Land surface temperature ( LST ) is an important parameter in meteorology , hydrology , ecology and so on. This paper has proposed a nonlinear iterative method for retrieving land surface temperature ( LST ) from MODIS data which needs two parameters ( land surface emissivity and atmospheret ransmittance). At first , two radiance transfer equations for MODIS band 31 and 32 had been built , which involves two unknowns ( landsurface temperature and average atmosphere temperature) . Because of complexity , a numerical algorithm has been developed to solve the equations using iterative approach. Then, the estimation of the two essential parameters of the nonlinear iterative method has been extensively discussed. The atmospheric transmittance can be estimated on the basis of the relationship between atmospheric transmittance and water content which can be retrieved from the visible and infrared bans of MODIS data. As MODIS image has the lower resolution, the pixels of MODIS for most natural surfaces can be viewed as composed of three land cover patterns: vegetatio , bare soil and water. The composition ration of vegetation and bare soil can be estimated from NDVI, and the land surface emissivity of MODIS31 and MODIS32 can be estimated by using the land surface thermal radiation equations of composed pixel and the known emissivity of land cover patterns. Finally , the sensitivity of parameters is analyzed and the results indicate that the parameters are not sensitive to the LST retrieval method we have proposed. The retrieved LST in Jiangsu province indicated the space difference, urban heat island effect and different ground object types.
Urban heat island effect is the typical representation of urbanization impacts on urban climate.The urban heatisland has different time and spatial characteristics for a different urban because of different urbanization level,essence, size and nature condition. The paper analyzes the time and space characteristics of Nanjing city combing high space-resolution Landsat TM with high time-resolution MODIS. This paper analyzes daily characteristics of UCL heat island by eight granule MODIS, seasonal characteristics by sixteen granule MODIS and probes the scale effect of UCL heat island. The diurnal urban heat island intensity is stronger than over nigh t’s. The strongest intensity of urban heat island happens on autumn,the second on summer, the third on spring, the last on winter. Themost extensive in scope occurs in summer, the second in autumn, the third in spring, the last in winter. There are three continuous and extensive heat islands in Naning city. The largest area heat island takes on clustere shape, distributing both the riversides of Qinhuai River. The second is the lineal shape along Rehe Road, Jiangn in Road, Longpan Road, Hongshan Road and Heyan Road. The third presents zonal shape and distributes the industry land use in Dachang district and Pukou district. The intensity and scope of urban heat island result s are different with different remote scale. The intensity and scope of urban heat island in Naning city respectively using TM and MODIS on April 17, 2000 and the scope and intensity using TM are all lager than that using MODIS.
The technique of InSAR have great potential in detecting displacements caused by ground subsidence which sometimes can't be achieved by other methods. But the application and accuracy of InSAR will be influenced because of its some inherent factors and variations of ground plant , humidity and atmosphere at dif ferent time. Meanwhile, application of GPS to measures land deformation has become an efficiently and accurately measuring technology. GPS-InSAR integration can enhance the ability of measuring land deformation in both temporal and spatial resolution; it is becoming an emphasis of land subsidence investigation. This paper introduces firstly the complement of the InSAR and GPS. Then, the approach to derive atmospheric corrections to the InSAR images from CGPS datas and the method to remove or mitigate SAR satellite orbit errors using GPS results as constraints are analyzed. Finally , the Double Interpolation and Double Prediction ( DIDP) approach for integrating InSAR and GPS results is given.
