A VHF interferometry system for detecting anomalous propagation of FM radio broadcasting waves related to earthquakes and some preliminary results

2013 ◽  
Vol 183 (1) ◽  
pp. 16-24
Author(s):  
Nozomi Ohno ◽  
Yuka Tone ◽  
Katsumi Hattori ◽  
Isao Yamamoto ◽  
Shin Shimakura ◽  
...  
2014 ◽  
Vol 14 (8) ◽  
pp. 2119-2124 ◽  
Author(s):  
K. Motojima ◽  
N. Haga

Abstract. This paper was intended to find out any relation between anomalous line-of-sight propagation on the very high frequency (VHF) band and occurrences of earthquakes near the VHF propagation paths. The television and FM radio broadcasting waves on the VHF band were monitored continuously over the long term. For that purpose, a multidirectional VHF band monitoring system was established and utilized. Anomalous line-of-sight propagation on the VHF band was distinguished from the monitored wave by using a statistical analysis. After the stochastic consideration, it was found out that earthquakes associated with anomalous propagation were characterized by magnitude of earthquakes M ≥ 4.5, and distances from epicenters L ≤ 75 km. The anomalous propagation was monitored on the VHF band a few days before the associated earthquakes occurred. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously. The anomaly on the line-of-sight propagation indicates the possibility of narrowly focusing the area of the epicenter of earthquake.


2011 ◽  
Vol 131 (9) ◽  
pp. 750-756
Author(s):  
Nozomi Ohno ◽  
Yuka Tone ◽  
Katsumi Hattori ◽  
Isao Yamamoto ◽  
Shin Shimakura ◽  
...  

2013 ◽  
Vol 1 (6) ◽  
pp. 6829-6848
Author(s):  
K. Motojima ◽  
N. Haga

Abstract. This paper was intended to find out any relation between anomalous line-of-sight propagation on the VHF band and occurrences of earthquakes near the VHF propagation paths. The television and FM radio broadcasting waves on the VHF band were monitored continuously over the long term. For that purpose, a multidirectional VHF band monitoring system was established and utilized. Anomalous line-of-sight propagation on the VHF band was distinguished from the monitored wave by using a statistical analysis. After the stochastic consideration, it was found out that earthquakes associated with anomalous propagation were characterized by magnitude of earthquakes M ≥ 4.5, and distances from epicenters L ≤ 75 km. The anomalous propagation was monitored on the VHF band a few days earlier the associated earthquakes occurred. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously. The anomaly on the line-of-sight propagation indicates possibility of narrow focusing the area of epicenter of earthquake.


2017 ◽  
Vol 1 (2) ◽  
pp. 33
Author(s):  
Defhany Defhany Defhany

This study discusses the management of Mora FM Radio broadcasting media in improving the quality of radio broadcasting programs in the New Media era. The purpose of this study is to describe the form of management of MoraFM Radio broadcast media in improving the quality of MoraFM Radio broadcasting programs. The research method used in this research is descriptive qualitative. The informants in this study were several managers and broadcasters from Radio MoraFM determined by purposive sampling. The final results derived from this research are: First, by implementing good and optimal management of radio broadcast media, Radio MoraFM can improve the quality of radio broadcast programs in the current new media era. Second, by using plans to develop radio radio broadcast media management specifically MoraFM in order increase the satisfaction of MoraFM radio listeners and increase the number of MoraFM Radio listeners, Third, improve the performance of MoraFM Radio in improving the quality of MoraFM radio broadcasting programs.


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Sang-Lim Ju ◽  
Myung-Sun Baek ◽  
Kyung-Seok Kim

The digital audio broadcasting (DAB) system is mainly designed for large-area coverage and is suited for a single-frequency network (SFN) operating in Very High Frequency (VHF) Band III. To operate successfully, the SFN requires a different network-planning approach for multiple-frequency networks and should avoid self-interference. This paper focuses on nationwide SFN planning and DAB channel-allocation planning to replace all frequency-modulation (FM) services with terrestrial DAB services in VHF Band III. In South Korea, VHF Band III has been used for terrestrial digital multimedia broadcasting (T-DMB) services; thus, available frequencies should be investigated for T-DAB services and the nationwide SFN. An approach for broadcasting channel-interference analysis is proposed herein. For the interference analysis, the geographical features and the information for stations of legacy FM radio broadcasting and T-DMB, such as transmission parameters, are considered. The ratio of the interference area to the coverage is calculated via the channel-interference analysis. Areas affected by the self-interference in the nationwide SFN are investigated. The results of this paper provide insights regarding channel-allocation planning for T-DAB services and an approach for nationwide SFN planning.


Author(s):  
Masaharu Era ◽  
Kousuke Yamasaki ◽  
Makoto Kaijima ◽  
Kenji Kawano ◽  
Tomohiro Kashio ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document