and wooden ships appear wanner than the sea be- 

 cause of their high emissivity. A ship will be 

 easily detectable at the platform heights con- 

 sidered with present state-of-the-art receiver 

 and antenna systems. 



4, Microwave radiometers operating alone offer very 

 little promise as a means of identifying fishing 

 vessels or their catch. If combined with a beacon 

 system, then the combined system would have the 

 capability to locate ships on a day/night, all- 

 weather basis and then identify and classify the 

 vessels by use of a beacon. Any beacon within 

 line-of-sight of the airborne radiometer would be 

 detectable. 



5, Vessel location accuracy is determined by the 

 accuracy with which platform position is known. 

 This is estimated to be 2000 ft in range and 2° 

 in bearing. 



6, Main advantages of the radiometric technique 

 appear to be the fact that (a) it is passive, 

 offering the advantage of surveillance without 

 radiation (the adversary does not know he is 

 being observed) ; (b) detection by day or night 

 and under almost all weather conditions is pos- 

 sible; and (c) the equipment can have a multi- 

 purpose capability providing information on 

 sea state, sea ice, and rainfall rates, if 

 properly designed, 



7, Ice, fog, dense clouds, and even moderately 

 heavy rainfall are not expected to seriously 

 degrade performance of the system. However, 

 heavy rainfall may degrade the system by reducing 

 contrast between the vessel and the sea, 



8, Equipment cost per platform equipped is estimated 

 at $200,000 with the unit cost decreasing to 

 approximately $100,000 in quantities of ten or 

 more. 



2 2 



9, Approximately 5.8 X 10 nmi can be searched 



per hour, at a cost of approximately $2.07 per 

 nmi2 FY 1975 dollars. 



67 



