 
of dimensionless parameters.) "That quantitative measurements in 
addition to those of classical photogrammetry can be made from 
aerial photographs emphasizes the importance of aerial photography 
as a tool in geologic research."l/ 
2) Identification or differentiation of images through selective 
wave length photography. "Recent studies indicate that certain 
measurements made prior to taking photography--such as spectral 
reflectance determinations of rocks--may be particularly significant 
in selecting films and filters for emphasizing. . . . features so 
that they can be measured on subsequently obtained photography."1/ 
* Publication authorized by the Director, U. S. Geological Survey