B = equivalent noise bandwidth, Hz 



T = integration time, s. 



The integration time, t, is chosen to equal the time the target dwells 

 within the scanning beam: 



^®l/2^^ h (0.01745) 

 ^ "^ Vcp 



where 



V = platform velocity, ft s 



cp = scan width (side-to-side), deg. 



Using a platform height of 6,2 x 10 ft, a receiver temperature of 500 K, 



an antenna temperature of 150 K, a platform speed of 200 kts, and the 



system characteristics of Table 11 gives AT = 1.66°K. 



min 



A temperature contrast of from 50° K to 80° K is 



expected between fishing vessels and the sea. For a beam filling factor 



of 107o, this produces a radiometer antenna temperature contrast between 



viewing and not viewing the vessel of 5° K to 8 K. The corresponding 



ratio of the antenna temperature contrast to the minimum detectable 



contrast of 1.7°K will be in the range of 3 to 5, which will be adequate 



for detection. 



(4) Areal Mapping Rates 



Areal mapping or surveillance rates depend on plat- 

 form altitude, platform speed, and search strip or swath width. Con- 

 siderations of detectability described earlier limit platform altitude 



3 

 to 6.2 X 10 ft, which precludes the use of satellites and severely 



restricts coverage. The maximum side-to-side scan angle is determined 



by the decreased contrast between vessel and sea at large angles of 



64 



