(2) Available Technology 



There do not appear to be any operational systems 

 in use at present that are specifically designed for the detection of 

 ships although from time to time such systems have been studied and 

 prototypes have been tested. Studies demonstrated the capability of 

 microwave radiometers operating at relatively low altitudes to detect 

 and, in some cases, to image ships (e.g., Reference 9). There has been 

 very little study of the classification of vessels by microwave radiometry, 

 and microwave radiometry operating alone offers little promise as a 

 technique for ship classification. 



Microwave radiometers are used widely in various 

 remote sensing applications from airborne and satellite platforms. 

 Electrically scanning radiometers at 19.35 GHz aboard NIMBUS 5 and at 37 

 GHz aboard NIMBUS 6 have proved very successful. The characteristics 

 of the NIMBUS 5 radiometer are tabulated in Table 9 to give an indication 

 of available technology. A five- frequency microwave radiometer system 

 covering the frequency range from 5 through 37 GHz has been developed 

 for the NIMBUS 6 and SEASAT satellites and a microwave imaging system is 

 under development for the SHUTTLE. 



Primary areas in which microwave radiometers are 

 finding application in remote sensing are the following: 



• Remote sensing of ocean temperature and by 

 inference sea state, wave conditions, and 

 surface wind fields. 



• Remote sensing and demarcation of areas of 

 sea ice. 



• Remote sensing of rainfall rates. 



• Remote sensing of thickness and volume of 

 oil spills. 



• Radiometric -map terminal guidance aids for 

 missiles. 



In each of these areas, a we 11 -developed technological base exists. 



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