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
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
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
Cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ observation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, ...Cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ observation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, a highly reliable cable switching and fault isolation method is essential. After reviewing the advantages and disadvantages of existing switching methods, we propose a novel active switching method for network configuration. Without additional communication path requirements, the switching method provides a way to communicate with a shore station through an existing power transmission path. A coded voltage signal with a distinct sequence is employed as the communication medium to transmit commands. The analysis of the maximum bit frequency of the voltage signals guarantees the accuracy of command recognition. A prototype based on the switching method is built and tested in a laboratory environment, which validated the functionality and reliability of the method.展开更多
Constant current power transmission is considered a good choice for subsea observatories due to its high resistance to shunt faults. A constant current subsea observatory is planned to be constructed in the East China...Constant current power transmission is considered a good choice for subsea observatories due to its high resistance to shunt faults. A constant current subsea observatory is planned to be constructed in the East China Sea. We discuss a constant current subsea observatory system used for scientific experiments. The power system and its heat dissipation system are carefully designed. The power conversion method is challenging due to the use of constant current power, which is considerably different from traditional power systems. Thus, we adopt power compensation circuits in the conversion system to obtain a constant 48-V output for science users. A power management system that performs overvoltage protection and real-time monitoring and control of junction box is discussed. An innovative heat dissipation structure of a junction box is designed in consideration of a sealed working environment to extend the useful life of the junction box. Simulations and experiments reveal that the system has high efficiency and stability, especially in long-term applications.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
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
INFOCUS|JUNO Formally Comes into Operation A new-generation large-scale neutrino experiment,the Jiangmen Underground Neutrino Observatory(JUNO)formally came into operation and started collecting data in late August.
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
Background The Global Cancer Observatory(GLOBOCAN)2022 and the Global Burden of Disease(GBD)2021 are two primary databases for assessing the global cancer burden.This study aimed to compare the incidence and mortality...Background The Global Cancer Observatory(GLOBOCAN)2022 and the Global Burden of Disease(GBD)2021 are two primary databases for assessing the global cancer burden.This study aimed to compare the incidence and mortality rates of tracheal,bronchus,and lung(TBL)cancer reported in these databases and to analyze the observed discrepancies.Methods Age-standardized rates(ASRs),including age-standardized incidence rates and age-standardized mortality rates for TBL cancer,were obtained from GLOBOCAN 2022 and GBD 2021 for the most recent available year.Differences in ASRs at the national level between the two databases were quantified using pairwise differences,calculated as the absolute difference in ASRs divided by the mean of the ASRs from both sources.Correlations between macroeconomic factors and pairwise differences in ASRs were evaluated,and country features correlated with high pairwise differences were assessed.The data sources and methods used in the two databases were also compared.Results Strong correlations were identified between ASRs reported by GLOBOCAN 2022 and GBD 2021;however,significant differences were observed between estimates from the two data sources.African countries commonly exhibited larger pairwise differences in ASRs,whereas European countries demonstrated smaller pairwise differences in ASRs.Additionally,some populous developing countries,including China,South Africa,Brazil and India,showed smaller differences in ASRs.Countries lacking vital registration systems or high-quality population-based cancer registries displayed larger differences in ASRs.Furthermore,differences in ASRs were negatively correlated with macroeconomic factors.The data sources and estimation methods used by the two databases were inconsistent.Conclusions Discrepancies in TBL cancer incidence and mortality were observed between GLOBOCAN 2022 and GBD 2021.While differences in sources and methods partially explain these discrepancies,a country's cancer surveillance maturity and economic status also correlate with the accuracy of the estimates.Estimating the cancer burden in less wealthy countries remains a substantial challenge,necessitating long-term assistance and investment.展开更多
