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Improved spatial resolution in soil moisture retrieval at arid mining area using apparent thermal inertia 被引量:4
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作者 雷少刚 卞正富 +1 位作者 John L.DANIELS 刘东烈 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第6期1866-1873,共8页
A surface soil moisture model with improved spatial resolution was developed using remotely sensed apparent thermal inertia(ATI).The model integrates the surface temperature derived from TM/ETM+ image and the mean ... A surface soil moisture model with improved spatial resolution was developed using remotely sensed apparent thermal inertia(ATI).The model integrates the surface temperature derived from TM/ETM+ image and the mean surface temperature from MODIS images to improve the spatial resolution of soil temperature difference based on the heat conduction equation,which is necessary to calculate the ATI.Consequently,the spatial resolution of ATI and SMC can be enhanced from 1 km to 120 m(TM) or 60m(ETM+).Moreover,the enhanced ATI has a much stronger correlation coefficient(R^2) with SMC(0.789) than the surface reflectance(0.108) or the ATI derived only from MODIS images(0.264).Based on the regression statistics of the field SMC measurement and enhanced ATI,a linear regression model with an RMS error of 1.90%was found. 展开更多
关键词 soil water content soil temperature difference thermal inertia remote sensing spatial resolution
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Improving Simulations of Vegetation Dynamics over the Tibetan Plateau:Role of Atmospheric Forcing Data and Spatial Resolution 被引量:4
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作者 Zhijie KANG Bo QIU +3 位作者 Zheng XIANG Ye LIU Zhiqiang LIN Weidong GUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第7期1115-1132,I0018-I0022,共23页
The efficacy of vegetation dynamics simulations in offline land surface models(LSMs)largely depends on the quality and spatial resolution of meteorological forcing data.In this study,the Princeton Global Meteorologica... The efficacy of vegetation dynamics simulations in offline land surface models(LSMs)largely depends on the quality and spatial resolution of meteorological forcing data.In this study,the Princeton Global Meteorological Forcing Data(PMFD)and the high spatial resolution and upscaled China Meteorological Forcing Data(CMFD)were used to drive the Simplified Simple Biosphere model version 4/Top-down Representation of Interactive Foliage and Flora Including Dynamics(SSiB4/TRIFFID)and investigate how meteorological forcing datasets with different spatial resolutions affect simulations over the Tibetan Plateau(TP),a region with complex topography and sparse observations.By comparing the monthly Leaf Area Index(LAI)and Gross Primary Production(GPP)against observations,we found that SSiB4/TRIFFID driven by upscaled CMFD improved the performance in simulating the spatial distributions of LAI and GPP over the TP,reducing RMSEs by 24.3%and 20.5%,respectively.The multi-year averaged GPP decreased from 364.68 gC m^(-2)yr^(-1)to 241.21 gC m^(-2)yr^(-1)with the percentage bias dropping from 50.2%to-1.7%.When using the high spatial resolution CMFD,the RMSEs of the spatial distributions of LAI and GPP simulations were further reduced by 7.5%and 9.5%,respectively.This study highlights the importance of more realistic and high-resolution forcing data in simulating vegetation growth and carbon exchange between the atmosphere and biosphere over the TP. 展开更多
关键词 SSiB4 meteorological forcing data vegetation dynamics spatial resolution Tibetan Plateau
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Areal density and spatial resolution of high energy electron radiography 被引量:4
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作者 Jiahao Xiao Zimin Zhang +13 位作者 Shuchun Cao Ping Yuan Xiaokang Shen Rui Cheng Quantang Zhao Yang Zong Ming Liu Xianming Zhou Zhongping Li Yongtao Zhao Chuanxiang Tang Wenhui Huang Yingchao Du Wei Gai 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第3期321-326,共6页
Ultrafast imaging tools are of great importance for determining the dynamic density distribution in high energy density(HED)matter.In this work,we designed a high energy electron radiography(HEER)system based on a lin... Ultrafast imaging tools are of great importance for determining the dynamic density distribution in high energy density(HED)matter.In this work,we designed a high energy electron radiography(HEER)system based on a linear electron accelerator to evaluate its capability for imaging HED matter.40 MeV electron beams were used to image an aluminum target to study the density resolution and spatial resolution of HEER.The results demonstrate a spatial resolution of tens of micrometers.The interaction of the beams with the target and the beam transport of the transmitted electrons are further simulated with EGS5 and PARMELA codes,with the results showing good agreement with the experimental resolution.Furthermore,the experiment can be improved by adding an aperture at the Fourier plane. 展开更多
