Removed 

 August 1965 



SNELLIUS in October 1964 at Portland dockyard. Again, the 

 field engineer assisted in the installation and rode the ship 

 to assist in operation and training. Because of the loss of 

 signals from Criggion, due to other commitments, the equip- 

 ment was removed at Halifax, Nova Scotia, in August 1965. 



Both installations were conventional and used the 

 Omega receiver manufactured by ITT (Type II, Serial 2) with 

 various whip and wire antennas. However, the internal 

 Manson oscillator was not used on the VDDAL which had a 

 precision frequency standard. 



SUPPORT 



Close liaison 



Tables and 

 skywave correc- 

 tions provided 



Date 



An engineer from the U. S. Navy Electronics 

 Laboratory spent a total of approximately five months 

 aboard the ships during the two years of operation. When 

 aboard, he assisted in navigation, receiver operation, and 

 maintenance and helped train the officers and crew. 

 Equally important, from the present viewpoint, he was 

 responsible for monitoring when the ship was in port. 



NEL also provided support to the ships in the form 

 of navigation tables and skywave corrections. Because of 

 the large area involved (approximately 10 million square 

 miles), this effort proved substantial although skywave 

 corrections were computed more sparsely than would have 

 been done for an operational system. All totalled, approxi- 

 mately 20 hours of computer time were used for support and 

 evaluation of the operation. 



Support was received as well as given. Both ships 

 monitored Omega signals in port and forwarded the results 

 to this Laboratory. Excellent cooperation was received and 

 the data have been of substantial importance in refining the 

 Omega system calibration. 



