Variations in ocean mixed layer depth(MLD)show a significant impact on energy balance in the global climate systems and marine ecosystems.At present,the accuracy of modeling MLD,especially in the region with complex o...Variations in ocean mixed layer depth(MLD)show a significant impact on energy balance in the global climate systems and marine ecosystems.At present,the accuracy of modeling MLD,especially in the region with complex ocean dynamics,remains a challenge,thus calling for an emergency using artificial intelligence approach to improve the assessment of the MLD.A novel convolutional neural network model was developed based on a dual-attention module(DA-CNN)to estimate the MLD in the Bay of Bengal(BoB)by integrating multi-source remote sensing data and Argo gridded data.Compared with the original CNN model,the DA-CNN model exhibits superior performance with notable improvements in the annual average root mean square error(RMSE)and R2 values by 13.0%and 8.4%,respectively,while more accurately capturing the seasonal variations in MLD.Moreover,the results using the DA-CNN model show minimum RMSE and maximum R2 values,in comparison to the calculation by the random forest,artificial neural network model,and the hybrid coordinate ocean model.Accordingly,our findings suggest that the newly developed DA-CNN model provides an effective advantage in studying the MLD and the associated ocean processes.展开更多
Crater is a geologic structure in solid bodies(including the terrestrial planets, moons, and asteroids) formed by hyperspeed impact, and the impact process is extremely important to the formation and evolution of thes...Crater is a geologic structure in solid bodies(including the terrestrial planets, moons, and asteroids) formed by hyperspeed impact, and the impact process is extremely important to the formation and evolution of these celestial bodies. This paper presents a review of the studies on remote sensing observation, formation mechanism, and scientific application of craters. On the remote sensing study of craters, the topographic characteristics of the micro-craters, simple craters, complex craters, and impact basins are described,the related parameters in the morphological studies of craters are subsequently introduced, and the distribution characteristics of the minerals and rock types during the impact excavation process are analyzed,the methods of crater identification and the crater databases on the Moon, Mars, Ceres, and Vesta are summarized. On the studies of crater formation mechanism, the general formation process of the craters is firstly described, and then the most frequently used methods are presented, and the importance of the empirical equations is also elucidated. On the scientific applications of the craters, the principle and currently utilization of the planetary surface dating method with crater size-frequency distribution are firstly presented, and the applications, including modeling the lunar regolith formation and thickness derivation of both the regolith and basalt, are reviewed. Finally, the future prospects of the formation mechanism study of the craters are discussed.展开更多
研究表明大地震之前由于地表温度的变化会引起长波辐射OLR(Outgoing Longwave Radiation)数据异常,但目前缺乏有效的技术来提取异常。我们提出了一种基于随机传感器和鞅理论的异常数据挖掘算法ADRM (Abnormality Detection based on Ran...研究表明大地震之前由于地表温度的变化会引起长波辐射OLR(Outgoing Longwave Radiation)数据异常,但目前缺乏有效的技术来提取异常。我们提出了一种基于随机传感器和鞅理论的异常数据挖掘算法ADRM (Abnormality Detection based on Randomized Transducer and Power Martingales),经过实验对比能有效挖掘异常。本数据集记录了尼泊尔地区2009-2018年10年间的NOAA卫星的OLR数据和经过异常数据挖掘后的相应数据序列。数据集在地域上,以尼泊尔地震震中为中心的周边地域划分为同样经纬度2.5°×2.5°为单位的25个网格;时间上,定义每个年度是从上一年的9月28日到下一年的9月28日,共计366天,2009-2018年10年的数据。数据集存储为1个.xls文件,数据量为3.92 MB。基于该数据集的研究成果分别发表在《地球信息科学学报》(2018年20卷8期)和《IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing》(2018年11卷8期)。展开更多
In order to alleviate the impact of radio frequency interference(RFI)on the accuracy of ocean salinity satellite remote sensing,scholars have proposed various detection and labeling algorithms for RFI based on remote ...In order to alleviate the impact of radio frequency interference(RFI)on the accuracy of ocean salinity satellite remote sensing,scholars have proposed various detection and labeling algorithms for RFI based on remote sensing data from the SMOS satellite.However,the signals that generate RFI are diverse,and the factors that influence remote sensing observation data are complex.Existing algorithms often target specific hypothetical conditions,lacking general applicability,which frequently leads to an important gap between the nominal performance of the literature and practical applications,posing great challenges to data labeling work.To address this problem,this study conducted a comprehensive and systematic analysis of RFI simulation based on scene modeling,algorithm modeling,and RFI energy modeling.Three typical RFI detection algorithms were selected,and the simulation scene was divided into 3 typical scenes:ocean,land,and sea–land scenes,and RFI was analyzed in terms of weak,moderate,strong,and extremely strong based on energy.Through simulation analysis and evaluation of RFI detection algorithms,lookup tables for algorithm selection,detection rate,and false-positive rate have been established for different intensities of independent RFI sources and multiple nearby RFI sources in the above scenario.These lookup tables have universal guiding significance and provide reliability assurance in complex situations.展开更多
