Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(...Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(MLT)and Abu Simbel(ABS)Egyptian geomagnetic observatories were processed and found to be of good quality.In this study,Egyptian observatory data were tested during both quiet and disturbed events and compared with data from INTERMAGNET observatories worldwide at different latitudes and within a narrow range of longitudes in both hemispheres.This study investigated the relationships between magnetic field components from Egyptian observatories and those from INTERMAGNET observatories using graphical representations of the X components;Pearson’s correlation for the X,Y,Z,and F components;cross-correlation for the X component;and wavelet coherence for the F component.The results of this study showed a high correlation between Egyptian observatories and all utilized INTERMAGNET stations,except those located at high latitudes,during both quiet and disturbed events.Additionally,the study confirmed the observed consistency between Egyptian observatories and selected INTERMAGNET stations.Therefore,Egyptian observatories can feasibly fill the gap in the Middle East and North Africa.展开更多
The Low Earth Orbit(LEO)geomagnetic satellites provide a large number of high-precision measurements,which are crucial for researching the Secular Variation(SV)of the geomagnetic field.We employ the combined constella...The Low Earth Orbit(LEO)geomagnetic satellites provide a large number of high-precision measurements,which are crucial for researching the Secular Variation(SV)of the geomagnetic field.We employ the combined constellation data from the Chinese Seismo-Electromagnet Satellite(CSES)and Swarm satellites to extract the SV in China and surrounding areas,based on the Geomagnetic Virtual Observatory(GVO)method.On this basis,we have developed two GVO products:the core field,and the SV series.The accuracies of these products are assessed using ground observatories measurements and geomagnetic field model.Moreover,the results indicate that the GVO products align well with the series from ground observatories and the CHAOS model.The majority of root-mean-square deviation(RMSE)values of the core field series are less than 5 nT,consistent with the INTERMAGNET standards for quasi-definitive data.In the GVO core field series,the maximum accuracy of one-month and four-month intervals are 2.24 nT and 1.16 nT,respectively.In the GVO SV series,the maximum accuracy of one-month and four-month intervals are 2.03 nT/yr and 1.36 nT/yr,respectively.The GVO SV series effectively capture geomagnetic jerks without losing temporal resolution comparing with the recording of ground observatories.We demonstrate that the GVO method serves as an effective and precise tool for extracting SV information of geomagnetic fields.In the GVO products,the RMSE of the horizontal component exceeds that of the vertical component,and the magnitude of RMSE deviation correlates with solar activity levels.With more and more geomagnetic satellites in orbit,we wish to use multi-constellation magnetic satellite data to assess the geomagnetic field more accurately.展开更多
A geomagnetic observatory was established at Karachi （geog coord： 24.95°N, 167.14° E）, Pakistan in 1983 which comprised of AMOS-Ⅲ （Automatic Magnetic Observatory System）. In 2006 SUPARCO （Space and Up...A geomagnetic observatory was established at Karachi （geog coord： 24.95°N, 167.14° E）, Pakistan in 1983 which comprised of AMOS-Ⅲ （Automatic Magnetic Observatory System）. In 2006 SUPARCO （Space and Upper Atmosphere Research Commission） planned to upgrade the old observatory of Karachi in order to qualify it as an IMO （Intermagnet Magnetic Observatory）. Dr. Jean Rasson agreed to give support and assist us in the upgradation. BGS （British Geological Survey） provided a complete observatory instrument setup. Due to perturbations traceable to the increased urbanization, the observatory has been shifted to a site ＂Sonmiani＂, 80 km north-west of Karachi, where long term protection from cultural noise is offered. This site in a sparsely built research complex was selected after a magnetic survey. A new observatory has also been established at Islamabad （geog cord： 33.75° N, 72.87° E） which is mountainous region. SUPARCO purchased new equipment for the establishment of new observatories. Plan of upgradation of observatory at Quetta is also under consideration in order to improve the monitoring of geomagnetic field on the western part of Pakistan. Repeat station work has been done for the northern part of Pakistan with the collaboration of IRM, Belgium. The obtained results also compared with the global geomagnetic model （IGRF）.展开更多
