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An analytical study of the oblique echo model for the topside plasma resonance

Published online by Cambridge University Press:  13 March 2009

E. J. Parkes
Affiliation:
Department of Mathematics, University of Strathclyde, Glasgow

Abstract

The oblique echo model for the resonance near the local plasma frequency fN observed by topside sounders involves the propagation of slow waves away from the sounder, which later return as echoes after reflexion due to an electron density gradient. The model is investigated using the WKB technique introduced by Fejer & Yu. The resulting set of saddle-point equations is solved by a method which can, unlike previous work, be applied to both the ‘strong’ resonance (for whichfN > fH wherefH is the electron gyrofrequency) and to the ‘weak’ (fN < fH) resonance. Throughout the calculations, the validity of the approximations made is checked. It is found that the weak resonance solution is not valid for typical topside parameters. For the strong resonance, the electric field of a small pulsed dipole is calculated. Expressions are found for the frequency of the two echoes that are received by the sounder and the frequency of the beating between them. Although these are only strictly valid for times longer than typical observation times, they yield results that agree well with the corresponding results from ray trajectory computations.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Benson, R. F. 1971 J. Geophys. Res. 76, 1083.CrossRefGoogle Scholar
Bitoun, J., Graff, P. & Aubry, M. 1970 Radio Sci. 5 1341.CrossRefGoogle Scholar
Budden, K. G. 1961 Radio Waves in the Ionosphere. Cambridge University Press.Google Scholar
Calvert, W. & Vanzandt, T. E. 1966 J. Geophys. Res. 71, 1799.CrossRefGoogle Scholar
Deering, W. D. & Fejer, J. A. 1965 Phys. Fluids, 8, 2066.CrossRefGoogle Scholar
Dougherty, J. P. & Monaghan, J. J. 1965 Proc. Roy. Soc. A 289, 214.Google Scholar
Fejer, J. A. & Yu, W.-M. 1969 J. Plasma Phys. 3, 227.CrossRefGoogle Scholar
Fejer, J. A. & Yu, W.-M. 1970 J. Geophys. Res. 75, 1919.CrossRefGoogle Scholar
Feldstein, R. & Graff, P. 1972 J. Geophys. Res. 77, 1896.CrossRefGoogle Scholar
Graff, P. 1970 J. Geophys. Res. 75, 7193.CrossRefGoogle Scholar
Graff, P. 1971a J. Geophys. Res. 76, 1060.CrossRefGoogle Scholar
Graff, P. 1971b J. Plasma Phys. 5, 427.CrossRefGoogle Scholar
McAfee, J. R. 1968 J. Geophys. Res. 73, 5577.CrossRefGoogle Scholar
McAfee, J. R. 1969a J. Geophys. Res. 74, 802.CrossRefGoogle Scholar
McAfee, J. R. 1969b J. Geophys. Res. 74, 6403.CrossRefGoogle Scholar
McAfee, J. R. 1970 J. Geophys. Res. 75, 4287.CrossRefGoogle Scholar
Muldrew, D. B. 1972 Radio Sci. 7, 779.CrossRefGoogle Scholar
Parkes, E. J. 1974a J. Plasma Phys. 12, 107.CrossRefGoogle Scholar
Parkes, E. J. 1974b J. Plasma Phys. 12, 217.CrossRefGoogle Scholar
Warnock, J. M., McAfee, J. R. & Thompson, T. L. 1970 J. Geophys. Res. 75, 7272.CrossRefGoogle Scholar