TABLE 3 

 Stereocamera Data 



Ship 



USS VALLEY FORGE (CVS45) 



USCGC UNIMAK(WAVP379) 



Type of Camera 



Aircraft Precision Mapping 

 Navy Type CA8 



Aerial K24 



Manufacturer 



Fairchild 



Eastman Kodak 



Manufacturer Serial Number 



292 



295 



35,540 



109,994 



Instruction Manual 



AN-10-10AC-63 1 Aug 1947 

 Revised 1 Jun 1953 



10-10AB-1 over AP2315A 30 Jul 1943 

 Revised 30 Oct 1943 



Position Installed on Ship 



Forward 



Aft 



Forward 



Aft 



Frame 



89 



105 



47 



73 



Height above Baseline 



111 ft 7 in. 



111 ft 7 in. 



56 ft 



55 ft 



Angle of View, Horizontal 



73° 40 ' 



39° 20' 



Separation 



63 ft m in. 



51 ft 9 in. 



Equivalent Focal Length 



153.57 mm 



152.83 mm 



179.66 mm 



180.03 mm 



Calibrated Focal Length 



153.59 mm 



152.86 mm 







FORGE estimates were averaged and plotted against time of observation (see Figure 4), and 

 a smooth curve was fitted to these points. 



In making their observations, the Weather Bureau personnel on the UNIMAK followed 

 the instructions of Reference 6, from which the following sentences are quoted as they appear 

 in the Ninth edition, pages 57 and 58: "Waves in the same system usually occur in a sequence 

 of a few, large, well-formed waves followed by an interval in which only small and poorly 

 formed waves appear, then another series of large, well-formed waves. To obtain uniform wave 

 data from all ships, observers will record only the larger, well-formed waves, and omit entirely 

 the low and poorly formed waves. . . . The wave height as recorded. . . is the average of the 

 estimated heights of the larger, well-formed waves." 



The Navy observers were guided by Reference 7 which says: "In view of the consider- 

 able variation in height between waves observed in a 7-minute period, reference is convenient- 

 ly made to the significant wave height. This wave height is the average of the higher, well- 

 defined waves present during the observation. Statistically, significant waves are defined 

 as the average of the 1/3 highest waves observed in a given time. As the height is the most 

 important wave characteristic from the operational point of view, care should be taken to ob- 

 serve and report it accurately."* It is apparent that the estimating procedures specified by 



"Italics added. 