Institutions of astronomic research within theChinese Academy of Sciences (CAS) are among thefirst to gain the access to the pilot project of the na-tional knowledge innovation program (KIP) carriedout at CAS. The ope...Institutions of astronomic research within theChinese Academy of Sciences (CAS) are among thefirst to gain the access to the pilot project of the na-tional knowledge innovation program (KIP) carriedout at CAS. The operating mechanism reform at Na-tional Astronomic Observatories (NAO) includes theestablishment of research teams and the introductionof a new system in which R&D projects are in展开更多
With the continuous exploration and research of low-carbon buildings in China,combined with foreign theories and practices,there are a few basic theoretical and practical projects for low-carbon construction in major ...With the continuous exploration and research of low-carbon buildings in China,combined with foreign theories and practices,there are a few basic theoretical and practical projects for low-carbon construction in major cities of China.However,throughout the entire academic research,there is still no comprehensive and clear guidance for the green and low-carbon research and transformation of rural self-built houses.Therefore,the existing development of low-carbon technology for rural self-built houses has been summarized,and some prospects for the future development of rural self-built houses have been summarized.It is hoped that this will have positive help for future rural low-carbon transformation.展开更多
The Lembang Fault is a major geological feature in West Java that borders the northern edge of Bandung(one of Indonesia’s largest cities).It lies just south of the active Tangkuban Perahu Volcano,exhibiting clear geo...The Lembang Fault is a major geological feature in West Java that borders the northern edge of Bandung(one of Indonesia’s largest cities).It lies just south of the active Tangkuban Perahu Volcano,exhibiting clear geomorphic signs of recent activity,and has been scientifically confirmed as active through geological and geophysical studies.In this work,we describe an Integrated along the Lembang Fault,which can be used for geodynamic research in Indonesia.We discuss the design of a seismic and Global Navigation Satellite System(GNSS)array sensor network for continuous monitoring,and report the status of monitoring stations that periodically collect highly accurate,continuous seismographic and GNSS readings,transmitting these data to a central server in Bandung for post-processing.Solutions from the array data are used to provide precise measurements of the deformation of the Earth’s surface over large distances,allowing for spatio-temporal tracking of tectonic movement,and resulting in a better understanding of seismic events in the region.In this study,our investigation revealed a significant compression rate of an estimated 13 microstrain/yr along the Lembang Fault,whereas the strain rate is much smaller farther south of the fault.This study presents the design of a seismo-geodetic observatory network that can be implemented in earthquake-prone regions for mitigation purposes,with particular utility for studying other active faults that also traverse populated areas in Indonesia.展开更多
