GEOCOMPUTATIONS AND RELATED WEB SERVICES J. A. Rod Blais Dept. of Geomatics Engineering Pacific Institute for the Mathematical Sciences University of Calgary, Calgary, Alberta T2N 1N4 blais@ucalgary.ca www.ucalgary.ca/~blais
OVERVIEW • Introduction • High Performance Computing (HPC) • Geodata, Metadata and Scientific Gateways • Web Services, Models and Frameworks • Virtual Globes: Earth, Virtual Earth & FreeEarth • Virtual Observatories (VOs) and HUBs • International Web Collaboration • Concluding Remarks
INTRODUCTION • Geocomputations often involve HPC • HPC grows exponentially but unfortunately, data often grow faster in volume and complexity • Communication networks are ever expanding in global coverage and capacity • Physically distributed data collections and computing services need to be integrated into a virtual system for research, development and public relations • Virtual Globe and Observatory approaches provide novel opportunuities for collaborative research and instructional purposes, and future developments
SOME HPC EXAMPLES Network and Block Adjustments NTS mapping: ~ 2000 stereomodels (7 par./model) NAD cdn networks: ~ 8000 stations (( φ , λ )/stn) NAD27 → NAD83: ~ 450 000 stns (( φ , λ )/stn) Spherical Harmonic Transforms (SHTs) SHT and SHT -1 in REAL*8 to ~ deg. & ord. 3800 Global grids: equiangular and near equiareal EGM08 ( http://earth-info.nima.mil/GandG/ ) Upgraded EGM96 using mostly Grace data Degrees ≤ 2190 and Orders ≤ 2159 ⇒ ~ 5 min. res’n
GLOBAL SPHERICAL GRIDS
2001 ANNUAL TEMPERATURE ANOMALY MAP Source: http://www.msc.ec.gc.ca/acsd/publications/RMD_msc_report/policy/image_4b_large_e.html
GEODATA and METADATA INTERNATIONALLY: World Data Centers: www.ngdc.noaa.gov • NASA, ESA: www.nesdis.noaa.gov • UNIDATA: www.unidata.ucar.edu • IAG Data Centers: www.iag-aig.org • Aviso for Altimetry: www.aviso.oceanobs.com • NATIONALLY: NRCAN Geoscience Data Rep.: http://gdr.nrcan.gc.ca • Cdn Soil Information System: http://sis.agr.gc.ca/cansis • Cdn Water Information System: http://map.ns.ec.gc.ca/reseau/ • LOCALLY: University Digital Libraries (DEMs, maps, airphotos, imageries, …) •
SCIENTIFIC GATEWAYS i Geoscience Network http://www.geongrid.org i Marine Metadata Interoperability http://marinemetadata.org i NASA World Wind Geo http://worldwind.arc.nasa.gov i Global Environmental & Earth Science Information System http://genesis.jpl.nasa.gov i Semantic Web for Earth and Environmental Terminology http://sweet.jpl.nasa.gov
WEB SERVICES A web service is some software available over a network with a formal description of how it is called and what it returns that a computer can understand. Note that web servers, ftp servers, database servers, etc., do not generally qualify as they lack the standardized descriptions of their inputs and outputs. Today, XML provides a language-neutral way for representing data and information. Remember that web services are meant for use by computers and not humans (unlike webpages in HTML, etc.)
WEB SERVICE MODELS RESOURCE-ORIENTED MODEL A resource is anything that can have an idenfier e.g. a service. SERVICE-ORIENTED MODEL A service is something capable of performing a piece of coherent functionality e.g. actions performed by agents. MESSAGE-ORIENTED MODEL A message is the basic unit of data exchanged between agents. POLICY-ORIENTED MODEL A policy is a set of assertions expressing capabilities and constraints.