The human-induced water-quality problem has long been concent rated and intensively studied all over the world. The Min River is the major river system in Fujian province of Southeast China, which runs across the center of the province from west to east and is called“Mother River”of the province because it provides the drinking water for the 1/3 of the provincial population. How ever, the water quality of the river has being threatened due to the human activities in the adjacent areas. Therefore, the change of the river water quality needs to be understand for the further protection. Nowadays, there are many methods to study water quality, among which the remote sensing technology is a valuable one employed recently especially in studing historical change of the water quality when the ground-based water measurement data are not available. Therefore, two Landsat TM /ETM + images of 1996 and 2003 have been used in this study to estimate suspended sediment concent ration ( SSC ) and its variation of the lower stream ( Fuzhou portion) of the Min River during the study period. A series of image pre-preccessing methods were first applied to the two raw images, including radiomet rical correction and image rectification. Then the open water-covered areas were extracted form the images using the Modified Normalised Difference Water Index (MNDWI). Finally, the slope method proposed by Lietal. (1999) was used to estimated the SSC of the studied river portion. Moreover, the SSC maps of the two study years were further subdivided into 4 concentration-levels using the density slicing technique. So a change detection method could be used to detect spatial and temporal variations of the SSC of the studied river portion during the years from 1996 to 2003.The results reveal that the SSCs have gone up during the 7 study years almost in the whole studied river portion. Comparing with the upper stream of the river, we found that the increase in the SSC was due largely to the heavy suspended sediment loads from the upper river with the contribution of the increasing
amount of industrial waste water and civil sewage because of fast urbanization of the Fuzhou City.
This paper used“Beijing-1”Micro-satellite CCD data to monitor Tianjin land use dynamic change from 2000 to 2005, studied the data usability and effect in the land use research field. The result indicated that: “Beijing-1”Micro-satellite remote sensing image spectrum information was rich, texture structure was clear, the whole interpret situation was better. Image can satisfy medium scale map request, has the usability in the land use research field, may be widespread used, became one kind of new data source which the remote sensing data renews. On the other hand the monitoring results showed: The whole land use in Tianjin displayed the urban land rapidly expanded through taking the suburb farming and other types land, the urbanization process was remarkable, and between the different land use type transforming was obvious.
The research is based on the Land cover/Land use classification of Fuzhou Lanqi island, on the basic of image in terpretation knowledge, using fusion image of TM and Aster , integrating DEM data.Based on Matlab software, appling Self-organization artificial neural net classification method. Without the training area date, the total precision of classification is 91. 14% and Kappa coefficient is 0. 89. The method has been aproved to be effective to meet classification accuracy.
Geological hazards such as landslides, rockfalls and debris flows happen frequently in Sichuan Tibet Highway and bring about great damage to peoples’ life and property. How to make clear the geological status is important to the design and maintenance and disaster’s father of Sichuan-Tibet Highway. The real status of Sichuan-Tibet Highway could be analyzed macroscopically by using remote sensing such as aerial photographs and CBERS data. As a powerful tool for spatial analysis and spatial database management, geographical information systems (GIS) are drawing more and more attention in the field of the geological investigation. In this paper, the aerial photographs and CBERS data combining the technique of geography information system were used to investigate the geology of Sichuan-Tibet Highway by image geometry correction and image enhancement and spatial analysis. The results shows there are 324 debris flows, 81 landslides and 367 rockfalls. It is predicted that the integrate application of remote sensing (RS) and geographical information systems (GIS) will promote the development of geological investigation.
The Tibet part of National Highway 214 locates in South-eastern part of Tibet . Geological hazards such as landslides and rockfalls happen frequently in this highway and bring about great damage to peoples' life and property . To make clear the geological status is important to the design and maintenance of National Highway 214. The ETM data combining the historical data and the investigation of field were used to study the landslides and rockfalls of the Tibet part of Natio nal Highway 214 by image geometry correction and image enhancement and spatial analysis. The results shows there are 76 places of rockfalls and 26 places of landslides along the highway . The developing state and harm characteristics of these geological hazards have been evaluated.
The method used in the study is based on surface energy balance equation, i. e. R n= KE T + H +G. By analyzing the spatial distribution of ET , we can draw that the spatial variation of ET is obvious.The estimated ET value ranges from 1. 2 to 8. 5mm , with the average value of 4. 7mm on April 15, 2000.Spatially, it increased from north to south. The highest value is occurred at the source of the river, where is woodland distributing. The results have been validated by field data, and the root meansquare error (RMSE) is 0. 8. The errors are less than 0. 7mm in most of the stations except one. It proved that the method is feasible to estimate ET in the study area. The study enables us to better predict land surface hydrological cycle and lays a foundation for ecological restoration and application of distributed hydrologic model.
