检索结果-南通市图书馆

Information flow and controlling in regularization inversion of quantitative remote sensing

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第1期48卷 74-83页

作者： YANG Hua, XU Wangli, zhao Hongrui, CHEN Xue & WANG Jindi research center for remote sensing and gis, School of geography, beijing normal university, State Key Laboratory of remote sensing Science, beijing Key Laboratory for remote sensing of Environment and Digital Cities, beijing 100875, china department of Mathematics, beijing normal university, beijing 100875, china 1. research center for remote sensing and gis School of Geography Beijing Normal University State Key Laboratory of Remote Sensing Science Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities 100875 Beijing China 2. department of Mathematics Beijing Normal University 100875 Beijing China

In order to minimize uncertainty of the inversed parameters to the largest extent by making full use of the limited information in remote sensing data, it is necessary to understand what the information flow in quantitative remote sensing model inversion is, thus control the information flow. Aiming at this, the paper takes the linear kernel-driven model inversion as an example. At first, the information flow in different inversion methods is calculated and analyzed, then the effect of information flow controlled by multi-stage inversion strategy is studied, finally, an information matrix based on USM is defined to control information flow in inversion. It shows that using Shannon entropy decrease of the inversed parameters can express information flow more properly. Changing the weight of a priori knowledge in inversion or fixing parameters and partitioning datasets in multi-stage inversion strategy can control information flow. In regularization inversion of remote sensing, information matrix based on USM may be a better tool for quantitatively controlling information flow.

关键词： regularization inversion, information flow, Shannon entropy decrease, information matrix.

Principle and application of three-band gradient difference vegetation index

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第2期48卷 241-249页

作者： TANG Shihao, ZHU Qijiang, WANG Jindi, ZHOU Yuyu & zhao Feng research center for remote sensing and gis, department of geography, beijing normal university, beijing 100875, china National Satellite Meteorological center, china Meteorological Administration, beijing 100081, china 1. research center for remote sensing and gis Department of Geography Beijing Normal University 100875 Beijing China 2. National Satellite Meteorological center China Meteorological Administration 100081 Beijing China

Vegetation index is a simple, effective and experiential measurement of terrestrial vegetation activity, and plays a very important role in qualitative and quantitative remote sensing. Aiming at shortages of current vegetation indices, and starting from the analysis of vegetation spectral characteristics, we put forward a new vegetation index, the three-band gradient difference vegetation index (TGDVI), and established algorithms to inverse crown cover fraction and leaf area index (LAI) from it. Theoretical analysis and model simulation show that TGDVI has high saturation point and the ability to remove the influence of background to some degree, and the explicit functional relation with crown cover fraction and LAI can be established. Moreover, study shows that TGDVI also has the ability to partly remove the influence of thin cloud. Experiment in the Shunyi District, beijing, china shows that reasonable result can be reached using the vegetation index to retrieve LAI. We also theoretically analyzed the reason why the normalized difference vegetation index (NDVI) owns the low saturation point, and show that it is determined by the definition of NDVI and the characteristic of vegetation spectra, and is unavoidable to some degree. Meanwhile, through model simulation, we also indicate that the relationship between simple ratio vegetation index (SR) and LAI closes to a piecewise linear one instead of a linear one, which is mainly caused by the influence of background and different change rates of reflectance in red and infrared bands with LAI increasing.

关键词： vegetation index, remote sensing, LAI, crown cover fraction, remote sensing inversion.

Matrix calculation of high-dimensional cross product and its application in automatic recognition of the endmembers of hyperspectral imagary

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第1期54卷 197-203页

作者： geng xiurui1,zhao yongchao1,LIU SuHong2 & WANG FuXiang3 1Key Laboratory of Technology in Geo-spatial Information Processing and Application System, Institute of Electronics,Chinese Academy of Sciences,beijing 100080,china 2State Key Laboratory of remote sensing Science,Jointly Sponsored by beijing normal university and the Institute of remote sensing Applications of Chinese Academy of Sciences, School of geography,beijing normal university,beijing 100875,china 3School of Electronics and Information Engineering,Beihang university,beijing 100191,china 1. Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences Beijing 100080 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications of Chinese Academy of Sciences School of Geography Beijing Normal University Beijing 100875 China3. School of Electronics and Information Engineering Beihang University Beijing 100191 China

This paper gives the definition of the high-dimensional cross product and its calculation by extending the 3-D cross product definition into the high-dimensional vector *** on the properties of the cross product,the volume variance index(VVI)is proposed to be used in extracting automatically the endmembers of the hypherspectral imagery which eliminates the shortcoming of the traditional method of using simplex only where the extraction results were easily impacted by the abnormal pixels.A case study of endmembers extraction experiment using the VVI method with the AVIRIS data for Cuprite has shown a very good result.

