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Automatic extraction of forest fire line using MODIS data bymulti-spectral image gradient technique
基于MODIS影像的森林火灾火线检测方法

GUO Tai-sheng,FU Ying-chun,YUAN Xiu-xiao,SONG Yan,CHEN Mi,
郭泰圣
,付迎春,袁修孝,宋妍,陈蜜

遥感学报 , 2009,
Abstract: From repeat pass SIR-C L band polarimetric SAR interferometric data and fully maximum likelihood inversion decomposition model of PolInSAR, a method for sub-canopy soil moisture estimation using repeat pass SIR-C PolInSAR data is proposed. At the same time, the potential and validity of fully maximum likelihood inversion decomposition model of PolInSAR for sub-canopy soil moisture inversion is investigated. Firstly, from the random oriented volume over ground two layer coherent scattering model and the statistical characteristics of Pol-InSAR coherency matrix, the fully maximum likelihood inversion decomposition model is used to reconstruct or recover the surface polarimetric coherency matrix with volume scattering components significantly removed; then, from recovered surface polarimetric coherency matrix, co-HH, VV and cross-HV polarization backscattering coefficient are obtained, and the sub-canopy soil moisture are inverted from Oh and Dihedral scattering model. At last, Compared the inversion result with the field measurement and the climate data of hetan region from 1951 to 2006, the preliminary result indicates that the proposed method based on fully maximum likelihood inversion decomposition model has enough high inversion accuracy, if the new spaceborne or airborne polarimetric SAR interferometric data with synchronously spaceborne or airborne-ground measurement will be acquired, the validity and accuracy of proposed inversion method will be further investigated and validated.
A New Image Registration Method for Repeat-Pass InSAR Based on Fourier-Mellin Transformation and Correlation-Coefficient Algorithm
基于Fourier-Mellin变换和相干系数法的重复轨道干涉SAR图像配准新方法

Shi Xiao-jin,Zhang Yun-hua,
石晓进
,张云华

电子与信息学报 , 2009,
Abstract: Compared with one pass InSAR system with two antennae, the registration of image pair of repeat-pass InSAR system is much more difficult due to parallel tracks are usually not guaranteed. In this paper, a new image co-registration algorithm for repeat-pass InSAR, which combines the Fourier-Mellin transform and correlation-coefficient algorithm, is proposed to perform accurate co-registration for complex image pair having rotation angle due to unparallel tracks. When the method is used as coarse co-registration step, a nonlinear amplitude transformation is introduced as pre-processing to overcome the failure of Fourier-Mellin transformation method in case of image pair with large dynamic amplitude range and non-uniform amplitude distribution, and when used as fine co-registration step, correlation-coefficient algorithm is incorporated to accurately estimate the small rotation angle between image pair. SIR-C/X X-band experimental data are used to test the proposed algorithm through comparing with traditional correlation-coefficient algorithm in both accuracy and run time. The experimental results prove the effectiveness of the proposed algorithm.
Experimental study on repeat-pass alrborne sar interferometry
重复飞行机载干涉SAR的实验研究

Wang Lei,Peng Hailiang,
王磊
,彭海良

电子与信息学报 , 2002,
Abstract: This paper describes the experimental study on repeat-pass airborne SAR interfcr-ometry. The key technologies include airline control of aircraft, baseline determination, motion compensation and signal processing. In this paper a motion compensation method based on INS/GPS data has been proposed and implemented. An interpolation approach in range and azimuth dimensions is used to eliminate the effect of non-parallel baseline on correlation. Some resultant interferograms demonstrate the validity of the interferometric L-SAR.
Research on the Single-Baseline PolInSAR Inversion Algorithms
单基线PolInSAR反演算法研究

Chen Bing,Xu Shao-jian,Zhang Ping,
陈 兵
,徐绍剑,张 平

电子与信息学报 , 2008,
Abstract: Polarimetric Interferometric SAR (PolInSAR) is a new advanced technique recently based on measurement techniques of polarimetric SAR and interferometric SAR, and making use of PolInSAR data for retrieving the vertical structure parameters of the vegetation layer becomes the hot research topic of the PolInSAR at present. The most useful Single-baseline PolInSAR inversion algorithm is the three-stage inversion algorithm, which was proposed by Cloude and Papathanassiou, but this algorithm has the errors on the its three aspects: coherence estimation, line fitting and volume coherence estimation, and this errors straightly effect the inversion precision. This paper proposes a new inversion algorithm based on the statistic characteristic and PolInSAR phase optimization algorithm, and takes the PolInSAR simulated data to prove the validity of this algorithm.
Spectral Filtering for Repeat-pass SAR Interferometry
重复轨道InSAR处理中的频域滤波研究

WU Tao,WU Tao,WU Tao,WU Tao,
吴涛
,王超,张红,汤益先

中国图象图形学报 , 2005,
Abstract: In repeat-pass synthetic aperture radar interferometry,the decorrelation caused by azimuth and range spectral shifts leads to a deterioration of the quality of SAR interferogram.There is a need to put proper spectral filters on the main and slave images.The paper discusses a new spectral filtering procedure that performs filtering before and after fine coregistration according to spectral characteristics.The procedure will reduce spectral misalignment,improve the accuracy of fine coregistration,and at last obtain high quality of interfeorgram.Four pairs of ERS-1/2 SLC data with different time interval and nominal baseline are used to analyze the validity of our method.Results show that the average values of coherence after spectral filtering flow are higher than that before spectral filtering flow,moreover the amount of residues is highly decreased.These give evidence to the goodness of the procedure.
Forest Mapping and Classification with Compact PolInSAR Data
Forest Mapping and Classification with Compact PolInSAR Data
 [PDF]