The city of LongHai was selected as a studying area in this paper, and adopts the ASTER image to extract the information of land utilization based on idea of division of layer step by step, which was depended on the analysis of the typical feather spectral in the studying area. First , divide the whole image into separate small area in order to avoid the fusion of the spectral each other. Then, in the separate small area, separate each kind of feather from the small area one by one depending on the each kind of feathers spectral and space characteristic. It was shown in the result that this method was better than the traditional supervised and unsupervised classification.
Land use/cover information is the precondition and foundation of LUCC ( land use/cover change) which is indispensab le to globe change research. Traditional classification method such as spectral-based classification can not solve the confusion of spectral similar problem. The classification method based on knowledge may sufficiently use remote sensing expert thought and experiences to improve remote sensing image classification accuracy. This article took Longkou city as an example, using spectral characteristic of land use/cover object and combining altitude, slope information, a geographic expert knowledge based classification method of Shandong hilly region was discussed. The study showed that, this method eliminates the deficiency of using spectral information simply, and the classification accuracy reached to 90.24% , which is much higher than maximum likely classification and proved that the classification method based on knowledge is efficient.
The image segmentation is not only a key step from the image treatment to the image analysis,but also one of the oldest and the most difficult problems in the image treatment . The significance of image segmentation in the image treatment is analyzed in this paper, followed by the characteristics and existing problems of the current image segmentation methods. Based on these analyses and aiming at the remote sensing image, an image segmentation method based on the information fusion of gray information of remote sensing image pixels of every band and texture information of remote sensing image is put forwards fr om the angle of information fusion, and thus a quadtree-based region split-and-merge algorithm was designed and realized. The SPOT5 satellite image obtained on 31 March 2004 in the Zhixin County of Jiangsu province, China, was treated by the above image segmentation method and the proposed quadtree-based region split-and-merge algorithm. It is found that this image segmentation method could utilize the gray information of remote sensing image pixels of every band and texture information of remote sensing image effectively , reduce the partial working capacity in practical drawing work, and provide some serves for the classification of remote sensing image. Based on these treating results, it is inferred that the proper combination of many kinds of information may provide a new idea for solving some problems, but the methods how to make many kinds of information fused more effectively , need to be deeply studied in the practical research work.
It is an application field to extract DEM using radargrammetry method in tropical rainforest area.Digital Elevation Model (DEM ) images are generated from nine Radarsat21 images (F, S and W beam modes) which make up six stereo pair combinations, based on range/Dopple imaging equation. The selected study area is a tropical rainforest area which consists of a mixture of plain, hilly and mountainous terrain. The DEM accuracies for all the stereo combinations have been validated and compared to each other.The results show that numerous factors affect the final DEM accuracy, the higher the stereo in tersect ion angle of the same beam mode, the better the accuracy of the final DEM. In flat areas, the final DEM accuracy is higher than hilly and mountainous areas, and the DEM accuracy can reach to about 14 m (average error) and 29 m ( root mean square error) in this study area.
For commercial high-resolution satellites, access to calibration and ephemeris data have been withheld from users, and therefore alternative empirical rectification models have been developed. In general, most of these models are based on the use of control points. Yet, in photogrammetry, it’s hard to find ground control points which opposite to the control points in image. And much attention has to be paid to deal with GCPs. To these situation, the paper discusses the feasibility of substituting control line for control point in geo-correction and rationality of Line Based Universal Geo-Correction Model for HRSI.Real data have been used to check the validity and fidelity of the model, and the results show that the LBTM performs to a level comparable with existing point based transformation models.
