Proc. SPIE. 7285, International Conference on Earth Observation Data Processing and Analysis (ICEODPA)
KEYWORDS: Human-machine interfaces, Landsat, Data modeling, Image processing, Geographic information systems, Data archive systems, Standards development, Earth observing sensors, Web services, Classification systems
With the increase of geospatial data and services, how to more efficiently utilize and share the geographic information
becomes a crucial problem. To effectively integrate and enhance abundant geographic information anywhere, this paper
presents a Registry Centre for Geospatial Web Service (RCGWS) based on the Open Geospatial Consortium (OGC)
Catalogue Service for Web and the ebXML Registry Information Model (ebRIM), which provides registration and
discovery portals for geospatial metadata for dataset and services. The design ideology and architecture of RCGWS are
introduced, and the techniques of appending GIS services classification in extended ebRIM and external interfaces of
RCGWS based on OGC CWS are discussed. The implementation of RCGWS platform shows that this Registry Centre
can satisfy the requirement of geospatial dataset and services.
Web services and web service composition technology have become the primary methods to realize geospatial
information sharing and interoperability. There are various integration models and many specifications for web services
composition, BPEL4WS is the most typical and prevailing one. But BPEL4WS is IT-oriented, the syntax structure is
complicated, a well understanding to XML specifications and web services specifications is demanded, the way to
describe processes and define activities in BPEL4WS are different from ways in certain domain, service contracts need
early binding before the process instance execution. For above reasons, BPEL4WS is not suit for geospatial processing
process's visual modeling. In this paper, an abstract geospatial service chain model based on data-dependent relationship
is designed. A mapping algorithm is also proposed for translating the abstract service chain model into BPEL4WS form.
So geospatial experts who are not web services experts can intuitively modeling service chain, translate the model into
BPEL4WS style and execute it using BPEL4WS engine. Based on these researches, a geospatial web service chain
visual modeling platform prototype is built, aiming to meet modeling demand of geospatial domain experts and common
Most spatial data organizations need automated conflation technology. For the same geographic area, an organization usually has several sources of spatial data, with each source differing in terms of available spatial features, attributes, resolution, accuracy, and other qualities. Processing multiple sources of spatial data, along with their respective differences and advantages, is a huge and ever increasing problem. The maintenance of spatial data is very costly and time consuming. This situation will become intensified when more and more digital spatial data are offered by using Internet technologies.In this paper the conflation technology for integration of spatial data from different source on the Internet is introduced. Conflation attempts to match the spatial data of the source and destination coverage. If the coverage have different origins, it is likely that the shapes, and even the locations of the features, do not match exactly. Most conflation algorithms only match similar features that are very close to each other. But indeed, spatial object is defined by its location, shape, attributes and relationship to others. Therefore, before the matching itself, the semantic relations, topological relations and geometrical matching technologies have to be probed. The research work is performed on road network, which are captured in different data models on the Internet. The approach is based on matching criterions between the spatial data of different data models. At first, the semantic relations have been considered, and then different data models compare with topological relations and select the similar data sets. The geometrical matching has been done in the selected data sets and chooses the best reasonable one for the conflation result. It can get more quickly speed than other conflation approach based on statistical investigations before.
In this paper, a model for web spatial data visualization based on the oracle spatial database is presented. The paper introduces the basic concept of spatial database and web services, then discusses the four-layer structure of the application on web services, that is: the client, the application server, the web services, and the database server. The paper analyzes the system structure of the data model, the data organization and the expression of spatial graphical features.
Moving objects are complicated to manage because they involve temporal attributes as well as spatial attributes. There are two methods to represent the motion of moving objects, function method and sampling method. Motion state modeling, based on sampling method, can give object's position, orientation and their changes at a specific epoch, and encapsulates all the calculation by object orientation method. A big job is to search the motion state vectors efficiently, which can be performed with the help of 2n index trees. 2n index tree is an efficient index method to multi-dimensional data. Different kinds of motion data retrieval can be transformed to basic searching in 2n index trees. With proper operation algorithm, 2n index trees work well with the indexing and retrieval of moving objects.