Data sharing could play an important role in the promotion of science development.Comprehensive scientific datasets should be serviced in the composite scientific data center.The rights of scientific data providers should be protected as the availability of the datasets,and should be guaranteed in the composite scientific data center.The current development of the scientific data sharing was reviewed,then a B2C pattern based data sharing system for composite scientific data center is designed which treats is treated scientific datasets as a kind of virtual commodity,and the functionalities of users,data providers and the manager of data center are also implemented.The key issues in scientific data sharing are discussed from five aspects:the description of scientific datasets,the release of scientific datasets,the discovery of scientific datasets,the circulation of scientific datasets and the evaluation of scientific datasets.As a case study,the environmental and ecological science data center for west China use the B2C pattern based data sharing system to service its users with good achievements.
Data collection could play an important role in the promotion of science data sharing,it is especially important in the major scientific research programs.While the integrated research on the eco-hydrological process of the Heihe River Basin (hereinafter referred to as “Heihe Plan”) was officially launched in 2010 by National Natural Science Foundation of China,the rule of data collection and sharing was also discussed by the experts of the Heihe Plan,and it was carried out in 2012 by the Heihe Plan data center.The current development of the scientific data collection was reviewed,then the core of the rule of data collection and sharing of the Heihe Plan was introduced,a series of workflow were designed for the data collection system with protecting the intellectual property of the collected data.The key technologies are discussed from four aspects in the implementation of the data collection system:the integration of GeoNetwork,the data auditing system to promote the data quality,the fast data service system and the data mining supporting system.
Data service is necessary for sharing scientific data and a good data service will significantly promote data sharing.Environmental and Ecological Science Data Center for West China (WestDC) established in 2006 has been operated stably now.We have accumulated rich experiences for data services,and have come to realize the importance of data services to data providers and users,as well as that of data quality controlling.To improve efficiency and quality of data services,some feasible service ways are applied,such as examining and approving of data application,data citing,data quality review and data collection.These efforts are helpful for promoting the atmosphere of data sharing in China.
Digital Object Identifier(DOI) provides a system for persistent and actionable identification and interoperable exchange of management information on digital networks.DOI has been widely used in scholar publishing.More and more people pay great attention on the application of DOI in scientific data sharing.Basides persistent and unique value,other potential values of DOI application in data sharing involves:citation value,data linked value,integration value and tracking value.This paper suggested that the data center,DOI registered agent and journal should collaboate for data citation.DOI registry agent should set up a data publishing platform that is similar to DataCite to provide standardized data citation information to users.Data centers should clarify the copyright information of data resources,and provide recommended reference formate of dataset to user Journal editors,which should guide the authors to cite data in refernce part of paper.
Scientific data publishing is an important mechanism to promote data sharing,which can encourage researchers to share their data,and can protect the intellectual property of data.This paper makes a review on scientific data publishing,proposes a framework for scientific data publication from the perspectives of data center and publisher.The data publication system involves five basic parts:peer review,publishing,long\|term data storage,data citation and data impact evaluation.And the goal of data publishing will achieve only via cooperation of data center,publisher and independent rating agency.This paper also discusses some key issues on scientific data publishing such as data licensing,digital object unique identifiers,and data reusage.We suggest establish data publication system in China as same as focus on service to key research projects.Academic journal in China should force authors open their data to public before paper publishing and encourage authors to publish data paper.Data centers with long-term data storage capacity should provide citable dataset with permanent link to users.Data centers also need to help academic journal for data registration and management.
This paper reviews the methods,state of the art and technical background of watershed science research and puts forward the current watershed research urgently needs watershed hydrology information system,and the hydrological information system focused on watershed data modeling and data sharing services.Hydrological information system is a combination of technologies geographic information systems,internet,database and hydrology research.Watershed information infrastructure for integrated observation and environmental information has become the important applications of “Digital Earth” in watershed science.Based on the latest progress of Arc Hydro geographic data model and open source hydrological information system have developed by Consortium of Universities for the Advancement of Hydrologic Science,Inc.(CUAHSI-HIS),this study proposes a function design for hydrology information systems as online portal of digital Heihe,which is suitable for typical inland river basin-the Heihe River Basin in Norwhwest China.Integrated watershed geographic data,observational data and data sharing services in a hydrological information system will be effective in promoting all aspects of watershed science research.