关键词 high energy density matter high energy electron radiography areal density resolution spatial resolution
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Effects of Different Spatial Resolutions on Prediction Accuracy of Thunnus alalunga Fishing Ground in Waters Near the Cook Islands Based on Long Short-Term Memory(LSTM)Neural Network Model 被引量:1
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作者 XU Hui SONG Liming +4 位作者 ZHANG Tianjiao LI Yuwei SHEN Jieran ZHANG Min LI Kangdi 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第5期1427-1438,共12页
Albacore tuna(Thunnus alalunga)is one of the target species of tuna longline fishing,and waters near the Cook Islands are a vital albacore tuna fishing ground.Marine environmental data are usually presented with diffe... Albacore tuna(Thunnus alalunga)is one of the target species of tuna longline fishing,and waters near the Cook Islands are a vital albacore tuna fishing ground.Marine environmental data are usually presented with different spatial resolutions,which leads to different results in tuna fishery prediction.Study on the impact of different spatial resolutions on the prediction accuracy of albacore tuna fishery to select the best spatial resolution can contribute to better management of albacore tuna resources.The nominal catch per unit effort(CPUE)of albacore tuna is calculated according to vessel monitor system(VMS)data collected from Chinese distantwater fishery enterprises from January 1,2017 to May 31,2021.A total of 26 spatiotemporal and environmental factors,including temperature,salinity,dissolved oxygen of 0–300 m water layer,chlorophyll-a concentration in the sea surface,sea surface height,month,longitude,and latitude,were selected as variables.The temporal resolution of the variables was daily and the spatial resolutions were set to be 0.5°×0.5°,1°×1°,2°×2°,and 5°×5°.The relationship between the nominal CPUE and each individual factor was analyzed to remove the factors irrelavant to the nominal CPUE,together with a multicollinearity diagnosis on the factors to remove factors highly related to the other factors within the four spatial resolutions.The relationship models between CPUE and spatiotemporal and environmental factors by four spatial resolutions were established based on the long short-term memory(LSTM)neural network model.The mean absolute error(MAE)and root mean square error(RMSE)were used to analyze the fitness and accuracy of the models,and to determine the effects of different spatial resolutions on the prediction accuracy of the albacore tuna fishing ground.The results show the resolution of 1°×1°can lead to the best prediction accuracy,with the MAE and RMSE being 0.0268 and 0.0452 respectively,followed by 0.5°×0.5°,2°×2°and 5°×5°with declining prediction accuracy.The results suggested that 1)albacore tuna fishing ground can be predicted by LSTM;2)the VMS records the data in detail and can be used scientifically to calculate the CPUE;3)correlation analysis,and multicollinearity diagnosis are necessary to improve the prediction accuracy of the model;4)the spatial resolution should be 1°×1°in the forecast of albacore tuna fishing ground in waters near the Cook Islands. 展开更多
关键词 albacore tuna fishing ground prediction accuracy VMS spatial resolution LSTM the Cook Islands
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Integrating cross-sensor high spatial resolution satellite images to detect subtle forest vegetation change in the Purple Mountains,a national scenic spot in Nanjing,China 被引量:1
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作者 Fangyan Zhu Wenjuan Shen +2 位作者 Jiaojiao Diao Mingshi Li Guang Zheng 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第5期1743-1758,共16页
