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Analysis of forest backscattering characteristics based on polarization coherence tomography

science china(Technological sciences) 2010年第S1期53卷 166-175页

作者： LUO HuanMin 1,LI XiaoWen 1,2.CHEN ErXue 3.CHENG Jian 4 & CAO ChunXiang 2. institute of Geo-Spatial Information {3. and Technology,University of Electronic {3. and Technology of china,Chengdu 610054,china 2.State key laboratory of remote sensing {3.,Jointly Sponsored by the{13. of chinese Academy of {3.s and beijing Normal University,beijing 100101,china 3.2} of Forest Resources Information Technique of chinese Academy of Forestry,beijing 100091,china 4 School of Electronic Engineering,University of Electronic {3. and Technology of china,Chengdu 610054,china State key Lab remote {2. Sci Beijing 100101 Peoples R China beijing Normal Univ Beijing 100101 Peoples R China Univ Elect Sci & Technol china Inst Geospatial Informat Sci & Technol Chengdu 610054 Peoples R China chinese Acad Forestry Inst Forest Resources Informat Tech Beijing 100091 Peoples R China Univ Elect Sci & Technol china Sch Elect Engn Chengdu 610054 Peoples R China

It is difficult to make an inventory of vertical profiles of forest structure parameters in field ***,analysis and understanding of forest backscattering characteristics contribute to estimation and detection of forest vertical structure because of the close relationships between backscattering characteristics and structure *** vertical structure function in the complex interferometric coherence definition,which represents the vertical variation of microwave scattering with the penetration depth at a point in the 2.D radar image and can be used to analyze the forest backscattering characteristics,can be reconstructed from polarization coherence tomography(PCT).Based on PCT,the paper analyzes the forest backscattering characteristics and explores the inherent relationship between the result of PCT and the forest structure parameters from numerical simulation of Random Volume over Ground model(RVoG),Polarimetric SAR interferometry(PolInSAR)simulation of forest scene and PolInSAR data at L-band of the test site ***,the effects of the extinction coefficient and surface-to-volume scattering ratio in RVoG model on vertical backscattering characteristics are analyzed by means of numerical ***,by applying PCT to L-band POLInSAR simulations of forest scene,different variations of vertical backscattering due to different extinction coefficients and the ratios of surface-to-volume scattering resulting from different polarizations,forest types and densities are displayed and *** a concept of relative average backscattering intensity is presented,and the factors which affect its vertical distribution are also *** results show that there is high sensitivity of the vertical distribution of forest relative average backscattering intensity to the polarization,forest type and ***,based on repeat pass DLR E-SAR L-band airborne POLInSAR data,the capability of PCT technology for detection

关键词： backscattering characteristic POLInSAR PCT vertical structure function

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Long term monitoring of urban subsidence by Permanent Scatterer DInSAR

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Progress in Natural science:Materials International 2007年第1期17卷 107-111页

作者： TANG Yixian, ZHANG Hong and WANG Chao ( The chinese remote {2. Satellite Ground Station, chinese Academy of sciences, beijing 100086, china State key laboratory of remote {2. IRSA, chinese Academy of sciences,{13., china) [a]The chinese remote {2. Satellite Ground Station Chinese Academy of Sciences Beijing China [b]State key laboratory of {2. {3. IRSA Chinese Academy of Sciences Beijing China

When using differential SAR interferometry (DInSAR) to monitor the surface deformation over a long time scale, it is often strongly affected by the spatial and temporal decorrelations and atmospheric dishomogeneities. The recently developed Permanent Scatterers (PS) technique proposed by Fertti et al. can overcome these difficulties by interpreting time-series of interferometric phase only at coherent point scatterers. In this study, we apply this PS technique using 2. ERS-1/2.scenes from 1992.to 2.00 to monitor the subsidence in Suzhou. By using the linear deformation model, the deformation map in Suzhou urban area over the eight years is obtained. And the calculated results are in good agreement with the measurements of leveling.

关键词： Permanent Scatterer differential SAR interferometry urban subsidence.

