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Multiple Endmember Hyperspectral Sparse unmixing Based on Improved OMP Algorithm

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Journal of Harbin Institute of Technology(New Series) 2015年第5期22卷 97-104页

作者： Chunhui Zhao Haifeng Zhu Shiling Cui Bin Qi College of Information and Communication Engineering Harbin Engineering University

In conventional linear spectral mixture analysis model,a class is represented by a single ***,the intra-class spectral variability is usually very large,which makes it difficult to represent a class,and in this case,it leads to incorrect unmixing results. Some proposed algorithms play a positive role in overcoming the endmember variability,but there are shortcomings on computation intensive,unsatisfactory unmixing results and so on. Recently,sparse regression has been applied to unmixing,assuming each mixed pixel can be expressed as a linear combination of only a few spectra in a spectral library. It is essentially the same as multiple endmember spectral unmixing. OMP( orthogonal matching pursuit),a sparse reconstruction algorithm,has advantages of simple structure and high efficiency. However,it does not take into account the constraints of abundance non-negativity and abundance sum-to-one( ANC and ASC),leading to undesirable unmixing results. In order to solve these issues,this paper presents an improved OMP algorithm( fully constraint OMP,FOMP) for multiple endmember hyperspectral sparse unmixing. The proposed algorithm overcomes the shortcomings of OMP,and on the other hand,it solves the problem of endmember *** ANC and ASC constraints are firstly added into the OMP algorithm,and then the endmember set is refined by the relative increase in root-mean-square-error( RMSE) to avoid over-fitting,finally pixels are unmixed by their optimal endmember set. The simulated and real hyperspectral data experiments show that FOPM unmixing results are ideally comparable and abundance RMSE reduces much lower than OMP and simple spectral mixture analysis( s SMA),and has a strong anti-noise performance. It proves that multiple endmember spectral mixture analysis is more reasonable.

关键词： hyperspectral image sparse representation multiple endmember spectral unmixing OMP ANC and ASC

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Open Journal of Applied Sciences 2013年第1期3卷 41-46页

作者： Xiawei Chen Jing Yu Weidong Sun Department of Electronic Engineering Tsinghua University Beijing China

To solve the problem of the spatial correlation for adjacent areas in traditional spectral unmixing methods, we propose an area-correlated spectral unmixing method based on Bayesian nonnegative matrix factorization. In the proposed me-thod, the spatial correlation property between two adjacent areas is expressed by a priori probability density function, and the endmembers extracted from one of the adjacent areas are used to estimate the priori probability density func-tions of the endmembers in the current area, which works as a type of constraint in the iterative spectral unmixing process. Experimental results demonstrate the effectivity and efficiency of the proposed method both for synthetic and real hyperspectral images, and it can provide a useful tool for spatial correlation and comparation analysis between ad-jacent or similar areas.

关键词： Hyperspectral Image Spectral unmixing Area-Correlation Bayesian Nonnegative Matrix Factorization

Reconstruction of Ore-controlling Structures Resulting from Magmatic Intrusion into the Tongling Ore Cluster Area during the Yanshanian Epoch

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Acta Geologica Sinica(English Edition) 2007年第2期81卷 287-296页

作者： DENG Jun WANG Qingfei YANG Liqiang GAO Bangfei HUANG Dinghua LIU Yah XU Hao JIANG Shaoqing State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of the Ministry of Education China University of Geosciences Beijing 100083 Faculty of Earth Sciences China University ofGeosciences Wuhan Hubei 430074

The Tongling ore cluster area experienced intensive compression and associated shearing during the Indosinian-Yanshanian Epoch, which formed a trunk ore-controlling fold and fault system in the caprock. The magmatic intrusion in the Yanshanian Epoch induced a multi-stage unmixing of poly-phase fluids, resulting in mineralization characterized by multi-layer, wide-range, and multiform styles. The magmatic intrusion in the Tongling area not only supplied the essential ore-forming materials, but also reconstructed the ore-controlling structures according to a trend surface simulation of the following five strata boundaries： Silurian-Devonian, Devonian-Carboniferous, Carboniferous- Permian, Middle Permian-Upper Permian and Permian -Triassic. The result of this simulation shows that there exists a significant difference between the strata in the upper part and those in the lower. The lower trend surfaces are antiform whereas the upper trend surfaces are synform. In addition, superposing of the trend surfaces of adjacent bed boundaries （such as, Silurian-Devonian boundary superposed upon Devonian-Carboniferous boundary） shows that the lower trend surface always pierces the one above. Moreover, the position and orientation of the pierced parts of the different superposed trend surfaces are similar and show E-W-trending zonal distribution in accordance with the distribution of the regional E-W-trending magmatic-metallogenic belt. Based on comprehensive analysis of the mechanical properties of the strata, structural deformation mechanisms, and field phenomena, it seems that the special characteristics of the stratal trend surface resulted from jacking due to magmatic intrusion into the caprock previously controlled by an E-W-trending basement fault. Therefore, it is deduced that the major ore-controlling structures, which formed during regional horizontal compression, were reconstructed by the vertical jacking function of ore-forming magmas during the Yanshanian Epoch. Durin

