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Grid Enabling Satellite Data using OWS and GRASS. Gail Millin Geodata Services Development Officer Pascal Ekin Software Developer Victoria, Canada FOSS4G 2007 24 th – 27 th September 2007. Mimas Data Centre. Main Activities. Satellite Data Provision to UK academia
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Grid Enabling Satellite Data using OWS and GRASS Gail Millin Geodata Services Development Officer Pascal Ekin Software Developer Victoria, Canada FOSS4G 2007 24th – 27th September 2007
Mimas Data Centre FOSS4G 2007 Victoria Canada
Main Activities • Satellite Data Provision to UK academia • Geospatial Support Services • Educational Materials • Research and Development • New Data Delivery Infrastructure • Applications of Radar & Optical Data • Dissemination & Outreach FOSS4G 2007 Victoria Canada
Who Uses Landmap? First 1000 Registered Users of the Landmap Service FOSS4G 2007 Victoria Canada
Data Archive • Optical Collection • Landsat 5, Landsat 7, SPOT, MERIS • Radar Collection • ASAR (AP, WS, IM), ERS 1, ERS 2 • Elevation Collection • SRTM, 25m DEM, KGPS • Available to academics attending an institute that has signed a licensing agreement. • Free service since 1st August 2007 FOSS4G 2007 Victoria Canada
Landsat 7 Bands 3,2,1 Landsat 7 Bands 7,4,3 Optical Collection - Landsat FOSS4G 2007 Victoria Canada
Optical Collection - SPOT FOSS4G 2007 Victoria Canada
Radar Collection - ASAR FOSS4G 2007 Victoria Canada
Elevation Collection – DEM & KGPS FOSS4G 2007 Victoria Canada
Landmap - Image Streaming • Image Streaming – ER Mappers Image Web Server 8.1 • Landmap Image Streaming Viewer • Free downloadable heavy clients • ArcGIS Explorer • Google Earth • GetCapabilities request for IWS • http://ims1.landmap.ac.uk/ecwp/ecw_wms.dll?request=GetCapabilities&service=wms FOSS4G 2007 Victoria Canada
Landmap OWS • WMS – web application which provides a portrayal of geographic data which is stored on the server. • WFS – is an interface allowing requests for geographical features across the web using the XML based GML for data exchange. • WCS – defines how to provide satellite data over the internet. This differs from WMS as actual data values are sent. • WMS/WCS via OGC Landmap viewer or OGC compliant software • UDig • Cadcorp • ArcGIS FOSS4G 2007 Victoria Canada
MapServer • Requires a variety of supporting libraries • PROJ 4 for on-the-fly projection • Geospatial Data Abstraction Library (GDAL) a translator library for raster data • GetCapabilities requests for GEMS II work • Landsat 5 - http://ims2.landmap.ac.uk/cgi-bin/mapserv.exe?map=..\chameleon\satellite\map\l5_wcs.map&SERVICE=WCS&REQUEST=GetCapabilities&WMTVER=1.0 • Landsat 7 - http://ims2.landmap.ac.uk/cgi-bin/mapserv.exe?map=..\chameleon\satellite\map\l7_wcs.map&SERVICE=WCS&REQUEST=GetCapabilities&WMTVER=1.0 • GetCoverage requesthttp://ims2.landmap.ac.uk/cgi-bin/mapserv.exe?map=..\chameleon\satellite\map\l7_wcs.map&SERVICE=WCS&REQUEST=GetCoverage&Coverage=orthol7_20123xs190600&BBOX=486600.00,252275.00,699975.00,468500.00&CRS=EPSG:27700&RESX=25&RESY=25&FORMAT=GEOTIFF FOSS4G 2007 Victoria Canada
Aim: To Provide Grid-enabled access to the aggregate statistics from the 2001 Census via OGSA-DAI on the National Grid Service Connect SQL Server database directly to the Grid via NGS Grid-enable current data access system Casweb to facilitate ease of use A fully working version was deployed on the NGS in November 2006 GEMS I http://casweb.mimas.ac.uk/ FOSS4G 2007 Victoria Canada
GEMS II • Aim and Objectives • Grid enable a subset of the Landmap Service Data archive • Landsat 4/5 Thematic Mapper Scenes 1988 - 1992 • Landsat 7 1999 - 2002 • 25m Digital Elevation Model • GEMS II provide a data processing service on the National Grid Service using OWS & Grid technologies • Make use of 128 CPU/compute node • High processing power FOSS4G 2007 Victoria Canada
