最新刊期
卷 ， 期 6 ， 2001
- 摘要：A simple but accurate model of the upwelling solar radiance is of great significance for the atmospheric correction in the case of satellite remote sensing of surface parameters. In this paper, a parameterized atmospheric correction model is developed for satellite remote sensing applicatioin, which includes two new parameterization models of the path radiance and Lambertian surface atmospheric coupled radiation. By using least square technology, the parameterized path radiance is expressed in terms of atmospheric optical depth, single scattering albedo, solar zenith angle, viewing zenith angle, azimuth angle, atmospheric asymmetry factor. Furthermore, the model is used in retrieving surface reflectance from simulated satellite data. As shown in numerical simulations, for four MODIS channels of 865 nm, 670 nm, 550 nm and 412 nm, the solar zenith angle from 0° to 70°, the viewing zenith angle of 0° to 66°, and the surface reflectance of 0.05 to 0.8, standard errors of the parameterized upwelling radiance and the reflectance solutions are less than 4% and 0.03, respectively.关键词：radiance;parameterization;surface reflectance
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发布时间：2021-06-10 - 摘要：The correct recognition of radiant directionality of non isothermal mixed pixel is a precondition to its retrieval of component temperatrues. Based on the local thermal equilibrium and component effective emissivity concept the radiant model of continuous vegetation has been studied. The model shows that the radiant directionality of isothermal mixed pixel is fully dependent on that of whole effective emissivity of pixel, which is a function of component emissivities and the crown construct. For nonisothermal mixed pixel, the component temperatures play important role in adjustment of radiant directionality. The paper studies the relationship between the radiant directionality with leaf facet emissivity, soil surface emissivity, leaves area index （ LAI ） and leaves angle distribution （ LAD ） by Monte Carlo simulated results, it further analyses the whole effective emissivity and radiance increments caused by cave effects. Take the spherical type of LAD as an example, and set the values of leaf facet emissivity and soil surface emissivity to 0.98 and 0.94 respectively, the increment of whole effective emissivity ranges from 0.01 to 0.025 when value of LAI is set to more than 1.0 in nadir direction. When the vegetation and soil system is isothermal with 293K temperature, the radiant brightness temperature increment is more than 0.8K, the maximum is 1.3K caused by cave effects.关键词：Component effective emissivity;thermal radiant directionality;cave effects;Monte Carlo simulation.
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发布时间：2021-06-10 - 摘要：Vegetation fraction, the radio of vegetation occupying unit area, is a very important parameter in developing climate and ecology model. However, to measure the vegetation fraction by fieldwork a job of wasting manpower and financial resources with lowprecision work, which requires estimation of vegetation fraction from remote sensing data. This study explores the potential of deriving vegetation fraction from normalized difference vegetation index （\%NDVI）\% using the TM data. Under the assumption that the pixel of TM image is a mosaic structure, subpixel models for vegetation fraction estimation are introduced firstly in this paper. Then the idea of using different subpixel model for vegetation fraction estimation based on land cover classification is proposed. The "dense vegetation model" is used to calculate the vegetation fraction in woodland, orchard and city zone, and the "nondense vegetation model" is used to calculate the vegetation fraction in cropland and meadow area.\;As a result of case study in Haidian district, Beijing, the accuracy rate of vegetation fraction estimation by using "dense vegetation model" and "nondense vegetation model" synchronously based on land cove classification is obtained about 75.4%, which is 5.8% higher than that of using "dense vegetation model" only. The accuracy rate of vegetation fraction estimation by using this model is high.\;Despite the difference between observed and estimated values for some conditions, the Subpixel model seems to be a good approach for estimating vegetation fraction at a regional scale. This approach may be an important tool for solving the problems in the monitoring of regional vegetation fraction over large area.关键词：vegetation fraction;land cover;subpixel model;\%NDVI;LAI\%
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发布时间：2021-06-10 - 摘要：Texture extraction from SAR image is an important frontier field because SAR image has characteristics of high spatial resolution and abundant texture information. Wavelet transformation can provide an effective tool for multi scale texture analysis of SAR image. This paper describes a method to extract multi scale textural information from satellite SAR image using wavelet transformation. Firstly the SAR image is decomposed using Daubechies3 orthogonal wavelet and l 1 norms of every band image are computed as feature value of image pixels. According to the feature value on every channel, texture images which respectively denote texture on different scale of SAR image are produced. The method has been applied for the extraction the textural informtion from a Radarsat image of Xuzhou city. The experiment shows that the facial target textural information can be effectively extracted using the mehtod.关键词：SAR image;wavelet transformation;Texture;feature extraction
