最新刊期
卷 ， 期 3 ， 1999
- 摘要：In the field of thermal infrared remote sensing, it is very difficult to calculate the surface reflected atmospheric downward radiance effect because the precise bi directional reflection distribution function can not be easily described. The simplicity is therefore, often used as a only way to deal with that problem under two assumptions: one is the Lambertian reflection of the surface, another is the isotropic downward thermal radiance of atmosphere. This paper puts forward a new method to calculate the effect under the general conditions which are non Lambertian surface and anisotropic atmospheric downward thermal radiance. Simulations show: （1） The method described in this paper can provide more precise calculation of this effect, and the accuracy improved at least 20.53%; （2） The relative error from this method is dependent on the atmospheric model, the scanning angle and channel. The relative errors in the channel 4 are higher than those in channel 5, and they decreases with the increase of scanning angle. The maximum relative error is less than 8%; （3） The amount of surface reflected atmospheric downward radiance effect is 4% less than the total value of radiance received by sensor at 30 degree of scanning angle.关键词：Thermal infrared remote sensing;The effect of atmospheric downward thermal radiance
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发布时间：2021-06-10 - 摘要：This paper introduces a fast automatic building extraction method by the fusion of spectral information and three dimensional information acquired by "Airborne Laser Image Mapping System", which integrates the image scanner, laser scanner, inertial navigating system and global positioning system. This method involves the breaking and merging algorithm of laser ranging points, the separation of buildings and trees, the selection of initial seeds, the self adjustment of the spectral reference and threshold in region growing, and the reconstruction of whole building contour with edges of high reliability. To overcome the distortions of airborne scanning image, we extensively used two dimension/three dimension transformations and the concept of curve template. To deal with the blurring and brokeness of edges and strong noise, we applied a statistical decision algorithm and a sampling template. This method is experimented on the data of City Huhehaote.关键词：Building extraction;Automatic extraction;Scanning image;Laser ranging;Inertial navigating system;Global positioning system;Digital elevation model;Shadow analysis
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发布时间：2021-06-10 - 摘要：A simple scheme to process solar diffuse radiation was added in a bidirectional reflectance distribution （BRDF） model of vegetation canopy. The canopy was regarded as turbid media in BRDF model. With ground remote sensing data of soybean canopy, in visible spectral band, the modified BRDF model was inverted. The inversion experiments were organized to include those considering initial values of model parameters, contribution of solar diffuse radiation, and the influences of solar zenith and azimuth during remote sensing data collection. These experiments can be benefit to the description of the physical processes in BRDF model, understanding of the model inversion and the selection of proper remote sensing data for the inversion. （1） For the BRDF model used in inversion experiments, the appropriate estimation of LAI initial value is helpful to obtain good model inversion. When LAI value scope is one times or a bit more larger than the actual data and coincides with LAI scope of random initial values, the results of inversion are good. （2） With the consideration of solar diffuse radiation in BRDF model, the inversion can give more physically reasonable explanations. （3） The ground remote sensing data, collected under small zenith （<45°） and less solar azimuth deviation （<45°） to 180°, support stable inversion of the BRDF model. These conditions hint the period for data collection from 10:00 a.m. to 2:00 p.m. （4） Within 31°—61° of solar zenith and 136°\258° of solar azimuth, the multi angle observations of canopy reflectance makes the influence on the results of LAI by BRDF model inversion insignificant. （5） The influence of solar diffuse radiation on the results of LAI by BRDF model inversion was not significant when diffuse part was not large in total solar radiation. If only focusing on LAI in BRDF model inversion, it is possible to use the ground remote sensing data without atmospheric corrections. Though these results were obtained when processing ground remote sensing data, it is still potential to be applied in the selection and processing of satellite remote sensing data. The above conclusions are useful to the inversion of vegetation BRDF model in trubid media assumption. At the same time, the data used in model inversion were observed from soybean canopy which was close to ideal condition. The consideration of complex canopy was not included in this study. The potential applications of these results with satellite remote sensing data still need verifications.关键词：vegetation;BRDF model;inversion
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发布时间：2021-06-10 - 摘要：Imaging Spectrometer is an important tool for quantitative analysis and discrimination of ground objects. The images of Imaging Spectrometer contain random noises to varying degrees of severity in all channels. To optimize the use of the images of an Imaging Spectrometer and to improve the effectiveness and accuracy of discriminating ground objects according to spectral absorption features, removal of random noises of images is necessary. Based on the analysis of previous methods of removing random noises of images, this paper develops a new method of removing random noises from Imaging Spectrometer images based on wavelet analysis （RRNW）. Experimental results show that the performance of this method is better than neighbor average and median filter in removing random noises and reserving richer fine textures and edge information.关键词：Imaging spectrometer;Removal of random noises;Wavelet analysis
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发布时间：2021-06-10 - 摘要：Today many methods have been used in classifying remote sensing images. However, developing classification algorithm which is capable of processing both images and other ancillary spatial data still remains to be an active research area. In this paper, the affinity index of David W. Goodall based on probability was explained, and its application possibility in remote sensing and other spatial data integrated classification was studied. Based on Goodall’s affinity index, a computer program for classifying both remote sensing and other spatial data was developed within GRASS environment. To see the result of this program, it was tested in a case study area and compared with other popular classification methods such as maximum likelihood classification and evidential classification. Through this study, we would like to know how the other spatial data can help improve the remote sensing image classification and whether the algorithm based on Goodall’s affinity index is good in classifying remote sensing images and other ancillary spatial data in an integrate way.关键词：remote sensing image;Spatial data;Multisource data classification;Affinity index.
