Interference imaging spectrometry is in the frontier and hotspot of remote sensing technology and application.It has enormous application potential for its characteristics such as high luminous flux,high spectral resolution,and high-stability of imaging.We introduce the basic principles of interference imaging spectrometer.We will also give an overview of data processing technologies including spectrum reconstruction,calibration and atmospheric correction.Some representative spectrometers and their applications are reviewed in brief.Finally,it is pointed out that the effective approach to promote the development of interference imaging spectrometry shall be carrying out some research and applications based on HSI instrument loaded on HJ-1A satellite in our country.
ENVISat ASAR data has been successfully applied in indentifying and mapping rice in numerous studies,however the application in wheat is still needed to improve.As a case study,in this paper,multi\|temporal ENVISat ASAR data were used to identify winter at Tongzhou district,Beijing.GPS measurements and high spatial resolution image (WorldView\|1) were used to validate the classification result.With the wheat/non\|wheat classification accuracy of 94.87%,the result shows that ENVISat ASAR data has great potentials in discriminating winter wheat in North China.
To identify and extract rice information from remote sensing images rapidly,correctly and objectively,satisfied the needs of rice remote sensing monitoring in a large scale,the spectral reflection characteristic of rice was analyzed by spectral analysis method,based on HJ-1B data.With field survey data,1∶5 million digital elevation model (DEM) data for the auxiliary parameters,a remote sensing information identification model for rice was established.Using decision tree classification method to extract the information of rice.And the rice information was extracted in Binyang country,Guangxi province by using this method.The accuracy of this rice identification model was verified by GPS measured sample data and the precision reached 94.9%,Kappa is 0.8533.Results show that this rice identification technology can provide a technological support for understanding rice planting situation,monitoring rice growing condition and estimating the yield of rice.
As the ability of SAR to acquire high\|resolution image is increasing,the geometrical features of building,which provides important clue to reconstruct 3D model of building,are becoming clearer.We discussed the imagery configuration of building on SAR image,and present how to use these geometrical features to reconstruct 3D model of building.At last,two SAR slice images which contain remarkable L-shape layover of building were experimented on to verify the feasibility of this method.
Study the potential application of polarimetric correlation coefficients in residential information extraction by using Polarimetric Synthetic Aperture Radar (POLSAR) image acquired by ALOS\|PALSAR,including R-L circular polarimetric correlation coefficient |ρrrll|,H\|V polarimetric correlation coefficient |ρhhvv|,and normalized R-L circular polarimetric correlation coefficient |ρrrll|/|ρ0|.The research shows that:① |ρrrll| can extract effectively the residential information of cities and towns.Combination of |ρrrll| with |ρhhvv| can improve the accuracy on residential information extraction;② |ρrrll|/|ρ0| can be used to study the structure of buildings,but not the residential information extraction,especially in town.
Urbanization caused land use/cover and its spatial structure change become a hot spot for urban study.Multi\|temporal remote sensing imagery can detect land use change amount and its quality,so it is widely used in urban expansion study.In recent year,the landscape structure analysis was introduced and proved to be capable method to extract spatial structure of the urban land use.Numerous landscape metrics make the base for landscape structure quantitative delineation.But most of these literatures detected landscape structure on whole study area and ignored the local spatio\|temporal changes.We proposed a new grid split method to extract spatio\|temporal changes on landscape and a case study on Beijing is used to prove the method efficiency.The results show that grid split based landscape change detection method can detect the landscape spatio\|temporal change amount,location and pattern.This method will aid the urban expansion understanding and modeling as another knowledge source except multi\|temporal remote sensing imagery change detection.
Remote Sensing (RS) based soil moisture monitoring and estimating has advantages than conventional methods in large scale land survey and environmental evaluations due to its convenience in data acquisition.The procedure of soil moisture estimation based on multi\|source information fusion is proposed.First,the multi\|source data,such as weather information,soil type,spectrum characteristic curves and RS images are preprocessed to get the attribute data.The land utilization classification and vegetation cover intensity are calculated based on the formerly obtained data and the real survey data.Then a spectral decomposition model is proposed for soil moisture estimation.A case study is provided and the computational results of soil moisture show that the approximate estimation precision is 89.78% in lands with lower vegetation cover intensity.Moreover,the computational results fit fairly well with the measured data and show that the proposed model is feasible to be used for drought monitoring and early warning.
Coral reef plays an important role in marine ecosystem.Extracting coral reef information with remote sensing starts late in China and is mainly based on visual interpretation.This paper tries to extract the component information of Swallow Reef and Dallas Reef in Nansha Islands automatically using SPOT5 10 m multispectral data,aiming to explore its identification capability of subsurface information of coral reef.First,the remotely\|sensed information was separated into two parts using threshold segmentation method:information above the sea surface and that below the sea surface.After implementing Deglint correction on the latter part of information and introducing a derived band from SPOT5 with it,these images being grouped into 4 different kinds of combinations,were classified using maximum likelihood method.At last,the classification results are compared with QuickBird images,which are regarded as the truth data when the ground data is absent.Results indicate that Deglint correction can reduce the surface noise effectively.NIR band may help avoid the errors in classification caused by the different depth of the sea in some extent.The effect is not as good as expected when the derived band takes place of NIR.In sum,through processes designed in this paper,we could use SPOT5 10 m multispectral data to map components of the coral reef at more than 80% accuracy.