In the light of the demand of resolution for assembling,storing,managing and sharing the WSN observation data uniformly,this paper puts forward a system solution,named “Field Observation Data Automatic Assembling System”,which includes several modular function components to assemble and preprocess WSN observation data automatically.Five independent components are designed in accordance with the characteristics of the WSN instrument.
In order to automatically receive data from different types of remote WSN observation instruments which were deployed in the Heihe River Basin and simplify the complexity of the back-end automated warehousing procedures,we have conducted normalization processes for the data interface by which remote data are received,based on their own different characteristics of instruments in all types.We designed and implemented a data storage system which can stores remote observational data with no needs of any human intervention.Those experiences provide a basis for an effective and efficient wireless sensor network in Heihe Watershed Allied Telemetry Experimental Research in future.
A database was designed using the object-oriented method especially for the ongoing research programme,titled Heihe Watershed Allied Telemetry Experimental Research.It was implemented by identifying entity classes and relationships between them,then mapping classes and their relationships into tables and tables relationships.The database contained seven data tables to implement a hierarchical structure to store information of observation sites,data logger instruments,sensors and observation records.This design supported dynamic hierarchical structure, without the need of modifying database structure.The observed records from any sensors were stored in a same table so as to reduce complexity of maintenance.An optimization schema by using PostgreSQL inherence was employed to optimize data storage,solving the conflict arising from efficiency consideration of data storage and inquiry speed.
The WSN system of ongoing programme,Heihe Watershed Allied Telemetry Experimental Research,generates a huge number and variety of observation data.In order to effective manage and apply these data,we designed and implemented an online visual Web system.Proceeding from the management of observation data and the visualization angle,we made the detailed design for the system which includes five functional modules,such as observational data visualization,static information input,the device monitoring,management,demonstrating application and provides visual means which contains a map,a variety of type Vector,topology diagrams,lists,pictures,and video.This system has been normally running more than ten months and handled over four hundred million observation records,which proves its significance in managing WSN devices and generating data.
Accuracy validation and cloud obscuration removal are the basis of using MODIS snow cover products to monitor snow cover change.In this paper,selecting Landsat ETM+ data of typical snow covered region as “ground truth” images,the accuracy of the MODIS Fractional Snow Cover (FSC) products over Tibetan Plateau (TP) is evaluated by comparing with these “ground truth” images.Then,to fill in the data gaps caused by clouds,a cloud removal method which based on cubic spline interpolation is developed.And the effectiveness of this method is evaluated by using the “cloud assumption” method and comparing the MODIS-derived Snow Covered Days (SCD) with the in-situ observed SCD.The results show MODIS FSC products have higher accuracy to reflect snow cover information over the TP.Comparing with the FSC “ground truth”,the overall absolute error,standard deviation and correlation coefficient for the MODIS FSC products over the TP is 0.098,0.156 and 0.916 respectively.The cloud removal method is efficient in retrieving the FSC information of these cloud covered pixels,the overall absolute error of the retrieved FSC data is 0.092.There is a relatively high consistency between MODIS\|derived SCD (which is derived from the cloud removed MODIS FSC products) and in-situ observed SCD,and the mean absolute error is 3.82 days.
3.Gansu Administration of Survey,Mapping and Geo-information,Lanzhou 730000,China)
Correcting RPC file come from WorldView-2 images on the basis of GPS ground control points,the Digital Elevation Model (DEM) in 1∶5 000 was rapidly extracted using the image matching technology of digital photogrammetry software system based on the three\|dimensional model in Dayekou watershed (DYK) in the upper stream of the Heihe river basin.Due to the complex terrain,inaccessible area,south of the study area hadnt ground control points covered.Based on the interactive operation of the three-dimensional model,60 tie points distributed uniformly were obtained to improve the accuracy of the automatic extraction of DEM.And in main areas,such as the shady forest coverage,the Dayekou reservoir and so on,we must edit the DEM by revising and adding the terrain feature points,and line data can improve the accuracy of the results.Check points were composed of 15 GPS points and 12 model confidential points,which used for quantitative validation.Results show that the maximum error was 1.9 m in the two sets,which achieve the requirements of one degree accuracy of 2.5 m in this mountain scale.