Accurate information on the location and magnitude of vegetation change in scenic areas can guide the configuration of tourism facilities and the formulation of vegetation protection measures.High spatial resolution r... Accurate information on the location and magnitude of vegetation change in scenic areas can guide the configuration of tourism facilities and the formulation of vegetation protection measures.High spatial resolution remote sensing images can be used to detect subtle vegetation changes.The major objective of this study was to map and quantify forest vegetation changes in a national scenic location,the Purple Mountains of Nanjing,China,using multi-temporal cross-sensor high spatial resolution satellite images to identify the main drivers of the vegetation changes and provide a reference for sustainable management.We used Quickbird images acquired in 2004,IKONOS images acquired in 2009,and WorldView2 images acquired in 2015.Four pixel-based direct change detection methods including the normalized difference vegetation index difference method,multi-index integrated change analysis(MIICA),principal component analysis,and spectral gradient difference analysis were compared in terms of their change detection performances.Subsequently,the best pixel-based detection method in conjunction with object-oriented image analysis was used to extract subtle forest vegetation changes.An accuracy assessment using the stratified random sampling points was conducted to evaluate the performance of the change detection results.The results showed that the MIICA method was the best pixel-based change detection method.And the object-oriented MIICA with an overall accuracy of 0.907 and a kappa coefficient of 0.846 was superior to the pixel-based MIICA.From 2004 to 2009,areas of vegetation gain mainly occurred around the periphery of the study area,while areas of vegetation loss were observed in the interior and along the boundary of the study area due to construction activities,which contributed to 79%of the total area of vegetation loss.During 2009–2015,the greening initiatives around the construction areas increased the forest vegetation coverage,accounting for 84%of the total area of vegetation gain.In spite of this,vegetation loss occurred in the interior of the Purple Mountains due to infrastructure development that caused conversion from vegetation to impervious areas.We recommend that:(1)a local multi-agency team inspect and assess law enforcement regarding natural resource utilization;and(2)strengthen environmental awareness education. 展开更多
关键词 High spatial resolution satellite images Vegetation change Direct detection method Objectoriented Purple Mountains
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Spatial resolution and image processing for pinhole camera-based X-ray fluorescence imaging: a simulation study 被引量:1
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作者 Ze He Ning Huang +2 位作者 Peng Wang Zi-Han Chen Bo Peng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第5期135-153,共19页
Spatial resolution and image-processing methods for full-field X-ray fluorescence(FF-XRF)imaging using X-ray pinhole cameras were studied using Geant4simulations with different geometries and algorithms for image reco... Spatial resolution and image-processing methods for full-field X-ray fluorescence(FF-XRF)imaging using X-ray pinhole cameras were studied using Geant4simulations with different geometries and algorithms for image reconstruction.The main objectives were:(1)calculating the quantum efficiency curves of specific cameras,(2)studying the relationships between the spatial resolution and the pinhole diameter,magnification,and camera binning value,and(3)comparing image-processing methods for pinhole camera systems.Several results were obtained using a point and plane source as the X-ray fluorescence emitter and an array of 100×100 silicon pixel detectors as the X-ray camera.The quantum efficiency of a back-illuminated deep depletion(BI-DD)structure was above 30%for the XRF energies in the 0.8–9 keV range,with the maximum of 93.7%at 4 keV.The best spatial resolution of the pinhole camera was 24.7μm and 31.3 lp/mm when measured using the profile function of the point source,with the diameter of 20μm,magnification of 3.16,and camera bin of 1.A blind deconvolution algorithm with Gaussian filtering performed better than the Wiener filter and Richardson iterative methods on FF-XRF images,with the signal-to-noise ratio of 7.81 dB and improved signalto-noise ratio of 7.24 dB at the diameter of 120μm,magnification of 1.0,and camera bin of 1. 展开更多
关键词 Full-field X-ray fluorescence(FF-XRF) X-ray pinhole camera spatial resolution Image processing
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High Spatial Resolution Mapping of Dykes Using Unmanned Aerial Vehicle(UAV) Photogrammetry: New Insights On Emplacement Processes 被引量:1
