最新刊期
卷 ， 期 3 ， 2002
- 摘要：Precise retrieval of land surface temperature from satellite remotely sensed data need atmospheric correction and a known effective emissivity of the pixel. Various split window algorithms have been used to solve the first problem, but they all need a known surface emissivity. LSF model can calculate the effective emissivity of the nonisothermal and heterogeneous pixel, but the data must be atmospherically corrected when using satellite images. In this paper, we have developed a model based algorithm that can correct the atmosphere effects and retrieve component temperatures using ATSR 2 dual angle observation. In this algorithm, QUAD algorithm is used to perform atmospheric correction, and LSF model is used to calculate the directional effective emissivity , by iteration, atmospheric correction and component temperatures retrieval can be completed synchronously. Good linearity was found between the difference of the directional emissivity and the difference of the directional brightness temperature after atmospheric correction. Although the range of the retrieved component temperatures is large, it is still clear that the component temperatures of vegetation and soil are separated. Further analysis of the uncertainty and sensitivity for the two component temperatures show that if only the most sensitive sample is used in inversion, the results tend to be more robust.关键词：ATSR data;LSF modal;QUAD algorithm;component temperatures
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发布时间：2021-06-10 - 摘要：A new type of framework associated with Spatial Decision making Support System （SDSS）, in which GIS is a kernel component, have been established and taken Xiamen Environmental Management Spatial Decision making Support System （XMEMDSS） as a case study. A new paradigm of environmental modeling and Model Bases organization, characterized by Model Groups→Model System→Model Base, is presented after the drawbacks and deficiency of current creation mechanism and organization pattern of Model Bases were explored. The approach to tightly integrate GIS with Model Bases is introduced during the process of integrated system development, and an example of system application in air pollutant dispersion and optimum total control is also presented.关键词：environmental management;spatial decision making support system;model system;model base;GIS;system integration;Xiamen city
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发布时间：2021-06-10 - 摘要：The atmosphere correction of multi angle remote sensing should consider the atmosphere surface coupled system and iterative inversion to calculate the coupled factor.This paper makes use of Rahman BRDF model and the iterative BRDF atmospheric correction method for NOAA satellite data to obtain multi angle atmosphere corrected images. The experiment has proved the feasibility of applying the MODIS atmosphere correction method to existing multi angle NOAA satellite data. Spectral curves after BRDF atmosphere correction match the surface curves mostly and the iteration converges fast. Under find weather condition, the error is very small after only one iteration. By comparison, the difference of image reflectance between the original image and the image after BRDF atmosphere correction can reach 30%. The variation trend of original images reflectance is different greatly from the measuring value of ground along with the angle changing. This result shows that BRDF atmosphere correction is indispensable,and even that the NOAA satellite data should not be used to quantitative remote sensing research,if it have not been corrected for atmosphere. Now, obtaining multi angle satellite remote sensing data exists a lot of difficulty, and the atmosphere correction is an indispensable step in multi angle remote sesing application for present obtainable abundance NOAA data.All these are only preliminary experimental results, and there still are some problems needed to do further study.For example, under bad weather condition,what will be the atmosphere correction result? It other BRDF modes such as Ambrals are adopted, will the atmosphere correction result be the same with the Rahmans? These also need the researchs on multi angle remote sensing theory to do futher study.关键词：multi directional Remote Sensing;NOAA;atmosphere correction;BRDF
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发布时间：2021-06-10 - 摘要：By the integrating satellite hardware’s design with ground software’s processing,the article presents a new theoretical method for improving the spatial resolution of satellite image.Computer simulations under different resolution levels are carried out on simulated target images,common scenery images and Remote Sensing images separately.The success results of experimental simulations show clearly the method for improving resolution we present is valid in theory,which also proved the theoretic feasibility to enhance the spatial resolution of satellite images up to twice,even N times,Obviously,practical applications of the research will enhance the spatial resolution of satellite images.In addition,it can also help shorten optical instruments’ focus,decrease satellite camera’s size and mass while remaining the same spatial resolution of satellite images.关键词：CCD;satellite images;spatial resolution;image reconstruction