Image fusion is a kind effective way which gets higher spatial resolution and spectral resolution,How to keep the spectral characteristics of different ground targets is the key of Image fusion.QuickBird is classic high space resolution satellite data,and studying on the practical methods for QuickBird data pretreatment and fusion has great significance in prompting the QuickBird data application.In this study,taking QuickBird data for example,comparison is made with four fusion algorithms suited for high spatial resolution remote sensing image,including High-pass filter,Wavelet,Gram-Schmidt and Pan-sharpening,and spectral angle and spectral distance that reflect different ground targets spectral curve diversification before fusion and later are used for quantificational assessment.Experimental results show that Wavelet fusion algorithm can improve spatial resolution while maintaining maximum spectral information of the original multispectral image,and it is the most suitable for QuickBird data fusion.
Spaceborne Synthetic Aperture Radar (SAR) sensors not only has the capabilities of penetrating clouds and providing day and night remote sensing data,but also has the capability of penetrating snow cover to retrieve subsurface information.In this paper,10 scenes of ENVSATASAR images were acquired with multiple incidence angles,which were used to characterize the seasonal variations of snow covered landscapes in the upper reaches of the Heihe River Basin from 10 April,2011 to 15 September,2011.Besides,12 MODIS images were used to provide background information,as well as support the monitoring of spatial and temporal variability of snow cover.During snow melt period,the presence of liquid water within the snowpack,which increased the snow dielectric constant,resulting in an appreciable decrease of backscatter coefficients in comparison with dry snow and snowfree soil surface.According to analysis of snow cover spatial and temporal variability of study area,the mostly common used -3 dB threshold clearly underestimates snow cover in our study area and the -2 dB threshold was applied to retrieve the wet snow cover.On the basis of the wet snow cover map,in association with DEM data and wet snow cover percent image which derived from Sigmoid function,the dry snow cover areas were mapped.The final snow mapping results were compared with the classification image of ETM+,and the total accuracy reached 78%.The spatial and temporal variability of snow cover indicated that the main errors were caused by snow rapidly melting process in northeast and northwest low altitude area from 10 April,2011 to 13 April,2011.
This paper gives an introduction about a new kind of data acquisition system which can collect certain kinds of eco-hydrological data such as soil temperature,humidity,salinity and conductivity.The system is based on microcontroller.The sensor interface circuits,communication timing control circuits,SD storage circuits and display circuits were designed for the Hydra Probe II soil property sensor.Based on the requirements of Eco-hydrological wireless sensor network in Heihe river basin,the communication protocol between data acquisition systems and the sensors were realized by SDI-12 bus.The Eco-hydrological data can be measured,stored and transfered by the proposed system.Combined with Network communication and Watershed data management platform,an eco-hydrological wireless sensor network can be easily realized.
Every MODIS Land Product includes Quality Assessment (QA) which that provides pixel level quality information in order to achieve an informed application.However,QA are stored in a packed bit layer,which is good to save space yet bad to input it into traditional image processing systems.This paper explored major steps to decode packed QA for MODIS Vegetation Continuous Filed,using LDOPE tools,induding(1) Understand QA-related Scientific Data Set (SDS) based on specific MODIS land product,“cloud” for current case study;(2) Installations of LDOPE and MRT;(3) Mosaic,unpack,and restore QA in LDOPE,two ways were tested-single file and multiple file;(4) Map re-projection and file reform in MRT;(5) Validate geo-location and QA attribute in ENVI.Through above processing,QA will be analyzed with relevant MODIS land products in pixel level.
It is difficult to obtain true color composite image that is consistent with human visual effects,since each spectral range of hyperspectral remote sensing image is narrow.In order to solve this problem,a true color correction model was proposed based on the physical mechanism of color generation.The model fully employed all spectral information in red,green,blue reflection zones of hyperspectral images and reconstructed true color composite images by band interpolation and band weighted integral.Then,in\|situ measured surface reflectance spectral data was added into MODTRAN atmospheric radiation model to obtain theoretical color of targets with radiant transfer simulation.Finally,in order to establish correction matrix between reconstructed color and theoretical color of targets,and construct a universal true color correction model we solved some overdetermined equations.The experimental results of airborne hyperspectral remote sensing images show clearly that the true color correction model can be applied to true color correction of hyperspectral remote sensing images,and can also be extended to multi\|spectral remote sensing images.
