(laboratory ship and submarine) and the sound velocity. Accordingly, one of the major require- 

 ments in the system is the precise synchronization of the two clocks. Two methods are now in 

 use. In the first method both clocks are synchronized with National Bureau of Standards Radio 

 Station WWV; in the second a pulse is sent from the laboratory ship over an FM radio circuit 

 and the submarine clock is synchronized with this pulse. 



Included as an option in the submarine electronics are a 50-kc power amplifier and a 

 50-kc transducer. These instruments may be used instead of the AN/UQC-IA to avoid inter- 

 ference with acoustic measurements in the AN/UQC-IA frequency range. 



SUBMARINE COMPONENT DESCRIPTION 



A detailed description of the ARMS equipment employed by the submarine follows. 



TIME STANDARD (Submarine) 



The time standard, as shown in Figure 2, is used to provide a precise time base for 

 the operation of ARMS. A drift from synchronization between the two time standards will re- 

 sult in an error in range. So that this error does not exceed 1 yd/day, the drift must not 

 exceed 600^ sec in a 24-hr period (8.64 x 10* sec) or 



600 X 10~^ sec drift _. 

 = 7 X 10 ^ sec drift/sec 



8.64 X lO'* sec 



cycle drift 



or 7x10"^ 



cycle operation 



The time stanaard used is Model FS-llOOT, manufactured by Sulzer Laboratories of Rockville, 

 Maryland. It is a lOO-kc oscillator with a stability figure of an order of magnitude better than 

 that required. 



ELECTRONIC TIMING PACKAGE 



The timing package, shown in Figure 3, uses the lOO-kc output of the time standard to 

 produce the pulses needed for the operation of the other parts of the submarine system. The 

 100-kc output is divided by successive decade dividers and then by two flip-flops to yield 

 10 kc, 100 cps, 1 cps, 1/2 cps, and 1/4 cps. Each decade divider or divide-by-ten circuit 

 consists of four flip-flops and associated gating circuits. 



These dividers must be phase synchronized, as has been mentioned. Two methods are 

 used: The first is to trigger an oscilloscope on the positive rise of the 1-cps pulse while 

 viewing the timing pulse from Radio Station WWV. Two switches located on the front panel 

 of the timing package allow the subtraction of a preset number of pulses or the addition of 