A detector's nondestructive readout mode allows its pixels to be read multiple times during integration,enabling generation of a series of"up-the-ramp"images that continuously accumulate photons between ...A detector's nondestructive readout mode allows its pixels to be read multiple times during integration,enabling generation of a series of"up-the-ramp"images that continuously accumulate photons between successive frames.Because noise is correlated across these images,optimal stacking generally requires the images to be weighted unequally to achieve the best possible target signal-to-noise ratio(SNR).Objects in the sky present wildly varied brightness characteristics,and the counts in individual pixels of the same object can also span wide ranges.Therefore,a single set of weights cannot be optimal in all cases.To ensure that the stacked image is easily calibratable,we apply the same weight to all pixels within the same frame.In practice,results for high-SNR cases degraded only slightly when we used weights derived for low-SNR cases,whereas the low-SNR cases remained more sensitive to the weights.Therefore,we propose a quasi-optimal stacking method that maximizes the stacked SNR for the case where the RSN=1 per pixel in the last frame and use simulated data to demonstrate that this approach enhances the SNR more strongly than the equal-weight stacking and ramp fitting methods.Furthermore,we estimate the improvements in the limiting magnitudes for the China Space Station Telescope using the proposed method.When compared with the conventional readout mode,which is equivalent to selecting the last frame from the nondestructive readout,stacking 30 up-the-ramp images can improve the limiting magnitude by approximately 0.5 mag for the telescope's near-infrared observations,effectively reducing readout noise by approximately 62%.展开更多
This paper presents an analysis of an equilateral triangular array formation initialization for space-based gravitational wave observatory(GWO)near Lagrange points in the circular-restricted three-body problem.A stabl...This paper presents an analysis of an equilateral triangular array formation initialization for space-based gravitational wave observatory(GWO)near Lagrange points in the circular-restricted three-body problem.A stable configuration is essential for the continuous observation of gravitational waves(GWs).However,the motion near the collinear libration points is highly unstable.This problem is examined by output regulation theory.Using the tracking aspect,the equilateral triangular array formation is established in two periods and the fuel consumption is calculated.Furthermore,the natural evolution of the formation without control input is analyzed,and the effective stability duration is quantified to determine the timing of control interventions.Finally,to observe the GWs in same direction with different frequency bands,scale reconfiguration is employed.展开更多
WASP(Wallops Arc Second Pointer)是由美国国家航空航天局(NASA)开发的一种临近空间天文台亚角秒级指向系统,旨在构建可适配多类科学载荷的临近空间天文观测平台.WASP系统由指向控制系统(PCS)和星跟踪器子系统(CARDS)组成,该系统结合...WASP(Wallops Arc Second Pointer)是由美国国家航空航天局(NASA)开发的一种临近空间天文台亚角秒级指向系统,旨在构建可适配多类科学载荷的临近空间天文观测平台.WASP系统由指向控制系统(PCS)和星跟踪器子系统(CARDS)组成,该系统结合精密机械和电子组件,辅以超压气球技术,能在临近空间执行长时飞行任务,同时保持亚角秒级的指向精度.WASP系统的灵活性和标准化设计使其能够适配多种科学载荷,满足不同的任务需求.在空间科学领域,WASP系统的应用不仅拓宽了高空科学气球的研究范围,也为临近空间天文台的建设提供了创新方案,推动了对临近空间的探索.WASP系统的成功试飞和应用,为其在行星科学、天体物理学和地球观测等领域的应用奠定了基础,也为中国临近空间科学的发展提供了可靠的参考.展开更多
文摘Geomagnetic observatory data are crucial for all branches of geophysics because they can contribute to earthquake research by detecting anomalies in the Earth’s magnetic field.Recently,data records from the Misallat(MLT)and Abu Simbel(ABS)Egyptian geomagnetic observatories were processed and found to be of good quality.In this study,Egyptian observatory data were tested during both quiet and disturbed events and compared with data from INTERMAGNET observatories worldwide at different latitudes and within a narrow range of longitudes in both hemispheres.This study investigated the relationships between magnetic field components from Egyptian observatories and those from INTERMAGNET observatories using graphical representations of the X components;Pearson’s correlation for the X,Y,Z,and F components;cross-correlation for the X component;and wavelet coherence for the F component.The results of this study showed a high correlation between Egyptian observatories and all utilized INTERMAGNET stations,except those located at high latitudes,during both quiet and disturbed events.Additionally,the study confirmed the observed consistency between Egyptian observatories and selected INTERMAGNET stations.Therefore,Egyptian observatories can feasibly fill the gap in the Middle East and North Africa.
基金supported by the Special Fund of the Institute of Geophysics,China Earthquake Administration(grant no.DQJB24X25).
