more restricted field of view and the necessity to fly below or avoid 

 cloud and fog cover, operating costs (and time) for covering a given 

 surveillance area may be higher than for equivalent coverage by micro- 

 wave radar. Data to determine the probable range of these increased 

 costs were not obtained for the survey because they are so dependent on 

 the enforcement scheme used and the weather conditions encountered. 



The third cost category covers the processing required 

 (usually on the ground) to extract information from the returned sensor 

 data that are usable for enforcement. These costs will vary widely 

 depending on whether the data are obtained from a NASA or DoD satellite 

 or from a USCG aircraft and on how nearly "real time" the information 

 output must be. Processing costs will also vary according to the kind 

 of processing done. Photographic analysis, for example, is labor inten- 

 sive (requiring highly skilled labor) but it requires relatively inexpen- 

 sive equipment, while automatic processing of line-scanner outputs, for 

 example, uses less labor but much more expensive processing equipment. 



Considering both the wide variability of costs for various 

 options and the critical dependence of option selection on enforcement 

 strategy, and the fact that optical and electrooptical techniques are 

 likely to play auxiliary or supporting roles, it was decided not to 

 expend sparse project resources in trying to quantify costs. 



5. Electromagnetic Intercept Techniques 



a. Background 



All ocean-going vessels are equipped with radio equipment, 

 and a large percentage also carry radar for navigation. Radio frequencies 

 are allocated for specific uses by international agreement and each radio- 

 equipped vessel is assigned an international radio call sign for use in 

 identifying its radio messages. Likewise, navigational radar frequencies 



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