A preliminary work for remote sensing applications on large region is to query the coverage of certain remote sensing data and to know whether there are substitutes with similar scales for regions covered by clouds or snows,or for regions not covered by this kind of data.Generally speaking,the querying systems of all kinds of satellite data are independent,which makes the querying for coverage of multi\|source remote sensing (RS) tiring and time consuming.To fast query the coverage of RS data on large regions,a batch processing approach is proposed and a tool is developed based on ENVI/IDL.Firstly,the metadata are read from the text file.Secondly,the outline vector is generated with desired attributes.Thirdly,the four corners of the valid range of image data are detected.Finally,the preview picture is registered automatically.The georeferenced images and the outline vectors can be overlaid correctly with the vector of administrative boundaries according to their geographic coordinates.After proper metadata format selected and the input directory and the output directory input,the software begins to run in the batch mode without any interactive.It will finish the task very soon.This approach can greatly improve the query efficiency of multi\|source RS image coverage.Then decision can be made according to whether the valid coverage can meet the demand of the application.Thus the approach mentioned above and the software developed according to it are very practical and worthy of popularization.
Karst rocky desertification is one of the most serious geo-ecological disaster in Southwestern China.The extraction of rocky desertification regions and grade division of rocky desertification are the most important premises to do rocky desertification research.The percentage of bare rock is an important index to do rocky desertification grade division.Using scientific and fast methods to calculate the percentage of bare rock is the basis for the extraction of rocky desertification regions and grade division of rocky desertification.We proposed a multi\|spectrum remote sensing image\|based method to calculate the percentage of bare rock and the TM image at 1987 of Houzhai stream in Puding County,Guizhou Province was chose as experiment data.Firstly,the image was processed to attain the image object.Then,extract the Normalized Difference Vegetation Index (NDVI) and Bare Soil Index (BI) from the image by band calculation.NDVI and BI were used to calculate vegetation coverage and soil bareness percentage,respectively.Finally,the percentage of bare rock could be calculated by making use of layers arithmetic operation.The experiment result shows that the method proposed in this paper has feasibility.
Using 11 phase’s FY3/MERSI,the EOS/MODIS satellite remote sensing phantom material of May to September in 2009,monitors the Panjin wetland vegetation growing trend dynamic change,and unifies according to on\|the\|spot investigation 1∶ 100 000 land utilization chart and the cover type chart withdraws the Panjin wetland 122 element vegetation index,discusses the the dynamic curve of FY3A/MERSI wetland vegetation growing trend as well as MERSI\|NDVI and the MODIS\|NDVI relations.The result indicated that the Panjin wetland vegetation changes every day equally in the growth earlier period and the later period by 1%~1.5% speeds,on August 9,2009,the vegetation index maximizing is 0.66.MERSI\|NDVI and MODIS\|NDVI describes the description wetland vegetation growing trend in the time series which in the year changes that the two's monitoring result is close,correlation coefficient R=0.981,this has made up the resolution satellite monitor wetland vegetation growing trend blank which our country uses itself to research and develop.
TM images in 2006 were selected as the basic data sources,378 sample points were collected with the method of typical and random sampling by GPS and the total station.With the help of the statistical analysis software like MATLAB,SPSS,SAS,as well as the tools for modeling and spatial analysis like ERDAS,with the technology of remote sensing,globe positioning system and geographical information system,using mathematical and physical theories to establish the prediction model of forest volume with pixel as the basic unit,quantitative estimation modeling of forest volume were based on the methods included principal component analysis and multi\|element linear regression.The purpose of the model is to make the forest ecological system of the basin in balance and provide the scientific basis for exerting the best function of the ecological,economy and social benefits.
A Hyper-Spectral Imaging sensor (HSI) developed independently by China was loaded on the HJ\|1A satellite and put into service on March 30,2009.As a new type of sensors,the applications of HSI are still in the exploration stage.In order to make full use of HSI data and carry out effective remote sensing applications,the first thing need to do is to eliminate the atmospheric effect in the process of imaging and obtaining the real land surface radiation information.The FLAASH (Fast Line of Sight Atmospheric Analysis of Spectral Hypercubes) atmospheric correction model is used to correct the atmospheric effect of HJ-1A/HSI data.The corrected spectral reflectance is compared with the apparent reflectance,and the validity of atmospheric effect correction method is well demonstrated.Meanwhile the preliminary application effect of HSI data is exhibited by the retrievals of modified soil adjusted vegetation index （MSAVI） and leaf area index (LAI) based on the atmospherically corrected spectral reflectance image.