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发布时间：2021-06-10 - 摘要：The precision of computer classification is the main obstacle to the wide application of computer remote sensing information processing system. We model the smoothing classification results process as a constraint optimization problem, and integrate it with the classification process through neural network method, then present a remote sensing image classification and postclassification integrated technique based on constraint satisfaction neural network. This paper analyses The judging process of careerman, and discusses the theoretic model of neural network classification method in detail. The experimental results show that this method can improve the precision of classification saliently.关键词：Classification;Postclassification;neural network
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发布时间：2021-06-10 - 摘要：A method is designed in this paper to identify the urban rural fringe by combining digitally processed remote sensing images and abrupt change test. Firstly, the urban and use information is extracted from the TM images, then it is to calculate the proportion of the urban land use in a given size window on the map of urban land use, and moving the window to smooth the proportion. Finally the moving t test of abrupt change is used to detect the abrupt changes for the proportion of the urban land use in the urban rural sections in all directions, and to identify the position of the inner boundary and outer boundary of the rural urban fringe between the city and county. Using the TM images of Beijing City in 1984 and 1996, a case study is made to identify the urban rural fringe with the method mentioned above. The result indicates that the method is practicable.关键词：Rural urban fringe;Proportion of the urban land use;Abrupt change test;TM
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发布时间：2021-06-10 - 摘要：The airborne radars can easily follow the observed phenomena and allow to scan meteorological systems in places where groundbased radars are not easy to operate and they are progressively used in meteorological studies. Due to the requirements of the applications. airborne radars use an Xband or Ku band frequency. However, the electromagnetic wave on the frequency is attenuated through rain, thus algorithms should be studied to correct for the attenuation effect. For the single beamsingle frequency rain radar, kZ and kZS algorithms demonstrate a promising interest for application. This paper applies kZ and kZS algorithms to the airborne data gathered in January and February 1993 during the TOGA/COARE experiments and studies the rain structure.关键词：Rain rate;Rain radar;Algorithm
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发布时间：2021-06-10 - 摘要：A method is described for retrieval of several column amounts of atmospheric trace gas from ground\|based mid\|resolution infrared solar spectrum. In the method, a line\|by\|line （LBL） algorithm is used to calculate column atmospheric absorption, the absorption in real atmosphere is obtained by measurement of differential absorption of IR solar spectrum, the column amounts of absorber have been derived by best\|likely method, the feasibility and accuracy are analyzed in the paper in detail. The results show that it has a relatively high accuracy. The method has been applied to monitor the seasonal variation of the column amounts of atmospheric methane and water vapor.关键词：IR solar spectrum;Trace gas;Retrieve
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发布时间：2021-06-10 - 摘要：A sustainable land development model is developed using GIS in an attempt to control urban sprawl under rapid rural urbanization in China. The recent land development in the Pearl River Delta is out of control, resulting in excessive encroachment on the best agricultural land in many rural areas as well as the urban fringe areas. Government interventions are needed to control such development because agricultural land use can not compete with urban land use. The objective of the model is to ensure that equity between generations and efficiency in land use can be achieved in land development so that development can be sustained in the future. The model is also used to study the impacts of agricultural land loss in Dongguan in 1988—1993 by comparing the actual development with optimal development derived from the sustainable land development model. Land use problems are identified in both spatial and time dimensions as some land conversions are found to occur at the ‘wrong’ time and locations. Future land development which can meet the objective of sustainable development is proposed using the model. By testing different development scenarios and land consumption parameters, planners and government officials can use the model as a decision support system for sustainable land development in China as well as other areas in the world which are under the pressure of rapid urban growth.关键词：Sustainable land development;remote sensing;GIS;Planning model;Pearl River Delta
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发布时间：2021-06-10 - 摘要：In this paper, We mainly present the method of exploring gold deposits covered by original soils from weathered rocks by means of analyzing and studying the laboratory spectrum’s relationship of both original soil and its weathering motherrock. In western Qinling Mountains, there are several large scale gold deposits in metallographic provinces. In the past, remote sensing technology was used to investigate this area, however, gold deposits exploration still have not been broken out. As bedrocks are covered by vegetation and soils, it is very difficult to efficiently apply remote sensing technology. During our study of remote sensing information characteristics on the earth, we found that most bedrocks are fortunately covered by original soils in gold metallographic provinces. Therefore, we hope that gold deposits covered by original soils can be directly determined by using the spectrum features of the soils overlain the bedrocks. The analyzed relevant samples were collected from several typical known gold mining areas, Pearson’s correlation analysis was adopted in order to study the linear correlation between soils and their corresponding rocks, at the same time, the obtained correlation coefficients were tested by means of Twotailed method. To single layer samples （original soil directly covers bedrock）, their correlation coefficients are in high positive relationship, the average number is about 0 942. To multilayer samples （more than one soil layer cover the bedrock）, the correlation coefficients are lower, however, there are still 0 763 in positive correlation. According to our results, we can conclude that there is a high positive relationship to the spectrum of both original soil and its weathering motherrock. It is possible for us to extract gold deposits information from covering original soil’s spectrum and provide a new method for gold deposits exploration.