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发布时间：2021-06-10 - 摘要：Due to the fact that SAR generates images by coherently processing the scattered signals, the images are highly susceptible to speckle effects, and the intensity of speckle noise obeys a negative exponential distribution and is a multiplicative noise. This phenomenon seems special more obvious on the ocean SAR images than the others. According to the feature of the speckle of ocean SAR image, a new mother wavelet function was constructed. It possesses narrow band in the lowpass and symmetry distribution of impulsion response coefficient in time region, enabling it has an excellent performance in dealing with wave signal aspect. For an original ocean SAR image with size of 1024 by 1024, the Wiener filter algorithm was adopted and the new wavelet filter was applied in order to firstly suppress speckle and then to extract the edge information with Prewitt filter algorithm. Compared several classic mother wavelet functions with the new wavelet function using the same processing method and uniform image, the result shows that the new mother wavelet function is much better than other compared mother wavelet functions in preserving the image’s edge information, though its performance is not good enough in suppressing speckle. Based on the above discussion, it is obvious that the wavelet filter is a very effective method in speckle filtering and the new constructed mother wavelet function plays an important role in extracting SAR image edge feature.关键词：Wavelet;SAR image;filtering speckle;extracting edge feature
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发布时间：2021-06-10 - 摘要：This paper presents design principle and realizable approach of Classification and Recognition Inference Decider for Soil Remote Sensing （CRID） in arid land. On the basis of nonsupervising classification for soils with TM images, the author discusses the reasoning mechanism by combining the direct inference combined with inverse reasoning for soil classification and recognition decision. The author also expresses soil classification and recognition knowledge of expert in soil science using data structure of producing rule linked with frame rule for knowledge expression in the CRID. Furthermore, the author make up the rules of soil classification and recognition with image structural model, and builds decision tree of soil classification in the CRID, and organizes files of decision for soil classifications with typical image case model. With these methods, the author carries out a test research on classification and distinguishing for soil in test region of Fukang Counry, situated on the northern foot of the Tianshan Mountains, Xinjiang Province. And the test result shows that the approach mentioned above has a high reliable precision, and it reclaims a new way for classification and recognition of soil in arid land.关键词：soil remote sensing;classification and recognition;inference decision
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发布时间：2021-06-10 - 摘要：The objective of this study was to monitor phenological stages of winter wheat in HHH plain of China. Three key phenological stages were defined based on NOAA/AVHRR NDVI time series data collected in the HHH plain of China from 1990 through 2000. In a winter wheatsummer maize rotation system, the recovering, heading and maturity stages of winter wheat were recorded using 6 km resolution decadal NDVI. Recovering of winter wheat was identified by two consecutive NDVI increments after a period of stagnating values. Similarly, maturity of winter wheat was identified by the last two consecutive NDVI decrements. The heading stage was identified by maximum NDVI value. The satellitederived data proved to be consistent with the ’green wave’ moving through the HHH Plain in spring. Through analysis of historical climate data, the recovering stage of winter wheat recorded by satellite was closely correlated to the temperatures measured in February, significant correlation between phenological stages and rainfall could not be detected. Comparison with synchronous phenological observations on the ground confirmed the coherence of satellitederived phenology data. The interannual variability of recovering stage is higher than that of heading and maturity stages. Application of irrigation and the relatively short tenyear period for which data were available explain why interannual fluctuation of crop phenology was relatively small. The 6 km spatial resolution decadal NDVI limited the prediction accuracy. It is expected that satellite data with greater spatial and temporal resolutions and the improved smoothing methods will further increase the precision of the estimated data.关键词：winter wheat;phenological stage;NOAA NDVI
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发布时间：2021-06-10 - 摘要：It is one of the most important and effective approaches in the researches on sustainable development to integrate social sciences with natural sciences and technology. In this paper, regional sustainable development indicators and spatial information technology applications in regional sustainable development management were discussed, and a Sustainable Development Evaluation Information System （SDEIS） was designed based on Geographical Information System （GIS）. The SDEIS, with the integration of techniques such as objectoriented and component software, distributed database, Web GIS, etc., is composed of sustainable development evaluation models and knowledge and Internetbased information sharing and service system. The system was developed by mainly using VB and VBA programming languages, in which sustainable development basic database was established based on Microsoft Access, indicators were calculated based on Excel and by using OLE Automation technique, regional resources and environmental situation were introduced through Web GIS, and Microsoft ASP （Active Server Pages） was used to produce homepages. With the capacity of managing large amount of data in attribute database, graphical database and image database and processing data by using models, the SDEIS system can be used to carry out regional sustainable development evaluation and implement information sharing.\;A pilot study was initiated in Panzhihua City, Sichuan Province, China. The Panzhihua Sustainable Development Indicator System （PSDIS） and the Panzhihua SDEIS （PSDEIS） were established. The PSDIS includes core indicators （social and economic indicators, resources indicators and environmental indicators） and reference indicators, which were used to identify the sustainable development status in the region. The PSDEIS, characterized by open, Internetbased, and integrating the basic database development, indicators calculation and visualization, automatic report and spatial query, is a very useful and convenient tool for regional sustainable development evaluating, planning and decision making and public participating.
