The ATLANTIS v/a,s instructed by radio at the moment each photo= 

 gi-apMc run started 3.nd a Kide=ma.rk was made on the record, of the dis= 

 tance monitoring device„ Ten paiis cf photographs were taken on each 

 run which required about 36 seconds. A total of 100 stereo pairs was 

 accomplished for the projects 



Stereo Analysis 



The stereophotogramrnetric graphic results were prepared by the 

 Photogrammetry Branch of the U^ S, IMavy Ilydrographic Office, A total 

 of four stereo pairs of aeri.al photographs was selected for detailed axs.aly= 

 sis. They were chosen on the basis of photographic quality and also be= 

 cause they showed the AT.LANTB=raft combinatio:t;,. The instrument used 

 was the Zeiss Stereoplariigrapha. considered to be among the most accurate 

 of the first-order photogrammetric plotting instruments. The direct read- 

 ing ability of this instrument is 0„01 mmo 



The first inodel fa inodel is iihe rectangular overlapping portion of 



two aerial photographs which can be viewed stereos copically) was contoured 



by establishing an assuixied vertical d,atum„ That is, in each corner of the 



model the low point of a tro^ugh wa,« assumed zero elevation and the contour 



data throughout the model was based en that datum. Each model represented 



a ground rectangle with sides of approximately 2700 feet and 1800 feet, or 



nearly 5 million square feet of ocean surfaces at a scale of 1;?,000. This 



model was used to determine the spacing to be used on the spot height grid, 



but it is not reproduced herein. 



45 



