This study aimed to evaluate the wake effect on the electric field detector(EFD) onboard the China Seismo-Electromagnetic Satellite(CSES-01). Through a series of experiments and analyses, we confirmed that the disturb...This study aimed to evaluate the wake effect on the electric field detector(EFD) onboard the China Seismo-Electromagnetic Satellite(CSES-01). Through a series of experiments and analyses, we confirmed that the disturbance phenomenon from probe B of the EFD is not caused by the boom layout. To validate and determine whether it is influenced by the wake effect, we conducted two experiments. In the first experiment, the entire satellite platform underwent a 90° counterclockwise yaw maneuver to allow probe B to avoid the plasma wake region. We then verified whether the disturbance was improved. In the second experiment, the satellite platform performed a 180° counterclockwise yaw maneuver, positioning probe B on the ram side of the satellite and completely avoiding all satellite wakes. The plasma wake effect of the satellite did not significantly influence the spherical probes of the EFD because the measurement accuracy stayed relatively stable under the two experiments, despite the observed abnormalities in the operating state of spherical probe B. This consistency in performance is important for electric field detection missions because the spatial electric field vector data obtained from these probes continue to effectively reflect information on spatial electromagnetic disturbances. These two experimental results showed that probe B consistently exhibited data jump phenomena under various maneuver states, whereas probes A, C, and D did not display such phenomena in any maneuver state.展开更多
Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by satellites.In this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionos...Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by satellites.In this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionospheric electromagnetic disturbance signals were acquired based on the CSES-01 satellite electric field data,and the maximum value of C in the earthquake preparation zones increased continuously from 2.0 three days before the earthquake and reached a maximum weight of 3.0 on the day of the earthquake,after the earthquake,it gradually decreased and recovered to about 2.0;its the C values fluctuated between-2 and 3,it is different from the C values range-2–12 of the previous seismic case study using the DEMETER satellite,which may be related to the orbital altitude and revisit period of the satellite.Then,the C values were normalized,and the time series analysis of the obtained θ values were done,and the results showed that:In the pregnant zone,the background variation of the disturbance amplitude θ is within 2σ,and the maximum disturbance amplitude of θ starts to increase gradually from the seventh period(one period of 5 days,i.e.,35–39 days before the earthquake),it reached 2σ by the fourth preseismic cycle(20–24 days before the earthquake),and then dropped sharply to about 1.5σ in the third pre-seismic cycle(15–19days before the earthquake),after two cycles of increase,the θ over the epicenter reached a maximum of 2.1σ at the time of the earthquake(combining the time of the earthquake and the satellite flight characteristics,the epicenter period is defined as January25-January 29,2020,and this defines the study time period line),and the θ decreases to within 2 times the standard range after the earthquake;The negative value of the disturbance amplitude θ in the central region of the pregnant seismic zone during the earthquake shows the transient energy release process.Through comparison,the θ values obtained by normalization based on the C-value method takes into account the variation of the background field,and the result can better reflect the energy change of the ionospheric field before the earthquakes.展开更多
基金a project funded by the China National Space Administration (CNSA) and China Earthquake Administration (CEA)supported by the National Key R&D Program of Intergovernmental Cooperation in Science and Technology (Grant No. 2023YFE0117300)+3 种基金the International Space Science Institute (ISSI in Bern, Switzerland, and ISSI-BJ in Beijing, China)supporting International Team 23-583 led by Dedalo Marchetti and Essam Ghamrythe Hebei Province Graduate Professional Degree Excellent Teaching Case (Library) Construction Project (Grant No. KCJPZ2023060)the Open Fund for the Key Laboratory of Seismic Disaster Instruments and Monitoring Technology in Hebei Province (Grant No. FZ224104)。
文摘This study aimed to evaluate the wake effect on the electric field detector(EFD) onboard the China Seismo-Electromagnetic Satellite(CSES-01). Through a series of experiments and analyses, we confirmed that the disturbance phenomenon from probe B of the EFD is not caused by the boom layout. To validate and determine whether it is influenced by the wake effect, we conducted two experiments. In the first experiment, the entire satellite platform underwent a 90° counterclockwise yaw maneuver to allow probe B to avoid the plasma wake region. We then verified whether the disturbance was improved. In the second experiment, the satellite platform performed a 180° counterclockwise yaw maneuver, positioning probe B on the ram side of the satellite and completely avoiding all satellite wakes. The plasma wake effect of the satellite did not significantly influence the spherical probes of the EFD because the measurement accuracy stayed relatively stable under the two experiments, despite the observed abnormalities in the operating state of spherical probe B. This consistency in performance is important for electric field detection missions because the spatial electric field vector data obtained from these probes continue to effectively reflect information on spatial electromagnetic disturbances. These two experimental results showed that probe B consistently exhibited data jump phenomena under various maneuver states, whereas probes A, C, and D did not display such phenomena in any maneuver state.
基金supported by the National Natural Science Foundation of China (Grant No. 42104159)the APSCO Earthquake Project (Phase Ⅱ)+1 种基金ISSI-BJ International Team (Grant No. 2019-33)Dragon 5 Cooperation Proposal (Grant No. #59308)。
文摘Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by satellites.In this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionospheric electromagnetic disturbance signals were acquired based on the CSES-01 satellite electric field data,and the maximum value of C in the earthquake preparation zones increased continuously from 2.0 three days before the earthquake and reached a maximum weight of 3.0 on the day of the earthquake,after the earthquake,it gradually decreased and recovered to about 2.0;its the C values fluctuated between-2 and 3,it is different from the C values range-2–12 of the previous seismic case study using the DEMETER satellite,which may be related to the orbital altitude and revisit period of the satellite.Then,the C values were normalized,and the time series analysis of the obtained θ values were done,and the results showed that:In the pregnant zone,the background variation of the disturbance amplitude θ is within 2σ,and the maximum disturbance amplitude of θ starts to increase gradually from the seventh period(one period of 5 days,i.e.,35–39 days before the earthquake),it reached 2σ by the fourth preseismic cycle(20–24 days before the earthquake),and then dropped sharply to about 1.5σ in the third pre-seismic cycle(15–19days before the earthquake),after two cycles of increase,the θ over the epicenter reached a maximum of 2.1σ at the time of the earthquake(combining the time of the earthquake and the satellite flight characteristics,the epicenter period is defined as January25-January 29,2020,and this defines the study time period line),and the θ decreases to within 2 times the standard range after the earthquake;The negative value of the disturbance amplitude θ in the central region of the pregnant seismic zone during the earthquake shows the transient energy release process.Through comparison,the θ values obtained by normalization based on the C-value method takes into account the variation of the background field,and the result can better reflect the energy change of the ionospheric field before the earthquakes.
