E-2 

 the navigational sensors on the R/V Eastward. 



1. velocity tracking with doppler sonar (resolution 

 of 0.1 knots) ; 



2. gyro-heading (resolution of 0.5% of arc) ; 



3. continuous Loran-C auto tracking of four master- 

 slave pairs on the East Coast U.S. networks 9 930 

 and 9960 (resolution of .01 microseconds); 



4. doppler positioning using four polar-orbiting 

 Navy Transit satellites (accuracy of 0.2 mm) ; 



5. radio ranging from two temporary shore installations 

 to a resolution of 0.01 lanes (=0.9 meters), having 

 the commercial name of ARGO. 



The highest degree of repeatability is provided by radio- 

 ranging. The ARGO equipment was loaned by NOAA and shore 

 stations were set up at Avalon, New Jersey and Asseteaque, 

 Delaware. At the operational frequency of 1868 kHz, a wave- 

 length (or lane) is approximately 90 meters in length. Be- 

 cause the shipboard master station simply measures a phase 

 difference, this technique only has the capability of 

 determining fractional wavelengths (or fractional lanes) . 

 Whole lane counts are determined from an autolane counting 

 capability. However, difficulties were encountered with 

 the whole lane counts as the consequence of unexpected brief 

 but complete interruptions in the radio transmissions. Fur- 

 ther, the ARGO system was not operated for Leg E-2B-79 

 at Oceanographer and Lydonia Canyons because of the signi- 

 ficantly greater propagation distances from potential land 



