@article{oai:nipr.repo.nii.ac.jp:00004086,
 author = {Hattori, Katsumi and Ishikawa, Kiyohiko and Hayakawa, Masashi},
 journal = {Proceedings of the NIPR Symposium on Upper Atmosphere Physics},
 month = {Nov},
 note = {P(論文), The previous direction finding measurements of chorus emissions with different spectral shapes (rising, falling, and constant tones) near the equator have indicated that those chorus emissions are generated around the equator with their wave normals being nearly aligned with the magnetic field in terms of the Cyclotron instability by energetic electrons. Their subsequent propagation in the outer magnetosphere is discussed in the present paper. First, the results of wave normal directions of chorus observed in the off-equatorial regions are reviewed; one from OGO 5 measurement and the other, our GEOS 1 result. These measurements are compared with the results of two-dimensional ray-tracing analyses for a realistic model of the outer magnetosphere. Finally, it is found that the subsequent propagation of chorus after the equatorial generation, is, on some occasions, ducted, and it is non-ducted on other occasions.},
 pages = {70--78},
 title = {Ray-tracing interpretation of wave normal directions of chorus emissions observed in the off-equatorial region of the outer magnetosphere},
 volume = {3},
 year = {1990}
}