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Multi-resolution representation of digital terrain models with terrain features preservation

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Science china(Technological Sciences) 2008年第S1期51卷 145-154页

作者： li QingQuan1,WANG Zhi1,2 & yang BiSheng1 1 state key laboratory of information engineering in surveying,mapping and remote sensing,wuhan university,wuhan 43.079,china 2 School of remote sensing and information engineering,wuhan university,wuhan 43.079,china 1. state key laboratory of information engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China2. School of Remote Sensing and Information Engineering Wuhan University Wuhan 430079 China

multi-resolution TIN model is an important issue in the contexts of visu-alization,virtual reality (VR),and geographic information systems (GIS). This paper proposes a new method for constructing multi-resolution TIN models with multi-scale topographic features preservation. The proposed method is driven by a half-edge collapse operation in a greedy framework and employs a new quadric error metric to efficiently measure geometric errors. We define topographic features in a multi-scale manner using a center-surround operator on Gaussian-weighted mean curvatures. Experimental results demonstrate that the proposed method performs better than previous methods in terms of topographic features preservation,and is able to achieve multi-resolution TIN models with a higher accuracy.

关键词： digital terrain models level of detail differential-geometry quadric error metrics topographic feature

Semi-Supervised Classification based on Gaussian Mixture Model for remote imagery

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Science china(Technological Sciences) 2010年第S1期53卷 85-90页

作者： XIONG Biao1,zhang XiaoJun1 & JIANG WanShou1,2 1 state key laboratory of information engineering in surveying,mapping and remote sensing,wuhan university,wuhan 43.079,china 2 state key laboratory of remote sensing Science,Beijing,china 1. state key laboratory of information engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China2. State Key Laboratory of Remote Sensing Science Beijing China

Semi-Supervised Classification (SSC),which makes use of both labeled and unlabeled data to determine classification borders in feature space,has great advantages in extracting classification information from mass *** this paper,a novel SSC method based on Gaussian Mixture Model (GMM) is proposed,in which each class’s feature space is described by one *** show the proposed method can achieve high classification accuracy with small amount of labeled ***,for the same accuracy,supervised classification methods such as Support Vector Machine,Object Oriented Classification,*** be provided with much more labeled data.

关键词： remote sensing image classification Semi-Supervised Classification Gaussian Mixture Model EM algorithms

Image City sharing platform and its typical applications

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Science china(information Sciences) 2011年第8期54卷 1738-1746页

作者： SHAO ZhenFeng & li DeRen state key laboratory for information engineering in surveying,mapping and remote sensing,wuhan university,wuhan 43.079,china 1. state key laboratory for information engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China

In this paper,the trend of urban spatial information sharing service from the electronic map to image is analyzed and its sharing framework based on service-oriented architecture is ***,the service implementation,feedback data service procedure and its processing service model are explored. Based on the software with independent intellectual property rights,image city of Taizhou is developed as an example to realize various image data and processing servicesLastly,the bright future prospects of image city are described.

关键词： Image City service-oriented architecture image data service function service model service

A new relative radiometric consistency processing method for change detection based on wavelet transform and a low-pass filter

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Science china(Technological Sciences) 2010年第S1期53卷 7-14页

作者： SUN KaiMin1,SUI HaiGang1,2,li DeRen1 & XU Chuan1,2 1 state key laboratory of information engineering in surveying,mapping and remote sensing,wuhan university,wuhan 43.079,china 2 state key laboratory of Subtropical Building Science,South china university of Technology,Guangzhou 510640,china 1. state key laboratory of information engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China 2. state key laboratory of Subtropical Building Science South China University of Technology Guangzhou 510640 China

The research purpose of this paper is to show the limitations of the existing radiometric normalization approaches and their disadvantages in change detection of artificial objects by comparing the existing approaches,on the basis of which a preprocessing approach to radiometric consistency,based on wavelet transform and a spatial low-pass filter,has been *** approach first separates the high frequency information and low frequency information by wavelet ***,the processing of relative radiometric consistency based on a low-pass filter is conducted on the low frequency *** processing,an inverse wavelet transform is conducted to obtain the results *** experimental results show that this approach can substantially reduce the influence on change detection of linear or nonlinear radiometric differences in multi-temporal images.

