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Information flow and controlling in regularization inversion of quantitative remote sensing

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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

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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

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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

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

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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

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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

基于gis的黄河上游龙羊峡库区生态环境遥感监测研究

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山地学报 2003年第2期21卷 140-148页

作者：曾永年冯兆东曹广超兰州大学西部环境教育部重点实验室兰州大学西部环境教育部重点实验室甘肃兰州730000青海师范大学青藏高原资源环境研究中心青海西宁810008 甘肃兰州730000

本项研究以黄河上游生态环境严重退化的龙羊峡库区为研究区 ,应用遥感与gis一体化的方法 ,建立了库区生态环境动态监测信息系统。在系统的支持下 ,利用多时相、多波段TM遥感数据 ,对库区近十年来生态环境变化进行监测分析 ,揭示了库区... 详细信息

本项研究以黄河上游生态环境严重退化的龙羊峡库区为研究区 ,应用遥感与gis一体化的方法 ,建立了库区生态环境动态监测信息系统。在系统的支持下 ,利用多时相、多波段TM遥感数据 ,对库区近十年来生态环境变化进行监测分析 ,揭示了库区土地沙漠化、水土流失、土地利用 /土地覆盖的现状 ,以及建库近十年来生态环境时空演化的过程与发展趋势 ,为库区生态环境治理提供科学依据。本项研究利用遥感和gis技术 ,采用生态环境综合分类系统 ,在一次分类处理中通过多层次不同级别的组合获得了基于同一信息源的土地沙漠化、草场盖度、土地利用 /土地覆盖等多种环境类型信息 ,并利用环境信息模型对库区的土壤侵蚀进行了评价。基于gis的分类后再处理使遥感分类精度有了一定程度的提高。研究表明 ,在gis的支持下充分利用遥感信息监测与评价生态环境 ,是区域生态环境定量化研究的有效途径

关键词：生态环境监测 RS&gis 黄河上游龙羊峡库区

基于特征光谱参数的叶片和冠层尺度茶多酚含量估算

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光谱学与光谱分析 2024年第3期44卷 814-820页

作者：段丹丹刘仲华赵春江赵钰王凡湖南农业大学园艺学院湖南长沙410128 国家农业信息化工程技术研究中心北京100097 北京市农林科学院智能装备技术研究中心北京100097

茶多酚具有很强的生理活性和抗氧化性,是茶品质的重要属性之一。相比传统茶多酚含量的测定方法,遥感技术监测茶多酚含量具有高效、精确及实时的优势,但如何利用遥感数据监测不同时期的茶多酚含量研究较少。该研究以广东省英德市的5个茶... 详细信息

茶多酚具有很强的生理活性和抗氧化性,是茶品质的重要属性之一。相比传统茶多酚含量的测定方法,遥感技术监测茶多酚含量具有高效、精确及实时的优势,但如何利用遥感数据监测不同时期的茶多酚含量研究较少。该研究以广东省英德市的5个茶园的茶叶为研究对象,对春茶、夏茶和秋茶的叶片与冠层两个尺度的茶多酚含量及对应高光谱数据进行测定,利用标准正态变量变换(SNV)对叶片和冠层的高光谱反射率数据进行预处理;然后,分别采用连续投影算法(SPA)和竞争性自适应重加权采样算法(CARS)筛选不同生长季节叶片和冠层两个尺度茶多酚的敏感波段;最后,通过偏最小二乘法(PLS)、随机森林(RF)和多元线性回归(MLR)分别构建不同时期的茶多酚含量模型并进行验证。结果表明:(1)茶多酚的含量随着季节推移显著增加,春茶茶多酚含量(15.37%)最低,夏茶茶多酚含量次之(18.29%),秋茶茶多酚含量(秋茶20.77%)最高;(2)不同敏感波段筛选的茶多酚含量的光谱特征波段主要为2100~2200 nm附近、1300~1400 nm附近、红波-红边波段及绿波段;(3)基于春茶、夏茶和秋茶冠层光谱特征构建的茶多酚模型中CARS-PLS、SPA-MLR和CARS-PLS模型精度最高,建模集R2分别为0.56、0.45和0.52,RMSE分别为1.15、1.68和1.77;验证集R2分别为0.43、0.40和0.41,RMSE分别为1.60、1.91和1.91;基于春茶、夏茶和秋茶冠层叶片光谱特征构建的茶多酚模型中SPA-PLS、CARS-PLS和SPA-MLR模型精度最高,建模集R2分别为0.50、0.42和0.42,RMSE分别为1.25、1.70和1.66;验证集R2分别为0.43、0.36和0.38,RMSE分别为1.44、1.96和2.49。研究结果表明,基于遥感数据进行不同季节的叶片和冠层两个尺度的茶多酚含量估算是可行的,在大面积实时监测茶品质特征方面具有较大的潜力。

