2 

 possible to have a line-of-sight access to 200,000 miles of sea 



surface per hour. 



Two or more airborne platforms can be used to decrease 

 the time to intercept and locate an emitter. These aircraft can be 

 flown at, say, 100-mile separation and can be coordinated in DF opera- 

 tion so that a near instantaneous triangulation may be made. 



This type of operation requires an air-to-air data 

 link between the aircraft. Preferably, one aircraft is the master in- 

 terceptor and controls the receiver tuning and direction finder opera- 

 tion in the slave aircraft via a digital data link. 



A single airborne platform may be used to take one, 

 or more, DF cuts on the emitter as the aircraft flies a known path. 



c. Cost Analysis 



(1) Ground-Based HF DF Techniques 



Use of Existing DoD Facilities--It is possible that 

 some signal intercept information can be made available from the DoD 

 files. However, most DoD operations are mission-oriented, and it is 

 most unlikely that there is much time spent in tracking fishing fleets. 



Because of the work load, it is reasonable to expect 

 that the minimum cost would be at least that of the extra DF operator 

 personnel required, which is estimated to be $60,000 per station per 

 year. 



Dedicated DF Stations --Assuming a low-cost HF DF 

 system such as the Army AN/TRD-26, cost factors for a dedicated station 

 are shown in Table 14, 



84 