SATech-01 is an experimental satellite for space science exploration and on-orbit demonstration of advanced technologies.The satellite is equipped with 16 experimental payloads and supports multiple working modes to m...SATech-01 is an experimental satellite for space science exploration and on-orbit demonstration of advanced technologies.The satellite is equipped with 16 experimental payloads and supports multiple working modes to meet the observation requirements of various payloads.Due to the limitation of platform power supply and data storage systems,proposing reasonable mission planning schemes to improve scientific revenue of the payloads becomes a critical issue.In this article,we formulate the integrated task scheduling of SATech-01 as a multi-objective optimization problem and propose a novel Fair Integrated Scheduling with Proximal Policy Optimization(FIS-PPO)algorithm to solve it.We use multiple decision heads to generate decisions for each task and design the action mask to ensure the schedule meeting the platform constraints.Experimental results show that FIS-PPO could push the capability of the platform to the limit and improve the overall observation efficiency by 31.5%compared to rule-based plans currently used.Moreover,fairness is considered in the reward design and our method achieves much better performance in terms of equal task opportunities.Because of its low computational complexity,our task scheduling algorithm has the potential to be directly deployed on board for real-time task scheduling in future space projects.展开更多
This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution ...This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution of LLR experiments conducted by some major world-class observatories,with a particular focus on addressing critical issues associated with LLR technology.Additionally,the article highlights the latest advancements in the field,elucidating scientific achievements derived from LLR data,including its contributions to gravitational theory,Earth Orientation Parameters,lunar physics exploration,and lunar librations.The review summarizes new challenges in LLR modeling and concludes with prospects for the future development of LLR.展开更多
Although Nigeria is not located within the major seismic zones of the world; over the years,several minor earthquakes have been experienced in some parts of the country.The first widely reported occurrence of an Earth...Although Nigeria is not located within the major seismic zones of the world; over the years,several minor earthquakes have been experienced in some parts of the country.The first widely reported occurrence of an Earth tremor in Nigeria was in 1933.Other events were reported in 1939,1964,1984,1990,1994,1997,2000 and 2006.The intensities of these events ranged from III to VI based on the Modified Mercalli Intensity Scale.Of these events,only the 1984,1990,1994 and 2000 events were instrumentally recorded.They had body wave magnitudes ranging from 4.3 to 4.5,local magnitudes between 3.7 and 4.2,and surface wave magnitudes of 3.7 to 3.9.When these events occurred,there were no functional seismological observatories in Nigeria.However,that has now changed with the establishment of a seismographic network managed by the Centre for Geodesy and Geodynamics（CGG）,Toro,Nigeria.Presently,the network has four operational stations equipped with 24-bit 4-channel recorders and broadband 30-second seismometers.Efforts are being made to establish more stations and migrate to real-time collection of seismic data using the general packet radio service（GPRS） technology as well as automatic location of events.Remote sensing,geological and geophysical studies have revealed the presence of a NNE-SSW trending Ifewara-Zungeru fault zone which has been shown to be linked with the Atlantic fracture system.The dynamics of the Atlantic fracture zones have been suggested to be responsible for the seismic activities experienced in the areas.展开更多
Strong atmospheric turbulence reduces astronomical seeing,causing speckle images acquired by ground-based solar telescopes to become blurred and distorted.Severe distortion in speckle images impedes image phase deviat...Strong atmospheric turbulence reduces astronomical seeing,causing speckle images acquired by ground-based solar telescopes to become blurred and distorted.Severe distortion in speckle images impedes image phase deviation in the speckle masking reconstruction method,leading to the appearance of spurious imaging artifacts.Relying only on linear image degradation principles to reconstruct solar images is insufficient.To solve this problem,we propose the multiframe blind deconvolution combined with non-rigid alignment(MFBD-CNRA)method for solar image reconstruction.We consider image distortion caused by atmospheric turbulence and use non-rigid alignment to correct pixel-level distortion,thereby achieving nonlinear constraints to complement image intensity changes.After creating the corrected speckle image,we use the linear method to solve the wavefront phase,obtaining the target image.We verify the effectiveness of our method results,compared with others,using solar observation data from the 1 m new vacuum solar telescope(NVST).This new method successfully reconstructs high-resolution images of solar observations with a Fried parameter r0 of approximately 10 cm,and enhances images at high frequency.When r0 is approximately 5 cm,the new method is even more effective.It reconstructs the edges of solar graining and sunspots,and is greatly enhanced at mid and high frequency compared with other methods.Comparisons confirm the effectiveness of this method,with respect to both nonlinear and linear constraints in solar image reconstruction.This provides a suitable solution for image reconstruction in ground-based solar observations under strong atmospheric turbulence.展开更多
