THE BALLISTIC CAMERA SYSTEM 
The following discussion has been taken from a previous 
paper by D. C. Brown, "Precision Photogrammetry in Missile 
Testing". 
The ballistic cameras currently employed at the Atlantic 
Missile Range, the Wild BC-l's consist essentially of modified 
RC-5 aerial cameras mounted on the base of the celebrated Wild 
T-4 astronomical theodolite. Three different camera cones are 
used: the 115mm Aviogon, the 210mm Aviotar, and the 300mm 
Astrotar. The distortion of each lens is calibrated by means of 
star recordings to an accuracy of one micron or better.  Photo- 
graphic recording is done on ultraflat (6 fringe) glass plates 
of 6mm thickness. 
Experiments have indicated that with suitable shutters, 
filters,and photographic emulsions, it is possible to employ 
ballistic cameras in daytime operations. At present, however, 
ballistic cameras are used almost exclusively at night to record 
missile-borne flashing lights. The nighttime operational pro- 
cedure at each ballistic camera station is generally as follows. 
Precalibration is performed shortly before the missile flashes are 
to be recorded. After the precalibration has been completed, the 
camera shutter remains closed until shortly before the programme d 
missile flashes are expected to appear in the field of view. It 
1s then opened and remains opened until the termination of the