4. SUMMARY 



a ■ Type of System 



(1) Mode of operation: hyperbolic or ranging. 



(2) Frequency: one frequency per chain in 1 .7 - 2 .0 mc band. 



(3) Operation: time -multiplexing of single frequency . 



(4) Number of frequencies available: 5 in 1 .7 - 2.0mc band, 

 selected by operator . 



(5) Type of transmission: cw . 



(6) Sampling rate: one/second. 



(7) Time -multiplexing trigger signal: 60 cps in master trans- 

 mission, lasting 0.1 second. 



(8) Radiated power: 10 watts (approximately). 



(9) Power required: 24 v @ 300 w (approximately) . 



(10) Personnel requirements: Master station can operate un- 

 attended, slave stations require one nontechnical attendant 

 each. 



b ■ Range and Accuracy 



(1) Range: 40 - 100 miles, dependent upon ground conductivity . 



(2) Accuracy: Over water, a = ± 0.01 -0 .02 lane, which is 

 equivalent to about ±2.5-7 feet . Over combination land 

 and water, a - ±0.05 lane, which is equivalent to ± 10 - 

 40 feet . 



REFERENCES 



1 . Technical Data Sheet No . S4, Decca Navigator Co . , Ltd . , February 1960 . 



2. P.O. Fagerholm and A. Thunberg, "Some Accuracy Tests with Hydrodist 

 and Hi -Fix for Position Determination in Hydrographic Survey, " Supplement 

 to the International Hydrographic Review, Volume 2, October 1961 . 



167 



artbxir ZD.ILittlrJnr. 



