The final sprint towards the end of the Google Summer of Code (GSoC) is over now. After fixing bugs, working on documentation and actually producing time-series in different formats, the “Exchangeable Encodings for SOS” project met most of its ambitious goals – and it is demonstrated on the 52°North Google summer of Code Demo Server. Users and developers documenation on the encoding mechanism has also found a place in the 52°North wiki.

We have integrated a plugin mechanism into an SOS server (source code branch), which is based on the main 52°North SOS development line (source code trunk). As a proof of the concept, two basic plugins are provided:

• Plain CSV (comma separated values) response format, which tries to stick to recommended NOAA IOOS Data Integration Framework CSV output,
• WaterML 2.0 (OGC WaterML 2.0 and Hydro DWG). I acquired a recent version of the WaterML 2.0 encoding profile, which is already adopted as a (candidate) standard. The schemas are not yet officially published and rumours have it that there might be last minute changes. The change request contains an extension regarding empty time-series responses which should not interfere with the existing implementation.

In the world of many diverse forms of observation types for natural phenomena, the two plugins demonstrated both rely on point-based measurement data.

Where to go from here?

Unfortunately we ran out of time to test the integration and plugin deployment through the 52°North GSoC SOS Administrator project. However, further developments will eventually bring exchangeable encodings, an administration and configuration framework, and the proven 52°North SOS server together.

The interoperability developments in the hydrological and meteorological domains are dynamic and very exciting. More projects and organizations around the globe implement services to deliver and visualise hydro(geo)logical, oceans observations and weather observation time-series. We think an SOS with a plugin mechanism can facilitate those developments.

A personal summary

It was a really interesting, but also challenging project for me. Entering the Java/XML world was a big step and I learned a lot. XML processing is now less scary, and it was never dull because it has come to life with actual environmental data about real world phenomena. I am still fascinated by working with a soon to-be-released international standard on hydrological time-series. And also important: the 52°North community got me! I intend to contribute and participate in the long term, even if “only” as an ambassador in New Zealand and Australasia in the next years.

Finally I would like to thank the 52°North community, as they have done a big deal in managing and supporting the 52°North GSoC projects and students. I could even visit them in their office in Münster, Germany. Without them, XMLBeans would still be shrouded in mystery for me :-).