TM No. 327 



between Hi-Fix transmitters and receivers are 5-35 miles, Hovever^ the 

 receiver can be used close to the transmitting station -without loss of 

 accuracy; or at a maximum offshore range of about 100 miles, if the radiated 

 pover from the transmitting station is increased. The radiated po^wer of 

 the transmitting stations in the Tongue of the Ocean is sufficient to ensure 

 a working range which is normally in excess of 50 miles over sea water. 

 During this program, the Hi-Fix system was used at a maximiim distance of 

 about 110 nautical miles (T1 in figure l) from the farthest slave station 

 with fair reliability. From a nomogram it was calculated that the lane width 

 along transect 1 was from I7OO to I9OO meters. Since the receivers were 

 capable of reading to l/lOO of a lane, this provided an accuracy in the order 

 of 17 - 19 meters, 



A series of Decca transformation charts were available for the Tongue of 

 the Ocean area to plot the positions of the drogue floats between 23° 50' and 

 2h° 50' north latitude. Although there was no chart coverage for the transect 

 in the Northeast Providence Channel, the Naval Oceanographic Office has a 

 computer program for converting Decca coordinates to latitude and longitude, 

 and this was used to plot the positions of the floats in these areas. 



In general, the Decca Hi-Fix system, backed up by radar, was quite 

 adequate for tracking the drogues, and the position fixes obtained were satis- 

 factory. 



DROGUE CURRENT MEASUREMENTS 



Transect 1 



Eight drogues were set at various depths and tracked along transect 1 

 (T1 in figure l). The drogue history and data sheets are included in appendix 

 A, Table 2 is a summary of the drogue data obtained along Tl, 



Table 2. Summary of Drogue Data - Transect 1 



""Questionable values 