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发布时间：2021-06-10 - 摘要：Image mosaicking is one of the most important tasks in the generation of orthophoto maps,which includes geometric mosaicking and gray seam line removal Geometric mosaicking can be strictly realized in computer according to the theory of Photogrammetry,whereas gray seam line removal is almost not well resolved The focus of the paper lies on the removal of the gray seam lines in the mosaicked image Firstly,the analysis of the advantages and disadvantages of existing methods such as ″ wavelet transform method ″ and ″overlapping image method ″is performed,and then the hard correction method is presented and tested using many real images The main idea of this method is as follows:for every piexl of cut lines in the whole mosaicked image,if it is the left right one,we compute the average gray difference between the pixels within a certain extent of the two sides of the cut line,and then adjust the gray difference to the pixels at a certain extent of the two sides of the cut line;if it is the top bottom one,this operation is done in top bottom sides of the cut line The results indicate that the method proposed above is very effective,simple,easy to realize and fit for gray level and color images
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发布时间：2021-06-10 - 摘要：The 3 dimensional visualization of a tree model is a difficult problem,especially in GIS field Spatial characters of trees have great differences from common objects It has clear fractal character,and it’s difficult to establish data model using common modeling methods Now,fractal theory is in use widely,and it could produce vivid effect However,the data amount is very large for 3 dimensional visualization in GIS Tree image is used more widely than that of tree model,but in the near viewpoint,tree image would have a bad effect because the essential characteristics of a tree are ignored in this way In this paper,the advantages of the modeling and Level of Detial（LOD）technology have been used Our modeling scheme is to use a tree 3D model produced from fractal algorithms This model is managed by BLOB type in database because it is difficult to do spatial analysis using fractal model One cuboid could envelope a tree model in spatial analysis process and in visualization process Tree fractal model could only be used in very near viewpoint Multi solution tree images are used to express trees in different view distances Theses images are also managed using BLOB data types in database Same cuboid in fractal model is also used in spatial analysis Fractal tree model and multi solution tree images are combined by a fix LOD division in visualization process according to system design or user selection LOD division is referred to view distance and tree images solution At the end of the paper,our experiment system is introduced It shows that our method could be used to solve 3 dimensional visualization in city environment in tree model,and have a good effect关键词：3 Dimensional visualization;tree model;3DGIS
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发布时间：2021-06-10 - 摘要：Spatial Modulation Imaging Fourier Transform Spectrometer（SMIFTS） is an important remote sensor for research and application.In this paper,based on application requirement and SNR equation,the prototype of Sagnac type IFTS is designed and manufactured.The spectral imaging experiment is carried out with the prototype in laboratory and an clear image has beer obtained in visible and near-infrared （VNIR） region .By processing and Fourier Transforming interferogram of each pixel,spectral image and pixel spectra is extracted with distinct spectral character.Comparison between the traget’s spectral reflectivity curve measured by standard device lambda 9 and it’s evaluated reflected spectral curve from spectral imaging experiment are carried out. The results indicate that the corresponding curves are similar.关键词：remote sensing;VNIR;prototype of Sagnac type IFTS;Fourier Transform spectral imaging experiment
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发布时间：2021-06-10 - 摘要：In order to make image interpretation more accurate, efficient and flexible, and to enable remote sensing more useful in updateing some of data sets in GIS, an Interactive Image Interpretation System （I 3S）has been developed in Windows NT and VC ++ 6.0 environment since 1998. I 3S,in fact, is a raster-based system with a structure of toolbox and friendly interfaces. Through an interactive way, the system integrates the advantages of computers and human brain, functions of image processing system and GIS, experience of visual image interpretation and knowledge of geosciences together. The system, in general, can be operated in three modes:module application, single system application and multi￣system application. The first mode means one of the modules in the system is used for solving some of problems in an image interpretation process, such as registration of image and corresponding map, etc. In the second mode,I 3S is applied to image interpretation with small or medium scale through the combination of some function modules of the system. The last one is the mode for the task with large scale through networking and operating of multiple I 3S together. The module functions of the system can be divided into two categories:support module and interpretation module functions. The former consist of those functions to support system operation in normal. The functions are data input and output, registration of images and maps, image enhancement and data fusion, image filtering, extraction of double edges, RGB-IHS transformation, color exchange, data conversion from vector to raster or reverse, and interface to network, etc. The latter includes the modules to support image interpretation or classification directly, which are map layer manager, classification manager, image browser, tools of manual interpretation （such as pan brush, semi-automatically or automatically edge tracking, attribute assignment, rubber, etc.）and post-processing of classification, statistical result generation, graphic editing in raster or vector format, etc. In the system application mode, the different combinations of the function modules can flexibly formulate a series of system functions for image interpretation. They are as follows:interactive visual interpretation, supervised classification, image-segmented classification, ancillary band-added classification, dynamic change interpretation and human-machine mixed interpretation. Therefore, I 3S gives interpretation experts more space to play their leading roles in image interpretation. The principle, architectures, functions and characteristics of the system are presented in the paper.关键词：remote sensing;image interpretation;GIS;interactive system
