ditions and airborne radiometers have been 

 successful in mapping weather fronts and sea 

 states. Radiometric measurement of oil spills 

 have been made with limited success and 

 radiometers have been frequently suggested 

 for use in missile terminal guidance systems. 



Although there do not appear to be any 

 operational systems at present that are 

 specifically designed for detection of ships, 

 such systems have been studied and pro- 

 totypes have been tested. The existing tech- 

 nology is more than adequate for the detection 

 of fishing vessels. 



However, constraints on maximum fre- 

 quency and the detectability of relatively small 

 ships severely restrict the height from which a 

 radiometer can effectively operate. Satellites 

 could not be used for radiometer detection of 

 fishing vessels, and aircraft would be limited 

 at altitudes of about 6,000 feet. At that altitude 

 fishing vessels could be located to within 

 2,000 feet in range and 2 degrees in bearing 

 (see figure 16). 



Optical and Electro-Optical Techniques*^ 



With existing technology a variety of opti- 

 cal and electro-optical sensors can be built 

 which could perform many useful functions 

 in enforcement of the 200-mile fishery zone. 



This category of sensors includes the tradi- 

 tional visual, aided visual, and photographic 

 techniques — ranging from the human eye to 

 electronically augmented viewing systems 

 and film cameras — and the more sophisti- 

 cated, recently developed methods of electro- 

 optics such as low-light-level television and 

 infrared or thermal mapping systems. These 

 systems are likely to play supporting or aux- 

 iliary, rather than primary roles, in enforce- 

 ment. 



Figure 16 



Airborne Scanning Microwave 



Radiometer 



6200 ft 



Source; Stanford Research Institute 



91-072 O - 77 - 5 



55 



