© university of reading 2007 11 september 2007 sharing and visualizing environmental data using...
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© University of Reading 2007 www.resc.reading.ac.uk
11 September 2007
Sharing and Visualizing Environmental Data using Virtual GlobesJon Blower, Alastair Gemmell, Keith HainesReading e-Science Centre, ESSC, University of Reading
Peter Kirsch, Nathan Cunningham, Andrew FlemingBritish Antarctic Survey, Madingley Road, Cambridge
Roy LowryBritish Oceanographic Data Centre, Liverpool
Virtual Globes, e-Science All Hands Meeting 2007
E-Science: Connected science
• We need to be able to connect data across the environmental sciences (right)
• Visualization is very important– But complicated by plethora
of file formats and tools
• Geographic Information Systems (GIS) often complex and vendor-specific
• Environmental science data are four-dimensional– GIS historically focussed on
land surface
Virtual Globes, e-Science All Hands Meeting 2007
How important is visualization?
(Microsoft case study with BP: Hurricane Management System)
• "This solution is changing the way we do business. When the data is presented through a map-based interface, it’s amazing. It gives you a richer, bigger, more intelligent picture of what’s going on. " – Steve Fortune, BP
http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=201427
Virtual Globes, e-Science All Hands Meeting 2007
The Virtual Solar System
• > 30 Virtual Globes currently available!
NASA World Wind
Google Earth
ArcGIS Explorer
FreeEarthMicrosoft
Virtual Earth
Virtual Globes, e-Science All Hands Meeting 2007
Combining data on a Virtual Globe:Hurricane Katrina, August 2005
• Storm track positions (analysed from ECMWF vorticity data) by Lizzie Froude, ESSC
• Sea surface temperature data from UK Met Office FOAM model
• Combination shows cooling of surface waters on right-hand side of cyclonic storm track
• High winds cause upwelling of cool, deep water
Virtual Globes, e-Science All Hands Meeting 2007
Keyhole Markup Language (KML)
• KML encodes simple geographic features in XML– "Points, lines and
polygons"– Image overlays
• <description> field can hold HTML with links, images etc
• Contains several types of information:– Geolocation– Style– Camera control
Virtual Globes, e-Science All Hands Meeting 2007
Some currently-availableenvironmental datasets in KML format
NERC Centre for Air-Sea Interactions and FluXes
http://www.research.plymouth.ac.uk/casix/
Weather data and storm tracks
http://www.gearthblog.com/blog/archives/2007/06/weather_and_storm_tr.html
UK Met Office ocean forecastshttp://lovejoy.nerc-essc.ac.uk:8080/ncWMS/godiva2.html
Virtual Globes, e-Science All Hands Meeting 2007
Virtual Globes as Discovery andBrowse tools
• BODC uses Google Earth as spatial metadata browsing tool for in-situ measurements
• Can easily check for errors– E.g. ocean data located on
land– Misplaced component of
linear ship track
• Displays “light” metadata, with links to more sophisticated information
• Developed in under a week!
Virtual Globes, e-Science All Hands Meeting 2007
Real-time data visualization
• British Antarctic Survey (BAS) used KML data feeds to support 2 scientific cruises in 2006
• Multiple data streams (ship location, sea temp and salinity, air temp and pressure) streamed to Google Earth in near real time
• Enabled real-time decision-making (e.g. tracking of predators, left)
• Saved ship time, hence £££King penguin track
overlain with concurrent chlorophyll and satellite
imagery
Virtual Globes, e-Science All Hands Meeting 2007
Beyond visualization:Extending the capabilities of VGs
• Approach 1: Extend the client– Only possible if VG exposes an API or is open source– ArcGIS Explorer (.NET API)– NASA WorldWind (Java API, Open Source)
• Approach 2: Do processing on a server– Expose results as KML via a Web Service– Can use web interface to control the Web Service– Useful for closed-source systems (e.g. Google Earth)
Virtual Globes, e-Science All Hands Meeting 2007
Example: ocean data assimilation
• Scientists need to compare ocean models and observations
• A Web Service performs comparison, then outputs results in KML
• Red dots show bad model-obs fits, green dots are good fits
• Clicking on an observation brings up more information
• Driving real improvements in the model
http://www.nerc-essc.ac.uk/~alg/OceanDIVA.html
Virtual Globes, e-Science All Hands Meeting 2007
Virtual Globes: pros and cons
• Pros:– Easy to use– Easy data formats– Compelling visualizations
• Cons:– Generally no data
analysis functions– Vertical and temporal
dimensions not always handled properly (left)
– Patchy support for OGC Web Services
• (But products vary widely)
Vertical structure of Gulf Stream shown above sea level in Google Earth
Virtual Globes, e-Science All Hands Meeting 2007
What is the best scientific use for VGs?
