6.1 Sentinal Sigma Project 
6.0 MIF STUDIES AND APPLICATIONS IN THE U. S. AIR FORCE 
In a concentrated effort to optimize the information content 
of aerial photography, the U. S. Air Force has instituted a service- 
wide program called Sentinal Sigma. The program is designed to 
control quality by standardizing procedures, first black and white 
photography and later other types, such as color, nonconventional, 
etc. The standardization and guidance will set the basic documentation 
and direction for USAF Commands more effectively to manage, utilize, 
and evaluate their photographic production resources and to unify 
procedures and techniques. 
An integral part of the effort is the Imagery Evaluation 
Working Group. This group is directed; (1) toward the establishment 
of tying together objective and subject measures for determining 
image quality, and (2) toward establishing a common technical photo- 
graphic language between engineers, operation personnel, and project 
managers. Techniques such as modulation transfer functions, visual 
edge matching, and holographic models are being used to determine 
clearly the quality and operational performance of Air Force recon- 
naissance platforms. These and similar techniques are being compared 
to establish operational methods of evaluation. 
6.2 Image Evaluation Program at the Air Force Avionics Laboratory 
Some of the biggest disadvantages of the use of MTF have been 
the cost and sensitivity of test equipment and the test and analysis 
time. These problems were faced by the Air Force Avionics Laboratory 
at Wright-Patterson Air Force Base by installing high-speed, automated 
equipment under close quality control, and testing many quantities 
and types of camera systems. 
The Dynamics Environmental Evaluation Branch notes in the paper 
on "Quality Control as applied to Imagery Analysis" 7? 
quality aspects are becoming increasingly important to the Air Force. 
More cartographic and reconnaissance systems are, therefore, being 
analyzed through an evaluation of their recorded photographic per- 
formance, some negatives being exposed under unknown environmental 
conditions and others in laboratory studies under controlled environ- 
ments. Simulated conditions equivalent to the extremes encountered 
in actual missions are also analyzed. 
Selected image edges, traced with microdensitometer, are recorded 
that image- 
on high-speed magnetic tape. This data is then operated on by a 
digital computer to provide edge-trace data, in either tabular or 
graphic form, for detailed visual inspection. Various computer 
programs are then available. It is routine to obtain information 
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