关键词：茶多酚高光谱偏最小二乘法随机森林多元线性回归

Precise orbit determination of Haiyang‑2D using onboard BDS‑3 B1C/B2a observations with ambiguity resolution

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Satellite Navigation 2023年第3期4卷 167-184页

作者： Kecai Jiang Wenwen Li Min Li Jianghui geng Haixia Lyu Qile zhao Jingnan Liu GNSS research center Wuhan University129 Luoyu RoadWuhan 430079China Key Laboratory of Space Ocean remote sensing and Application Ministry of Natural Resources8 Dahui Temple RoadBeijing 10081China Collaborative Innovation center of Geospatial Technology 129 Luoyu RoadWuhan 430079China department of Land Surveying and Geo‑Informatics The Hong Kong Polytechnic University11 Yuk Choi RoadHung HomKowloonHong KongChina

The Haiyang-2D altimetry mission of china is one of the first Low Earth Orbit(LEO)satellites that can receive new B1C/B2a signals from the BeiDou-3 Navigation Satellite System(BDS-3)for Precise Orbit Determination(POD).In this work,the achievable accuracy of the single-receiver ambiguity resolution for onboard LEO satellites is studied based on the real measurements of new BDS-3 *** normal conditions,six BDS-3 satellites on average are ***,the multipath of the B1C/B2a code observations presents some patchy patterns that cause near-field variations with an amplitude of approximately 40 cm and deteriorate the ambiguity-fixed *** modeling those errors,for the B2a code,a remarkable reduction of 53%in the Root Mean Square(RMS)is achieved at high elevations,along with an increase of 8%in the ambiguity-fixed ***,an analysis of the onboard antenna’s phase center offsets reveals that when compared to the solutions with float ambiguities,the estimated values in the antenna’s Z direction in the solutions with fixed ambiguities are notably *** independent validation of the resulting POD using satellite laser ranging at 16 selected high-performance stations shows that the residuals are reduced by a minimum of 15.4%for ambiguity-fixed solutions with an RMS consistency of approximately 2.2 ***,when compared to the DORIS-derived orbits,a 4.3 cm 3D RMS consistency is achieved for the BDS-3-derived orbits,and the along-track bias is reduced from 2.9 to 0.4 cm using ambiguity fixing.

关键词： Ambiguity resolution B1C/B2a Onboard BDS-3 Precise orbit determination Haiyang-2D

Identifi cation and decomposition of regional economic disparity for the west coast of Taiwan Strait of china

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Ecological Economy 2008年第4期4卷 394-402页

作者： zhao Xiaofang geng Jianzhong Institute of Geographic Sciences and Natural Resources research Chinese Academy of Sciences Beijing 100101 P R. China Graduate School Chinese Academy of Sciences Beijing 100039 P. R. China College of geography and remote sensing Beijing Normal University Beijing 100875 P R. China

Regional economic disparity is a hot issue in the development of society and economy. As the conjunct of the Yangtze River Delta and the Pearl River Delta and the frontier to Taiwan, the west coast of the Taiwan Strait （WCS） is of great social and political significance. The paper defines the connotation of the WCS, decomposed the regional economic disparity by using weighted coefficient of variation and Theil coefficient, and explores the industrial and regional source of the regional economic disparity of the WCS. The analysis results show that：（1） the WCS has important political, economic and military position, so it＇s better to regard it to be comprehensive region, not just refer to Fujian Province; （2）from the industrial decomposition of weighted variation coefficient, the influence o.f the primary industry was tiny; conversely, the development inequity of the secondary and the tertiary, indusoy was the main source of regional economic disparity. Their contribution has had the converse trend and the secondary contribution has gone beyond the tertiary since 2003; （3）from the regional decomposition of Theil coefficient, the regional economic disparity mainly came from inter-area inequity of 4 areas. Moreover, the inner economic disparity mainly drove by Fujian, suggesting that the urban development inequity in Fujian Province was comparatively outstanding.

关键词： WCS Regional economic disparity Industrial decomposition Regional decomposition