* 
reflects a summary of the nominal characteristics of Apollo 15 
Metric Camera Photography, pertinent to photogrammetric reduction. 
The USAF Aeronautical Chart and Information Center (ACIC) 
initiated photogrammetric reduction of Apollo 15 photography and 
data in October 1971. The project is being accomplished for NASA, 
with development of an initial selenodetic system scheduled for 
completion in 1973. As of the time of this writing, work has 
been concentrated on evaluation of Apollo 15's photography and 
data, as well as testing of procedures to be employed in photo- 
grammetric exploitation of these first results from NASA's Metric 
Camera System. Twenty-one terrain and related stellar exposures 
accomplished during Apollo 15's 22nd, 27th, and 60th orbital 
revolutions were selected for generation of test data. They 
cover an area of approximately 80,000 square kilometers surround- 
ing the Apollo 15 landing site (Figure 1), and represent a small 
and apparently representative sampling of Apollo 15 materials. 
- 
Initial testing was necessarily concerned with validation of 
the geometric fidelity of obtained photography. In particular, 
identification of quantity and source of film deformation, evalua- 
tion of adjustment procedures using measured and calibrated reseau 
values, and determination of ability to recover interior orienta- 
tion through relation of the reseau and fiducial systems. The 
5 mm reseau: present in the stellar photography readily enables 
compensation for the minimal film distortion existent over the 
small (22 x 32mm). film format. However, the terrain photography 
presents a considerably more complex situation in that significant 
distortion exists over the 127 mm film format and the position 0% 
the lOmn calibrated reseau (Figure 2) varies with respect to 
fiducial marks for each exposure. This variance is a function of 
motion of the camera's glass plate reseau in conjunction with 
camera film platen movement for image motion compensation. Three 
parameter adjustments (rotation, translation, scale) of measured 
to calibrated reseau values shows an x-y scale differential 
typically resulting from tension placed on film while being 
spooled in the camera or reproduction process. The quantity of 
distortion approximates 20 micrometers at format extremities. 
Testing of manually processed reproductions of original film 
showed little difference in quantity and pattern of distortion, 
indicating that the principal source of film deformation is in 
the taking camera or original film processing. Adjustment tests 
performed at ACIC and the NASA Manned Spacecraft Center show that 
4 parameter (rotation, translation, and differential x and y 
scale correction) and higher order transformations of measured 
reseau values reduce residual film distortion to a 5-6 micrometer 
maximum at reseau extremities. This maximum level of residual 
film distortion is not in itself disturbing. It is equivalent to 
7-9 meters at ground scale and is consistent with project accuracy 
e 
6 
  
  
FILM FORMAT TERRAIN CAMERA