the bottom transponder at that time. The final location 

 of the bottom reference transponder was based on a total 

 of 86 satellite passes. The scatter of these passes had 

 a standard deviation of I5OO feet In the east-west direction 

 and 1000 feet in the north-south direction. 



Telemetry 



During the search for THRESHER in I963 and 1964 the 

 operation of multiple sensors was difficult and Ineffective 

 due to telemetry difficulties. The long cable telemetry 

 system reported at the Fifth Symposium on Military Ocean- 

 ography by Buchanan and Isaacson was available for the 

 SCORPION search. This system used a special filter design 

 in a frequency division multiplex system and permitted 

 simultaneous operation of all sensors and control function 

 with a minimum of interference. Without this system the 

 search time requirement would have been much greater. 



61 