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发布时间：2021-06-10 - 摘要：Under the theory of adjustment structure, the deduction about south north trending transverse confirmed commonly occurring in the east west trending paleo asiatic tectonic system has been certificated through integrated analysis of remote sensing and aeromagnetic data in the paper. More than 10 transverse structures have been found in the middle west segment of Yinshan mountains. Few of them are known in the existing geological maps, and few of them had been considered in some regional geological theories. Analysis to the typical new discovered transverse structures demonstrates that the transverse structure controlling the granitic magma activities is "diagnosis" ore controlling structure. In the case of strike structure controlled distribution of mineralized belt, the transverse structure controlling the granitic magma activities determines the location of ore deposit, which has very obvious significance for exploration of mineral deposits.关键词：Transverse structure;remote sensing;aeromagneitc anomaly;integration analysis;ore controlling structure
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发布时间：2021-06-10 - 摘要：This paper introduces the remote sensing mechanism and methods of water pollution and application on water pollution monitoring in Guangzhou Section of Pearl River. The research indicates that water reflectance in VI NIR bands becomes decreasing as the increase of water pollution. Through comparison, it can be found that classification and segmentation image of remote sensing may distinguish and recognize water pollution more effectively after logarithm, IHS and KL transformation. Time spatial distribution images of water pollution are made through the above techniques, and the time spatial distribution characteristics and changing trends are summarized through combination to ground analytical and investigation data of water quality. A regional early warning system of water pollution of whole drainage area is built up by use of GIS technology, processing of latest remote sensing data and the research of pollution sources. This research provides new information for the large scaled monitoring of water pollution and water resources protection.关键词：remote sensing;water pollution monitoring;pollution source evaluation;GIS;time spatial distribution
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发布时间：2021-06-10 - 摘要：The paper based on the data as following: ① the TM, NOAA, FY 1 image data; ② the dust storm data dated from 1951\1980; ③ meteorological statistic data dated from 1951\1994; ④ soil property; ⑤ land use data. Using the RS/GIS method, all the data are processed to describe the spatial distribution of sand dust storm. The dynamic process of the sand dust storm is analyzed, and the results show that the air circulation of northern China causes the special wind field accompanied with which the sand supplying areas and sand descending areas are identified out. Up to date meteorological satellite data are used to analyze the trajectories of the sand dust storms that have influenced the north China during the spring of 2000, including its out bursting places and moving direction. Also the spatial distribution of sand dust storm from 1951 to 1980 has been analyzed.\ \ The regions that have varied annual total days of sand dust storm are identified out. The results show that from northwest to southeast, the frequency of sand dust storm is decreasing with the most serious area lying to the northwest and west of North China.\;The analysis work of the spatial distribution of main factors that influence the sand supplying of the surface soil are carried out as well as their relation to the frequency distribution of sand dust storm. These factors include the vegetation coverage, soil surface water content, soil property, geomorphologic factor and the land use. Each factor shows high relationship with the frequency distribution of sand dust storm.\;Then the results of remote sensing investigation of wind erosion are analyzed showing that the intensity of wind erosion is decreasing from northwest to southeast with the middle part of Inner Mongolia as the most seriously eroded area. At last, the sand supplying information of the land to the dust storm is revised. The area where the wind intensity strengthens, its frequency of annual dust storm also increases, vice versa. It seems that all these areas are possibly supplying the sand when the sand dust storm happens. There are mainly three routes for the sand dust storm, however the dust storm that has different routes also has varied sand supplying places as pointed out in the paper.
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发布时间：2021-06-10 -
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