The geometric correction is a bottleneck problem which baffles the remote sensing images' application. Geometric rectification is a nonlinear, uncertain, complex dynamic function and hard to be described completely , so a method of remote sensing image geometric correction based on the RBF neural networks and Ground Control Point ( GCP) is made in this paper. Firstly , the algorithm determines the control point used to correct . Then, use the characteristic of RBF neural network can represent all functions at any accuracy to simulated surface of this complex spatial distribution function of the nonlinear.From the experimental results, it comes to some conclusions: The algorithm' s principle is simple, and easy to be realized. Usually , the algorithm has an error less than one-pixel , which is accurate enough for geometric correction. It is a kind of more practical algorithm of the remote sensing image correction.
According to Syntheticaperture radar ( SAR) explainable is very different because of implicit multiply noise, the paper discusses a processed method based on direction filter and fuzzy logic-Fuzzy Direction Filtering. At first , the method selects a plane to be characteristic-plane according to contrast , then aggrandizes and fuzzesit , to get its fuzzy parameter; further more, it computes credibility according to the designed fuzzy rule. The final filtered image is composed of all the pixels with corresponding maximal credibility.In the experiment of SAR image, it tests the performance of different method by speckle-index and normalized meansquare error ( NMSE ) , All of the data and image effect has proved that the proposed method is superior to that of Lee's filter, Esafa's algorithm and weighted morphological filter. It can not only filter noise but also save image detail. It is a power ful idea and tool for SAR image processing .
This paper summarized the method and existent problems of visual in terpretation. According to the defects of grassland remotely sensed imagery in terpretation. We image to study a method of grassland remo te sensing image and background map semitransparent overlapped to improve visual in terpretation.The remote sensing image and thematicmap spatially will be overlapped on web. The operator can control the transparence of the remote sensing image to contrast and analyze the two maps. The study will develop the experimental software by applying the language of JAVA , the principle of WebGIS and the technology of in ternet.
From the programs and projects, the development status and strategies on Earth observing technology of the main countries in the world, such as America, ESA , Canada, Japan, India and Russia, are introduced and analyzed. Earth observing system (EOS) put forward in 1990s puts the Earth observing technology to the newphase, and compared with EOS, NASA Earth Science Enterprise (ESE) is in higher level by in troducing Earth System Science. ESA is in the front of the technology in the world after launching ERS satellites and ENVISATS. France is characteristic of high-resolution satellites such as SPOT series, and Canada is characteristic of RADARSATS. Japan draws up it s“Basic Strategy for Effects Regarding Future Earth Ob servation”in 2005 to be leadership in the field. Russia is strong space country but laps in development on Earth observing technology, so it will plan to develop quickly in the field. India, as a developing country, now has been paid at tention by the world.
Wetland specifies with both ecologic and scientific values. Because of most wetlands located too far to be monitored, satellite imagery characters with quantity information, multi-temporal, multi-platform , comparability will largely favor wetland research, so remotely sensed data have been widely proved an effective too lin wet land investigation in the past decades. The application of satellite RS technology on wet land research in China is reviewed from the aspects of the survey of wet land resource inventory, the model of wet land identification and classification, research of wetland dynam ic change, wetland vegetation biomass estimation and lately development trends as well as its principal characters of satellite RS research of wetland. Particularly, the paper introduces some progress of RS application on urban wet and in China.The detection study on dynamic change of wetland as natural resources by RS methods is also presented in a wide scope from in land plain wet land, deltaor riverine wetland to plateau wetland. Both academic Achievements and prospect comments are also presented in the paper by reviewing both home and abroad researches. The application trends of remote sensing in wetland research will be the following three aspects: much more multi-temporal and multi-spatial RS platforms will be provided for future research, the scale of research on wetland will be smaller due to the continuous loss of wetland as well as its fragmentation, and in tegration of RS, GIS, GPS and wetland will be much more emphasized.
