Monitoring of equatorial plasma bubbles using aeronautical navigation system: a feasibility study

Earth, Planets and Space

Frontier Letter

Ichiro Tomizawa¹  Keisuke Hosokawa¹  Jun Sakai¹  Chien-Hung Lin²  Jia-Ting Lin²  Susumu Saito³  Toru Takahashi³  Hiroyuki Nakata⁴  Mamoru Ishii⁵  Takuya Tsugawa⁵  Michi Nishioka⁵  Pornchai Supnithi⁶ 

[1] Center for Space Science and Radio Engineering, University of Electro-Communications, Chofugaoka 1-5-1, 182-8585, Chofu, Tokyo, Japan;Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan;Electronic Navigation Research Institute, National Institute of Maritime, Port and Aviation Technology, Jindaiji-Higashicho 7-42-23, 182-0012, Chofu, Tokyo, Japan;Graduate School of Engineering, Chiba University, Chiba, Japan;National Institute of Information and Communications Technology, Nukui-Kitamachi 4-2-1, 184-8795, Koganei, Tokyo, Japan;School of Engineering, King Mongkuts Institute of Technology Ladkrabang, 10520, Bangkok, Thailand;

关键词: Equatorial plasma bubbles;    Radio propagation;    Airglow observation;   

DOI  :  10.1186/s40623-023-01911-7

 received in 2023-05-31, accepted in 2023-09-21,  发布年份 2023

来源: Springer

【 摘 要 】

It has long been known that field-aligned irregularities within equatorial plasma bubbles (EPBs) can cause long-range propagation of radio waves in the VHF frequencies such as those used for TV broadcasting through the so-called forward scattering process. However, no attempt has been made to use such anomalous propagations of VHF radio waves for wide-area monitoring of EPBs. In this study, we investigated the feasibility of monitoring of EPBs using VHF radio waves used for aeronautical navigation systems such as VHF Omnidirectional radio Range (VOR). There are 370 VOR stations in the Eastern and Southeastern Asian region that can be potentially used as Tx stations for the observations of anomalous propagation. We have examined the forward scattering conditions of VHF waves using the magnetic field model and confirmed that it is possible to observe the EPB-related anomalous propagation if we set up Rx stations in Okinawa (Japan), Taiwan, and Thailand. During test observations conducted in Okinawa since 2021, no signal has been received that was clearly caused by anomalous propagation due to EPBs. This is simply because EPBs have not developed to high latitudes during the observation period due to the low solar activity. In March 2023, however, possible indications of EPB-related scattering were detected in Okinawa which implies the feasibility of observing EPBs with the current observation system. We plan to conduct pilot observations in Taiwan and Thailand in future to further evaluate the feasibility of this monitoring technique.Graphical Abstract

【 授权许可】

CC BY   
© The Society of Geomagnetism and Earth, Planetary and Space Sciences / The Seismological Society of Japan / The Volcanological Society of Japan / The Geodetic Society of Japan / The Japanese Society for Planetary Sciences 2023

【 图 表 】

12936_2023_4742_Article_IEq18.gif

Fig. 3

12936_2015_1050_Article_IEq030.gif

Fig. 2

Fig. 1

Fig. 1

Fig. 8

Fig. 7