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Question 6; 
a. What is hottest temperature at which you do aerial surveying? 
b. How do you protect camera prior to flight. 
c. What is the maximum highest temperature during flight. 
Again a and b were evaluated together and are shown on the same Figure 2. 
This curve is narrower than the extreme cold curve defined. Note that ‘at 
its lower edge it includes the controlled temperature at which most 
laboratories operate. Note also that the peak of the extreme cold temp- 
erature curve is 50°C lower than the laboratory temperature. 
Preflight protection is as follows: 
No protection 29 
Air Condition 6 J e 
Store in Aircraft 9 
Store in Hanger 5 
Canvas covers or 
case 5 
Gradually Condition 1 
Question 7: 
To what pressure changes is the camera subjected during the survey? If you 
have a window what is the pressure within the cabin? If no window what 
is maximum altitude? 
Figure 3 is a graph showing maximum altitudes of surveys without windows 
reaching altitudes as high as 32,000 ft. Approximately 86% use no window. 
The curve shows that 7072 flyabove 20,000 ft. Those who use windows 144 
maintain cabin pressures equivalent to 10,000 and 14,000 ft. One quotes 
a differential of 9 psi at 50,000 ft altitude. 
€ 9 
Question 8: 
Are there other environmental conditions which you think are signifieant 
causing loss of image quality and/or affecting geometry? If vibration, 
please supply amplitudes and frequency if possible. 
The answers fell (mostly) into the following catagories: 
No known problems/no answer 22 
Vibration negligible 14 
Vibration affects imagery 6 
Extreme temperature changes cause 
condensation 4