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Spatial Data Access Tool:

Spatial Data Access Tool:. Enable visualization and access of geospatial data using OGC services and Google Earth. Yaxing Wei, Suresh-Kumar Santhana-Vannan, Robert B. Cook, Bruce E. Wilson, and Tammy W. Beaty weiy@ornl.gov Oak Ridge National Laboratory. December 14 th 2009. ORNL DAAC.

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Spatial Data Access Tool:

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  1. Spatial Data Access Tool: Enable visualization and access of geospatial data using OGC services and Google Earth Yaxing Wei, Suresh-Kumar Santhana-Vannan, Robert B. Cook, Bruce E. Wilson, and Tammy W. Beaty weiy@ornl.gov Oak Ridge National Laboratory December 14th 2009

  2. ORNL DAAC • Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) • NASA-sponsored source for biogeochemical and ecological data and models useful in environmental research • Data in ORNL DAAC • field campaign, land validation, regional and global data • over 800 data sets, ~220,000 files, ~1.1TB size • various formats

  3. MAST-DC • The Modeling and Synthesis Thematic Data Center (MAST-DC) • provide data management support for North American Carbon Program (NACP) project • provide data to users in the formats, resolutions, and projections based on their requirements • Data in MAST-DC • model inputs, model outputs, observations (forest/crop, tower flux), and other related data

  4. Challenges faced by data centers • Rapidly increasing archiving rate • Heterogeneity of geospatial data • Rapidly growing user community and user requirements • Heterogeneity of data delivering mechanism • Diverse ways in which data centers publish and deliver geospatial data introduce extra burden to users to access data from multiple data centers

  5. New solutions needed! • Data users need to: • Find and visualize data efficiently • Access diverse data in ready-for-use formats • Access diverse data in a standard way • ORNL DAAC and MAST-DC have tapped into the benefits offered by Open Geospatial Consortium (OGC) standards, Web-enabled GIS tools, and Virtual Globe technology.

  6. OGC and its Standards • Open Geospatial Consortium (OGC) • non-profit, international, voluntary consensus standards organization that is leading the development of standards for geospatial and location based services. • OGC Web Coverage Service (WCS) • Web servicefor actual geospatial coverage data access • OGC Web Map Service (WMS) • Web servicefor geospatial data (coverage or feature) visualization • Goal: interoperability

  7. The ORNL WCS and WMS Servers • MapServer-based • WCS • http://webmap.ornl.gov/ogcbroker/wcs? • Version 1.0.0 • Customized geospatial coverage access • Spatial/temporal/band subsetting • Reprojection/resampling • Reformatting: GeoTIFF, Arc/Info ASCII Grid, netCDF, NITF, and ERDAS Imagine • WMS • http://webmap.ornl.gov/ogcbroker/wms? • Version 1.1.1 • Customized geospatial data visualization • Automatic/manual-defined color scheme • Spatial/temporal/band subsetting • Reprojection/resampling • Popular image formats: PNG, JPEG, and GIF

  8. Spatial Data Access Tool (SDAT) • http://webmap.ornl.gov/wcsdown • OGC standards-based Web application for geospatial data visualization and download • Web-based GUI brings the benefits of ORNL WCS/WMS servers to end users • interactive map widget – driven by WMS • customized data download – driven by WCS • Two levels of data organization • Data set • Data file (granule)

  9. 65 Data Sets in SDAT • Land Cover – 6 • MODIS, AVHRR, GLC2000, NLCD 2001, etc. • Elevation – 2 • GTOPO30, SRTM • Soil – 4 • Climate – 5 • Koppen-Geiger climate classification • Ecoregion – 1 • Carbon cycling model outputs – 30 • ORCHIDEE, SiB3, CLM-CASA, etc.

  10. SDAT User Interface – Set Level • Browse data sets/files • Link to detailed metadata in data set level data file (granule) list data set list

  11. SDAT User Interface – File Level • file-level metadata • projection definition in OGC WKT format • OpenLayers-based interactive map widget • On the fly map reprojection • WCS-based data access options

  12. Virtual Globe technology • World-Wide Web • SDAT is Web-based • Web-Wide World • Emerging “virtual globe” technology, like Google Earth, brings a new platform and many more benefits for geospatial data visualization and delivery Web-Wide World (Google Earth) World-Wide Web (SDAT) Local Computer

  13. Google Earth KMZ • A KMZ file for each data set is provided for users to visualize data in Google Earth • thanks to Karl Benedict and Renzo Sanchez-Silva for the ESIP-EDAC WMS to KML converter • WMS-based dynamic maps generation • WMS-based dynamic legend images generation

  14. Benefits (1) • Rich and valuable background maps (high resolution satellite images, roads, landmarks, borders, etc.)

  15. Benefits (2) • Powerful address/keywords-based locating capability • what if the user want to see a data near Yosemite?

  16. Benefits (3) • Excellent data visualization capability • globe-based • arbitrary angle of view • fly • 3-D • terrain Google Earth wraps National Land Cover Data (NLCD 2001) to terrain

  17. Benefits (4) • Overlay any map from any data set • Land cover change in Three Gorges Dam area What we see • Increase of water area • Reduce of croplands • Woody Savannas replaced by Mixed Forests MODIS Land Cover (IGBP) in 2001 MODIS Land Cover (IGBP) in 2007 What we think • Impact on environment • residency relocation • more …

  18. Benefits (5) • Time-series animation • Monthly CO2 flux for the period 1998 – 2006 at 1 degree spatial resolution (simulated by SiB3 model)

  19. Benefits (6) • Embed SDAT tool within Google Earth • support of Javascript and iframe since version 5

  20. Summary and future work • ORNL DAAC and MAST-DC are rich sources for biogeochemical and ecological data useful in environmental research. • The ORNL OGC servers and SDAT provide efficient and customizable visualization and access to geospatial data in a standard way • Google Earth serves as a new platform and brings many more benefits for geospatial data visualization and delivery • Incorporate more OGC standards, such as WFS

  21. Thank you!

  22. Role of SDAT User Client Software SDAT Metadata Catalog (Mercury) Data Order System OGC Servers (WCS/WMS/…) Metadata Archive Data Archive Data Center (ORNL DAAC, MAST-DC, ..)

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