HR: 0800h
AN: T51B-0450    [Abstracts]
TI: Interferometric observation of over-horizon and ionospheric VHF radio waves associated with earthquakes.
AU: * Gotoh, T
EM: take@whistler.ee.uec.ac.jp
AF: University of Electro-Communications, 1-5-1 Chofugaoka Chofu, Tokyo, 182-8585 Japan
AU: Hayakawa, M
EM: hayakawa@whistler.ee.uec.ac.jp
AF: University of Electro-Communications, 1-5-1 Chofugaoka Chofu, Tokyo, 182-8585 Japan
AB: Recently it has been found that the perturbations in the atmosphere and ionosphere take place in association with earthquakes (Hayakawa and Molchanov, 2002 Monograph). Fukumoto et al. (2001) have found that the over-horizon VHF waves (FM broadcasting signals) are occasionally observed prior to an earthquake, and their VHF direction finding has indicated that the reception of those over-horizon VHF signal is due to the perturbation in the atmosphere. Additionally Takano et al. (2001) have found that the TV VHF signals in the South-East Asia (like Thailand and China) are often received in Japan in possible association with earthquakes. In order to investigate the mechanism of those VHF anomalous signals, we have developed an interferometric measurement for those VHF signals to determine their direction of arrival (incident (elevation) angle and azmuthal angle (bearing)). We first describe our interferometer system, then show some preliminary observational data, and followed by the future system.
DE: 6924 Interferometry
DE: 3360 Remote sensing
DE: 2435 Ionospheric disturbances
DE: 2487 Wave propagation (6934)
DE: 2494 Instruments and techniques
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting