ed 
(9 
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(9 
ies. 
ATE HEURE FCD OMA SH rs IT RT SLA ST Hs Rs I 0 I A be EN AC o LUC Let Den UMEN Md oHG PE NODE ar as aU o UN EMIL. 
With a BS in electronics, he is now completing his MS, emphasing the modern 
optics applicable to image quality analysés. 
He is a member of the Optical Society of America, Society of Photographic 
Scientist and Engineers, the American Society of Photogrammetry, and the 
Society of Photographic Instrumentation Engineers. 
Status of Environmental Studies 
  
Itek Study: There are few papers on environmental effects which are published 
in the literature. Perhaps this is due to the design engineer's belief that 
environment is only one of many problems and not worthy of separate con- 
sideration. Be that as it may a short paper by George Wood, presented at 
the Fall 1976 ASP Convention, cites a number of significant facts which 
he presents as nomographs. Half of these are concerned with environments which 
affect photographic sensors. There are nomographs used to evaluate "tradoffs" 
in the consequences of operational conditions relative to resolution and 
also to show how camera modifications and environmental control can be used 
to increase effective resolution. 
Wood treats the effects of temperature change (from controlled laboratory 
temperature) showing changes of focus and resolution for four focal lengths 
and four apertures. To show the refractive properties of air, which vary with 
density of air, which in turn is dependent on temperature and pressure, he 
uses the same four focal lengths and apertures to again show focal changes 
and resolution degradation. He does not treat vibration as such but the 
angular motions of pitch, roll, and yaw are evaluated in terms of resolu- 
tion loss per millisecond duration. He selects two similar 152 mm f/6 
lenses and subjects them to different conditions of flight; different 
temperatures, pressures, altitudes, ground speed, and angular motions. 
In analyzing the results, Wood notes that the "index of refraction change, 
temperature change, and forward motion smear contribute markedly to re- 
solution loss." 
His conclusion is succinct and applicable to all aerial and space cameras. 
Wood says "It becomes clear then that systemmatizing can pay benefits relative 
to the maintenance of resolution and, thus, should be taken seriously. What 
hasn't been discussed here is the similar penalties that are paid in terms 
of geometrical changes when cameras and aircraft are employed as general 
purpose tools. All factors that induce focal shifts also upset one's 
knowledge of geometry and thus, degrade the photogrammetric quality of 
derivative products." The Itek engineer suggests focusing cameras to 
operate under a limited range of conditions which includes environments. 
Testing and Environmental Simulation-an Air Force Policy 
  
A Technical Report A-FAL-TR-74-204 of July 1974 consists of eight papers au- 
thored by Air Force personnel (AFAL/RSE) Wright Patterson Air Force Base 
which were presented at the National Aerospace and Electronics Conference. 
They are involved with dynamic and environmental test evaluations and analyses 
Of reconnaissance systems. This review is such as to briefly show the im- 
portance of environmental testing in the U.S. Air Force and the status of 
simulated environmental analysis at this research facility. 
17