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发布时间：2021-06-10 - 摘要：Natural disaster such as the large flood took palce in 1998 in China and the dust storm in 2000 around Beijing makes our government paying more attention to improve the ecological environment in China. In order to improve the ecological environment, a great deal of the dry land must be returned back to forest or grass land. Where the dry land must be changed inlo the forestland or grassland is a very important question.In our study GIS is used to find the place where the dry land must be changed into forestland or grassland. In includes four steps. Firstly, the database is extablished including land use database, soil erosion database,DEM, slope database, aspect database, normalization vegetation index （NDVI） database, precipitation database and temperature database. The ecological environment quality database is oltained thtough evaluating the ecological environment quality. Secondly, the dry land from Landuse database was overlain with slope database, soil erosion database, normalization vegetation index（NDVI） database and the ecological environment quality database. The distribution of the dry land of different slope was analyzed. The distribution of the dry land of different slope under different soil erosion, different NDVI and different ecological environment quality was also analyzed. Thirdly, the expert knowledge about the dry land was collected, and a model of finding suitable places for changing into forestland or grassland is formulated on the basis of the knowledge. Finally, the suitable places are overlain with the precipitation layer to decide where trees need to be planted or where grass need to be planted. It shows that the results provide an important scientific decision base for government to construct the ecological environment in China.关键词：Geographic information system;dry land;Forest land;grass land
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发布时间：2021-06-10 - 摘要：In this study, three test sites with the same longitude have been selected from south to north in wetland area（the monsoon region） of Eastern China. Five test sites with the same latitude have been selected in arid or semi-arid area of North Western China（the Non-monsoon region）. Production of 24J month time series of one month maximum NDVI composites have been accomplished based on NOAA AVHRR and Landsat-TM data. Average temperature, precipitation and wind-speed data in each average of the month to be synchronous have also been input into computer for analyzing the dynamically correlated model of driving forces of land cover Changes Conclusions have been drawn that land- cover change in China has distinct seasonal fragileness in each test site and their relationship has been found. In the study, we draw the following conclusions: （1）Vegetation is the connection of soil, atmosphere and precipitation.When using vegetation as an indicator of land cover change, not only seasonal but also spatial change has been found in the land cover change. In addition, some unstable phase has also been identified. We conclude that the unstable phase in land cover was related to the seasonal and longitudinal change. （2）The zone and coastal plain of east of China belong to East Asian Monsoon.The climate is rather wet. The correlation between NDVI and temperature is obvious. But the correlation between NDVI and precipitation is not so good. Therefore, we conclude that in a region of high precipitation, temperature is the key affecting factor for growth of vegetation. （3）In northwestern China, the Big Xingan Mountain forest area, the typical grassland area and arid desert area almost lie on the same latitude. From east to west, the land cover types are forest, forest grassland, typical grassland, desertgrassland and arid desert. In the line, as the distance from coastal line increase, the monthly average NDVI value depends largely on precipitation. Thus, compared with temperature, precipitation is the key affecting factor for vegetation growth in arid area. （4）From south to north, under the limitation of temperature, the deviation of averages NDVI is not obvious. However, the seasonal deviation is high. From east to west, under the limitation of precipitation, the regional deviation of NDVI coincide with the productivity of vegetation. It implies that temperature affect the budding, flowering, fruiting of vegetation. On the other hand, precipitation affects the productivity of vegetation. （5）Wind is one of the driving forces causing desertification in dry and semi dry region. The period of lasting of strong wind seems to be coincident with the degradation of vegetation for each test sites. In contrast, when the cover of vegetation was at maximum, wind speed was found to be minimum, because of the inverse relationship between wind speed and NDVI , desertification and land degradation happen in the grassland and cultivated land in northern China. Some researches show that desertification and land degradation happened on winter and spring, which coincide with the unstable stage, found in our study.
