(3 
halves it was required that target coordinates be 
determined with a standard deviation of 0.04 inch or 
better. Given this requirement it is implied that the 
distance between any two targets must have a standard 
deviation off? x 0.04 or about 0.06 inch. Clearly 
then, the taped measurements must be more accurate 
than thís. 
Photography 
Nominal locations from which photographs are to be 
taken are almost always pre-planned by the photogrammetrist. 
Variables which must be considered are camera focal length, 
camera field of view, desired accuracy of target coordinates 
and physical limitations and obstructions on the job-site. 
In this case the shipyard specified that target coordinates 
must have an "accuracy" of 0.04 inch (standard deviation) 
or better, provided a dimensioned sketch of the frame to be 
surveyed and nominal dimensions from each ship-half to 
possible interferences to the photographic work. With this 
information camera locations were planned and submitted to 
the shipyard for approval as to feasibility. These 
locations were then marked off on the ground by the shipyard, 
within to feet as requested by the photogrammetrist. 
As the planned day for taking the photographs approached, 
the shipyard closely watched weather forecasts. The 
photogrammetrist was not ordered to the job-site unless 
it appeared likely that good weather would be available 
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