The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed...The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed that the Moon resembles a terrestrial planet with a layered core–mantle–crust structure,which formed in the early lunar differentiation initialized by a magma ocean.The important results on the early differentiation of the Moon derived from the ongoing analyses of lunar samples and geophysical data,and experimental studies with different initial conditions,are reviewed in this study.The outstanding problems in the early lunar differentiation,including the formation of the lunar anorthositic crust,the origin of lunar dichotomy,lunar mantle convection,the lunar interior interface,and the chronology of early differentiation,are highlighted and summarized.These unsolved questions may provide research directions for future studies of early differentiation of the Moon.The upcoming lunar exploration missions will return new samples and geophysical data.Comprehensive analyses of the returned samples and the geophysical data(seismology,gravity and topography,and crustal magnetic field),coupled with experimental studies,could provide important results to answer the unsolved questions and constrain the early lunar differentiation.展开更多
基金Supported by the Ministry of Science and Technology of the People’s Republic of China(No.2019 YFE 0125000)the National Natural Science Foundation of China(No.42376032)。
文摘Variations in ocean mixed layer depth(MLD)show a significant impact on energy balance in the global climate systems and marine ecosystems.At present,the accuracy of modeling MLD,especially in the region with complex ocean dynamics,remains a challenge,thus calling for an emergency using artificial intelligence approach to improve the assessment of the MLD.A novel convolutional neural network model was developed based on a dual-attention module(DA-CNN)to estimate the MLD in the Bay of Bengal(BoB)by integrating multi-source remote sensing data and Argo gridded data.Compared with the original CNN model,the DA-CNN model exhibits superior performance with notable improvements in the annual average root mean square error(RMSE)and R2 values by 13.0%and 8.4%,respectively,while more accurately capturing the seasonal variations in MLD.Moreover,the results using the DA-CNN model show minimum RMSE and maximum R2 values,in comparison to the calculation by the random forest,artificial neural network model,and the hybrid coordinate ocean model.Accordingly,our findings suggest that the newly developed DA-CNN model provides an effective advantage in studying the MLD and the associated ocean processes.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41972321, 41941003)。
文摘Crater is a geologic structure in solid bodies(including the terrestrial planets, moons, and asteroids) formed by hyperspeed impact, and the impact process is extremely important to the formation and evolution of these celestial bodies. This paper presents a review of the studies on remote sensing observation, formation mechanism, and scientific application of craters. On the remote sensing study of craters, the topographic characteristics of the micro-craters, simple craters, complex craters, and impact basins are described,the related parameters in the morphological studies of craters are subsequently introduced, and the distribution characteristics of the minerals and rock types during the impact excavation process are analyzed,the methods of crater identification and the crater databases on the Moon, Mars, Ceres, and Vesta are summarized. On the studies of crater formation mechanism, the general formation process of the craters is firstly described, and then the most frequently used methods are presented, and the importance of the empirical equations is also elucidated. On the scientific applications of the craters, the principle and currently utilization of the planetary surface dating method with crater size-frequency distribution are firstly presented, and the applications, including modeling the lunar regolith formation and thickness derivation of both the regolith and basalt, are reviewed. Finally, the future prospects of the formation mechanism study of the craters are discussed.