The purpose of this study was to analyze the associated spectrum of geomagnetic field,frequencies intensity and the time of occurrence.We calculated the variation of the correlation coefficients,with mobile windows of...The purpose of this study was to analyze the associated spectrum of geomagnetic field,frequencies intensity and the time of occurrence.We calculated the variation of the correlation coefficients,with mobile windows of various sizes,for the recorded magnetic components at different latitudes and latitudes.The observatories we included in our study are USA(Surlari),HON(Honolulu),SBA(Scott Base),KAK(Kakioka),THY(Tihany),UPS(Uppsala),WNG(Wingst)and Yellowknife(YKC).We used the data of these observatories from International Real-time Magnetic Observatory Network(INTERMAGNET)for the geomagnetic storm from October 28-31,2003.We have used for this purpose a series of filtering algorithms,spectral analysis and wavelet with different mother functions at different levels.In the paper,we show the Fourier and wavelet analysis of geomagnetic data recorded at different observatories regarding geomagnetic storms.Fourier analysis hightlights predominant frequencies of magnetic field components.Wavelet analysis provides information about the frequency ranges of magnetic fields,which contain long time intervals for medium frequency information and short time intervals for highlight frequencies,details of the analyzed signals.Also,the wavelet analysis allows us to decompose geomagnetic signals in different waves.The analyses presented are significant for the studies of the geomagnetic storm.The data for the next days after the storm showed a mitigation of the perturbations and a transition to quiet days of the geomagnetic field.展开更多
We are playing a lead role for growth of astronomy and its quality teaching and research in Manipur, a State located at northeast India (longitude = 93°58'E;latitude = 24°44'N;altitude = 782 m). We h...We are playing a lead role for growth of astronomy and its quality teaching and research in Manipur, a State located at northeast India (longitude = 93°58'E;latitude = 24°44'N;altitude = 782 m). We have innovatively designed and constructed three cost effective observatories, each costing a few hundred USD. These observatories are completely different in design and are perfectly usable for doing serious work on astronomical observation and measurements, using small ground-based telescopes. One Celestron CGE1400 telescope is housed with equatorial mounting in one of three constructed observatories and the same observatory has been inducted, since January 2012, as one of the members of the “Orion Project”, which is an international project headquartered at Phoenix, Arizona, USA, dedicated for photometric and spectroscopic observations of five bright variable stars of the Orion constellation. We have been producing high precision BVRI photometric data that match well with those produced by other observatories enrolled in the Orion project. Our photometric data were presented and discussed in the 33rd Annual Conference of the Society for Astronomical Sciences: Symposium on Telescope Science, held at Ontario, California, USA during June 12 - 14, 2014. Further, we could successfully demonstrate them to the entire population of the State and play live shows of the observation of three spectacular astronomical events namely, solar eclipse of 15th January 2010, lunar eclipse of 10th December 2011 and Transit of Venus of June 6, 2012. We have conducted a number of seminars and workshops for training and research in astronomy. In the present paper, we would like describe our self-built observatories, our observational facilities, the BVRI photometric data that we acquired for the Orion project, and other activities undertaken for growth of astronomy activities in the State of Manipur, India.展开更多
