最新刊期
卷 ， 期 6 ， 2005
- 摘要：The complexity of surface parameters can be characterized by cross radiance and BRDF in VIS/NIR band.In this paper,MODTRAN4 code and atmospheric point spread function were used for the simulation and analysis of the influences of a set of factors on cross radiance.The results show that the variance of cross radiance could be resulted from every factor,so it must be computed on the basis of measurement conditions.A new methodology is developed to eliminate cross radiance from total radiance based on modification of analytical solution of PSF and combination of it with radiation transfer code of MODTRAN.The applications to AMTIS image show a good precision.关键词：high geometric resolution;airborne remote sensing;cross radiance
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发布时间：2021-06-10 - 摘要：The feature is an essential element that comprises spatio-temporal data information and the event is a fundamental factor that result in changing spatio-temporal data.Basing on analyzing several existing Spatio-temporal Data Model,this paper introduces a new Spatio-temporal Data Model based on feature and event double mechanisms.The character of spatio-temporal data changing is analyzed.And how to organize data,build relations between features and storage data in spatio-temporal database are also emphatically discussed.At last,a software package of dynamic land use information system based on above model and methods are introduced.Its running network environment is Windows NT Server 2000 and client is Windows workstation 4.0/2k/xp professional operation systems.Another important technology used in dynamic land use information system is a self-developed Attribute Database Engine（Dblink） combined with Spatial Database Engine（SDE）.It is proven efficient in realizing the query and retrospect of the history information during system’s operating.关键词：TGIS;spatio-temporal data model;spatio-temporal database;historical retrospect
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发布时间：2021-06-10 - 摘要：In order to estimate directional variation of gap frequency over a over covered maize canopy（LAI=5）,an experiment using a narrow FOV thermal infrared camera mounted on a crane boom was conducted at night on July 26,1999.A geometric optical and radiative transfer model was proposed to simulate hemispherical gap frequency.Observations showed most gaps appeared between the adjacent hedgerows,which lead the canopy still to keep row feature in thermal infrared images.The measured gap frequency confirmed the results mentioned in many papers that very little azimuthal variation appeared except the observations parallel to the rows.Based on already obtained geometrical parameters,the developed model captured the main features of the measured gap frequency,the simulated gap frequency showed a fairly good agreement with observed gap frequency.关键词：maize canopy;gap frequency;GORT model;night TIR images
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发布时间：2021-06-10 - 摘要：The majority of spatio-temporal DBMS assume objects to be precise,but this simplification can’t work in many military,navigation and environmental applications.Many forms of spatio-temporal data can’t be measured exactly,and in these kinds of objects exists spatio-temporal indeterminacy.Spatio-temporal uncertainty management is a new topic for researchers on spatio-temporal databases.The current method based on Fuzzy Sets is not well applicable because it imposes strict restrictions on the objects’ uncertainty.In this paper,a new abstract model of uncertain spatio-temporal objects is presented.This model is based on the Grey Sets and is more applicable for the presentation and manipulation of partial unknown spatio-temporal objects.This paper first gives the formal definition of uncertain abstract data types based on the Grey Sets,such as the definition of base types,spatial types and spatio-temporal types.Then we take a glimpse at the aspect of uncertain spatio-temporal analysis.Finally,examples of uncertain query is presented.关键词：spatio-temporal database;grey sets;uncertainty;abstract data type
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发布时间：2021-06-10 - 摘要：Based on the characteristics of target identification,a new method for target location fast correction in satellite image is proposed in this paper.First,the targets and the nearby ground control points（GCPs） are detected in the satellite image which has been processed with basic geometric correction method.Then the outliers of GCPs are detected.Finally,the geometrical location of the targets are corrected by the GCPs.Also in this paper,a new algorithm based on regional cliques is proposed to automatically detect the outliers of GCPs.The example results indicate that the processing speed for target location correction can be greatly improved and the target location precision can also be ensured.关键词：satellite image;target location;fast correction;outlier detect;regional clique
