Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-27T13:00:10.906Z Has data issue: false hasContentIssue false
  • English
  • Français

Loran-C Chains: Determination of Extent of Cover

Published online by Cambridge University Press:  21 October 2009

K. F. Woodman ,
J. Juleff  and
R. A. Allen
K. F. Woodman
Affiliation:
(Admiralty Research Establishment, Slough)
J. Juleff
Affiliation:
(Admiralty Research Establishment, Slough)
R. A. Allen
Affiliation:
(CAP, New Maiden, Surrey)
Get access Rights & Permissions [Opens in a new window]

Abstract

A mainly theoretical study has been undertaken to demonstrate how the extent of cover from a hyperbolic navigation system chain can be evaluated. The impetus for the study was the need to assess how Loran-C could be extended over Western Europe, particularly in the South western Approaches, North Sea, English Channel and Bay of Biscay sea areas.

The technique described in this article leads to an accurate determination of the electric field strength at a distance from each transmitting site and takes into account the complexities of the ground-wave propagation path. This field-strength contour is combined with the geometric effects of station siting (expansion factors) to yield a constant S/N contour (–10 dB) which defines the ¼n.m. error and hence the limit of cover for the hyperbolic chain under study.

In order to exercise the analytical methods a hypothetical Loran-C chain was studied comprising a master station at Lessay (France), with secondary stations at Soustons (also in France), at Sylt (dual rated; off the North Sea coast of Germany, near the Danish border) and at a fourth station located in north-west Britain on the Hebridean island of Barra. The study indicated that such a hypothetical chain would significantly improve Loran-C cover over much of western Europe.

Type
Research Article
Information
The Journal of Navigation , Volume 41 , Issue 2 , May 1988 , pp. 149 - 173
Copyright
Copyright © The Royal Institute of Navigation 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Admiralty (1983). Admiralty List of Radio Signals and Diagrams Relating to Radio Communications and Position-Fixing Systems. NP2 85a.Google Scholar
2Braisted, P., Eschenbach, R. and Tiwari, A. (1986). Combining LORAN and GPS - the best of both worlds. Navigation: J. of Inst. Navigation, 33, 20.CrossRefGoogle Scholar
3 LORAN-C Working Group (1985). Final Report, July 1985.Google Scholar
4IALA (1987). Proceedings, IALA Special Radionavigation Conference, London.Google Scholar
5Wenzel, R. J. and Thrall, W. J. (USCG Europe) (1986). Dual-rating of Sylt experiment, Report.Google Scholar
6Norton, K. A. (1936). Propagation of radio waves over the surface of the Earth and upper atmosphere. Proc. IRE, 24, 1367.CrossRefGoogle Scholar
7Bremmer, H. (1949). Terrestrial Radio Waves. London: Elsevier.Google Scholar
8Millington, G. (1949). Ground-wave propagation over an inhomogeneous smooth Earth. Proc. IEE, Part 3 (Radio Engineering), 53.Google Scholar
9USCG (1950). Data on Loran-C Field Intensity. Source Document TM 11–499, 27 August 1976.Google Scholar