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The Accuracy and Coverage of Loran-C and of the Decca Navigator System — and the Fallacy of Fixed Errors

Published online by Cambridge University Press:  21 October 2009

David Last
David Last
Affiliation:
(University of Wales, Bangor)
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Abstract

The proposal to develop an extensive North-West European Loran-C system, replacing many existing chains of the Decca Navigator System (DNS), has led to an intensive debate on the merits of the two navigation aids, especially in the United Kingdom. The paper reviews the principal sources of random and systematic position errors in the two systems. The wide range of DNS random errors, predominantly due to skywave interference, are compared with the Loran-C random errors, and typical coverage limits of acceptable repeatable accuracy are presented. The paper also identifies the factors which control the magnitudes of Loran-C and DNS systematic effects due to land paths. It demonstrates that differences between the two systems are substantially less than are predicted by simple models. Loran-C and DNS techniques for dealing with land paths are compared and the errors experienced by Loran users are shown to be reduced by modelling and publishing ASF values.

This paper is based on a presentation made by the author at a technical symposium of the Wild Goose Association.

Keywords

Hyperbolic systemsRadionavigationErrors
Type
Research Article
Information
The Journal of Navigation , Volume 45 , Issue 1 , January 1992 , pp. 36 - 51
Copyright
Copyright © The Royal Institute of Navigation 1992

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References

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