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发布时间：2021-06-10 - 摘要：Image filtering preprocessing which is helpful for increasing the signal to noise ratio（SNR）,decreasing the intra-class spectral variability and spatially smoothing homogeneous areas on the image can prove very useful for further discrimination of ground objects,image segmentation and classification processing.In this paper,two nonlinear anisotropic diffusion filtering methods are presented and they are based on the multispectral anisotropic diffusion models proposed by Pope and Acton.We build a couple of new diffusion coefficients in partial derivative equation（PDE） based on Tukey’s biweight estimator error norm by recurring to the relationship between robust statistics and anisotropic diffusion incorporated with the nonlinear time-dependent cooling technique for gradient threshold.Our methods not only effectively remove the impulsive noise caused by sensors,but also preferably preserve important detailed edges and image quality in remotely sensed images.Experimental results are given to show that the improved methods have superiority capability over the multispectral anisotropic diffusion schemes proposed by Pope and Acton on visual judgment and quality statistical analysis and they are very ideal edge-preserving filtering methods.关键词：anisotropic diffusion;multispectral remote sensed image;diffusion coefficient;robust statistics;nonlinear cooling technique
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发布时间：2021-06-10 - 摘要：The traditional post classification comparison change detection of remote sensing is greatly restricted by the classification accuracy which is influenced by the uncertainty of many factors such as the atmospheric condition,the correlation between the bands of remote sensing data etc.The prior knowledge is often introduced into the classification in order to improve the accuracy.The Bayesian Networks model is a new model for data expression and learning.It has no strict precondition of normal distribution of the input data and can increase the classification accuracy efficiently though adjusting the prior probability density dynamically.The Bayesian Networks classification algorithm was developed in this paper,taking the Landsat TM data in Beijing acquired on May 29th,1996 and May 19th,2001 as an example in detail and then the change detection using the temporal remote sensing data was realized.The experimental result indicates that the post classification comparison based on Bayesian Network classification algorithm is a newly effective approach for remote sensing imageries change detection.关键词：Bayesian networks;change detection;post classification comparison
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发布时间：2021-06-10 - 摘要：This paper discusses a new partial differential equation model for resolution enhancement of image.This model adapts the prior information of piecewise continuity of image to construct a nonlinear diffusion model,which is used to smooth an enlarged image by nearest interpolation to reduce the blocky effect caused by enlargement,simultaneity,and interpolation condition is added into the iterated process to avoid a too smooth image.The algorithm is tested by three remote sensing images,all of the results show that the new model has higher peak signal to noise ratio and higher edge preserve index than the known methods.
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发布时间：2021-06-10 - 摘要：The HY-1 satellite is the first satellite for remote sensing of ocean environment in China.Because there is no onboard calibration facility and the coefficient of Chinese Ocean Color & Temperature Scanner（COCTS） has been drifting,calibrations and corrections must be carried out continually.One of the calibration methods is described in this paper.The Sea-viewing Wide Field-of-view Scanner（SeaWiFS） supplies highly accurate ocean color satellite data acknowleged internationally,its data for case I water,such as water-leaving radiance and chlorophyll concentration,etc.,is regarded as the standard by international fields on remote sensing of ocean color.Therefore,we can adopt the calibrate COCTS continually by the normalized water-leaving radiance and aerosol parameters derived from SeaWiFS.This method can also be used to monitor the long-term charge of calibration coefficient of COCTS.Our results indicate that the accuracy of the data retrieved from COCTS can be greatly improved after the cross-calibration.关键词：remote sensing of ocean color;calibration of sensor;system cross-calibration;COCTS;SeaWiFS
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发布时间：2021-06-10 - 摘要：The visibility,effective radii and liquid water path（LWP） of fog are the fundamental parameters for fog monitoring.This paper uses the data from MODIS and digital elevation model（DEM） of geographic information system（GIS） to obtain the fog geometrical thickness.Meanwhile,proper algorithms are used to calculate the horizontal visibility,through testing the example of the fog in Northwest of China.There are a validated result through comparing the visibility of conventional observation,and the encouraging accuracy have been proved.The other parameters,such as effective radii and liquid water path（LWP）,have been obtained.The former sounding and remote sensing result have shown that it has a true trend.All these show the retrieving method is valid for remote sensing fog in Northwest of China.关键词：MODIS;fog;geometrical thickness;visibility;effective radii;LWP
