PRECISE POSITIONING OF A SHIP AT SEA UTILIZING VLF TRANSMISSIONS

Long range relative precise positioning was attempted with the use of existing very low frequency (VLF) radio transmitters, shipboard receivers and precision frequency standards. The VLF receivers were initially set to a calculated time delay at the known geographic location. The change in range (determined from the transmission time delays and propagation velocities) combined with known transmitter locations was used to determine an updated ships position. A computer algorithm which converts the observed time delays to precise ships position was used and is described in this paper. The analytic approach uses the Andoyer-Lambert distance formula for computing propagation distances and azimuth angles relative to the transmitter locations by an iterative method. A shipboard digital computer was used to solve the algorithm which converges on the true ships position from an assumed ships position, even with large initial position errors. Computer simulation of the navigation system and actual shipboard results are presented. ( Author )

  • Supplemental Notes:
    • Prepared in Cooperation with IBM Corporation, Rockville, Md. Presented at The Institutes Annual Meeting ( 24th ) Monterey, Calif.
  • Corporate Authors:

    Institute of Navigation

    815 14th Street, NW
    Washington, DC  USA  20005

    Woods Hole Oceanographic Institution

    Woods Hole, MA  USA 
  • Authors:
    • Ruppert, G NPA
    • BERNSTEIN, R
    • Brown, C O
  • Publication Date: 1969-10

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Filing Info

  • Accession Number: 00007102
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: WHOI-Ref-69-76 Tech. Rpt., WHOI-Contrib-2141
  • Files: TRIS
  • Created Date: Dec 22 1973 12:00AM