文摘The Low Earth Orbit(LEO)geomagnetic satellites provide a large number of high-precision measurements,which are crucial for researching the Secular Variation(SV)of the geomagnetic field.We employ the combined constellation data from the Chinese Seismo-Electromagnet Satellite(CSES)and Swarm satellites to extract the SV in China and surrounding areas,based on the Geomagnetic Virtual Observatory(GVO)method.On this basis,we have developed two GVO products:the core field,and the SV series.The accuracies of these products are assessed using ground observatories measurements and geomagnetic field model.Moreover,the results indicate that the GVO products align well with the series from ground observatories and the CHAOS model.The majority of root-mean-square deviation(RMSE)values of the core field series are less than 5 nT,consistent with the INTERMAGNET standards for quasi-definitive data.In the GVO core field series,the maximum accuracy of one-month and four-month intervals are 2.24 nT and 1.16 nT,respectively.In the GVO SV series,the maximum accuracy of one-month and four-month intervals are 2.03 nT/yr and 1.36 nT/yr,respectively.The GVO SV series effectively capture geomagnetic jerks without losing temporal resolution comparing with the recording of ground observatories.We demonstrate that the GVO method serves as an effective and precise tool for extracting SV information of geomagnetic fields.In the GVO products,the RMSE of the horizontal component exceeds that of the vertical component,and the magnitude of RMSE deviation correlates with solar activity levels.With more and more geomagnetic satellites in orbit,we wish to use multi-constellation magnetic satellite data to assess the geomagnetic field more accurately.
文摘A geomagnetic observatory was established at Karachi （geog coord： 24.95°N, 167.14° E）, Pakistan in 1983 which comprised of AMOS-Ⅲ （Automatic Magnetic Observatory System）. In 2006 SUPARCO （Space and Upper Atmosphere Research Commission） planned to upgrade the old observatory of Karachi in order to qualify it as an IMO （Intermagnet Magnetic Observatory）. Dr. Jean Rasson agreed to give support and assist us in the upgradation. BGS （British Geological Survey） provided a complete observatory instrument setup. Due to perturbations traceable to the increased urbanization, the observatory has been shifted to a site ＂Sonmiani＂, 80 km north-west of Karachi, where long term protection from cultural noise is offered. This site in a sparsely built research complex was selected after a magnetic survey. A new observatory has also been established at Islamabad （geog cord： 33.75° N, 72.87° E） which is mountainous region. SUPARCO purchased new equipment for the establishment of new observatories. Plan of upgradation of observatory at Quetta is also under consideration in order to improve the monitoring of geomagnetic field on the western part of Pakistan. Repeat station work has been done for the northern part of Pakistan with the collaboration of IRM, Belgium. The obtained results also compared with the global geomagnetic model （IGRF）.
文摘Institutions of astronomic research within theChinese Academy of Sciences (CAS) are among thefirst to gain the access to the pilot project of the na-tional knowledge innovation program (KIP) carriedout at CAS. The operating mechanism reform at Na-tional Astronomic Observatories (NAO) includes theestablishment of research teams and the introductionof a new system in which R&D projects are in
文摘With the continuous exploration and research of low-carbon buildings in China,combined with foreign theories and practices,there are a few basic theoretical and practical projects for low-carbon construction in major cities of China.However,throughout the entire academic research,there is still no comprehensive and clear guidance for the green and low-carbon research and transformation of rural self-built houses.Therefore,the existing development of low-carbon technology for rural self-built houses has been summarized,and some prospects for the future development of rural self-built houses have been summarized.It is hoped that this will have positive help for future rural low-carbon transformation.
基金the National Research and InnovationAgency of Indonesia (BRIN) under research grant Rumah Program Kebencanaan 2022-2025support from the Earth Observatory Singapore (EOS)supported by the Ministry of Higher Education, Science,and Technology, and Institut Teknologi Bandung through the Indonesian Collaborative Research Program.