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Cascade recursion models of computing the temperatures of underground layers

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science china(Technological sciences) 2006年第z2期49卷 30-38页

作者： HAN Liqun, BI Siwen & SONG Shixin School of Information Engineering, beijing Technology and Business University, beijing 10003.,{2. State {3. laboratory of remote sensing science, institute of remote sensing applications, chinese Academy of sciences, beijing 100101,{2. beijing Technol & Business Univ Sch Informat Engn Beijing 100037 Peoples R China chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China

An RBF neural network was used to construct computational models of the underground temperatures of different layers, using ground-surface parameters and the temperatures of various underground layers. Because series recursion models also enable researchers to use above-ground surface parameters to compute the temperatures of different underground layers, this method provides a new way of using thermal infrared remote sensing to monitor the suture zones of large areas of blocks and to research thermal anomalies in geologic structures.

关键词： RBF network, underground temperature, modeling, cascade, recursion.

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Study on NDVI-T_s space by combining LAI and evapotranspiration

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science china Earth sciences 2006年第7期49卷 747-754页

作者： HAN Lijuan1,2.3. WANG Pengxin4, YANG Hua1,2.3. LIU Shaomin1,2.3.& WANG Jindi1,2.3.1. Research Center for remote sensing and GIS, School of Geography, {2. Normal University, {2. 100875, china 2. State key laboratory of remote sensing science, {2. 100875, china 3. {2. key laboratory for remote sensing of Environment and Digital Cities, {2. 100875, china 4. Department of Information Management, College of Information and Electronic Engineering, china Agricultural University, {2. 100083. china 1. Research Center for remote sensing and GIS School of Geography Beijing Normal University Beijing 100875 China 2. State key laboratory of {2. sensing science Beijing 100875 China 3. beijing key {2. for {3. sensing of Environment and Digital Cities Beijing 100875 China 4. Department of Information Management College of Information and Electronic Engineering China Agricultural University Beijing 100083 China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.

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Iterative implementation of the adaptive regularization yields optimality

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science china Mathematics 2005年第4期48卷 485-492页

作者： MA Qinghua & WANG Yanfei Department of Information sciences, College of Arts and science of {2. Union University, {2. 10003., china national key laboratory on remote sensing science, institute of remote sensing applications, chinese Academy of sciences, beijing 100101, china Department of Mathematics, University of Central Florida, P. O. Box 1613.4, Orlando, FL 3.2}16-13.4, USA 1. Department of Information sciences College of Arts and Science of Beijing Union University 100038 Beijing China 2. national key laboratory on remote sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China

The adaptive regularization method is first proposed by Ryzhikov et al. for the deconvolution in elimination of multiples. This method is stronger than the Tikhonov regularization in the sense that itis adaptive, i.e. it eliminates the small eigenvalues of theadjoint operator when it is nearly singular. We will show in this paper that the adaptive regularization can be implemented iterately. Some properties of the proposed non-stationary iterated adaptive regularization method are analyzed. The rate of convergence for inexact data is proved. Therefore the iterative implementation of the adaptive regularization can yield optimality.

关键词： ill-posed problems, non-stationary iterated adaptive regularization, optimality.

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Earth system multi-body restriction dynamics model research

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science china(Technological sciences) 2006年第z2期49卷 80-87页

作者： ZHANG Qingxian, BI Siwen& GONG Huili key laboratory of Three-Dimensional Information Acquisition and Application, Ministry of Education, Capital Normal University, {2. 10003.,{3. national key laboratory of remote sensing science, institute of remote sensing applications of chinese Academy of sciences,{13.,{3. Capital Normal Univ Minist Educ Key Lab Dimens Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China chinese Acad Sci Inst Remote Sensing Applicat Natl Key Lab Remote Sensing Sci Beijing 100101 Peoples R China

Research provides a theoretical basis for an Earth system multi-body mechanics model and its dynamics, including the Earth system multi-body restriction function and its power, Earth system multi-body restriction under decreasing generalized velocity and decreasing partial palstance, the Earth system multi-body decreasing generalized force, a moving mechanics function, and the Earth system multi-body restriction's wattful and wattless forces.

关键词： Earth system, multi-body restriction, dynamics model.

