Instrument systein priority 3. 



II. d. TOWED SUBSURFACE INSTRUMENT SYSTEM 



Primary Use: 



This device is designed for utilization on oceanographic survey 

 ships for underway operations to obtain horizontal profiles of certain 

 key oceanographic variables. It is to be a streamlined, compact 

 platform to which will be attached modular sensors and other special 

 miniaturized instruments capable of being towed submerged at 

 moderate speeds. 



Requirements and Specifications: 



a. The platform with associated instruments shall be capable 

 of being towed from an oceanographic survey ship at any constant 

 depth within a depth range of 0-Z,000 feet at any ship's speed ranging 

 from 3 to 15 knots. In addition, a feature should be incorporated in 

 the vehicle design to permit continuous, controlled variation of the 

 platform's depth over the entire operating depth range or any incre- 

 ment thereof. 



b. The towing wire angle shall not exceed 25 from the vertical. 



c. The platform and associated instruments shall be compact, 

 .streamlined, and not excessively heavy or bulky in order to allow 



rapid and adequate deck stowage and/or to permit smooth entry into 

 or hoisting out of the water. 



d. The following sensors shall be included: 



Sensor 



Temperature Range: -Z to 35 C. 



Accuracy: ±0.01°C. 

 Salinity (two inter- Range: to 25%o 



changeable modules) 25 to 45%o 



Accuracy: ±0.01%o 

 ±0.01%o ' 

 Sound Velocity Range: 4, 500 to 5, 500 feet/ 



second 



398 



