• The data-collection (or surveillance) mission may 

 be redirected in real time as the visual output is 

 assimilated (either by the aircraft crew or at the 

 shore-based command center) to improve data quality 

 in required areas. 



• The "longitudinal" (serial) nature of the elec- 

 trical signal, as opposed to the parallel nature 



of a photograph (or, time distributed as opposed to 

 space-distributed) makes digitization and computer 

 use much easier. Thus, while real-time "coarse" 

 images are available for instant review, computer 

 image processing can proceed to provide, slightly 

 later, refined images and data analysis. 



The value of the latter characteristic would be hard to 

 overemphasize; large-area surveillance photographs contain astronomical 

 amounts of information, most of it superfluous (especially over the ocean). 

 Manual (i.e., human) processing of all this information is tedious and 

 inefficient; .an electronic data processor can screen out most, if not 

 all, of the image detail due to clouds and shadows, wind, waves, and 

 sunglint on the water surface, and even uninteresting surface traffic. 

 The "expurgated" image and data then provided to interpreters allow 

 for much faster and more definitive analysis. When multiple, sequential 

 images are being returned (as from an airborne or spaceborne TV, for 

 example), the computer can also maintain a running record of the course 

 and speed of all vessels of interest within the area. This information 

 is of great value in the classification of vessels, and the determination 

 of their activity (e.g., fishing). 



The previous discussion has generally assumed aircraft 

 platforms for the sensors; also candidate platforms, of course, are 

 satellite and surface craft. The combination of timeliness of coverage 

 and operational economics makes aircraft seem the most useful surveil- 

 lance craft for the near future, with some data being derived from 

 existing or projected satellites, and with final follow-up performed 

 by surface vessel. 



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