关键词： endmember simplex hyperspectral imagery cross product

Spatial prediction and analysis of Himalayan marmot plague natural epidemic foci in china based on HJ-1 satellite data

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第S1期53卷 8-15页

作者： GAO MengXu1,4,LI XiaoWen1,2,CAO ChunXiang1,ZHANG Hao1,LI Qun3,ZHOU Hang3 HE QiSheng1,4,XU Min1,4,zhao Jian1,4,ZHENG Sheng1,4 & CHEN Wei1,4 1State Key Laboratory of remote sensing Science,Jointly Sponsored by the Institute of remote sensing Applications of Chinese Academy of Sciences and beijing normal university,beijing 100101,china 2School of geography,beijing normal university,beijing 100875,china 3Office for Disease Control and Emergency Response,Chinese center for Disease Control and Prevention,beijing 102206,china 4Graduate university of Chinese Academy of Sciences,beijing 100049,china 1. State Key Laboratory of remote sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China4. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. School of Geography Beijing Normal University Beijing 100875 China3. Office for Disease Control and Emergency Response Chinese Center for Disease Control and Prevention Beijing 102206 China

Plague,caused by the gram-negative bacterium Yersinia pestis,is a serious and rapidly progressing illness in humans that can be fatal if not treated *** Qinghai-Tibet Plateau is the largest area of natural Himalayan marmot(Marmota himalayana) plague foci in china and covers more than 630000 *** County in Gansu Province is a part of this natural focus of plague and was chosen as a study *** study used an ecological niche modeling(ENM) approach to predict the potential distribution of the Himalayan *** and Disaster Monitor Satellite(HJ-1) data was used to investigate environment factors that affect plague host animal *** animal point data from active surveillance was combined with environmental variables from the HJ-1 satellite and other databases,and the models of the potential distribution of Himalayan marmot were produced with the Genetic Algorithm for Rule-Set Production(GARP).The probability of marmot presence was divided into 0-5%,5%-20%,20%-40%,40%-80%,and 80%-100% *** with 80%-100% probability exhibited the greatest potential for the presence of Himalayan *** to the predicted potential distribution of Himalayan marmot in the study area,active surveillance of plague hosts and plague control and prevention could be more efficient.

关键词： Himalayan marmot plague spatial prediction GARP HJ-1 satellite

Geologic body three-dimensional model generation and visualization method

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2005年第S1期15卷 190-192页

作者： ZHANG Song-mei~(1, 2), LI Jing~1, zhao Wen-ji~3, Gong Hui-li~3, Duan Fu-zhou~3, GONG zhao-ning~3, LI Jia-hong~4 (1. beijing normal university, beijing 100875, china 2. Jilin university, Changchun 130061, china 3. The Key Lab of Resource Environment and gis, beijing 100037, china 4. National remote sensing center of china, beijing 100862, china) beijing normal Univ Beijing 100875 Peoples R China Jilin Univ Changchun 130061 Peoples R China Key Lab Resource Environm Beijing 100037 Peoples R China gis Beijing 100037 Peoples R China Natl remote sensing Ctr china Beijing 100862 Peoples R China

The divergence three-dimensional millet-seed body model and the continuous distributing layer-imitating model were introduced, which were used to express geologic body, and the procedure of generating these two models and their merits and demerits were synthesized. Three methods of geologic body’s three-dimensional expression were separately introduced, and the merits of the continuous distributing layer imitating model were proposed as comparing with the divergence three-dimensional millet-seed body model. The three-dimensional cubes were observed from any direction and any tangle with the application of dealing methods such as peeling, hollowing out, transparent or half-transparent.