关键词： magma trend surface multi-layer mineralization unmixing Tongling ore cluster area Yanshanian

Geochemical Characteristics of the Ore-forming Fluids of the Haigou Gold Deposit, Jilin

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Acta Geologica Sinica(English Edition) 1994年第3期68卷 283-297页

作者： Li Yinqing Institute of Mineral Deposits, C AGS, Beijing Chinese Academy of Geological Sciences Beijing

The quartz in the Haigou gold deposit contains a great abundance of three-phase CO2-NaCl-H2O and two-phase CO2-rich inclusions, which are associated with two-phase NaCl-H2O ones. The ore-forming fluids, which were rich in CO2, are classified into two types with two different sources: the high-salinity CO2-rich NaCl-H2O fluid derived from magmatic hydrothermal solution, and the low-salinity NaCl-H2O fluid from ancient meteoric water. The optimum conditions for gold mineralization are 220-300℃ for the temperature, 4-20 MPa for the fluid static pressure, 1-3 km for the mineralization depth, 2-7 w (NaCl)/10-2 for the fluid salinity, and 0.644 g/cm3 for the total density. The fluid was in a critical or supercritical state at the initial stage of mineralization, and it boiled and was unmixed with CO2 and NaCl-H2O in the climax of mineralization, leading to the decomposition of Au-chlorine complexes and the bulk precipitation of *** type, association, homogenization temperature and composition (CO2/H2O value etc.) are the microscopic criteria for distinguishing the auriferous quartz vein from the barren quartz

关键词： monzonitic granite characteristics of fluid inclusion boiling unmixing

Analysis of Seasonal Characteristics of Thermal Environment Based on Urban Sub-Pixel Land Use Types

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Journal of Computer and Communications 2018年第11期6卷 77-90页

作者： Jingyuan Cheng Youshui Zhang Institute of Geography Fujian Normal University Fuzhou China School of Geographical Science Fujian Normal University Fuzhou China

Seasonal variations will cause the differences in the distribution of urban thermal environment. Therefore, it is essential for analyzing the distribution of land surface temperature (LST) in different seasons under the same land use type. In this paper, fully constrained least squares method of linear spectral mixture analysis was used to extract the information of land cover fraction. According to the differences in the degree of the urban development, the study area is divided into three regions, for estimating the differences in the distribution of urban thermal environment. Ternary triangular charts were drawn to analyze the impact of each land use type on seasonal UHI. Contribution index (CI) of each land cover was calculated to analysis of the impact of each land use type on LST. The results of this study indicate that the extreme differences in temperature extremes occur in summer, followed by spring, autumn, and winter. In the spring, high LST areas appear in industrial, bare land;high LST areas in summer occur in the CBD, light industrial, and cover crops;the high LST areas in autumn appear in the CBD, high-density residential;in winter, the distribution of low-density and medium-density residential areas, crops and lawns will inhibit the urban heat island effect. The analytical methodologies that be used in this study can help to quantify urban thermal environmental functions effect of different land use type and explore the climate adaptation potential of cities.

关键词： Land Surface Temperature Linear Spectral unmixing Loop Zoning Ternary Triangular Charts Fuzhou Province

Estimate of Heavy Metals in Soil with Non-Soil Removed

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Journal of Data Analysis and Information Processing 2017年第4期5卷 140-155页

作者： Ji Jian Yao Fang Wei-Le Li Qian-Yu Chen Heng-Yu Tian Shuang-Lin You Key Laboratory of Geoscience Spatial Information Technology Ministry of Land and Resources of the P.R. China Chengdu University of Technology Chengdu China

Quantifying and mapping heavy metals’ concentrations in the soil are important in monitoring and managing heavy metal pollution in the mining areas. However, the cover on the soil acts as a balk when retrieving information from soil. In order to retrieve heavy metal pollution precisely and quickly from hyperspectral images, this study presents a new method to remove non-soil information based NDVI from hyper-spectral and multi-spectral images. The method assumed that the mixed objects in each pixel of remote sensing images are composed only of soil and vegetation-based non-soil end-generational endmembers, then, the soil information of each pixel can be compensated with the non-soil information removed based on its NDVI. Thus, the soil DN value can be corrected to retrieve soil information more precisely. The method has been used on the Hyperion image in June 8, 2002 and the Gaofen-2 (GF-2) image in February 14, 2016 to retrieve the heavy metals’ contents in Bai-ma and De-sheng mining areas, Miyi County, Sichuan Province. From the non-soil information removed images, the R2 and RMSE of the models of estimating Cr, Ag, Cu and Ba in soil are 0.68, 0.724, 0.71, 0.695 and 75.96, 0.03, 52.88, 284.70 respectively. From the original images, the R2 and RMSE of the models of estimating Cr, Ag, Cu and Ba in soil are 0.67, 0.385, 0.425, 0.406 and 80.11, 0.18, 53.43, 396.49 respectively. The retrieval results show that the non-soil information removed images are superior to original images in soil heavy metals’ contents retrieval. This indicates that this method is feasible, and it can be used in soil information retrieval.

关键词： Non-Soil Information Removal Heavy Metal NDVI Spectral unmixing