Direction Finding of Magnetospheric VLF/ELF Emissions and Their Generation Mechanism
The purpose of this report is to review our recent studies on the generation and propagation mechanisms of magnetospheric VLF/ELF emissions based on the direction finding measurements on board spacecrafts in order to demonstrate the potential use of the direction finding measurements in plasma wave studies. The plasma waves treated in this report are, (1) half-gyrofrequency VLF emissions, (2) ELF hiss in detached plasma regions of the magnetosphere, (3) plasmaspheric ELF hiss, and (4) VLF/ELF chorus. We then point out the technical problems to be investigated concerning the spacecraft direction finding measurement to be used for the future satellite experiments.
KeywordsPlasma Wave Oblique Wave Chorus Emission Wave Normal Angle Cold Plasma Density
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- 1.Hayakawa M., Yamanaka Y., Parrot M., Lefeuvre F (1984) The wave normals of magnetospheric chorus emissions observed onboard GEOS-2. J.Geo- phys. Res. 89: 2811–2821Google Scholar
- 4.Hayakawa M (1989) Direction finding of half-gyrofrequency VLF emissions in the off-equatorial region of the magnetosphere. Proc.NIPR Symp. on Upper Atmosphere Phys. 1: 168–172Google Scholar
- 6.Hayakawa M (1987) The generation mechanism of ELF hiss in detached plasma regions of the magnetosphere as based on the direction finding results. Mem. Natl Inst. Polar Res. Tokyo, Special Issue 47: 173–182Google Scholar
- 8.Hayakawa M., Parrot M., Lefeuvre F (1987) The wave distribution functions of plasmaspheric ELF hiss: Geos 1 observation in equatorial region. Mem. Natl Inst. Polar Res. Tokyo, Special Issue 47: 157–172Google Scholar
- 9.Hayakawa M., Hattori K., Shimakura S., Parrot M. Lefeuvre F (1990) Direction finding of chorus emissions in the outer magnetosphere and their generation and propagation. Planet.Space Sci. 38: 135–143Google Scholar
- 10.Hayakawa M., Muto H., Shimakura S., Hattori K., Parrot M., Lefeuvre F (1989) The wave normal direction of chorus emissions in the outer magnetosphere. Proc. NIPR Symp. on Upper Atmosphere Phys. 2: 67–73Google Scholar
- 11.Hattori K., Ishikawa K., Hayakawa M (1990) Ray-tracing interpretation of wave normals of chorus emissions observed in the off-equatorial region of the outer magnetosphere. ibid, in press.Google Scholar
- 12.Hayakawa M., Lefeuvre F., Rauch JL (1985) The direction finding aboard Aureol 3 of ELF waves at frequency above and below the proton gyro- frequency. Resultats du Project ARCAD 3 et des programmes recents en Physique de la magnetosphere et de 1’ionosphere, Toulouse “84”, Cepadues Edit. 499–507Google Scholar
- 13.Hayakawa M., Lefeuvre F., Rauch JL (1990) On the system of Aureol-3 satellite direction finding for ionospheric and magnetospheric ELF waves. Trans.Inst.Elect.Inform.Comm.Engrs.Japan, in pressGoogle Scholar