To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevan...To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevant information about those objects in visual and graphical form. The package calculates object visibility based on a provided time window and observing location as well as maximum airmass and limiting magnitude requested by the user. The pysky application images of the target objects with identifying and astrometric data to provide context for the images. In addition, pysky creates polar plots of each object’s horizontal coordinates, and the images and plots are designed to be shown side-by-side. The package also generates an HTML table of the selected target objects with their related data to relay the entire target list as one. The pysky application draws on a variety of Python packages to collect and process data from databases such as JPL Horizons and SIMBAD. Results for a test event were verified by hand using database web interfaces. The pysky application provides a platform for further integration of automated observation planning with websites and apps to enhance multi-target observation sessions.展开更多
This paper presents a method to associate land use/cover with productivity in 16 Agrotech Observatories (AOTs) in Mexico. Compact agricultural areas in Mexico have been identified, which are monitored as to their beha...This paper presents a method to associate land use/cover with productivity in 16 Agrotech Observatories (AOTs) in Mexico. Compact agricultural areas in Mexico have been identified, which are monitored as to their behavior concerning production and rural productivity in a network of AOTs, which is a compact agricultural area representative of agro-ecological, technological and social conditions in the country. To optimize production and agricultural productivity in compact areas, a multidisciplinary and holistic approach with four lines of activity (agro-ecological, technological, economic, and social), and ten actions are used. The objective of this work was to obtain the land use/cover and productivity of sixteen compact agricultural areas (AOTs) in the Mexican Republic, using panchromatic and multispectral SPOT 5 imagery, in order to provide information to the agricultural sector of the country, and to support decision making contributing to the optimization of production in areas with high actual and potential productivity. As an example, in this paper the land use/cover and productivity “AOT 20 Hidalgo” were described. Currently, it is important to have updated and accurate information to support actions and programs of federal, state and local government for farmers, particularly in compact areas with high agricultural production potential.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）.
基金supported by the National Natural Science Foundation of China(Nos.51409229,41676089,and 51521064)the National High-Tech R&D Program(863)of China(No.2012AA09A410)the Zhejiang Provincial Natural Science Foundation of China(No.LQ14E070002)
文摘Cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ observation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, a highly reliable cable switching and fault isolation method is essential. After reviewing the advantages and disadvantages of existing switching methods, we propose a novel active switching method for network configuration. Without additional communication path requirements, the switching method provides a way to communicate with a shore station through an existing power transmission path. A coded voltage signal with a distinct sequence is employed as the communication medium to transmit commands. The analysis of the maximum bit frequency of the voltage signals guarantees the accuracy of command recognition. A prototype based on the switching method is built and tested in a laboratory environment, which validated the functionality and reliability of the method.
基金Project supported by the National Natural Science Foundation of China(No.41676089),the Natural Science Foundation of Zhejiang Province,China(No.LY18E090003)the Fundamental Research Funds for the Central Universities,China(No.2018QNA4005)。
文摘Constant current power transmission is considered a good choice for subsea observatories due to its high resistance to shunt faults. A constant current subsea observatory is planned to be constructed in the East China Sea. We discuss a constant current subsea observatory system used for scientific experiments. The power system and its heat dissipation system are carefully designed. The power conversion method is challenging due to the use of constant current power, which is considerably different from traditional power systems. Thus, we adopt power compensation circuits in the conversion system to obtain a constant 48-V output for science users. A power management system that performs overvoltage protection and real-time monitoring and control of junction box is discussed. An innovative heat dissipation structure of a junction box is designed in consideration of a sealed working environment to extend the useful life of the junction box. Simulations and experiments reveal that the system has high efficiency and stability, especially in long-term applications.
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.
文摘INFOCUS|JUNO Formally Comes into Operation A new-generation large-scale neutrino experiment,the Jiangmen Underground Neutrino Observatory(JUNO)formally came into operation and started collecting data in late August.
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.
基金supported by the Major Program of Scientific and Technical Innovation 2030(grant number:2020AAA0109504)the Science and Technology Planning Project of Beijing City(grant number:Z191100006619116).