In view of the existing problem that spatial information at different levels lacks association,a new calculation method of spatial information regional relationship which is based on the subdivision codes,is put forward in this paper.First,based on GeoSOT subdivision framework,subdivision grids are used as the basic unit to represent geographic objects at different levels,and geographic object subdivision codes are generated by the multi\|scale expression oriented subdivision Encoding Method.Then we propose the calculation method of spatial information area inclusion relationship which is based on the subdivision codes,and present the detailed algorithm flow.Simulation experiments on the prototype system show that the method is concise,easy to implement,and the association between spatial information at the different levels can be established effectively.Furthermore,the subdivision information tree is adopted to achieve a unified management of spatial information,which provides an effective solution to organize and manage spatial information at different levels in subdivision system.
The use of sensitivity has limited application in evaluating the performance of the Aperture Synthesis Radiometers (ASRs) with complicated calibrations.These limitations are overcome by instead of the measurement uncertainty.Considering the linear mapping between the reconstructed brightness temperature distribution and the visibility samples,a measurement uncertainty estimation approach to the visibility samples is introduced to characterize the performance of the ASRs.Firstly,the mathematic model of the visibility sample and the calibration parameters is established by the calibration procedures.Then,the measure uncertainty of each calibration parameter is estimated.Finally,the combined measurement uncertainty of the visibility sample is estimated based on the mathematic model and the measure uncertainty of each calibration parameter.For ASRs calibration,the measurement uncertainty estimation approach of the visibility sample could be used to choose the reasonable calibration parameters and optimize the calibration procedures.
Blind Source Separation (BSS) is a frontier basic technique in modern signal processing.These blind source separation techniques have a good application foreground in hyperspectral unmixing.The basic principles,concepts and mathematical models of independent component analysis (ICA),Non\|negative Matrix Factorization (NMF),Complexity Analysis (CA) and sparse component analysis (SCA) are systematically introduced,and the application status of these techniques in hyperspectral unmixing are also emphatically elaborated in this paper.Finally,by comparing the advantages and disadvantages of each method,the challenges and the potential to applications of blind source separation techniques in hyperspectral unmixing are discussed.
With the increasing needs of multi-source image in various fields,it becomes a hot spot that how to efficiently manage multi-source massive remote sensing data.At present,many scholars at home and abroad have researched into construction of multi-source remote sensing image database,but the study of multi-source remote sensing image data organization,the remote sensing image data pre-processing and fast index are still insufficient.This paper designed a multi-source remote sensing data organization model,and it can achieve the aim of integrated management of multi-source image.This paper developed a semi-automatic preprocessing mechanism of multi-source mass image,which greatly reduced the processing time.A hybrid retrieval method was proposed to search image data efficiently.The results showed that the efficiency of building a database significantly improved.According to experiments,the hybrid index greatly speeded retrieval efficiency.When the amount of image data is smaller,the hybrid index at least can improve query speed by 4 times.While the amount of image data is very larger,the hybrid index at least can improve query speed by 12.83 times.
Based on the ground observation data measured by sun\|photometer,the applicability of C005 AOD products and the AOD’s character in China’s different climatic agricultural regions are evaluated and analyzed,the results show that:(1) The applicability of C005 AOD products in different climatic agricultural regions reach the desirable precision of NASA.Compared with the applicability of C004 AOD products,C005 AOD products can not improve the applicability in subtropical monsoon climatic agricultural region;Some improvements are gained in the temperate monsoon climatic agricultural region;the greater progress is proved in the temperate continental climatic and plateau climatic agricultural regions.C005 AOD products can get quite accurate inversion in July with dense vegetation.Compared with ground observation data,there are small positive differences of the inversion values in plateau and temperate continental climatic agricultural regions,however,small negative differences exists in subtropical monsoon and temperate monsoon climatic agricultural regions.(2) The changes of AOD in plateau climatic agricultural region are smooth,other regions show a significant variability with temporal change.What’s more,the AOD in temperate continental climatic agricultural region presents a minimal diminished trend,but a minimal increased trend in other three regions.