Under complicated geographic conditions,the spatial distribution of aerosol is comparatively significiant.It is hard to achieve desirable result only by using measured parameter of Aerosol or Dark Objects to carry out the atmospheric correction.Moreover,manually selecting dark objects requires sufficient expertise.Program is used to automatically find out dense vegetation pixels and vegetation pixels under shadow in mountainous areas as dark objects,which are evenly distributed in different district and evaluation,as many as possible.Next,a good imitation was made for complicated geography of atmospheric condition.Based on the radiative transfer model,some mathematical methods such as iteration and interpolation are used to obtain the optical depth of TM1 and TM3 bands.Then,the aerosol wavelength exponent and turbidity coefficient are calculated.Finally,the atmospheric optical depth of each band is calculated to implement the atmospheric correction.
Using the principal component analysis method of QuickBird image obtained the information of the first and the second principal component was 67.09% and 31.73% respectively,totaling 98.82%.Therefore,the first and the second principal component were selected to extract texture.We used the absolute variogram to extract the texture,the window size is 3×3 and the step size is 1.The land type was divides into four types,it is building, water body,vegetation and bare land. The topological structure of BP artificial neural network is 4-4-1,the hidden layer transfer function is S (logsig) and the output layer transfer function is linear function,the training function is Trainscg.Adopted the neural network to classified QuickBird multispectral image and the principal components texture image,also figure out the preceding kind of P=84.54%,Kappa coefficient K=78.50%;later kind of P=89.46% and Kappa coefficient K=85.29%.The results demonstrated that the image classifications were enhanced after texture was added.
Experiment was carried out using IRS-P5 stereo images in order to extract DEM and corresponding DEM precision analysis was performed.With at least 4 well\|distributed reliable ground control points,planar and vertical orientation accuracy can reach 2 m RMSE separately.Meanwhile this paper proposed two methods to inspect DEM precision,that is,sampling and differencing methods.By these two algorithms,we are convinced that this DEM can meet the geometric requirements of 1∶50 000 large scale maps.Actually,it has proven that this DEM acted as an effective auxiliary tool for power line selection.
The ubiquitous Bowtie effect in MODIS images seriously affects the application and subsequent processing of MODIS images,so it is necessary to recitify Bowtie effect during MODIS image processing.Bowtie correction method based on net function interpolation is proposed,which determines the number of repetitive rows using the latitude included in MODIS Level 1B products.The examples show that the method effectively recitifies Bowtie effect as well as solves the instability of calculating the number of repetitive rows by correlative coefficient method.
The adaptive fidelity model and adaptive total variation(ATV) model are analyzed,and the strongpoint and disadvantage of the variational method models are compared according to experiments.The ATV model and texture preserving adaptive fidelity model are combined to deduce a gradient descent flow,and the result proved that it can remove noise effectively applying to remote sensing images,at the same time,the textures of the images are preserved.Finally,improved research tasks needed by remote sensing image noise removal based on partial differential equation are discussed.
In July,2008,during the large\|scale synchronous remote sensing experiment of “WATER:Watershed Airborne Telemetry Experiment Research” in Zhangye district,Gansu province,we did the adjacency effect measurement synchronous with satellite at Lanzhou University grass site,with the device designed by ourselves.The adjacency effect correction coefficient was computed using backward least square algorithm.Then it was imported into the actual reflectance transformation equation to correct the adjacency effect of the synchronous ASTER image.The quality of the result image was improved.Moreover,the result image was analyzed compared with that the SHDOM equation.The result showed that,both the reflectance and normalized difference vegetation index of the result image corrected with the adjacency effect correction coefficient had greater differences,meanwhile the spatial autocorrelation between pixels decreased obviously.〖JP〗
Processing remote sensing image was always a time\|consuming task in WebGIS,because all the process was placed in server side.Presently,using FlashPlayer 10,Flex has the ability to leverage customized shader which can be written by PixelBender for image processing and enhancement.Based on this technology we designed a new WebGIS architecture,placing remote sensing image process in browser side.The result of a prototype system of this architecture is promising and shows that the architecture can achieve better performance than traditional methods.
By study of current grassland background,it described an application combining J2EE,JSP,JDBC,MVC,ArcIMS and MS SQL database to achieve the display results by invoices,maps,reports on the Web.This would provide decision support and modern management platform for governmental work on grassland protection.It makes officers in government departments to login system,monitors the general information about national grassland construction and protection,local engineering scope,progress of works,and the comparative analysis before and after each project.It also provide essential support and remote sensing monitoring for biohazard and natural disaster.
he oceanic internal wave information system is mainly designed for effectively manage and publish oceanic internal wave data and provide spatial query and thematic map for specific users through Internet/Intranet.Based on the system structure and functions of WebGIS development platform\|ArcIMS 9.2,it describes the system design,data structure and development in details.By using this system,authorization user can search spatial distribution,velocity,wavelength,amplitude,direction and other relative information of oceanic internal waves.Besides that,this system also provide functionalities to make their own custom thematic map of oceanic internal waves,which could be a great tool for the relative department to make decisions.
Rigidization technology is one of the key factors of inflatable and deployable antenna for space use,especially for defending the space debris.The antenna materials together with the rigidization technology are analyzed and devised,furthermore,analized the rigidization of aluminium foil and plastic foil in detail,a possible solution of the Al/Mylar layer rigidization technology for a parabolic antenna is proposed.