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作者 Alexander CRUDEN Stefan VOLLGGER +1 位作者 Greg DERING Steven MICKLETHWAITE 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第S1期52-53,共2页
Remote sensing has played a pivotal role in our understanding of the geometry of dykes and dyke swarms on Earth,Venus and Mars(West and Ernst,1991;Mege and Masson,1995;Ernst et al.,2005).Since the 1970’s
关键词 PHOTOGRAMMETRY High spatial resolution Mapping of Dykes Using Unmanned Aerial Vehicle New Insights On Emplacement Processes UAV
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A spatial resolution effect analysis of remote sensing bathymetry 被引量:3
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作者 LIANG Jian ZHANG Jie MA Yi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第7期102-109,共8页
A spatial resolution effect of remote sensing bathymetry is an important scientific problem. The in situ measured water depth data and images of Dongdao Island are used to study the effect of water depth inversion fro... A spatial resolution effect of remote sensing bathymetry is an important scientific problem. The in situ measured water depth data and images of Dongdao Island are used to study the effect of water depth inversion from different spatial resolution remote sensing images. The research experiments are divided into five groups including Quick Bird and World View-2 remote sensing images with their original spatial resolution(2.4/2.0 m)and four kinds of reducing spatial resolution(4, 8, 16 and 32 m), and the water depth control and checking points are set up to carry out remote sensing water depth inversion. The experiment results indicate that the accuracy of the water depth remote sensing inversion increases first as the spatial resolution decreases from 2.4/2.0 to 4, 8 and16 m. And then the accuracy decreases along with the decreasing spatial resolution. When the spatial resolution of the image is 16 m, the inversion error is minimum. In this case, when the spatial resolution of the remote sensing image is 16 m, the mean relative errors(MRE) of Quick Bird and World View-2 bathymetry are 21.2% and 13.1%,compared with the maximum error are decreased by 14.7% and 2.9% respectively; the mean absolute errors(MAE) are 2.0 and 1.4 m, compared with the maximum are decreased by 1.0 and 0.5 m respectively. The results provide an important reference for the selection of remote sensing data in the study and application of the remote sensing bathymetry. 展开更多
关键词 remote sensing spatial resolution water depth remote sensing inversion
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Monitoring of Karst Rocky Desertification Control Projects Based on Remote Sensing Images with Medium and High Spatial Resolution——A Case Study of Disi River Basin in Puan County 被引量:1
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作者 Haixiang Guo Yulun An 《Meteorological and Environmental Research》 CAS 2013年第7期32-34,38,共4页
[ Objective] The study aimed to improve methods of monitoring Karst Rocky Desertification (KRD) control projects and increase the working efficiency. [Method] Based on remote sensing images with medium and high spat... [ Objective] The study aimed to improve methods of monitoring Karst Rocky Desertification (KRD) control projects and increase the working efficiency. [Method] Based on remote sensing images with medium and high spatial resolution, KRD control projects in Disi River basin in Puan County were monitored, that is, information of the project construction in the study area was extracted using supervised classification and hu- man-computer interactive interpretation, and the monitoring results were testified with the aid of GPS. [Result] It was feasible to monitor KRD con- trol projects in Disi River basin based on remote sensing images with medium and high resolution, and the monitoring accuracy was satisfactory, reaching above 80% or 90%, so the method is worthy of popularizing. [ Conclusion] Remote sensing images with medium and high resolution can be used to monitor other KRD control Droiects. 展开更多
关键词 Karst Rocky Desertification (KRD) Remote sensing images with medium and high spatial resolution MONITORING Puan County China
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A Cloud Framework for High Spatial Resolution Soil Moisture Mapping from Radar and Optical Satellite Imageries
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作者 GUO Tianhao ZHENG Jia +8 位作者 WANG Chunmei TAO Zui ZHENG Xingming WANG Qi LI Lei FENG Zhuangzhuang WANG Xigang LI Xinbiao KE Liwei 《Chinese Geographical Science》 SCIE CSCD 2023年第4期649-663,共15页
