(3) Minimum lag in stabilization action, easy accessibility 

 for maintenance. 



(4) Alarm system to detect malfunctions. 



f. Receiver -transmitter : 



(1) Frequency: 10 - 18 kc. 



(2) Transmission: Pulsed CW emission and reception. 



(3) Frequency Control: Precise intermediate frequency (IF). 



(4) Scale Range: Several and concurrently shifted. 



(5) Phasing: Automatic phase detection. 



(6) Pinging: Single or continuous. 



(7), Output: Output suitable for audible depth indication and 

 use with an external precision recorder. 



g. Recording: 



(1) Data Display: To present travel-timie data to a display 

 which automatically connects horizontal and vertical components and 

 displays data from successive sweeps as contours at pre-selected in- 

 tervals varying between 5-100 fathoms. 



(2) Data Recording: Output data to be compatible to present 

 and planned data reduction methods. 



(3) Must record continuous bottom profiles in addition to 

 plotting "contours." 



(4) "Alternate" Recorder: 



(a) Paper Width: 18 inches. 



(b) Time Accuracy: 1 part/million. 



(c) Paper Speeds: 24 and 72 inches/hour and also geared 

 to own ship's speed for various chart scales. 



(d) Marking area of recorder paper to have accessibility 

 for ease of immediate reading of trace. 



(e) Adjustable for setting correction for ship's draft. 



(f) Provision for a gating circuit. 



(g) Means for a numerical depth print-out. 



(h) Means for changing vertical scale of recording, 

 (i) Automatic depth phase recording on trace, 

 (j) A reflectivity meter should be built into the system 

 to provide a continuous recording of the reflectivity of the sea floor. 



360 



