COMMISSION VI 
to tha INT. ARC 
come 
  
Reprinted from 
PHOTOGRAMMETRIC ENGINEERING 
April 
1956 
New Developments in Photogrammetric 
DAVID LANDEN,T] U. S. Geological Survey 
ABSTRACT: Within the U. S. Geological Survey many geologists have been 
applying certain photogrammetric techniques and using some of the less 
elaborate photogrammetric instruments in their geologic mapping prob- 
lems since 1930. Also, photogeology has been used in field and office pro- 
cedures for many years although the refinements in techniques and 
equipment are of more recent origins. The present emphasis on training 
many geologists in the Geologic Division in photogrammetric techniques is 
broadening their understanding of the potential of these techniques and 
with an excellent effect. An introduction lo the fundamentals of photo- 
grammetry and a familiarization with the most widely used stereoplotting 
instruments appears to be the most effective approach in introducing 
photogrammetric techniques for the first time; it is also important to 
convey a knowledge of their limitations. 
INTRODUCTION 
HE United States Geological Survey has been conducting, over the past two 
T a an interesting experiment in training large numbers of geologists in 
the fundamentals of photogrammetry and in the application of stereoscopic 
plotting machines to the problems of geologic mapping. The results of this ex- 
periment have been, on the whole, so conclusive as to warrant communication 
of our experiences to our colleagues abroad; and to point out, in addition, the 
advantages of introducing training in photogrammetric instrumentation not 
only in geology, but in all the earth sciences through a training program which 
includes instruction in stereoscopic plotting methods. Some of the newer instru- 
ments and materials are being applied to both the qualitative and quantitative 
aspects of geology. 
FAVORABLE CLIMATE FOR PHOTOGRAMMETRIC TRAINING 
Several factors contributed to the adoption of extensive training programs 
for Survey geologists. One of these is the practical nature of photogrammetry 
itself; as a science of measurement it becomes, in due time, applicable to many 
of the problems of surveying and measurements that are normally found in 
this field. The most compelling reasons, however, seem to be found in the 
expanding requirements for geologic mapping in recent years and the need for 
more detailed mapping. There are also unique organizational advantages in the 
Geological Survey; these have made it possible to develop a program of photo- 
grammetric training in geology as an organization activity, under unified con- 
trol. 
* Publication authorized by Director, U. S. Geological Survey. 
1 This paper is a contribution to Commission VI of the International Society of Photogram- 
metry. 
I United States Reporter, Commission VI, Education, Terminology and Bibliography. 
U.S.A-1