关键词： wavelet transform radiometric normalization low-pass filter change detection

A multi-scale and multi-orientation image retrieval method based on rotation-invariant texture features

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Science china(information Sciences) 2011年第4期54卷 732-744页

作者： SHAO ZhenFeng,li DeRen & ZHU XianQiang state key laboratory for information engineering in surveying,mapping and remote sensing,wuhan university,129 Luoyu Road,wuhan 43.079,china 1. state key laboratory for information engineering in surveying Mapping and Remote Sensing Wuhan University 129 Luoyu Road Wuhan 430079 China

Texture retrieval is a vital branch of content-based image ***-invariant texture retrieval plays a key role in texture *** paper addresses three major issues in rotation-invariant texture retrieval: how to select the texture measurement methods,how to alleviate the influence of rotation for texture retrieval and how to apply the proper multi-scale analysis theory for texture ***,the spectrum influence between a Radon transform and a Log-polar transform was compared after the rotation effect was *** average retrieval performance of wavelet and NSCT with different retrieval parameters was also *** on such analysis,we developed a multi-scale and multi-orientation texture transform spectrum,as well as a rotation-invariant feature vector and its measurement criteria,which can represent the human visual perception sensitive to texture *** a new rotation-invariant texture retrieval algorithm was *** algorithm was developed based on non-parametric statistical features and it applies low band and high frequency directional bands of NSCT coefficients for coarse filtering and fine retrieval,*** on the Brodatz image database show that the constructed rotation-invariant feature vector is appropriate for capturing major orientations and describing detail ***,the combination of the two-step progressive retrieval strategy and multi-scale analysis method can effectively improve retrieval efficiency while ensuring a high precision compared with traditional algorithms.

关键词： NSCT Log-polar Radon rotation-invariant texture retrieval

Untethered Micro/Nanorobots for remote sensing:Toward Intelligent Platform

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Nano-Micro Letters 2024年第2期16卷 450-483页

作者： Qianqian Wang Shihao yang li zhang Jiangsu key laboratory for Design and Manufacture of Micro‑Nano Biomedical Instruments School of Mechanical EngineeringSoutheast UniversityNanjing 211189People’s Republic of China Department of Mechanical and Automation engineering The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China Chow Yuk Ho Technology Centre for Innovative Medicine The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China T Stone Robotics Institute The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China Department of Surgery The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China

Untethered micro/nanorobots that can wirelessly control their motion and deformation state have gained enormous interest in remote sensing applications due to their unique motion characteristics in various media and diverse *** are developing micro/nanorobots as innovative tools to improve sensing performance and miniaturize sensing systems,enabling in situ detection of substances that traditional sensing methods struggle to *** the past decade of development,significant research progress has been made in designing sensing strategies based on micro/nanorobots,employing various coordinated control and sensing *** review summarizes the latest developments on micro/nanorobots for remote sensing applications by utilizing the self-generated signals of the robots,robot behavior,microrobotic manipulation,and robot-environment *** recent studies and relevant applications in remote sensing,we also discuss the challenges and future perspectives facing micro/nanorobots-based intelligent sensing platforms to achieve sensing in complex environments,translating lab research achievements into widespread real applications.

