pose. The Loran-C network is now planned 

 or in operation in the regions proposed. A 

 Hcensing arrangement and installation tech- 

 nique for fitting transponders on each foreign 

 fishing vessel entitled to fish in the region 

 would need to be devised. Control stations 

 and receivers on patrol ships or aircraft would 

 need to be installed. 



It is estimated that the transponder which 

 would go onboard each foreign vessel would 

 cost less than $2,500. Once the system were 

 installed, operational costs would be roughly 

 equivalent to the operational cost of the 

 aircraft carrying each control station, $1 

 million to $1.6 million annually. Funds for 

 evaluating the pilot project would be in addi- 

 tion to these costs. 



The Georges Bank pilot program would re- 

 quire about 150 transponder units and a con- 

 trol station most likely at a Coast Guard shore 

 base in New England. Each vessel entering the 

 200-mile zone at Georges Bank for fishing 

 would be required to activate its transponder 

 which would automatically transmit iden- 

 tification and location to the shore base. The 

 shore base would keep plots of all foreign 

 fishing activity on the banks and give this to 

 patrol craft. Regular patrols of the region 

 would use this information to check on any 

 fishing activity that wasn't reported by this 

 system. At the end of one season, an evalua- 

 tion of the usefulness of this system could be 

 made. 



In the Bering Sea region a similar network 

 of transponders could be required aboard 

 foreign fishing vessels. In this region it may be 

 desirable to combine the transponder network 

 with microwave radar systems already used 

 aboard Coast Guard patrol aircraft and receiv- 

 ing stations. In this way a specific region could 

 be covered by regular overflight, all vessels 



operating in the region located by radar, each 

 vessel interrogated to determine whether an 

 approved transponder is aboard stating ID 

 and location, and any vessels without trans- 

 ponders investigated. 44 There are several ad- 

 vantages to a system thus described, especially 

 in Alaska where long distances and large areas 

 can best be covered by aircraft and where fre- 

 quent cloud cover makes visual observation 

 difficult or impossible. After a season of 

 operations with such a system a comparative 

 evaluation of its usefulness would determine 

 whether it could be beneficial to expand use or 

 coverage. 



Microwave Radar^s 



Microwave radar has been used for ocean 

 surveillance by aircraft and ships for almost 

 40 years. The technology is highly developed 

 and the design principles are so well known 

 that it is possible to predict with high confi- 

 dence the performance of any given design 

 chosen for use. Microwave radar has better 

 potential for large area coverage than any 

 other system now in use. 



Microwave radar operates by transmitting 

 pulses of energy from a directional antenna. 

 The pulses are reflected by any material object 

 encountered. The reflected energy is subse- 

 quently received and analyzed to determine 

 the position and characteristics of the reflect- 

 ing objects. The direction of the objects can be 

 determined by tracking the reflected signals 

 and the distance is determined by measuring 

 the time delay from pulse transmission to 

 reception of the reflected signal. 



The basic information for fisheries enforce- 

 ment which can be supplied by microwave 

 radar is: 



. the presence or absence of a vessel in a 

 given area; 



50 



