Articles | Volume 38, issue 5
https://doi.org/10.5194/angeo-38-969-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/angeo-38-969-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
10 Sep 2020
Regular paper |
| 10 Sep 2020
| 10 Sep 2020
The very low-frequency transmitter radio wave anomalies related to the 2010 Ms 7.1 Yushu earthquake observed by the DEMETER satellite and the possible mechanism
Shufan Zhao
CORRESPONDING AUTHOR
National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing 100085, China
XuHui Shen
National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing 100085, China
Zeren Zhima
National Institute of Natural Hazards, Ministry of Emergency Management of China, Beijing 100085, China
Chen Zhou
Electronic Information School, Wuhan University, Wuhan, 430072,
China
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Subject: Earth's ionosphere & aeronomy | Keywords: Modelling and forecasting
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High-resolution vertical total electron content maps based on multi-scale B-spline representations
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Tatjana Gerzen, David Minkwitz, Michael Schmidt, and Eren Erdogan
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Gizaw Mengistu Tsidu and Mulugeta Melaku Zegeye
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The monthly averages of the F2 critical frequency (foF2), its peak height (hmF2), and the E-region critical frequency (foE) acquired by the DPS4-D installed in Santa Maria, Brazil, is compared to the International Reference Ionosphere (IRI-2016) model predictions. It is important to test the performance of the IRI over Santa Maria because it is located in the SAMA, which is a region particularly important for high-frequency (HF) ground-to-satellite navigation signals.
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This paper describes an approach to model VTEC solely from NRT GNSS observations by generating a multi-scale representation (MSR) based on B-splines. The unknown model parameters are estimated by means of a Kalman filter. A number of products are created which differ both in their spectral and temporal resolution. The validation studies show that the product with the highest resolution, based on NRT input data, is of higher accuracy than others used within the selected investigation time span.
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Mingyu Kim and Jeongrae Kim
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Spatial extrapolation of an ionosphere TEC map was carried out using a SVM learning algorithm. There has been much research on the temporal extrapolation or prediction of TEC time series, but the spatial extrapolation has rarely been attempted. Some researchers have performed simultaneous extrapolation both in time and in spatial domains, but this research covers the spatial extrapolation only by using an inner TEC map. This spatial TEC extrapolation can be useful for small countries.
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Short summary
We use satellite data to analyze precursory anomalies of the western China Ms 7.1 Yushu earthquake by analyzing the signal-to-noise ratio (SNR) and using the full-wave model to illustrate a possible mechanism for how the anomalies occurred. The results show that very low-frequency (VLF) radio wave SNR in the ionosphere decreased before the Yushu earthquake. The full-wave simulation results confirm that electron density variation in the lower ionosphere will affect VLF radio signal SNR.
We use satellite data to analyze precursory anomalies of the western China Ms 7.1 Yushu...
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