molded edges. Also, a 1-inch circle was scribed on the 
painted side using the hole as the center. The plates were 
then aligned at the desired as-built points on the ship 
and tack-welded in place. l-inch diameter flat-white dots 
with adhesive backing were then set within the scribed 
  
circles to complete the bull's-eye targets. Finally, each 
target was inspected and notes made if any deviations of 
  
target centers from as-built molded edges were observed. 
(Such displacements are readily accounted for in subsequent 
data analyses.) Figure 4 shows typical targets in place. 
Although the target design was that of the photogrammetrist, 
fabrication and attachment of the targets were performed by 
the shipyard. It should be mentioned that target dimensions 
are:unique to a particular project and are dictated by the 
need to obtain very small but yet measurable images on the 
photographs. Targets can be supplied and attached by the 
photogrammetrist, but in this case it was more productive 
forthe shipyard to assume this responsibility. Actual 
attachment of the targets was performed one to two days in 
advance of the photogrammetrist's arrival on-site and 
involved 38 man-hours per ship half. 
With regard to tack welding of the targets, this was 
considered to be a necessity. Earlier work under the 
  
MarAd/Todd project mentioned in Section 1 demonstrated 
that attachment by magnets was not desirable for beveled 
edges nor in any instance when shipyard work is in progress 
on the hull. Constant movement of men, equipment and hoses 
dislodged many targets from their intended locations in that 
  
  
  
project. 
-12-