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发布时间：2021-06-10 - 摘要：The idea of constructing the relationship of temperature distribution to spatial structure of Beijing areas was brought forward in the research.Firstly,Landsat7 ETM+ remote sensing data of Beijing city（22,May,2002） was used to build the relationships between temperature distribution and Fractal Parameters such as Box dimensions,Lipshitz-Hlder exponents αmax,αmin,(αmax-αmin) and information dimension D（1）.Then,Landsat5 TM remote sensing data of Beijing city（16,May,1997） and Hangzhou city（11,Aug,1998） were used to verify the previous relationships.Finally,this research showed that the distribution of city temperature fields existed the evidenced linear relationship with Box dimensions,αmin and D（1）,and their correlative coefficients are higher,however,with αmax and(αmax-αmin) was uncertain.City spatial characteristic is very complex,when explains the relationships of environmental factor and（or） phenomena to spatial structure of city by fractal theory,the physical and real significance of fractal parameters must be explained carefully.关键词：Beijing;temperature distribution;box dimension;multi-fractal;spatial structure
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发布时间：2021-06-10 - 摘要：Nowadays,investigations on land use / land cover change detections constitute a main objective for the global research.As a part of rapid development in technology,remote sensing has become an important tool to acquire the information of the land use/cover.Therefore,how best the extraction of timely and accurate information from these remotely sensed images is an impending problem.Recently,the knowledge-based interpretation of these images has become an effective and efficient approach to realize the automatic interpretation,which can integrate the spectral and other associated information based on experts’ knowledge and experience to improve the accuracy.However,it is a bottleneck problem to obtain the knowledge for its wide application.A case study on the land use/cover classification of Jiangning study area in Jiangsu Province is discussed in the present article.At first,the data are preprocessed,then the relevant sixteen variables including geographical coordinate,grey value of four bands,textural statistics,DEM,slope and aspect are selected and extracted.The defined training sample areas are picked up by stratified random sampling techniques based on geographical coordinates.Thirdly,classification rules are discovered from these samples through Classification and Regression Tree（CART） Analysis,which integrates spectral,textural and the spatial distribution characters.Fourthly,the interpretation was performed by a judgment based on these rules.Finally,the traditional supervised as well as logic channel classifications are also performed to check the classification accuracies.The results have suggested that the accuracy of classification based on the CART is higher than others’,which can obtain a lot of reasonable rules most quickly and effectively.So,it was felt that it is a good way to promote the wide application of knowledge-based interpretation of remote sensing images.关键词：Classification) and Regression（Tree（CART）） Analysis;remote sensing;land use/cover classification;Knowledge
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发布时间：2021-06-10 - 摘要：Many gold mines in China and even around the world are in close relationship to silicification,and the more silicification,the more mineralization.But geological researches on silicification about alteration’s degree and scope only stand still and keep qualitative for a long time,and still yet very seldom quantitative Remote Sensing Models have been set up.Therefore,we choose Yingzuishan goldmine which is complex and has many kinds of wall rock alterations in the research area,aiming to set up quantitative Remote Sensing Model for silicification.By cluster analysis,correlation analysis and factor analysis etc,and also by the use of in situ spectral survey data and the results of rock & minerals component analysis and microanalysis of Au etc,finally we found out the optimal variable sets to extract the silicification information,and set up the Linear Regression Equation of them:SiO2=85.047TM5/TM7-4.348TM5/TM4+16.51TM5/TM3-41.866 R=0.703,which just was the quantitative Remote Sensing Model for silicificaion we wanted.With the help of this model,we took an enhance ment treatment for Remote Sensing data of Landsat TM and extracted out gold mineralization abnormal information in this area.Through actual verification,the proved the results have good correspondence to the actual condition.This model can also provide reference to geological investigation and prospecting for goldmines in those area with the similar geologic background as Yingzuishan,such as in the east of Altun mountain and the west of Northern Qilianshan mountain,where early Paleozoic sea facies volcanic rocks spread widely.关键词：mineralization（alteration）;) quantitative remote sensing model;silicificative;yingzuishan in Gansu province;goldmine;PLS（partial least squares regression）
