Using Google Maps and other OpenSource GIS software for displaying geospatial data

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