文摘Background The Global Cancer Observatory(GLOBOCAN)2022 and the Global Burden of Disease(GBD)2021 are two primary databases for assessing the global cancer burden.This study aimed to compare the incidence and mortality rates of tracheal,bronchus,and lung(TBL)cancer reported in these databases and to analyze the observed discrepancies.Methods Age-standardized rates(ASRs),including age-standardized incidence rates and age-standardized mortality rates for TBL cancer,were obtained from GLOBOCAN 2022 and GBD 2021 for the most recent available year.Differences in ASRs at the national level between the two databases were quantified using pairwise differences,calculated as the absolute difference in ASRs divided by the mean of the ASRs from both sources.Correlations between macroeconomic factors and pairwise differences in ASRs were evaluated,and country features correlated with high pairwise differences were assessed.The data sources and methods used in the two databases were also compared.Results Strong correlations were identified between ASRs reported by GLOBOCAN 2022 and GBD 2021;however,significant differences were observed between estimates from the two data sources.African countries commonly exhibited larger pairwise differences in ASRs,whereas European countries demonstrated smaller pairwise differences in ASRs.Additionally,some populous developing countries,including China,South Africa,Brazil and India,showed smaller differences in ASRs.Countries lacking vital registration systems or high-quality population-based cancer registries displayed larger differences in ASRs.Furthermore,differences in ASRs were negatively correlated with macroeconomic factors.The data sources and estimation methods used by the two databases were inconsistent.Conclusions Discrepancies in TBL cancer incidence and mortality were observed between GLOBOCAN 2022 and GBD 2021.While differences in sources and methods partially explain these discrepancies,a country's cancer surveillance maturity and economic status also correlate with the accuracy of the estimates.Estimating the cancer burden in less wealthy countries remains a substantial challenge,necessitating long-term assistance and investment.
基金supported by the Strategic Priority Program on Space Science,Chinese Academy of Sciences。
文摘SATech-01 is an experimental satellite for space science exploration and on-orbit demonstration of advanced technologies.The satellite is equipped with 16 experimental payloads and supports multiple working modes to meet the observation requirements of various payloads.Due to the limitation of platform power supply and data storage systems,proposing reasonable mission planning schemes to improve scientific revenue of the payloads becomes a critical issue.In this article,we formulate the integrated task scheduling of SATech-01 as a multi-objective optimization problem and propose a novel Fair Integrated Scheduling with Proximal Policy Optimization(FIS-PPO)algorithm to solve it.We use multiple decision heads to generate decisions for each task and design the action mask to ensure the schedule meeting the platform constraints.Experimental results show that FIS-PPO could push the capability of the platform to the limit and improve the overall observation efficiency by 31.5%compared to rule-based plans currently used.Moreover,fairness is considered in the reward design and our method achieves much better performance in terms of equal task opportunities.Because of its low computational complexity,our task scheduling algorithm has the potential to be directly deployed on board for real-time task scheduling in future space projects.
基金supported by the National Key Research and Development Program of China (2021YFA0715101)the National Natural Science Foundation of China (12033009, 12103087)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA0350300)the International Partnership Program of Chinese Academy of Sciences (020GJHZ2022034FN)the Yunnan Fundamental Research Projects (202201AU070225, 202301AT070328, 202401AT070141)the Young Talent Project of Yunnan Revitalization Talent Support Programsupported by ESA (European Space Agency) under the ESA-INFN contract n. 4000133721/21/NL/CR and by ASI (Agenzia Spaziale Italiana) under the Research Agreement n. 2019-15-HH.0
文摘This paper provides a comprehensive overview of the development of Lunar Laser Ranging(LLR),covering key components such as ground observatories,lunar retro-reflectors,and data formats.The paper details the evolution of LLR experiments conducted by some major world-class observatories,with a particular focus on addressing critical issues associated with LLR technology.Additionally,the article highlights the latest advancements in the field,elucidating scientific achievements derived from LLR data,including its contributions to gravitational theory,Earth Orientation Parameters,lunar physics exploration,and lunar librations.The review summarizes new challenges in LLR modeling and concludes with prospects for the future development of LLR.