Soil moisture plays an important role in crop yield estimation,irrigation management,etc.Remote sensing technology has potential for large-scale and high spatial soil moisture mapping.However,offline remote sensing da... Soil moisture plays an important role in crop yield estimation,irrigation management,etc.Remote sensing technology has potential for large-scale and high spatial soil moisture mapping.However,offline remote sensing data processing is time-consuming and resource-intensive,and significantly hampers the efficiency and timeliness of soil moisture mapping.Due to the high-speed computing capabilities of remote sensing cloud platforms,a High Spatial Resolution Soil Moisture Estimation Framework(HSRSMEF)based on the Google Earth Engine(GEE)platform was developed in this study.The functions of the HSRSMEF include research area and input datasets customization,radar speckle noise filtering,optical-radar image spatio-temporal matching,soil moisture retrieving,soil moisture visualization and exporting.This paper tested the performance of HSRSMEF by combining Sentinel-1,Sentinel-2 images and insitu soil moisture data in the central farmland area of Jilin Province,China.Reconstructed Normalized Difference Vegetation Index(NDVI)based on the Savitzky-Golay algorithm conforms to the crop growth cycle,and its correlation with the original NDVI is about 0.99(P<0.001).The soil moisture accuracy of the random forest model(R 2=0.942,RMSE=0.013 m3/m3)is better than that of the water cloud model(R 2=0.334,RMSE=0.091 m3/m3).HSRSMEF transfers time-consuming offline operations to cloud computing platforms,achieving rapid and simplified high spatial resolution soil moisture mapping. 展开更多
关键词 soil moisture(SM) Google Earth Engine(GEE) Cloud Computing Platform High spatial resolution Soil Moisture Estimation Framework(HSRSMEF) remote sensing Sentienl-1 Sentinel-2 Northeast China
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A stopping layer concept to improve the spatial resolution of gas-electron-multiplier neutron detector
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作者 Jianjin Zhou Jianrong Zhou +9 位作者 Xiaojuan Zhou Lin Zhu Jianqing Yang Guian Yang Yi Zhang Baowei Ding Bitao Hu Zhijia Sun Limin Duan Yuanbo Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期225-230,共6页
In recent years,gas electron multiplier(GEM)neutron detectors have been developing towards high spatial resolution and high dynamic counting range.We propose a novel concept of an Al stopping layer to enable the detec... In recent years,gas electron multiplier(GEM)neutron detectors have been developing towards high spatial resolution and high dynamic counting range.We propose a novel concept of an Al stopping layer to enable the detector to achieve sub-millimeter(sub-mm)spatial resolution.The neutron conversion layer is coated with the Al stopping layer to limit the emission angle of ions into the drift region.The short track projection of ions is obtained on the signal readout board,and the detector would get good spatial resolution.The spatial resolutions of the GEM neutron detector with the Al stopping layer are simulated and optimized based on Geant4 Garfield Interface.The spatial resolution of the detector is 0.76 mm and the thermal neutron detection efficiency is about 0.01%when the Al stopping layer is 3.0μm thick,the drift region is 2 mm thick,the strip pitch is 600μm,and the digital readout is employed.Thus,the GEM neutron detector with a simple detector structure and a fast readout mode is developed to obtain a high spatial resolution and high dynamic counting range.It could be used for the direct measurement of a high-flux neutron beam,such as Bragg transmission imaging,very small-angle scattering neutron detection and neutron beam diagnostic. 展开更多
关键词 high spatial resolution Al stopping layer GEM neutron detector spallation neutron source
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SPATIALLY SCALABLE RESOLUTION IMAGE CODING METHOD WITH MEMORY OPTIMIZATION BASED ON WAVELET TRANSFORM
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作者 WangNa ZhangLi +2 位作者 ZhouXiao'an JiaChuanying LiXia 《Journal of Electronics(China)》 2005年第1期94-97,共4页
This letter exploits fundamental characteristics of a wavelet transform image to form a progressive octave-based spatial resolution. Each wavelet subband is coded based on zeroblock and quardtree partitioning ordering... This letter exploits fundamental characteristics of a wavelet transform image to form a progressive octave-based spatial resolution. Each wavelet subband is coded based on zeroblock and quardtree partitioning ordering scheme with memory optimization technique. The method proposed in this letter is of low complexity and efficient for Internet plug-in software. 展开更多
