Brief Summary of GALEON-related Highlights of the
Ottawa April 2007 OGC TC Meeting
Draft by Ben Domenico
Last Modified: May 1, 2007
The meeting was not as well
attended by GALEON participants as some OGC meetings -- partly because
several GALEON participants were at the
European Geophysical Union meetings in Vienna. But a strong GALEON
core was present and GALEON presentations were given in the Earth
Observations session in addition to the usual presentation in the
Coverages session where Peter Baumann was voted in as co-chair of the
Coverages Working Group.
There were discussions about common classifications of data types that stemmed
from presentations at the Fall AGU meeting and a followup meeting at the
Rutherford Appleton Laboratory. These discussions were spawned by the realization that there are strong similarities and
overlap among:
- BADC: scientific feature types, a part of their Climate Sciences Modelling Language
- OGC Observations & Measurements: sampling feature types spearheaded by CSIRO
- Unidata's CDM (Common Data Model): scientific data types
These commonalities are leading to a possible
clarification of the relationship among SOS (sensor observation
service), WFS (Web Feature Service) and WCS (Web Coverage Service).
For GALEON, a key element of this is the fact that binary encoding of
the
payload as CF-netCDF coverages might work within the WFS and SOS
protocols as well as for WCS. The underlying unifying concept is that
a "coverage" is in fact a special case of a "feature" and ncML-GML and
CSML dialects of GML can provide the needed "wrapper."
So far GALEON focused on gridded data, but strong
interest continues to be voiced in providing point/station datasets
using the same protocols. To foster movement in that direction, it
would be necessary to clearly define the CF-netCDF for
point/station dataset collections and get it blessed as a CF
convention. There seems to be a growing consensus that this would fit
with the ISO 19123 standard for coverages.
An
OGC-wide discussion of more general coordinate systems specifications
(e.g. the met community's use of atmospheric pressure as the vertical
coordinate) are issues that go beyond the context of the GALEON Web
Coverage Services in some of the issues arose.
There
was increased activity among other GEO disciplines, e.g., the Ocean
Sciences Interoperability Experiment; CUAHSI (Consortium for
Advancement of Hydrological Sciences, Inc gave a presentation
describing "WaterML."
There were several discussion relating to the OGC TC meeting
the week of the September 17 that will be hosted at Undiata/NCAR where
it would be good to have a special demo day on Friday and possible
sessions during the TC meetings themselves on GALEON related topics
such as earth observations and so forth.