Spatial Data Access Tool Enable visualization and access

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 • 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. 1 TB size – various formats 2

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 3

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 4

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. 5

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 service for actual geospatial coverage data access • OGC Web Map Service (WMS) – Web service for geospatial data (coverage or feature) visualization • Goal: interoperability 6

The ORNL WCS and WMS Servers • Map. Server-based • WCS – http: //webmap. ornl. gov/ogcbroker/wcs? – Version 1. 0. 0 – Customized geospatial coverage access • Spatial/temporal/band subsetting • Reprojection/resampling • Reformatting: Geo. TIFF, Arc/Info ASCII Grid, net. CDF, 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 7

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) 8

65 Data Sets in SDAT • Land Cover – 6 – MODIS, AVHRR, GLC 2000, NLCD 2001, etc. • Elevation – 2 – GTOPO 30, SRTM • Soil – 4 • Climate – 5 – Koppen-Geiger climate classification • Ecoregion – 1 • Carbon cycling model outputs – 30 – ORCHIDEE, Si. B 3, CLM-CASA, etc. 9

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

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

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 12

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 13

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

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

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 16

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

Benefits (5) • Time-series animation – Monthly CO 2 flux for the period 1998 – 2006 at 1 degree spatial resolution (simulated by Si. B 3 model) 18

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

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 20

Thank you! 21

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