Have an idea Discuss/explore Do the work Publish
Virtual Globes
MATLAB, IDL etc
Virtual Globes, e-Science All Hands Meeting 2007
Alternatives to Virtual Globes: WebGIS
• Lots of systems now available for displaying geographic data on the Web– Google/Yahoo Maps– Microsoft Virtual Earth– OpenLayers– FreeEarth– WorldKit
• Usually based on Javascript API
• Usually read imagery from map tile services
• Can often overlay simple features (KML, GeoRSS)
ICEDS (UCL)
Godiva2 (ReSC)
Virtual Globes, e-Science All Hands Meeting 2007
Did Hurricane Felix cause the seasurface to cool?
• Storm track from www.hurricane-tracking.co.uk
• Sea surface temperature from OSTIA (analysed satellite product), UK Met Office
• Little visible evidence of cooling.
• Why different behaviour from Katrina?
http://gearthblog.com/blog/archives/2006/07/weather_and_sto.html
http://lovejoy.nerc-essc.ac.uk:8080/ncWMS/godiva2.html?dataset=OSTIA&variable=analysed_sst
http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html
© University of Reading 2007 www.resc.reading.ac.uk
11 September 2007
The Bigger Picture
Virtual Globes, e-Science All Hands Meeting 2007
Beyond KML:Geography Markup Language (GML)
• KML ≈ GML v2 (simple features)
• GML v3 adds much more sophistication (complex features)
• Communities create profiles of GML ("Application Schema")– Describes features of
interest
• NERC Data Grid created CSML– Climate Science Markup
Language
ProfileSeriesFeature
ProfileFeature
GridFeature
Thanks to Andrew Woolf (STFC and NDG)
Virtual Globes, e-Science All Hands Meeting 2007
Open Geospatial Web Services
• Open Geospatial Consortium publishes open standards for geospatial Web Services:
(plus many more!)
Web Coverag
e Service
Gridded data(NetCDF, GeoTIFF)
Web Map
Service
Map imagery(PNG, JPG, GIF)
Web Feature Service
Features(GML)
Virtual Globes, e-Science All Hands Meeting 2007
Importance of sharing geospatial data
• "Approximately 80% of business and government information has some reference to location, but until recently the power of geographic or spatial information and location has been underutilized as a vital resource for improving economic productivity, decision-making, and delivery of services" – OGC vision
• EU INSPIRE directive mandates that all public bodies must provide:– Discovery services– View services– Download services
Virtual Globes, e-Science All Hands Meeting 2007
What I haven't discussed
• Security– Need solution based on simple HTTP GET
• Licensing
• Public outreach
Virtual Globes, e-Science All Hands Meeting 2007
Summary• Virtual Globes allow easy simultaneous visualization
of lots of types of environmental data• Well-suited to "exploratory" phases of scientific work• Good way for data providers to advertise their wares• KML is simple but limited way of encoding data
– It's a visualization format really
• GML should be used to encode data for true interoperability– But needs concerted community effort to define feature types
• Simple interfaces are good!– "scriptability" enables mashups
Virtual Globes, e-Science All Hands Meeting 2007
Also see …• Reading e-Science Centre booth• Satoshi Sekiguchi, "GEO Grid"
– Keynote, Tuesday 09:45
• Tim Foresman, "Digital Earth: The New Digital Commons"– Keynote, Wednesday 15:00
• Gen-Tao Chiang, "Driving Google Earth from Fortran"– Session 2.2, Tuesday 15:10
• Gobe Hobona, "Workflow enactment of grid-enabled geospatial Web Services"– Session 3.4, Wednesday 11:25
• Geolinking demo, White Rose Grid– Demo session, Wednesday 14:30
• E-Science Highlights, Issue 2 (in your delegate pack!)