the Air Force had never been in favor of a 
separate type of aircraft for reconnais- 
sance and mapping purposes prior to World 
War II, two types of aircraft were then 
procured for use for photographic pur- 
poses. These were the F-1 and F-2 air- 
craft: (The Fairchild 70D and Beachcraft 
18-S with certain modifications for carry- 
ing photographic equipment.) 
With the advent of World War II in 
1941 it was necessary to provide installa- 
tions in aircraft that could be readily used 
for carrying photographic equipment and 
the following airplanes were modified for 
reconnaissance purposes: 
P-38 modified to the F-5 
B-24 4 F-7 
British Mosquito s F-8 
B-17 & F-9 
B-29 « F-13 
Late in 1944 the F-11 aircraft, which was 
designed primarily for reconnaissance pur- 
pose, was produced by the Hughes Air- 
craft Company. 
' In 1946 the Republic Aircraft Company 
built the F-12 which was also a basic pho- 
tographic airplane. However, neither of 
these two airplanes to date has been ac- 
cepted by the Air Force as reconnaissance 
aircraft. 
'The Shoran Straight Line Indicator was 
standardized and placed in use in the US 
Air Force in 1948; fifty-five of these in- 
struments were in use in 1952. Conceived 
originally and developed by this Labora- 
tory, an application for a patent for the 
device was made in 1947. The indicator 
24 HISTORY OF PHOTOGRAMMETRY IN THE UNITED STATES 
is capable of handling flight lines up to 400 
miles in length and represents the first use 
of a precision flight line navigation aid 
based on electronic means, or Shoran, 
keyed in with two ground stations. 
Later, in 1949, an entirely new system 
was developed for the navigation of straight 
and parallel flight lines. This method in- 
volved the use of a modified Land-Polaroid 
hand-held camera. It was first used in 
flight between Dayton, Ohio and Pitts- 
burgh, Pa. when two mapping flight lines 
300 miles long were flown, with continu- 
ous side lap of 30%, and with no variation 
of more than 500 feet. The technique in- 
volved in this system is astonishingly sim- 
ple and effective and is planned for stand- 
ardization by US Air Force. 
During the development of cameras, 
processing equipment and sensitized ma- 
terials it was also necessary to produce 
auxiliary equipment, such as stereoscopes, 
magnifying stereoscopes, height finders, 
stereocomparators and other accessories 
which were required to make the best use 
of aerial photographs in the production of 
maps and charts. 
Commercial mapping agencies have 
been benefited considerably by the devel- 
opments that were initiated and carried to 
successful conclusion by the Air Force. 
This is evidenced by the great amount of 
surplus war photographic equipment which 
has been purchased by commercial map- 
ping agencies for use in conducting aerial 
surveys and in the production of photog- 
raphy for use by Federal and commercial 
mapping agencies. 
AERONAUTICAL CHART AND INFORMATION SERVICE 
The global aspect of World War II 
made apparent that extensive coverage of 
aeronautical charts for the planning and 
execution of air operations would be re- 
quired. For this material to be made avail- 
able, it was necessary that terrain infor- 
mation be procured for the large areas of 
the world over which American aircraft 
might be expected to operate. To meet 
this, the Map Section of the Information 
Division of Headquarters, Army Air Corps 
was redesignated in 1942 as the Map-Chart 
Division of Air Traffic Service, Army Air 
Corps, and assigned the responsibility for 
providing the required aeronautical charts 
* See report of the U, S. Geological Survey, p. 857 
for operations of the Army Air Corps. 
From a nucleus of some 20 personnel there 
grew the current organization, the US Air 
Force Aeronautical Chart and Informa- 
tion Service, with responsibility for provid- 
ing all US Air Force map and chart re- 
quirements. 
The need for reliable terrain information 
resulted in the development of the trimet- 
rogon system of aeronautical charting by 
the Alaskan Branch* of the U. S. Geo- 
logical Survey. This work was done in 
1940 under the leadership of Gerald Fitz- 
Gerald. The primary objective of the sys- 
tem was securing photographic coverage 
   
  
    
   
  
  
  
  
  
  
  
  
  
  
  
    
    
  
  
  
  
  
    
  
   
  
   
  
  
   
   
  
  
  
  
  
  
  
  
  
   
  
  
  
  
  
    
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