319 
COMMISSION VII 
Photographic interpretation 
President: Mr. C. G. Coleman Jr, ILS. A. 
Secretary: Mr. E. J. Rogers, U. S. A. 
Minutes of the Proceedings of July 18, 1956, Session a, 
photographic interpretation 
The session was opened by the president with the following statement: 
»The science of photographic interpretation has made great strides during the 
past four years, as those of you who have had the opportunity to view the Com 
mission report will agree. 
Photographic Interpretation (or PI, as it is often abbreviated) has been in 
formally defined as the act of identifying objects imaged on photographs and 
deducing their significance. Therefore it is somewhat more concerned with the 
nature of function of what is seen on an aerial photograph, rather than with the 
precise distances between objects. Photographic interpretation has therefore be 
come a very useful tool for many branches of science, some of those are: geo 
graphy, geology, forestry, engineering and the military sciences. We hope that 
the Commission VII sessions will serve to bring to light much that is being 
accomplished in this fast-growing field.» 
The president introduced Professor K. Stone of IJ.S.A. who presented his K. Stone: Air Photo 
paper, on Air Photo Interpretation Procedures: Interpretation Procedures. 
1 (Publ. VII S 1 in General 
Air photo interpretation is a way of using research material. It is a technique Report VII) 
belonging to all fields of study with procedures similar to those of other research 
methods. 
Four general procedures are suggested for interpretation to be done: 1) in a 
methodical manner, 2) from the general items to the specific, 3) from the known 
features to the unknown, and 4) after analysis of the photographic quality of 
the coverage. 
Interpretation should be done topically and a topic at a time. A tested useful 
order of topics is: transportation, drainage, surface configuration, natural vegeta 
tion, agriculture, rural non-agricultural features, urban features, heavy industry, 
and special features. 
Recommended specific procedures for each topic are arranged on the basis 
of photographic scales in the order: 1) 1/70 000—1/30 000, 2) 1/30 000—1/10 000, 
and 3) larger than 1/10 000. From 10 to 21 specific procedures are outlined for 
each topic on the basis of the general procedures. Usually the specific procedures 
in the smallest scale category are based on observable non-technical characte 
ristics for large areas, those of the middle scale group on photographic appear 
ances and general knowledge of the content of the topic, and those of the largest 
scale category are dependent primarily on detailed knowledge of the topic. 
Too many interpretation keys resemble only the last of these categories. 
Des procédés d’interprétation de photos aériennes 
L’interprétation doit se faire sujet par sujet, un detail à la fois. Un ordre de sujets éprouvé et 
C’est une technique propre à toutes les branches d’étude avec des procédés pareils à ceux d’autres 
méthodes de recherche.