Job Scheduling Research In Virtual Observatory Data Access Service(VO-DAS) And VO-DAS Application

The resources of observed data in astronomy have such characters as large time span, great quantity of data, break-up storage and management, heterogeneous management tool, and so on. An important research subject of the virtual observatory is about how to provide the astronomers with a programme on visiting these resources stored in different organisms.The great development of the computer and the internet technology, the emerge of the totally up-to-date IT technology, such as grid technology, XML technology, semantic network technology, and so on, and on this technology background, according to the character of astronomy itself, the International Virtual Observatory Alliance(IVOA) continuously put forward and make them perfect various standard document, this make it possible the merge monolithic of the astronomy data which great capacity, break-up and multiple wave band.As for consolidated visit to the resources stored in different organisms, basing on OGSA, we put forward a solution programme for the grid: making use of the OGSA-DAI technology, we can carry out the DataNode of the astronomy data about the surface of the stars, the picture data and the spectrum data in different organisms; taking advantage of ADQL language, we can go through with the description of the whole task; grouding on WSRF structure, we can make it perfect in dispatching tasks of the data resources, caculation resources and storage resources. The VO-DAS that we have designed bring into effect the close-coupled work pattern: auto-discover the data resources, caculation resources and storage resources, visite the resources stored in different organisms and data-analyse the result , this will make it possible the multiple wave band cross-authentication, the data-analysis and the visualisation of the analysis result. VO-DAS support all the related standards of the IVOA, this makes it have excellent operability, its external interface is simple and practical, it can develop various grid application products aimed at different demands of different astronomy data clients.Focusing on diapatching VO-DAS tasks and bringing it into effect, we elaborate on the modules of VO-DAS, such as its design mode, Session organisms, life cycle, resources destroying, exception handling, and so on, and put forward the blue prints of the system indifferent angles. To verify the feasibility and performance of the visit to the astronomy data basing on OGSA-DAI, we adopt two scientific model to test the prototype of VO-DAS.Take for example the expansion of the VO-DAS to the caculation platform of the China-VO Ephemeris WS, we introduce the expansion method of VO-DAS' exterior interface, and VO-DAS' application in the caculation of the star calendar, and we also elaborate on VO-DAS' application in the scientific applications in the other fields.