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发布时间：2021-06-10 -
Study on Spatial-Temporal Features of Land Use/Land Cover Change Based on Technologies of RS and GIS
摘要：The research of land use and land cover change is a core and focus point for studying on the global changes.Also the research of spatial-temporal features of land use/land cover change is significantly important for better understanding land use/land cover change and environmental management for sustainable development.In order to study the spatial-temporal changes of land use/land cover,the technologies of Remote Sensing and Geographical Information System were used to analyze the spatial dynamical features and temporal dynamical features of land use.Take land use in Hubei province for example,the mathematical methodology for study on land use change was explored and developed.This research focused on the dynamical analysis of spatial-temporal features of land use/land cover change of Hubei province in five years.Firstly,the author made land use dynamic degree map and land use degree change map through defining the land use dynamic degree index and land use degree index.The equation form of land use dynamic degree index is:S=∑nij（dS i-j /S i）×100×（1/t）×100%where S is the dynamic degree of land use（×100）; S i is the total area of the i th land use type before monitoring; dS i-j is the total area of land use type i turn to other one of land use type from the beginning of monitoring to end; t is the monitoring period; The equation form of land use degree change index is: Δ I b-a =I b-I a=∑ni=1A i×C ib )-（∑ni=1A i×C ia ）×100where I a , I b is the synthetical index of land use degree in time a and time b ;A i is the grade index of land use degree; C ia ,C ib is the percentage of area for grade i land use degree in time a and b.If Δ I b-a >0,the land use is continuely developing in this region,or the land use is regressing.Secondly,the cultivated land change,forestland change,grassland change and NDVI change were studied in this paper.Thirdly,the mechanism of land use change and its driving forces were discussed and the quantitative approach and track of study on land use/land cover change in China were given in this paper.关键词：remote sensing;GIS;land use change;spatial temporal feature- 211
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发布时间：2021-06-10 - 摘要：This is one of a series study on yellow substance in seawater.Based on the results of experiment,the distribution on fluorescence relative intensity of yellow substance in China Sea area is obtained firstly by using the fluoricence.The distribution on fluorescence intensity in Jiaozhou Bay is as following ,The fluorescence intensity of yellow substance is the highest ,more than over 7.5 *10 -7 ,along the northern and western shore especially in the river estuary.It decreases in the central area of the Bay,and reaches the lowest in the outside mouth of the Bay.There is a clear differentce in yellow substance between the inner and the exterior of the Bay.The fluorescence intensity of yellow substance is uneven in the Jiaozhou Bay,and its distribution is relatively close to the rivers along the shore.It is suggested that the yellow substance in the Jiaozhou Bay is originated from the land,carried by the rivers to the Bay.关键词：yellow substance;fluorescence intensity;distribution
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发布时间：2021-06-10 - 摘要：Based on internal and external research literature in recent years,this paper emphatically deal with the utility problems of remote sensing（RS）technique,the new land monitoring technology,in landscape ecological studies.Five research areas were discussed respectively: Structure and pattern study:The attribute description of landscape structure and the utility of quantitative analysis methods need large amount of basic data,therefore the landscape structure and pattern study is the category that RS technique has been used extensively.Using RS technique has also stimulated the development of quantitative methods for landscape structure and pattern study.Choosing and improvement of most landscape indices often used to describe the characteristics of landscape pattern,are strictly related to the applicaltion of RS technique. Function study:RS data is mainly used in energy flow study of landscape,combined with field survey information,it can also be used for transferring research of nutrient elements in landscape.Although the application of RS technique in landscape function study has not achieved greatly,but a finite number of literature indicates that RS technique is a reliable tool for different ecological flow study on landscape.Along with its further development,RS technique will produce a strong support to achieve new breakthroughs in ecological function study. Dynamic study:Most of landscape dynamic studies have used RS technique,by integrating the RS data with different kinds of natural,social,economic,and historical information,the landscape changing process can be reconstructed,and the analysis precision can be enhanced greatly.These advantages have contributed a lot to the study of internal driving mechanism of landscape changing. Scale effect study:Scale effect is also a category that RS technique has been used widely.In the study of scale effect by using RS data,a fruitful study area is the scale sensitive analysis of landscape study methods. Because of the he terogeneous characteristics of landscape.it is very important to study the predictability of landscape analysis methods based on RS data in different resolution status. Practice study:Biodiversity conservation and landscape planning are the two typical practice areas of landscape ecology.Because the relationship between landscape attributes and biodiversity characteristics is very complicated, RS technique has become the best tool for landscape scale biodiversity monitoring and species survey.Application of RS technique in landscape planning concentrates mainly in the areas of landscape assessment,landscape simulation,and decisionmaking support,and often be used together with GIS and other quantitative analysis methods. It can be concluded that the application of RS technique,which has become an important driving force for the deve lopment of landscape ecology,has covered almost all landscape study areas .This technique has significant superiority in landscape study,but its advantages and potentials have not been practiced adequately.Tasks needed henceforth include the extending its using scope,standardization computer assistant survey methods,developing intellectualized landscape analysis system,and stimulating landscape practice study.关键词：landscape ecology;remote sensing;geographic information system
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发布时间：2021-06-10
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