关键词： Micro/nanorobot remote sensing Wireless control Self-propulsion Actuation at small scales

Post-earthquake assessment of building damage degree using liDAR data and imagery

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Science china(Technological Sciences) 2008年第S2期51卷 133-143页

作者： li ManChun1,CHENG liang1,2,GONG JianYa2,liU YongXue1,CHEN ZhenJie1,li FeiXue1,CHEN Gang1,CHEN Dong1 & SONG XiaoGang3.1 Department of Geographic information Science,Nanjing university,Nanjing 210093,china 2 state key laboratory of information engineering in surveying,mapping and remote sensing,wuhan university,wuhan 43.079,china 3 state key laboratory of Earthquake Dynamics,Institute of Geology,china Earthquake Administration,Beijing 100029,china Department of Geographic information Science Nanjing University Nanjing 210093 China state key laboratory of information engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China state key laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed *** the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes realistic to identify damages on the scale of individual *** the low accuracy of the results has often led to the use of visual interpretation ***,it is very difficult to estimate the degree of building damage(*** damage,moderate damage,or severe damage) in detail using the existing ***,a novel approach integrating liDAR data and high resolution optical imagery is proposed for evaluating building damage degree *** approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change ***,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake liDAR data and high resolution ***,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake liDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop *** novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.

关键词： post-earthquake assessment building damage degree rooftop patch liDAR imagery

UAV image target localization method based on outlier filter and frame buffer

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Chinese Journal of Aeronautics 2024年第7期37卷 375-390页

作者： yang WANG Hongguang li Xinjun li Zhipeng WANG Baochang zhang Institute of Unmanned System Beihang UniversityBeijing 100191China School of Electronics and information engineering Beihang UniversityBeijing 100191China Institute of Artificial Intelligence Beihang UniversityBeijing 100191China

With rapid development of UAV technology,research on UAV image analysis has gained *** the existing techniques of UAV target localization often rely on additional equipment,a method of UAV target localization based on depth estimation has been ***,the unique perspective of UAVs poses challenges such as the significant field of view variations and the presence of dynamic objects in the *** a result,the existing methods of depth estimation and scale recovery cannot be directly applied to UAV ***,there is a scarcity of depth estimation datasets tailored for UAV perspectives,which makes supervised algorithms *** address these issues,an outlier filter is introduced to enhance the applicability of depth estimation networks to target localization.A frame buffer method is proposed to achieve more accurate scale recovery,so as to handle complex scene textures in UAV *** proposed method demonstrates a 14.29%improvement over the *** with the average recovery results from UAV perspectives,the difference is only 0.88%,approaching the performance of scale recovery using ground truth ***,to overcome the limited availability of traditional UAV depth datasets,a method for generating depth labels from video sequences is *** to state-of-the-art methods,the proposed approach achieves higher accuracy in depth estimation and stands for the first attempt at target localization using image *** algorithm and dataset are available at https://***/uav-tan/uav-object-localization.

关键词： Object localization Deep learning Depth estimate Scale recovery Unmanned Aerial Vehicle(UAV)

Formation and growth of nanophase iron particles on the surface of Mercury revealed by experimental study

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Acta Geochimica 2024年第4期43卷 774-784页

作者： Ronghua Pang yang li Chen li Pengfei zhang Zhuang guo Sizhe Zhao Han Yu li Wang Chenxi Zhu Shuangyu Wang Kairui Tai Qinwei zhang Yuanyun Wen Rui li Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyangChina university of Chinese Academy of Sciences BeijingChina Center for Excellence in Comparative Planetology Chinese Academy of SciencesHefeiChina Institute of remote sensing and Geographical information System School of Earth and Space SciencesPeking UniversityBeijingChina state key laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina Faculty of Metallurgical and Energy engineering Kunming University of Science and TechnologyKunmingChina state key laboratory of High Performance Ceramics and Superfi ne Microstructures Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbinChina Research Center for Planetary Science College of Earth ScienceChengdu University of TechnologyChengduChina key laboratory of Planetary Sciences Purple Mountain ObservatoryChinese Academy of SciencesNanjingChina

Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless ***,current research on space weathering focuses mainly on the Moon and certain types of *** particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being *** weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind *** in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering *** to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic ***,the lunar model of space weathering may not apply to *** studies have extensively explored the eff ects of micrometeoroid ***,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar *** the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the *** experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but

关键词： Mercury Space weathering Np-Fe^(0) Solar thermal radiation Solar wind