Atmospheric aerosols impact the geochemistry, climate and environment . But it is difficult to study the distribution of the spectrum, the chemical composition and the circulation of atmospheric aer osols in detail, due to the indetermination of aerosol source and distribution in atmosphere. As a result ,the investigation of the aerosol dependents on the development of monitoring manners. Many detection means and instruments were adopt on aerosols research, especially the application of satellites remote sensing . Taking advantage of their space location, satellites can obtain the global, real-t ime, precise imagery ,which promote the evolution of aerosol learning . In the paper, the evolution of the earth observation system,and the application of EOS data and information on aerosol investigation was presented. At the end,it w s evaluated that the present status and major achievements of international atmospheric aerosol research based on the EOS program.
Land-cover data was foundation about study for globe change. The USGS Multi-Resolution Land Characteristics (MRLC) Consortium was originally formed in 1993 in order to meet the needs of several federal agencies for Landsat 5 imagery, and land-cover information. One of the results of this consortium was the completion of a successful mapping of the conterminous United States into the National Land Cover Dataset (NLCD 1992). The growing need for current Landsat 7 data, land-cover and other geospatial data with in the federal government culminated in reforming the MRLC Consortium in 2000 (MRLC 2000) ,
and derived a second-generation National Land Cover Database (NLCD 2000). This multi-layer, multisource, value-added database will include a suite of 302meter resolution data that will serve as standardized ingredients for the production of land cover-both nationally and locally. There was systematic Image Processing for standard image data. At first, mapping zones as a re-classification stratification method that was stratified landscapes into sub-regions of similar biophysical and spectral characteristics. To meet the requ irements of the land cover database, the scene selection strategy was based on image quality and vegetation dynamics of target land cover types over a growing season. For MRLC 2000 image Preprocessing,images are geometrically corrected using cubic convolution resampling. Images are radiometrically corrected using standard methods at the USGS EROS Data Center to eliminate band bias and gain anomalies. And then images are converted to at-satellite reflectance for the 6 reflective bands and to at satellite temperature for the thermal band. TC transformations distill original resolution TM bands into spectral-efficient transformations without losing important information. NLCD 2000 classification included clustering, expert system , neural network and decision tree classifiers. Land cover derivative data layers were initially assessed using cross validation in both regression and decision treemodels. At the meantime, there are some method to enrich the land-cover dataset. Image segmentation is the process of separating an image into homogeneous polygons that depict distinct regions on the ground. Using the segmentation output, four shape measures are calculated including, convexity, compactness, fractal dimension, and form. Image texture is indicated by variance in pixel DN values across space. Per-pixel imperviousness and tree canopy estimates that is based on empirical relationships between tree canopy density and Landsat data, established using regression tree techniques. In this text,We are expecting that could reflect its progress situation, enlighten to the local related work.
This paper expounded the application of wheat variable-rate nitrogen fertilization based on crop simulation models and remote sensed data. It was regarded as trends of precision fertilization by variablerate fertilization technology and nondestructive monitoring technology , progress of crop simulation models and precision variable rate technology were investigated and researched systematically. Crop simulation models aim at estimating agricultural production as a function of weather and soil conditions as well as crop management practices, and provide descriptions of canopy state variables and time integration of biophysical processes. Remote sensing technique is applying in many studies, such as the monitoring and protection of agricultural field, the estimation of yield in large area crop, the monitoring of crop growth, the monitoring of agricultural and meteorologic disaster and so on. So a data assimilation of crop simulation models and remote sensing data will improve grain yield and grain protein content and decrease the environment pollution rate. At last , the facing difficulties and out let of developing precision fertilization in China was brought forward.
The number of global land imaging satellites is rapidly increasing with the development of satellites technologies. Now 17 countries have middle to high resolution satellites in orbit , and by the end of decade there would be 20 countries. W. E. Stoney collected information about global land imaging satellite systems through the opennet sources. Then under standable tables and visual figures were made and the concise and comprehensive Guide to Land Imaging Satellites was edited for broad remote sensing users. In this technology report , we translated and edited this guide and 1 table and 4 figures were selected. The aim is to afford references for the internal relative researchers.