GEMS II Use Case • Urban Change Detection for the UK • Satellite Image Processing renown for computer intensive tasks. “There are many studies that take place in the remote sensing community focused on change detection of urban areas; however these studies can be limited to local areas due to the lack of computer power to enable much larger areas to be assessed” (Comert, 2004) • Subset from the Data Archive for Use Case • Landsat 4/5 Thematic Mapper Scenes 1988 - 1992 • Landsat 7 1999 - 2002 • 25m Digital Elevation Model FOSS4G 2007 Victoria Canada
GEMS II Architecture - Tier 1 • Provide the Visualisation of the WCS data results and querying of the CSW using OGC compliant clients on the Users System Clients Evaluated for this Role: • Cadcorp SIS MapBrowser • Free to download but not open source • Browse OGC Data services • Supports WMS, WFS, WCS • MPGC1.0 • Data menu allows users to add/remove WCS, WFS and WMS • Client offers image processing capabilities • Quantum GIS • Open source, free of charge GIS supports WMS and WCS results (GeoTiffs). • GRASS layers can be imported into the interface using a GRASS plug-in FOSS4G 2007 Victoria Canada
GEMS II Architecture - Tier 1/2 • Developments of a GEMS GridRelay Client/Server Proxy • GEMS GridRelay client proxy - install on the user’s system • GEMS GridRelay proxy server – installed on Mimas Server (Linux OS) • Benefits of GridRelay • GridRelay allows user accreditation (Athens, UK eScience certificates) verifiable of the service side • Deployment of the client proxy is seamless • Works at the TCP level • GridRelay can be extended to include other authentication/authorisation protocols such as Shibboleth FOSS4G 2007 Victoria Canada
GridRelay – Further Benefits • Dependent on traditional internet protocols & tools • OS independent as it is Java based • Very small (a jar file with few dependencies) • Configurable through an internet browser (developed) • Can be combined with existing Web Service protocols • REST, SOAP, WSDL, existing Grid Security (GSI) FOSS4G 2007 Victoria Canada
Overview of GEMS II Architecture FOSS4G 2007 Victoria Canada
GRASS - Scripts • Change Detection of Urban Areas • i.cluster – Clustering algorithm • Pixel clusters = imagery categories that can be related to land cover types on the ground • Output = Cluster spectral signatures, cluster means and covariance matrices • i.maxlik – Classifies the cell spectral reflectances in imagery data based on the spectral signatures generated by i.cluster • Output = Raster map layer of classified image in which each cell has been assigned a spectral class. FOSS4G 2007 Victoria Canada
GEMS II Outcomes • Exploit GRID Technologies • Expand on OWS work initiated by the JISC funded Interoperability Project • Use OWS in a Grid Context • Users can benefit from high CPU computer power of the NGS • Create the use case demonstrator using Landsat 4/5, Landsat 7 and DEM FOSS4G 2007 Victoria Canada
Future Developments • New Website – due to be released in January 2008 • New Release of ASAR data – January 2008 • Monthly acquisitions of TOPSAT data from QinetiQ • 10 images per month • International locations • 2m/3m resolution 3 band optical imagery • Extend the Image Streaming Viewer to display the recently updated metadata FOSS4G 2007 Victoria Canada
Register • Institutes must sign a licensing agreement form to use the service after July 31st 2007 • 93 sites are already registered • The service is now free! • Further information available at http://landmap.mimas.ac.uk • Users require Athens Username and Password • Access to download area • Access to the online learning materials e.g. Image Processing Course FOSS4G 2007 Victoria Canada
Thanks for Listening Enquiries spatial@mimas.ac.uk Website landmap.mimas.ac.uk FOSS4G 2007 Victoria Canada