Using Google Maps and other OpenSource GIS software for

displaying geospatial data

Jon Blower, Dan Bretherton, Keith Haines, Chunlei Liu, Adit Santokhee

Reading e-Science CentreEnvironmental Systems Science Centre

University of Reading

Exploring environmental data with Google Maps and Google Earth

• “Godiva2” website provides very quick visualisations of numerical model and satellite data

• Scientists use an interactive website to select dataset to visualise on a draggable, zoomable map

– can view data at large range of scales• Can then view same data in Google

Earth– 3-D globe– Lightweight, easy to use GIS tool– Can visualise alongside other

datasets• Don’t have to download any data!• Images generated dynamically on the

server• Spin-off from GODIVA project

Architecture

DATA WMS

Webserver

HTML,Javascript

Web server and WMScould be co-located

WMS = OGC-compliantWeb Map Service

metadata(XML)

images(PNG)

DATA WMS

Could useimages frommany otherWMSs

Open standards and open source• Godiva2 website gets its images from a standards-compliant

Web Map Server– (or at least it will do soon…)

• We built a WMS for dynamically generating images from NetCDF data– takes ~0.3 seconds to generate an image– are working on an intelligent cache for greater efficiency

• Means that third-party GIS software can get images from our WMS

• And we can display images from other WMSs• Are considering switching from Google Maps to OpenLayers

– Open Source equivalent, no licensing or API issues– Better support for WMS

The intention / the future• Project generates CF-compliant NetCDF• Run a Web Map Server out of the box

– i.e. the Godiva2 server

• Visualise the data instantly on Godiva2 website and Google Earth– Alongside other datasets from third parties e.g. satellite images

• Need to handle vectors for currents!!!• Would be nice to visualise derived fields

– Temporal and spatial averages– Can we generate the images fast enough on the server?

• Also visualise on other WMS-compliant tools– NASA WorldWind– Cadcorp SIS