关键词：Gold deposits;Laboratory spectrum;Relationship
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发布时间：2021-06-10 - 摘要：On the basis of previous research results on potential agricultural productivity, the potential grain productivity of China is studied in this paper with the support of geographic information system （GIS） and national agricultural data\|base including spatial databases and attribute databases. At frist, the concept and development of potential grain productivity are expounded, and the method of GIS based study on the potential grain productivity is discussed. Then, after stressed research on such factors of potential grain productivity as soil effective coefficient, potential land productivity, social effective coefficient, and potential social productivity, the authors put forward some new computing models. Furthermore, using the mechanism methodology and computing models mentioned above, they calculated computed China’s national potential grain productivity by county unit. Finally, the predominance of exploiting potential grain productivity regions of China is determined through comparing the computing results with current grain productivity.关键词：GIS;Potential Grain Productivity;Soil Effective Coefficient;Social Effective Coefficient;Predominance of Exploiting Potential Grain Productivity
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发布时间：2021-06-10 - 摘要：The main challenge in GIS data sharing is semantics sharing of the data. Of the main basis for data sharing including technological development, data standardization and legal basis, the standardization is the most direct one. The design of one standard conceptual data model, which is a data sharing related fundamental task, is the most important strategy to make a precise semantics sharing. The authors’ perception of standard conceptual model design is intended to find a suitable, systematic set of rules to ensure the safety of data sharing. The model designed must provide abstract concepts that can be interfaced for data sharing and therefore the concepts must be geographic concepts instead of spatial concepts. The abstract mechanism must also be designed in the process of modeling. The GIS semantic data modeling approach has been used as a tool to design the needed conceptual model. As a basic geographic concept, geographic feature has been used as a semantic object.关键词：data sharing;Semantics sharing;Conceptual data model
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发布时间：2021-06-10 - 摘要：This paper explores the research status and future trends of geo\|referenced visualization, and aims to establish a research framework via the discussion of geo\|visualization, multi\|dimensional geo\|graphical interpretation and virtual geographical environment.\;In terms of geo\|visualization, three concepts including cartographic visualization, geographical visualization, and GIS\|visualization are scrutinized, and their relationship is established. Cartographic visualization emphasizes visual thinking, spatial cognition and analysis, and graphic information communication. GIS\|visualization focuses on data structure and model, realistic 3\|D graphics rendering, dynamic interaction, real\|time processing, etc. In this paper, cartographic visualization and geographical visualization are regarded as the same in nature.\;Multi\|dimensional geo\|graphical interpretation is proposed from non\|visualization, whose goal is to establish methodology and rules for graphics\|based unknowns\|seeking upon around a thousand past and present geo\|referenced maps/graphics/images. Only from one special case or a kind of map and supported by computer\|based visualization, geo\|visualization, especially cartographic visualization, facilitates users to explore data for revealing unknowns. But with the same goal of graphics\|based unknowns\|seeking, geo\|visualization and multi\|dimensional geo\|graphical interpretation should be integrated to further the study on visual thinking, spatial cognition, and graphics\|based data exploration, based upon both long human accumulated experiences and knowledge and the modern computer\|based visualization technology.\;Resulting from the integration of virtual reality technology, Internet and regional geographical systems, virtual geographical environment （VGE） will be taken as the advanced system which will eventually contain all theories and techniques associated with geo\|visualization and multi\|dimensional geo\|graphical interpretation and so on. VGE is very important for the development and practice of Geography, which permits users to go into geo\|referenced data, interact directly with geo\|referenced objects rather than 3\|D graphics of objects, and generate hypotheses or valid others’ geo\|models. VGE is a virtual laboratory for geographers. But the establishment of VGE depends upon not only virtual reality technology, but as well as the development of geo\|visualization, multi\|dimensional geo\|graphical interpretation, acquisition and processing technique of geo\|referenced information, etc..
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发布时间：2021-06-10
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