关键词 Memory optimization spatially resolution scalability Wavelet transform Quard-tree partitioning
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A Method to Estimate Spatial Resolution in 2-D Seismic Surface Wave Tomographic Problems
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作者 Jorge L.de Souza 《International Journal of Geosciences》 2014年第8期757-770,共14页
A novel methodology to quantify the spatial resolution in 2-D seismic surface wave tomographic problems is proposed in this study. It is based on both the resolving kernels computed via full resolution matrix and the ... A novel methodology to quantify the spatial resolution in 2-D seismic surface wave tomographic problems is proposed in this study. It is based on both the resolving kernels computed via full resolution matrix and the concept of Full Width at Half Maximum (FWHM) of a Gaussian function. This method allows estimating quantitatively the spatial resolution at any cell of a gridded area. It was applied in the northeastern Brazil and the estimated spatial resolution range is in agreement with all previous surface wave investigations in the South America continent. 展开更多
关键词 Surface Waves Seismic Tomography Wave Propagation spatial resolution Northeastern Brazil
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High-Resolution Remote Sensing Imagery for the Recognition of Traditional Villages
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作者 Mengchen Wang Linshuhong Shen 《Journal of Architectural Research and Development》 2024年第1期75-83,共9页
Traditional Chinese villages,vital carriers of traditional culture,have faced significant alterations due to urbanization in recent years,urgently necessitating artificial intelligence data updates.This study integrat... Traditional Chinese villages,vital carriers of traditional culture,have faced significant alterations due to urbanization in recent years,urgently necessitating artificial intelligence data updates.This study integrates high spatial resolution remote sensing imagery with deep learning techniques,proposing a novel method for identifying rooftops of traditional Chinese village buildings using high-definition remote sensing images.Using 0.54 m spatial resolution imagery of traditional village areas as the data source,this method analyzes the geometric and spectral image characteristics of village building rooftops.It constructs a deep learning feature sample library tailored to the target types.Employing a semantically enhanced version of the improved Mask R-CNN(Mask Region-based Convolutional Neural Network)for building recognition,the study conducts experiments on localized imagery from different regions.The results demonstrated that the modified Mask R-CNN effectively identifies traditional village building rooftops,achieving an of 0.7520 and an of 0.7400.It improves the current problem of misidentification and missed detection caused by feature heterogeneity.This method offers a viable and effective approach for industrialized data monitoring of traditional villages,contributing to their sustainable development. 展开更多
关键词 Traditional villages Building rooftops High spatial resolution remote sensing Instance segmentation
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Resolution analysis of thermal neutron radiography based on accelerator-driven compact neutron source 被引量:7
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作者 Lian-Xin Zhang Si-Ze Chen +6 位作者 Zao-Di Zhang Tao-Sheng Li Chuan Peng Lei Ren Rui Zhang Dan Xiao Yong Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第5期139-151,共13页
Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applicati... Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applications.Recently,thermal neutron radiography experiments based on a D-T neutron generator performed by Hefei Institutes of Physical Science indicated a significant resolution deviation between the experimental results and the values calculated using the traditional resolution model.The experimental result was up to 23%lower than the calculated result,which hinders the achievement of the design goal of a compact neutron radiography system.A GEANT4 Monte Carlo code was developed to simulate the CTNR process,aiming to identify the key factors leading to resolution deviation.The effects of a low collimation ratio and high-energy neutrons were analyzed based on the neutron beam environment of the CTNR system.The results showed that the deviation was primarily caused by geometric distortion at low collimation ratios and radiation noise induced by highenergy neutrons.Additionally,the theoretical model was modified by considering the imaging position and radiation noise factors.The modified theoretical model was in good agreement with the experimental results,and the maximum deviation was reduced to 4.22%.This can be useful for the high-precision design of CTNR systems. 展开更多