文摘Although Nigeria is not located within the major seismic zones of the world; over the years,several minor earthquakes have been experienced in some parts of the country.The first widely reported occurrence of an Earth tremor in Nigeria was in 1933.Other events were reported in 1939,1964,1984,1990,1994,1997,2000 and 2006.The intensities of these events ranged from III to VI based on the Modified Mercalli Intensity Scale.Of these events,only the 1984,1990,1994 and 2000 events were instrumentally recorded.They had body wave magnitudes ranging from 4.3 to 4.5,local magnitudes between 3.7 and 4.2,and surface wave magnitudes of 3.7 to 3.9.When these events occurred,there were no functional seismological observatories in Nigeria.However,that has now changed with the establishment of a seismographic network managed by the Centre for Geodesy and Geodynamics（CGG）,Toro,Nigeria.Presently,the network has four operational stations equipped with 24-bit 4-channel recorders and broadband 30-second seismometers.Efforts are being made to establish more stations and migrate to real-time collection of seismic data using the general packet radio service（GPRS） technology as well as automatic location of events.Remote sensing,geological and geophysical studies have revealed the presence of a NNE-SSW trending Ifewara-Zungeru fault zone which has been shown to be linked with the Atlantic fracture system.The dynamics of the Atlantic fracture zones have been suggested to be responsible for the seismic activities experienced in the areas.
基金sponsored by the National Natural Science Foundation of China(NSFC)under the grant numbers(11773073,11873027,U2031140,11833010)Yunnan Key Laboratory of Solar Physics and Space Science under the number 202205AG070009+1 种基金Yunnan Provincial Science and Technology Department(202103AD50013,202105AB160001,202305AH340002)the GHfund A202302013242 and CAS“Light of West China”Program 202305AS350029.
文摘Strong atmospheric turbulence reduces astronomical seeing,causing speckle images acquired by ground-based solar telescopes to become blurred and distorted.Severe distortion in speckle images impedes image phase deviation in the speckle masking reconstruction method,leading to the appearance of spurious imaging artifacts.Relying only on linear image degradation principles to reconstruct solar images is insufficient.To solve this problem,we propose the multiframe blind deconvolution combined with non-rigid alignment(MFBD-CNRA)method for solar image reconstruction.We consider image distortion caused by atmospheric turbulence and use non-rigid alignment to correct pixel-level distortion,thereby achieving nonlinear constraints to complement image intensity changes.After creating the corrected speckle image,we use the linear method to solve the wavefront phase,obtaining the target image.We verify the effectiveness of our method results,compared with others,using solar observation data from the 1 m new vacuum solar telescope(NVST).This new method successfully reconstructs high-resolution images of solar observations with a Fried parameter r0 of approximately 10 cm,and enhances images at high frequency.When r0 is approximately 5 cm,the new method is even more effective.It reconstructs the edges of solar graining and sunspots,and is greatly enhanced at mid and high frequency compared with other methods.Comparisons confirm the effectiveness of this method,with respect to both nonlinear and linear constraints in solar image reconstruction.This provides a suitable solution for image reconstruction in ground-based solar observations under strong atmospheric turbulence.