文摘The Lembang Fault is a major geological feature in West Java that borders the northern edge of Bandung(one of Indonesia’s largest cities).It lies just south of the active Tangkuban Perahu Volcano,exhibiting clear geomorphic signs of recent activity,and has been scientifically confirmed as active through geological and geophysical studies.In this work,we describe an Integrated along the Lembang Fault,which can be used for geodynamic research in Indonesia.We discuss the design of a seismic and Global Navigation Satellite System(GNSS)array sensor network for continuous monitoring,and report the status of monitoring stations that periodically collect highly accurate,continuous seismographic and GNSS readings,transmitting these data to a central server in Bandung for post-processing.Solutions from the array data are used to provide precise measurements of the deformation of the Earth’s surface over large distances,allowing for spatio-temporal tracking of tectonic movement,and resulting in a better understanding of seismic events in the region.In this study,our investigation revealed a significant compression rate of an estimated 13 microstrain/yr along the Lembang Fault,whereas the strain rate is much smaller farther south of the fault.This study presents the design of a seismo-geodetic observatory network that can be implemented in earthquake-prone regions for mitigation purposes,with particular utility for studying other active faults that also traverse populated areas in Indonesia.
基金supported by the National Key R&D Program of China (2022YFF0503400)the National Natural Science Foundation of China grant (U1931208)China Manned Space Program through its Space Application System.
文摘A detector's nondestructive readout mode allows its pixels to be read multiple times during integration,enabling generation of a series of"up-the-ramp"images that continuously accumulate photons between successive frames.Because noise is correlated across these images,optimal stacking generally requires the images to be weighted unequally to achieve the best possible target signal-to-noise ratio(SNR).Objects in the sky present wildly varied brightness characteristics,and the counts in individual pixels of the same object can also span wide ranges.Therefore,a single set of weights cannot be optimal in all cases.To ensure that the stacked image is easily calibratable,we apply the same weight to all pixels within the same frame.In practice,results for high-SNR cases degraded only slightly when we used weights derived for low-SNR cases,whereas the low-SNR cases remained more sensitive to the weights.Therefore,we propose a quasi-optimal stacking method that maximizes the stacked SNR for the case where the RSN=1 per pixel in the last frame and use simulated data to demonstrate that this approach enhances the SNR more strongly than the equal-weight stacking and ramp fitting methods.Furthermore,we estimate the improvements in the limiting magnitudes for the China Space Station Telescope using the proposed method.When compared with the conventional readout mode,which is equivalent to selecting the last frame from the nondestructive readout,stacking 30 up-the-ramp images can improve the limiting magnitude by approximately 0.5 mag for the telescope's near-infrared observations,effectively reducing readout noise by approximately 62%.
基金supported by the China Scholarship Council(CSC)(No.202206290131)。
文摘This paper presents an analysis of an equilateral triangular array formation initialization for space-based gravitational wave observatory(GWO)near Lagrange points in the circular-restricted three-body problem.A stable configuration is essential for the continuous observation of gravitational waves(GWs).However,the motion near the collinear libration points is highly unstable.This problem is examined by output regulation theory.Using the tracking aspect,the equilateral triangular array formation is established in two periods and the fuel consumption is calculated.Furthermore,the natural evolution of the formation without control input is analyzed,and the effective stability duration is quantified to determine the timing of control interventions.Finally,to observe the GWs in same direction with different frequency bands,scale reconfiguration is employed.
文摘WASP(Wallops Arc Second Pointer)是由美国国家航空航天局(NASA)开发的一种临近空间天文台亚角秒级指向系统,旨在构建可适配多类科学载荷的临近空间天文观测平台.WASP系统由指向控制系统(PCS)和星跟踪器子系统(CARDS)组成,该系统结合精密机械和电子组件,辅以超压气球技术,能在临近空间执行长时飞行任务,同时保持亚角秒级的指向精度.WASP系统的灵活性和标准化设计使其能够适配多种科学载荷,满足不同的任务需求.在空间科学领域,WASP系统的应用不仅拓宽了高空科学气球的研究范围,也为临近空间天文台的建设提供了创新方案,推动了对临近空间的探索.WASP系统的成功试飞和应用,为其在行星科学、天体物理学和地球观测等领域的应用奠定了基础,也为中国临近空间科学的发展提供了可靠的参考.