关键词 Neutron radiography spatial resolution Accelerator-driven neutron source GEANT4 MTF ESF
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Temporal sequence Object-based CNN(TS-OCNN) for crop classification from fine resolution remote sensing image time-series 被引量:3
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作者 Huapeng Li Yajun Tian +2 位作者 Ce Zhang Shuqing Zhang Peter MAtkinson 《The Crop Journal》 SCIE CSCD 2022年第5期1507-1516,共10页
Accurate crop distribution mapping is required for crop yield prediction and field management. Due to rapid progress in remote sensing technology, fine spatial resolution(FSR) remotely sensed imagery now offers great ... Accurate crop distribution mapping is required for crop yield prediction and field management. Due to rapid progress in remote sensing technology, fine spatial resolution(FSR) remotely sensed imagery now offers great opportunities for mapping crop types in great detail. However, within-class variance can hamper attempts to discriminate crop classes at fine resolutions. Multi-temporal FSR remotely sensed imagery provides a means of increasing crop classification from FSR imagery, although current methods do not exploit the available information fully. In this research, a novel Temporal Sequence Object-based Convolutional Neural Network(TS-OCNN) was proposed to classify agricultural crop type from FSR image time-series. An object-based CNN(OCNN) model was adopted in the TS-OCNN to classify images at the object level(i.e., segmented objects or crop parcels), thus, maintaining the precise boundary information of crop parcels. The combination of image time-series was first utilized as the input to the OCNN model to produce an ‘original’ or baseline classification. Then the single-date images were fed automatically into the deep learning model scene-by-scene in order of image acquisition date to increase successively the crop classification accuracy. By doing so, the joint information in the FSR multi-temporal observations and the unique individual information from the single-date images were exploited comprehensively for crop classification. The effectiveness of the proposed approach was investigated using multitemporal SAR and optical imagery, respectively, over two heterogeneous agricultural areas. The experimental results demonstrated that the newly proposed TS-OCNN approach consistently increased crop classification accuracy, and achieved the greatest accuracies(82.68% and 87.40%) in comparison with state-of-the-art benchmark methods, including the object-based CNN(OCNN)(81.63% and85.88%), object-based image analysis(OBIA)(78.21% and 84.83%), and standard pixel-wise CNN(79.18%and 82.90%). The proposed approach is the first known attempt to explore simultaneously the joint information from image time-series with the unique information from single-date images for crop classification using a deep learning framework. The TS-OCNN, therefore, represents a new approach for agricultural landscape classification from multi-temporal FSR imagery. Besides, it is readily generalizable to other landscapes(e.g., forest landscapes), with a wide application prospect. 展开更多
关键词 Convolutional neural network Multi-temporal imagery Object-based image analysis(OBIA) Crop classification Fine spatial resolution imagery
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Multi-domain High-Resolution Platform for Integrated Spectroscopy and Microscopy Characterizations 被引量:1
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作者 Li Wang Shen-long Jiang +1 位作者 Qun Zhang Yi Luo 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第6期680-685,I0002,共7页
In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establi... In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future. 展开更多
关键词 Multi-domain platform Spectral/spatial/temporal resolution Integrated characterizations SPECTROSCOPY MICROSCOPY Imaging
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Observations of Dynamic Turbulence in the Lower Stratosphere over Inner Mongolia Using a High-resolution Balloon Sensor Constant Temperature Anemometer