文摘研究表明大地震之前由于地表温度的变化会引起长波辐射OLR(Outgoing Longwave Radiation)数据异常,但目前缺乏有效的技术来提取异常。我们提出了一种基于随机传感器和鞅理论的异常数据挖掘算法ADRM (Abnormality Detection based on Randomized Transducer and Power Martingales),经过实验对比能有效挖掘异常。本数据集记录了尼泊尔地区2009-2018年10年间的NOAA卫星的OLR数据和经过异常数据挖掘后的相应数据序列。数据集在地域上,以尼泊尔地震震中为中心的周边地域划分为同样经纬度2.5°×2.5°为单位的25个网格;时间上,定义每个年度是从上一年的9月28日到下一年的9月28日,共计366天,2009-2018年10年的数据。数据集存储为1个.xls文件,数据量为3.92 MB。基于该数据集的研究成果分别发表在《地球信息科学学报》(2018年20卷8期)和《IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing》(2018年11卷8期)。
基金supported by the National Natural Science Foundation of China (Grant No. 62031005).
文摘In order to alleviate the impact of radio frequency interference(RFI)on the accuracy of ocean salinity satellite remote sensing,scholars have proposed various detection and labeling algorithms for RFI based on remote sensing data from the SMOS satellite.However,the signals that generate RFI are diverse,and the factors that influence remote sensing observation data are complex.Existing algorithms often target specific hypothetical conditions,lacking general applicability,which frequently leads to an important gap between the nominal performance of the literature and practical applications,posing great challenges to data labeling work.To address this problem,this study conducted a comprehensive and systematic analysis of RFI simulation based on scene modeling,algorithm modeling,and RFI energy modeling.Three typical RFI detection algorithms were selected,and the simulation scene was divided into 3 typical scenes:ocean,land,and sea–land scenes,and RFI was analyzed in terms of weak,moderate,strong,and extremely strong based on energy.Through simulation analysis and evaluation of RFI detection algorithms,lookup tables for algorithm selection,detection rate,and false-positive rate have been established for different intensities of independent RFI sources and multiple nearby RFI sources in the above scenario.These lookup tables have universal guiding significance and provide reliability assurance in complex situations.
基金supported by a National Natural Science Foundation of China(NSFC)grant(42125303)the B-type Strategic Priority Program of the Chinese Academy of Sciences(XDB41000000)the Natural Science Foundation of Henan Province(232300420174).
文摘The analyses of returned samples and data from in situ and remote sensing observations have substantially advanced our understanding of the lunar internal structure since the Apollo era.Previous studies have confirmed that the Moon resembles a terrestrial planet with a layered core–mantle–crust structure,which formed in the early lunar differentiation initialized by a magma ocean.The important results on the early differentiation of the Moon derived from the ongoing analyses of lunar samples and geophysical data,and experimental studies with different initial conditions,are reviewed in this study.The outstanding problems in the early lunar differentiation,including the formation of the lunar anorthositic crust,the origin of lunar dichotomy,lunar mantle convection,the lunar interior interface,and the chronology of early differentiation,are highlighted and summarized.These unsolved questions may provide research directions for future studies of early differentiation of the Moon.The upcoming lunar exploration missions will return new samples and geophysical data.Comprehensive analyses of the returned samples and the geophysical data(seismology,gravity and topography,and crustal magnetic field),coupled with experimental studies,could provide important results to answer the unsolved questions and constrain the early lunar differentiation.