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Polynomial analysis of canopy spectra and biochemical component content inversion

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science china Earth sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1, LIU Qiang1, NIU Zheng1, WANG Jihua2. HUANG Wenjiang2.& LIU Liangyun 2.1. State {3. laboratory of {2. sensing science, Jointly Sponsored by the institute of remote sensing applications of chinese Academy of sciences and beijing Normal University, beijing 100101,{13. 2. national Engineering Research Center for Information Technology in Agriculture, beijing 100089,{13. State key laboratory of {2. {3. science Jointly Sponsored by the institute of remote sensing applications of chinese Academy of sciences and beijing Normal University beijing china national Engineering Research Center for Information Technology in Agriculture beijing{2.

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

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Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data

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science china(Technological sciences) 2008年第S2期51卷 176-187页

作者： BAO YunFei1,2.CAO ChunXiang1,ZHANG Hao1,CHEN ErXue3.HE QiSheng1,2.HUANG HuaBing1,LI ZengYuan3.LI XiaoWen1,4 & GONG Peng1 1 State key {3. of {2. sensing science,jointly sponsored by the institute for {2. sensing applications of chinese Academy of sciences and {13. Normal University,{13. 100101,china 2.Graduate University of the chinese Academy of sciences,{13. 100049,china 3.institute of Forest Resource Information Technique,the chinese Academy of Forestry,{13. 100091,china 4 Research Center for {2. sensing and GIS,Department of Geography and {13. key {3. for {2. sensing of Environment and Digital Sites,{13. Normal University,{13. 100875,china State key laboratory of {2. {3. science jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China Graduate University of the chinese Academy of sciences Beijing 100049 China institute of Forest Resource Information Technique the Chinese Academy of Forestry Beijing 100091 China Research Center for remote sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites Beijing Normal University Beijing 100875 China

We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change *** method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested *** does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested *** ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of *** method was tested in a test area of 10000 square meters.A LiteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 *** this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602.and TOPCON GTS -7002.for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±2..9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction *** of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential *** gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical *** R2.for the regression of fractional vegetation cover from these ALS data and the respective field measurements is *** this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data.

关键词： LIDAR intensity skewness synchronous DTM fractional vegetation cover

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Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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science china Earth sciences 2009年第1期52卷 108-117页

作者： GUO JianXia1,2.BIAN LinGen3.& DAI YongJiu2.1 Meteorological Observation Center of china Meteorological Administration,{3. 100081,{2. 2.State key laboratory of remote sensing science,School of Geography and remote sensing science,{3. Normal University,{3. 100875,{2. 3.chinese Academy of Meteorological sciences,{3. 100081,{2. Meteorological Observation Center of china Meteorological Administration Beijing 100081 China State key laboratory of {2. {3. science School of Geography and Remote Sensing Science Beijing Normal University Beijing 100875 China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

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A study on correlativity between Qinghai-Tibet Plateau thermal infrared remote sensing data and underground temperature

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science china(Technological sciences) 2006年第z2期49卷 114-120页

作者： HAN Liqun, BI Siwen & SONG Shixin School of Information Engineering, beijing Technology and Business University, beijing 10003.,{2. {3. laboratory of remote sensing Information sciences, institute of remote sensing applications, chinese Academy of sciences, beijing 100101,{2. beijing Technol & Business Univ Sch Informat Engn Beijing 100037 Peoples R China chinese Acad Sci Inst Remote Sensing Applicat Key Lab Remote Sensing Informat Sci Beijing 100101 Peoples R China

Based on an analysis of the correlativity between Qinghai-Tibet Plateau thermal infrared remote sensing data (QPTIRSD) and underground temperature field distribution, the main factors which obviously influence underground-layer temperatures were derived. Using neural network technology, a model was built to compute underground temperatures via parameters out of the inversion of thermal infrared remote sensing (TIRS) and then analyze the correlativity between above-ground parameters and underground temperatures. This method offers a new way to apply TIRS in monitoring the suture zone of a large-area massif as well as to research structural thermal anomalies.

关键词： Qinghai-Tibet Plateau, TIRS, artificial neural network, temperature.

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