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作者 Xiaoyu REN Yi LIU +1 位作者 Zhaonan CAI Yuli ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第3期519-528,共10页
We present characterizations of the dynamic turbulence in the lower stratosphere measured by a new balloon-based system designed for detecting finer scale dynamic turbulence. The balloon-based system included a consta... We present characterizations of the dynamic turbulence in the lower stratosphere measured by a new balloon-based system designed for detecting finer scale dynamic turbulence. The balloon-based system included a constant temperature anemometer(CTA) operating at a sampling rate of 2 k Hz at an ascent speed of 5 m s^(-1)(corresponding to a vertical resolution of 2.5 mm), an industrial personal computer, batteries, sensors for ambient temperature and humidity, an A/D converter, and others. The system was successfully launched to 24 km altitude over Bayannur City, Inner Mongolia Province. Results show the spatial intermittence of the turbulence layers, with clear boundaries between turbulent and nonturbulent regions. This is the first time that the dynamic turbulence spectrum down to the viscous sub-range has been obtained throughout the lower stratosphere over China. With that, the energy dissipation rates of dynamic turbulence could be calculated with high precision. The profile of the dissipation rates varied from 7.37 × 10^(-7) to 4.23 W kg^(-1) and increased with altitude in the stratosphere. 展开更多
关键词 dynamic turbulence STRATOSPHERE balloon payload high spatial resolution dissipation rates Inner Mongolia
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Spatial downscaling of climate variables using three statistical methods in Central Iran
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作者 Zahra JABERALANSAR Mostafa TARKESH Mehdi BASSIRI 《Journal of Mountain Science》 SCIE CSCD 2018年第3期606-617,共12页
Spatial downscaling methods are widely used for the production of bioclimatic variables(e.g. temperature and precipitation) in studies related to species ecological niche and drainage basin management and planning. Th... Spatial downscaling methods are widely used for the production of bioclimatic variables(e.g. temperature and precipitation) in studies related to species ecological niche and drainage basin management and planning. This study applied three different statistical methods, i.e. the moving window regression(MWR), nonparametric multiplicative regression(NPMR), and generalized linear model(GLM), to downscale the annual mean temperature(Bio1) and annual precipitation(Bio12) in central Iran from coarse scale(1 km × 1 km) to fine scale(250 m ×250 m). Elevation, aspect, distance from sea and normalized difference vegetation index(NDVI) were used as covariates to create downscaled bioclimatic variables. Model assessment was performed by comparing model outcomes with observational data from weather stations. Coefficients of determination(R2), bias, and root-mean-square error(RMSE) were used to evaluate models and covariates. The elevation could effectively justify the changes in bioclimatic factors related to temperature and precipitation. Allthree models could downscale the mean annual temperature data with similar R2, RMSE, and bias values. The MWR had the best performance and highest accuracy in downscaling annual precipitation(R2=0.70; RMSE=123.44). In general, the two nonparametric models, i.e. MWR and NPMR, can be reliably used for the downscaling of bioclimatic variables which have wide applications in species distribution modeling. 展开更多
关键词 Statistical models Climatic data ELEVATION spatial resolution Temperature PRECIPITATION
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HIGH RESOLUTION, HIGH SENSITIVITY MOIRE METHOD
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作者 王朝阳 戴福隆 蒋小林 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1999年第2期176-181,共6页
Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patter... Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patterns are produced by the superposition of two high frequency gratings through a microscope system. Compared with other grating-based photo-mechanics methods, microscopic moire method could provide whole-field moire patterns of both high spatial resolution and high sensitivity. The frequency of specimen and reference gratings used in this method can be from 1 line/mm to 10000 lines/mm. Additionally, a 4F optical filter system is used to enhance the contrast of microscopic moire patterns effectively. 展开更多
关键词 high spatial resolution high sensitivity geometric moire MICROSCOPE
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