As watershed management involves multidisciplinary sciences including not only natural physical science but socio\|economic science,a good practice generally should take into account multidisciplinary model integration so as to bring together their individual strengths to solve complex watershed problems encountered.Decision Support System (DSS) plays an important role in watershed management in helping decision makers evaluate water resources scenarios and make optimal decisions by applying latest achievements of scientist community to management practices.Traditional DSS is insufficient to solve multidisciplinary problems because it usually acts like a toolkit containing a single or several models and is not designed to address model integration issues.In this paper,a new DSS prototype supporting multidisciplinary model integration is proposed.A node\|link based approach is adopted to enable technical integration of models with different temporal and spatial scales.By introducing the definition of compound node,the system can theoretically be extended to model arbitrarily complex watershed problems.In the underlain layer,the model library is implemented by a flexible script mechanism and can include any model with small modifications to encapsulate original model.A multiple criteria decision method is implemented to support evaluation of decision scenarios,through a special design that links model outputs to decision indicators.In view of common obstacles to optional run,this paper also highlights our consideration and implementation of a scenario-driven conceptual decision making flow,GIS supports,and easy to use for user interface such as wizard\|style scenario setup steps.
ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) has been used extensively in lithological discrimination.However,using multi-methods to enhance and identify the mafic-ultramafic rocks have rarely been reported in China.This study took Huitongshan in Beishan area,Gansu as the study area.Multi-methods such as band ratio,minimum noise fraction and mafic index were adopted to enhance and identify the mafic-ultramafic rocks using ASTER data.The study results were compared with the geological map,and conformed to be consistent with the geological map of the study area.Eleven new gabbro prospects were identified at the first time by synthetic analyses of remote sensing results and geological data.Through ground inspections of nine prospects,all the nine sites were consistent with the prospects and nine new gabbro occurrences were discovered.The result shows that using remote sensing data and multi-image processing methods are effective to map mafic-ultramafic occurrences and can be used in the remote inaccessible region.
Because of the high salinity,the spectral features of the salt field in the coastal areas in Shouguang of Shandong are greatly different from marine water bodies and other ground objects spectral features; the salt field is man-made,so,it has regular arrangement and significant geometric characteristics.In the remote sensing images,the above characteristics are shown as significant texture features (chessboard-like texture and stripe-like texture) and the texture indices have an excellent computability.In this paper,Firstly,using the tasseled cap transform to enhance spectral features of the salt field and using the directional convolution and the gray level co-occurrence matrix to enhance the texture features of the salt field.Secondly,based on the enhanced spectral and texture features,the TM image of the study area is classified by using the application-oriented interested ground objects extraction.The classification result is compared with the classification results based on spectrum only or texture only,the overall accuracy is respectively 90.8985%,84.9102% and 60.4017%.The result indicates that the accuracy of the classification method proposed in this paper is the highest.
With the launch of the WindSat instrument on the Coriolis spacecraft on January 6,2003,a new era in microwave radiometer began.WindSat is the first fully polarimetric spaceborne microwave radiometer.Fully polarimetric microwave radiometer is a new passive remote sensing instrument,which can measure the whole of four Stokes parameters of sea surface radiation,providing a new technique for sea surface wind vector measurement.In the first place,some instrument characteristics and application in ocean remote sensing for some advanced spaceborne microwave radiometers in the world are introduced in this paper.The radiometers include SSM/I,TMI,AMSR-E,AMSR2 and WindSat.Secondly,the variation mechanism of microwave emission signals from ocean is reviewed,and wind direction harmonics of polarimetric signals from wind-induced roughened sea surface and their advantages in wind vector retrieval are discussed.Finally,the main ideas of retrieval accuracy and difficulties of sea surface wind vector retrieval technique using fully polarimetric microwave signal are summaried in detail,and development direction of this technique is prospected.
This paper takes Ebinur Lake as the research object.In order to establish the linear and nonlinear regression models which are significant correlation between phytoplankton biomass and remote sensing factors,the correlation between remote sensing of various factors and phytoplankton biomass is analyzed based on spectral data of CBERS-2.The optimal model that is used to inverse Ebinur Lake phytoplankton biomass is selected by result comparison and residual analysis,and make biomass production map which is used to analyze the distribution of phytoplankton biomass and estimate the total phytoplankton biomass in Ebinur Lake.The optimal model is for the independent variable binary linear regression model:Y=3.819-0.027 (G-B)-0.04(G-R),its degree of fitting is 0.832,and the average residual coefficient is 6.9%.Ebinur Lake phytoplankton biomass total is 9.95×105 kg.Using remote sensing means to study Ebinur Lake phytoplankton biomass has important significance in Ebinur Lake biological yield estimation,its biomass growth rule and Ebinur Lake ecological system.The analysis of the space distribution features of Ebinur Lake phytoplankton biomass provides powerful basis for Ebinur Lake wide range,fast,long\|term dynamic monitoring and obtains plankton information and water quality parameters.