Ningxiao Sun,Yuejin Zhao,Lin Sun,Qiongzhi Wu
- , 2018, DOI: 10.15918/j.jbit1004-0579.17084
Abstract: An unsupervised classification method was applied to compact polarimetric-interferometric SAR(C-PolInSAR) data to investigate its potential for forest mapping and classification. Unsupervised classification requires an initial class as a training set. In this paper, the compact polarimetric entropy H and the optimal coherence spectrum A were computed, and their capabilities for initial classification were analyzed. Based on the H and A, a partition method was proposed to subdivide the H-A plane, and initial classes were hence obtained. Next, unsupervised C-PolInSAR segmentation procedures based on H-A and the complex coherence matrix J4 were investigated. The effectiveness of the unsupervised classification of C-PolInSAR data was demonstrated by using an E-SAR L-band PolInSAR dataset of the Traunstein test site.
An unsupervised classification method was applied to compact polarimetric-interferometric SAR(C-PolInSAR) data to investigate its potential for forest mapping and classification. Unsupervised classification requires an initial class as a training set. In this paper, the compact polarimetric entropy H and the optimal coherence spectrum A were computed, and their capabilities for initial classification were analyzed. Based on the H and A, a partition method was proposed to subdivide the H-A plane, and initial classes were hence obtained. Next, unsupervised C-PolInSAR segmentation procedures based on H-A and the complex coherence matrix J4 were investigated. The effectiveness of the unsupervised classification of C-PolInSAR data was demonstrated by using an E-SAR L-band PolInSAR dataset of the Traunstein test site.
An Improved Topography-Dependent Motion Compensation Approach for Airborne Repeat-Pass Interferometric SAR Systems
一种改进的基于DEM的机载重轨干涉SAR运动补偿算法

Tang Xiao-qing,Xiang Mao-sheng,Wu Yi-rong,
唐晓青
,向茂生,吴一戎

电子与信息学报 , 2009,
Abstract: In this paper, the precise topography-dependent motion compensation for repeat-pass InSAR is studied. The effects of the residual motion errors caused by the flat surface assumption and center-beam approximation are analyzed, which shows the necessity of performing a precise topography-dependent motion compensation for the repeat-pass InSAR systems. The precision requirement for the external DEM data is analyzed to show the feasibility of deriving precise DEM data by motion compensation based on rough DEM data. An improved approach is presented according to the deficiencies of the existing topography-dependent motion compensation approaches. It can adjust the parameters according to the conditions of trajectory deviations and topography variations, so it has the advantage of performing the precise motion compensation efficiently. Finally, the processing results of the X-band airborne repeat-pass interferometric SAR data confirm its validity and superiority in precision and efficiency compared to the original algorithms.
Canopy Structural Changes Following Widespread Mortality of Canopy Dominant Trees  [PDF]
Brady S. Hardiman,Gil Bohrer,Christopher M. Gough,Peter S. Curtis
Forests , 2013, DOI: 10.3390/f4030537
Abstract: Canopy structure affects forest function by determining light availability and distribution. Many forests throughout the upper Great Lakes region are dominated by mature, even-aged, early successional aspen and birch, which comprise 35%–40% of canopy leaf area, and which are senescing at accelerating rates. In 2008 at the University of Michigan Biological Station, we initiated the Forest Accelerated Succession ExperimenT (FASET) by stem girdling all aspen and birch in replicated stands to induce mortality. Our objective was to understand type and rate of canopy structural changes imposed by rapid but diffuse disturbance consisting of mortality of a single age-species cohort. We characterized changes in canopy structural features in 2008–2011 using ground-based Portable Canopy Lidar (PCL) in paired treated and control stands. As aspen and birch in treated plots died, gap fraction of the upper canopy increased, average leaf height decreased, total canopy height declined, and openness of the whole-canopy increased. All of these trends became more pronounced with time. Our findings suggest that as forests throughout the region pass through the impending successional transition prompted by widespread mortality of canopy-dominant early successional aspen and birch species, the canopy will undergo significant structural reorganization with consequences for forest carbon assimilation.
Study on the Impact of Polarimetric Error on Optimal Coherence Phase of PolInSAR
PolInSAR极化误差对最优相干相位的影响研究

Zhang Lin-tao,Hong Jun,Ming Feng,
张林涛
,洪峻,明峰

电子与信息学报 , 2011,
Abstract: The polarimetric error will cause optimal interferometric phase estimation error. In this paper the polarimetric error transferring in the Polarimetric Interferometric SAR (PolInSAR) measurement is studied and a new polarimetric error transfer model is proposed based on polarimetric interferometric coherence optimization. The model is proved through the experimental simulation and the impact to the precision of optimal interferometric phase estimation due to the polarimetric error is analyzed based on the model. The conclusions could provide theoretical support and reference for the precision analysis and calibration requirements in the application.
Forest height estimation methods using polarimetric SAR interferometry
极化干涉SAR森林高度反演方法研究

LUO Huanmin,CHEN Erxue,CHENG Jian,LI Xiaowen,
罗环敏
,陈尔学,程建,李小文

遥感学报 , 2010,
Abstract: Forest height extraction with polarimetric SAR interferometry (POLInSAR) is a hot research field of imaging SAR remote sensing. Several available forest height inversion methods using POLInSAR data were validated and compared with repeat pass E-SAR datasets and the corresponding ground measured forest stand height through the analysis of the Random Volume over Ground (RVoG) scattering model. After analyzing the experiment results in the view of physical mechanisms, we developed an integrated inversion method combining interferometric coherence optimization and compensation of non-volumetric scattering decorrelation. Validation result shows that the general performance of the developed forest height inversion method is superior to the others.
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