WEB SERVICE FRAMEWORKS LANGUAGE PACKAGE or LIBRARY Java Apache Axis ( http://ws.apache.org/axis ) Xfire ( http://xfire.codehaus.org ) C# .NET ( http://msdn2.microsoft.com/en-us/netframework/ ) Mono ( http://www.mono-project.com ) Perl SOAP::Lite ( http://www.soaplite.com ) Python SOAPPy/ZSI ( http://pywebsvcs.sourceforge.net ) C++/C gSOAP ( http://www.cs.fsu.edu/~engelen/soap.html ) Ruby soap4r ( http://dev.ctor.org/soap4r )
VIRTUAL GLOBES GOOGLE TM EARTH ( http://earth.google.com ) Software from Keyhole Inc. (2004) • Multilingual and multi OS (Windows, Mac, Linux) • Three version levels (Free, $20/year, $400/year) • Ground resolutions: 15 cm … 15+ m • DEM data from NASA SRTM global coverage • 3D data in KML language for visualization • Google Street View available with version 4.3 (May ’07) • Errors re MSL (e.g. Death Valley: -86m instead of -420m) •
VIRTUAL GLOBES (continued) Microsoft Virtual Earth ( http://www.microsoft.com/virtualearth/ ) Immersive imagery with city views in 3D • Cross-browser and improved printer support • Improved location functionality (traveling directions) • Global satellite imagery with uptodate map details • Online mapping and searching ( http://maps.live.com ) • VE Interactive SDK ( http://dev.live.com/virtualearth/sdk/ ) • VE ISDK provides hands-on, task-based demos of APIs • Designer Tools and Technologies for own website •
VIRTUAL GLOBES (continued) Poly9 FreeEarth ( http://freeearth.poly9.com ): Essentially no download with Adobe Flash Player 9 • Cross-browser and multi OS (Windows, Mac, Linux) • Very light (main application ~ 300 KB) • Global satellite imagery with high resolutions for U.S. cities • All features exposed using simple JavaScript interface • Web Map Service (WMS) supported for GIS applications • Data encoded in XML (GeoRSS specs.) displayed easily • Imagery for other planets included •
VIRTUAL OBSERVATORIES Web environment for interactive Browsing, searching and downloading data and tools • Integrating, synthesizing and analyzing new and legacy • datasets Correlating, modeling and assimilating datasets • Prototyping and developing new tools and procedures • Examples NVO in Astronomy ( http://us-vo.org ; http://ivoa.net ) • VO in Geomagnetism ( http://mist.engin.umich.edu ) • VO in IPY (Walker and Kulesa, at AGU Fall Meeting, 2006) •
NATIONAL VIRTUAL OBSERVATORY
NVO APPLICATIONS • Web-based applications thru web browser • Downloaded applications run locally on desktop or notebook local workstation, cluster or grid • Computationally intensive applications initiated thru web browser carried out on some cluster or grid status info thru web browser visualization of results • Toolkits for building other applications scripting languages such as IDL, Python, … programming languages such as Java, C++, …
APPLICATIONS OF THE NVO STAND-ALONE APPLICATIONS • VOPlot for plotting and visualizing the data • TOPCAT for graphical viewing table data • MIRAGE for image displaying and segmentation • ALADIN for image processing and visualization • SKYVIEW for viewing images and catalog services WEB-BASED TOOLS • Datascope for accessing data holdings and related services • Registry for descriptions of data archives and services • … … …
Wilkinson Microwave Anisotropy Probe Recent WMAP 5-year Results Source: http://lambda.gsfc.nasa.gov/product/map/current
HUBzero and nanoHUB A ‘HUB’ is a web site built with many familiar open source packages: A Linux operating system running an Apache web server with LDAP (Lightweight Directory Access Protocol) for user logins • PHP (Personal Home Page) for web scripting • Joomla (Open Source Content Management System) • MySQL database for storing content and usage statistics. • Web reference: http://www.hubzero.org Demo with nanoHUB: http://www.hubzero.org/demo.html
WEB COLLABORATION KEY WEB-BASED FEATURES: • Interactive Simulation Tools and Online Presentations • Mechanism for uploading New Resources • Tool Development Area and Usage Statistics • User Groups for Private Collaboration • Ratings and Citations and User Support Area • News and Events, and Feedback Mechanisms
CONCLUDING REMARKS • Advanced Geocomputations often involve HPC • Web environments are more and more common for HPC • Virtual Globes allow interactive displaying of data • Virtual Globes are very useful with Satellite Imagery • Online globes like FreeEarth also allow presentation of data entirely within a web portal • Virtual Observatories offer numerous possibilities for web collaboration and development activities • Geoscience collaboration can really be international! • For more references: The Virtual Earth : http://teachserv.earth.ox.ac.uk/resources/v_earth.html The Soft Earth : http://teachserv.earth.ox.ac.uk/resources/s_earth.html
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