文摘The purpose of this study was to analyze the associated spectrum of geomagnetic field,frequencies intensity and the time of occurrence.We calculated the variation of the correlation coefficients,with mobile windows of various sizes,for the recorded magnetic components at different latitudes and latitudes.The observatories we included in our study are USA(Surlari),HON(Honolulu),SBA(Scott Base),KAK(Kakioka),THY(Tihany),UPS(Uppsala),WNG(Wingst)and Yellowknife(YKC).We used the data of these observatories from International Real-time Magnetic Observatory Network(INTERMAGNET)for the geomagnetic storm from October 28-31,2003.We have used for this purpose a series of filtering algorithms,spectral analysis and wavelet with different mother functions at different levels.In the paper,we show the Fourier and wavelet analysis of geomagnetic data recorded at different observatories regarding geomagnetic storms.Fourier analysis hightlights predominant frequencies of magnetic field components.Wavelet analysis provides information about the frequency ranges of magnetic fields,which contain long time intervals for medium frequency information and short time intervals for highlight frequencies,details of the analyzed signals.Also,the wavelet analysis allows us to decompose geomagnetic signals in different waves.The analyses presented are significant for the studies of the geomagnetic storm.The data for the next days after the storm showed a mitigation of the perturbations and a transition to quiet days of the geomagnetic field.
文摘We are playing a lead role for growth of astronomy and its quality teaching and research in Manipur, a State located at northeast India (longitude = 93°58'E;latitude = 24°44'N;altitude = 782 m). We have innovatively designed and constructed three cost effective observatories, each costing a few hundred USD. These observatories are completely different in design and are perfectly usable for doing serious work on astronomical observation and measurements, using small ground-based telescopes. One Celestron CGE1400 telescope is housed with equatorial mounting in one of three constructed observatories and the same observatory has been inducted, since January 2012, as one of the members of the “Orion Project”, which is an international project headquartered at Phoenix, Arizona, USA, dedicated for photometric and spectroscopic observations of five bright variable stars of the Orion constellation. We have been producing high precision BVRI photometric data that match well with those produced by other observatories enrolled in the Orion project. Our photometric data were presented and discussed in the 33rd Annual Conference of the Society for Astronomical Sciences: Symposium on Telescope Science, held at Ontario, California, USA during June 12 - 14, 2014. Further, we could successfully demonstrate them to the entire population of the State and play live shows of the observation of three spectacular astronomical events namely, solar eclipse of 15th January 2010, lunar eclipse of 10th December 2011 and Transit of Venus of June 6, 2012. We have conducted a number of seminars and workshops for training and research in astronomy. In the present paper, we would like describe our self-built observatories, our observational facilities, the BVRI photometric data that we acquired for the Orion project, and other activities undertaken for growth of astronomy activities in the State of Manipur, India.
文摘To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevant information about those objects in visual and graphical form. The package calculates object visibility based on a provided time window and observing location as well as maximum airmass and limiting magnitude requested by the user. The pysky application images of the target objects with identifying and astrometric data to provide context for the images. In addition, pysky creates polar plots of each object’s horizontal coordinates, and the images and plots are designed to be shown side-by-side. The package also generates an HTML table of the selected target objects with their related data to relay the entire target list as one. The pysky application draws on a variety of Python packages to collect and process data from databases such as JPL Horizons and SIMBAD. Results for a test event were verified by hand using database web interfaces. The pysky application provides a platform for further integration of automated observation planning with websites and apps to enhance multi-target observation sessions.
文摘This paper presents a method to associate land use/cover with productivity in 16 Agrotech Observatories (AOTs) in Mexico. Compact agricultural areas in Mexico have been identified, which are monitored as to their behavior concerning production and rural productivity in a network of AOTs, which is a compact agricultural area representative of agro-ecological, technological and social conditions in the country. To optimize production and agricultural productivity in compact areas, a multidisciplinary and holistic approach with four lines of activity (agro-ecological, technological, economic, and social), and ten actions are used. The objective of this work was to obtain the land use/cover and productivity of sixteen compact agricultural areas (AOTs) in the Mexican Republic, using panchromatic and multispectral SPOT 5 imagery, in order to provide information to the agricultural sector of the country, and to support decision making contributing to the optimization of production in areas with high actual and potential productivity. As an example, in this paper the land use/cover and productivity “AOT 20 Hidalgo” were described. Currently, it is important to have updated and accurate information to support actions and programs of federal, state and local government for farmers, particularly in compact areas with high agricultural production potential.