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发布时间：2021-06-10 - 摘要：A method to monitor grassland vegetation health was used in this study.The relations of grassland bio-parameters related with grassland health were analyzed by Principal Component Analysis（PCA） on the basis of combining community survey and vegetation spectrum in Xilin River basin,Inner Mongolia.1.Three specific Principal Components（PCs） with specific ecological meaning were extracted from a 12-variables data set that contains community information using principal component analysis（PCA）.Based on the three PCs,we proposed a new index-GHI,which is proved to be qualified for monitoring grassland vegetation health condition,and sensitive to degradation.2.We extracted two PCs: visible light component and infrared light component from 6-band vegetation spectral reflection data.3.We got the regression models of GHI and visible light/infrared light,based on the PCs correlated to plot spectral reflection and GHI,which indicate community gross and grazing degradation.The model can be used to monitor grassland health condition by vegetation spectrum.关键词：vegetation spectrum;community structure;principal component analysis（PCA）;grassland health
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发布时间：2021-06-10 - 摘要：To discover spatial association rule is one of the important contents for spatial data mining and knowledge discovery（SDMKD）,which extensively concerns with spatial,especially geographic spatial knowledge expression and reasoning.Combining with epistemic logic,formal expression is described by Inductive Logic Programming（ILP）,on the basis of geographic spatial cognition.And then the spatial predicates,possibly used in SDMKD from GIS,are analyzed and listed.Subsequently,the formal expression of spatial association rules is explained through taking examples for the relation rules between roads,rivers and towns in Suzhou region.The major problem to mine spatial association rule from GIS is to mine multi-level and multi-relational rules.And the key to solve the problem is how to effectively compute,store and express the spatial predicates among different spatial objects of different thematic layers.Firstly,the spatial data are transformed to the non-spatial data,which can be described in the related tables.And then the original problems are transformed into the problems in Boolean logic rules.Finally,on the basis of the mentioned above,according to the concept hierarchy of spatial objects,the spatial association mining approach,from top to bottom and deepening step by step,is introduced.And the spatial predicates are organized by spatial join index for predicates.关键词：spatial association rule;data mining;GIS;cognition;spatial predicate
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发布时间：2021-06-10 - 摘要：Vegetation chlorophyll content is a key component in ecosystem function.Study on vegetation chlorophyll content retrieval is carried out in 3 directions in which developing or modifying spectral index to retrieve canopy chlorophyll content is a direction which may be a compromise between multiple stepwise regression and inverting physical models because it has some physical meaning while is easier than the latter.At leaf level,we analyzed the applicability of the spectral indices when applied to chlorophyll content retrieval.The reasons that why some studies found these spectral indices are highly correlated with chlorophyll content of their observed samples and why these relationships can not be applied to other peoples’ observed samples are explained in this paper.A recent study developed a semi-empirical model to retrieve canopy crop chlorophyll content which combines spectral index TCARI and soil adjusted index OSAVI.According to this study,the chlorophyll content is determined by the slope of the intersected isolines whose independent variable y is the value of TCARI and the dependent variable x is the value of OSAVI.So a semi-empirical model was derived which is a logarithmic function of TCARI/OSAVI value and through validation with observed corn canopy reflectance and chlorophyll content,this model gives promising results.In this paper,we give some modifications for this semi-empirical model.First, the intersection point of the isolines is considered which was taken as the origin while actually is not,i.e,the chlorophyll content is determined by（TCARI-a/OSAVI-b） with a and b being the Y-coordinate and X-coordinate of the intersection point respectively in TCARI-OSAVI space.Second,a reciprocal function is thought to be more appropriate than a logarithmic one.Considering these two points,a modified model is given in this paper.With our observed corn canopy reflectance and chlorophyll content,this modified model gives better results.关键词：chlorophyll content;spectral indices
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发布时间：2021-06-10 - 摘要：It) is fundamental to calculate photosynthesis of terrestrial vegetation quantificationally for estimating agricultural and terrestrial ecosystem net primary productivity.In this paper,some methods of observing CO2 flux and some problems of scaling on geography in the world are reviewed briefly, and stomata conductance model and photosynthesis model are analyzed in detail.At the same time,four kinds of upscaling models from leaf to canopy（big-leaf model,multi-layer model,two-big-leaf model,and multi-layer-two-big-leaf model） and some upscaling methods from canopy to community are summarized at length.Advantages and disadvantages are analyzed for all the models and methods, through which a conclusion was drawn that the key of the success in remote sensing researches is how to select suitable models and parameters according to different objects.关键词：scaling;CO2 flux;stomata conductance;remote sensing
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发布时间：2021-06-10
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