@article{oai:nipr.repo.nii.ac.jp:00006369,
 author = {Hosotani,Akira and Ono,Takayuki and Iizima,Masahide and Kumamoto,Atsushi},
 journal = {Advances in polar upper atmosphere research},
 month = {Sep},
 note = {P(論文), The second harmonic wave properties of auroral kilometric radiation(AKR) were examined using data obtained by the Akebono satellite. The results of our statistical analysis indicate that the probability of a harmonic event occurrence is more than 60% of all AKR events. The relationship between the frequencies of the fundamentals and the second harmonics is exactly two times for the upper and lower cut-off frequencies of the spectra as well as the fine structures, within the resolution of the Akebono observations. The intensity ratio of the second harmonics to the fundamentals exhibits a two-fold nature, with both a linear and a quadratic relationship. Further data analyses also revealed that the second harmonic waves of AKR, which propagate in the X-mode, are generated from a source that is identical to that of the fundamental waves that propagate in the O-mode. These results suggest that the mechanism of AKR harmonic structure generation should allow the coexistence of different AKR emission processes.},
 pages = {146--154},
 title = {Second harmonics of auroral kilometric radiation observed by the Akebono satellite},
 volume = {17},
 year = {2003}
}