关键词： geologic body regular grid net irregular triangle net three-dimensional visualization

Quantitative estimation of the shrub canopy LAI from atmosphere-corrected HJ-1 CCD data in Mu Us Sandland

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第S1期53卷 26-33页

The leaf area index(LAI) is an important ecological parameter that characterizes the interface between vegetation canopy and the *** addition,it is used by most process-oriented ecosystem *** paper investigates the potential of HJ-1 CCD data combined with linear spectral unmixing and an inverted geometric-optical model for the retrieval of the shrub LAI in Wushen Banner of Inner Mongolia in the Mu Us ***(Moderate Resolution Atmospheric Radiance and Transmittance Model) was used for atmospheric *** was extracted using the threshold of the normalized difference vegetation index,with which water bodies and farmland were separated,in combination with a vegetation map of the People's Republic of china(1:1000000).Using the geometric-optical model,we derive the per-pixel reflectance as a simple linear combination of two components,namely sunlit background and *** fraction of sunlit background is related to the shrub *** the support of HJ-1 CCD data,we employ linear spectral unmixing to obtain the fraction of sunlit background in an atmospherically corrected HJ *** addition,we use the measured shrub canopy structural parameters for shrub communities to invert the geometric-optical model and retrieve the pixel-based shrub *** total,18 sample plots collected in Wushen Banner of Inner Mongolia are used for *** results of the shrub LAI show good agreement with R2 of 0.817 and a root-mean-squared error of 0.173.

关键词： shrub leaf area index inversion HJ-1 data geometric-optical model MODTRAN Mu Us Sandland

基于空间分析的机井管理系统总体设计及其关键技术探讨

在线全文

学校读者我要写书评

暂无评论

水文地质工程地质 2004年第1期31卷 101-104页

作者：赵祥张晔刘素红北京师范大学资源环境系遥感与gis研究中心北京100875 天津市龙脉水资源咨询中心天津300060

在gis空间分析技术支持下 ,对机井管理系统从总体设计、系统功能结构、数据库建库方法、系统实现等多方面进行了阐述 ,并探讨了系统开发的关键技术和主要的程序编码 ,在机井管理信息化方面进行了有益的尝试 ,为建立类似系统提供了一个... 详细信息

在gis空间分析技术支持下 ,对机井管理系统从总体设计、系统功能结构、数据库建库方法、系统实现等多方面进行了阐述 ,并探讨了系统开发的关键技术和主要的程序编码 ,在机井管理信息化方面进行了有益的尝试 ,为建立类似系统提供了一个应用范例。

关键词：空间分析机井管理系统设计数据库总体设计管理信息化地下水资源管理

在线全文

学校读者我要写书评

暂无评论

gis支持下不同坡度的土壤侵蚀特征分析

水土保持学报 2002年第6期16卷 46-49页

作者：杨存建刘纪远张增祥周全斌赵晓丽四川师范大学遥感与应用研究中心四川成都610066 中国科学院地理科学与资源研究所北京100101 中国科学院遥感应用研究所北京100101

利用地理信息系统技术对不同坡度等级情况下的土壤侵蚀特征进行了分析。首先,利用地理信息系统软件从DEM数据中产生坡度数据,将其分级为6个等级。然后与土壤侵蚀数据集进行叠加统计分析,从而得到不同坡度等级情况下的土壤侵蚀特征。本... 详细信息

利用地理信息系统技术对不同坡度等级情况下的土壤侵蚀特征进行了分析。首先,利用地理信息系统软件从DEM数据中产生坡度数据,将其分级为6个等级。然后与土壤侵蚀数据集进行叠加统计分析,从而得到不同坡度等级情况下的土壤侵蚀特征。本文研究表明:(1)坡度等级从2～5级,轻度以上水蚀所占百分比逐渐降低。(2)在所有坡度等级上,轻度以上风蚀所占百分比均在86.8%以上。在第2坡度等级上,风蚀综合指数最高,而在第5坡度等级上,风蚀综合指数最低。(3)冻融侵蚀综合指数的最高值出现在第3坡度等级上,其最低值出现在第6坡度等级上。(4)在各个坡度等级上,均以水蚀为主,均在46%以上,其最高值为73.8%,出现在第4坡度级上。此外,在第1坡度级上,风蚀占次优势,而在第2～6坡度等级上,冻融占次优势。(5)坡度等级在1,2和3级上,其轻度侵蚀所占百分比和土壤侵蚀综合指数均相对较高,而在坡度等级4,5和6级上,轻度侵蚀所占百分比和土壤侵蚀综合指数均相对较低。这主要是由于在坡度等级较低的情况下,人为活动比较多,土地利用程度较高,对植被和土壤的破坏较大,从而导致这种反常现象。

关键词：地理信息系统坡度等级土壤侵蚀

Synchronization System among remote Heterogeneous Database Systems

在线全文

学校读者我要写书评

暂无评论

Synchronization System among Remote Heterogeneous Database S...