interpretation being accomplished. Perhaps the most significant of these is 
the cartographic function. While considered primarily dependent on either 
analog projectors or analytical mathematics or some combination of 
techniques, photo interpretation to some degree must be accomplished 
in such tasks as pass point selection, tracing of contours and transfer 
of planimetric data. 
Any comprehensive discussion of photo interpretation, therefore, 
must consider aspects of all disciplines within the photogrammetric field, 
Similarly, any report that attempts to review advances that have occurred 
under the subject heading of Automation in Photo Interpretation must con- 
sider the interpretive aspects of all photogrammetric disciplines ranging 
from the easily recognized interpretation of geologic features to the picking 
of control pass points on a series of cartographic photographs. 
Why Automate? 
One of the papers t, prepared for distribution during this session 
asks the question, Why Automate? The reasons given are: 
1. The ever increasing need for information from aerial 
photographs. 
The need to make constant improvements in the speed, accuracy, 
and completeness of the information extracted from photography. 
The need to supplement the short supply of skilled humans 
with aids and devices that complement their skill. 
These reasons are, of course, quite valid but present little 
insight into how they came into being. Briefly, these circumstances have 
(2) "An Approach to Change Detection" by H. Robert Gribben, Raytheon 
Company, Autometric, Alexandria, Virginia, 1967.