 |
| Titel |
Investigation of over-horizon VHF radio signals associated with earthquakes |
| VerfasserIn |
Y. Fukumoto, M. Hayakawa, H. Yasuda |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 1, no. 3 ; Nr. 1, no. 3, S.107-112 |
| Datensatznummer |
250000176
|
| Publikation (Nr.) |
 copernicus.org/nhess-1-107-2001.pdf |
|
|
|
|
|
| Zusammenfassung |
| This paper presents
the preliminary results on the possible reception of over-horizon VHF
radio signals from a FM (frequency modulation) transmitter during abnormal
situations (probably in close association with earthquakes). The
transmitter is FM Sendai (frequency = 77.1 MHz) and the receiving station
is our university (UEC) at Chofu, Tokyo, with the transmitter-receiver
distance being about 310 km. We first show a typical example of the
reception of over-horizon VHF signals in which we present the amplitude
behavior, azimuthal and incident angle estimation, etc. Then, we study the
correlation between a signal anomaly and an earthquake and it seems that
the over-horizon VHF signals observed are probably associated with
earthquakes, observed about 7 to 0 days before an earthquake. The
direction finding measurements have indicated that such signals are due to
favorable tropospheric (but not ionospheric) conditions attributed to the
effects of earthquakes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|