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A Comparison of Two Systems for Avoiding Collision

Published online by Cambridge University Press:  18 January 2010

E. S. Calvert
E. S. Calvert
Affiliation:
(Royal Aircraft Establishment)
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Extract

In the last number of the Journal (14, 243) Hollingdale showed mathematically that anticollision manoeuvres for the case of two craft moving in a plane can be formulated on a rigorous logical basis; and that a simple set of manoeuvres could be devised to meet all the geometrical requirements for anti-collision. The convention adopted was that each craft should manoeuvre so that if the other craft stood-on, the sight-line (the line joining the two craft) would always rotate in an anti-clockwise direction. The analysis showed that, mathematically, this was the complete and only answer to the basic problem.

The author of the present paper compares systems, such as that represented by the Collision Regulations and the Rules of the Air, based on onus to avoid, with a system based on a convention as to the direction of rotation of the sight-line. The first type of system, he holds, is defective for visual sightings and almost useless for radar sightings. The system put forward in the paper can be applied to both visual and radar sightings whether unilateral or bilateral by orientating a simple diagram with own course. A means of inter-communication is desirable but even without it such a system can, the author believes, safely be employed in the greater proportion of encounters.

The collision problem as a whole is beset by operational factors which are entirely distinct from the geometry of the situation, and for that reason no purely mathematical approach can, in isolation, be entirely valid. Nevertheless, there can be no doubt that studies such as the present one, based on a proper understanding of the geometry, can contribute greatly to the solution of this most pressing problem of navigation.

Type
Research Article
Information
The Journal of Navigation , Volume 14 , Issue 4 , October 1961 , pp. 379 - 401
Copyright
Copyright © The Royal Institute of Navigation 1961

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References

REFERENCES

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