Presentation on theme: "Viewing and Features ShowSky - a Jini aware Applet/API astronomical archive discovery tool Object Design and Implementation Guide Star Catalog-II Jini."— Presentation transcript:
Viewing and Features ShowSky - a Jini aware Applet/API astronomical archive discovery tool Object Design and Implementation Guide Star Catalog-II Jini Enabled Interface A Demonstration of Jini Technology applied to Astronomical Archives A visualization tool has been developed for accessing both astronomical image and catalog archives using Jini. This technology provides many inherent features which are beneficial in managing a distributed community of archive services. Using the GSC-2 export catalog, the COMPASS database, and the DSS image archive at STScI, an extensible object-model was designed to include cross access to these internal datasets as well as external archives such as Hipparcos, Tycho, and the SDSS Science Archive. What is presented here are the JAVA components and the Jini architecture as applied to a query for small field acquisition, viewing, and analysis that is conducive to multi-archive interoperation. Multiple Catalog Viewing Users may select several source or image catalogues to overlay. We have found this to be essential for quality control in the GSC- II project. Publicly available archives Listing the sources in a Table - Star, Galaxy, etc. List grouped by catalog sources from each selected catalogue which are in the current field of view matches selected filter options ShowSky Catalog and Image Community A simplified view Service-based architectures are one of the simplest systems to design, maintain, and enhance. They support network growth as both the internal complexity of a network evolves as well as expansion to external network connectivity. There is a shift from a brittle wire-based network to a distributed set of services with failover protection insured by strategic placement of services. As the network contencts change, a Jini community can adapt to what is present. Filtering Allows filtering of the displayed sources Selections for Magnitude Range Source Classification Band Code Propermotion The COMPASS filter applies only to catalog sources coming from the COMPASS database. More field will be added to this in due course. Special Features Multiple Catalog Viewing It is possible to select several source or image catalogues to overlay both for quality control inspection Animation Proper motions are available for some GSCII stars and all ESA'S Hipparcos and Tycho Catalogue entries. This tool uses the proper motion information to plot star motions into the future. The motion Panel on the right of the tool allows the user to select a step (how fast the animation goes) in years and checkbox for tails. When "tails" are selected the old star is not un-plotted so a tail effect is seen showing the path of motion. Hierarchical Triangulated Mesh Object naming scheme common to multiple archives based on Spatial subdivision of celestial sphere using quad-tree algorithm 4 spherical triangles at each level Acknowledgements The Digitized Sky Surveys and Guide Star Catalogs are produced by the Catalogs and Surveys Branch of the Space Telescope Science Institute with the support and assistance of the following institutions. The Association of Universities for Research in Astronomy, National Aeronautics and Space Administration, Osservatorio Astronomico di Torino, European Southern Observatory, Space Telescope European Coordinating Facility, International GEMINI Telescope, European Space Agency Astrophysics Division, Canadian Astronomical Data Center, Centre de Données astronomiques de Strasbourg, Anglo Australian Observatory, Royal Observatory Edinburgh, Palomar Observatory, National Astronomical Observatory of Japan, Beijing Astronomical Observatory, Astronomical Society of the Pacific. G. Greene 1, W. OMullane 2, B. McLean 1 1 Space Telescope Science Institute, 2 ESA/ESTEC Why Jini? JINI service Http RMI transport COMPASS ooDB GSC-2 GSC-I Tycho Hipparcos DSS ShowSky UI Archive Server SDSS JINI registered ArchiveServer allows WWW served archives to join community. RMI archives registered as separate JINI services. Jini Servers Archive Server Servers Many servers and services may be made available via JINI. Any machine may be used to host the JINI services. The main service required here is the lookup service called reggie. Reggie requires rmid (The RMI activation daemon). ShowSky Package Object-Oriented Configuration Client Broadcast JINI discovery works on broadcasts and as such will not work over WAN. There is however also the possibility to provide one or more hostnames which should be checked as well as doing a broadcast. This provides the best of both worlds. The JINI servers and the JINI client have been written to take advantage of this. A host name may be specified in the property LOOKUPURL in a propertyfile. Then this host will be searched/used for registration. Should this host not be running reggie the broadcast will still find another host on the network running reggie if possible. Rational Rose component and logical model JAVA code generation Software Infrastructure - JAVA (1.3 ok), Jini 1_1, JAI 1_0_2, nomfits Open Source Software Activatable Jini Services The class.stsci.server.LaunchService is provided to launch Activatable servers and register them with the rmi activation registry. For this to work rmid must be running on the machine. RMID keeps a log of activated services and restarts them each time rmid restarts.