SHAVER: Sharing and Visualizing large-volume environmental data

The SHAVER project is a 1-year NERC-sponsored Knowledge Transfer project that will run during the calendar year 2008. The objective of the project is to transfer technology from the DEWS project into two widely-used software systems for sharing environmental data, THREDDS and GeoServer. The new software will then be applied to two test cases.

Project partners

• JonBlower (Reading e-Science Centre, Principal Investigator and first point of contact for enquiries)
• AditSantokhee (Reading e-Science Centre)
• PaulineMak (University of Tasmania)
• JohnCaron (Unidata)
• StephenReid (Lehigh University and Director of the Earth System Atlas)
• ... (Need to add GeoServer team)

Project plan

The BroadProjectPlan contains the major milestones of the project. At the end of February 2008 a more detailed plan will be released, following consultation with project partners.

Project meetings

Agendas and minutes for project meetings (mostly teleconferences)

• ShaverTelecon6Feb08 Initial telecon to discuss THREDDS-related issues
• ShaverTelecon25Feb08 Initial telecon to discuss GeoServer-related issues
• ShaverTelecon28Feb08 Second telecon to discuss THREDDS-related issues
• ShaverTelecon07Oct08 Third telecon to discuss THREDDS-related issues
• ShaverTelecon15Dec08 Fourth telecon to discuss THREDDS-related issues

Background: the DEWS project

The DEWS project created a functional demonstrator system that served environmental data to the healthcare and marine safety sectors. Marine data were served using an OGC-compliant Web Coverage Server (WCS) and the same data were visualized using a Web Map Server (WMS). The data themselves (four-dimensional gridded marine forecast data) were held in CF-compliant NetCDF files. At the time of DEWS there was no existing available technology that could serve 4D, CF-NetCDF through WCS and WMS and therefore new software was developed.

The DEWS WCS software had to satisfy other project requirements that are not currently in the WCS specification. These included the need to secure the data server (using the security mechanism of the NERC Data Grid) and the need to support asynchronous delivery of large data volumes. These "extensions" are outside the scope of the SHAVER project. (The issue of asynchronous delivery is now under discussion in the WCS community, and in particular the recently-formed "WCSplus" working group.)

Links:

• DEWS demonstrator web portal: http://www.dews.org.uk.
• Non-technical DEWS overview poster: http://www.resc.rdg.ac.uk/publications/posters/DEWS-nontechnical.zip (zipped PDF)
• Poster showing large-scale architecture (a little dated): http://www.resc.rdg.ac.uk/publications/posters/dews_poster_2006.ppt
• Godiva2 data visualization portal (powered by the DEWS WMS): http://www.reading.ac.uk/godiva2
• DEWS WMS project page (The DEWS WMS is also known as "ncWMS"): http://ncwms.sf.net
• Powerpoint presentation about the DEWS WMS (applied in the MERSEA project as the "Dynamic Quick View" system): http://www.resc.rdg.ac.uk/publications/MERSEA_DQV_Blower_Rome_23-04-2007.ppt

THREDDS Integration

About THREDDS

THREDDS (Thematic Realtime Environmental Distributed Data Services) is a data serving system that is already widely-used for serving 4D, CF-compliant gridded data. Although it supports data access through WCS, it does not currently support data visualization through WMS. The objective of the SHAVER project will be to integrate the DEWS WMS with THREDDS. This work will be done in collaboration with Unidata and the University of Tasmania.

THREDDS test case

TODO

GeoServer integration

About GeoServer

GeoServer provides access to geospatial data through the WFS, WMS and WCS protocols. At the time of DEWS it lacked support for four-dimensional gridded data, although this capability is under active development and has been worked on by a number of groups. In the SHAVER project these strands of development will be brought together produce a new version of GeoServer that supports the serving (through WCS) and visualization (through WMS) of large-volume, 4D CF-NetCDF data in an efficient manner.

GeoServerDetails (more information about GeoServer integration)

GeoServer test case

TODO

Comparison of technology

The above paragraphs, and links therefrom, contain information about the separate technologies that are relevant to this project. A summary of this information can be found in the TechnologyComparison.

Some useful documents

These documents have been written to collect discussions on mailing lists and so forth.

• StatusOfCoveragesInGeoAPI This page collects information about the status of the Coverage classes in GeoAPI and GeoTools. It also clarifies the different Coverage concepts.

-- JonBlower - 01 Feb 2008