[wcsplus] WCS 1.0+ interoperability and application profiles

Hi All,

Sorry that it's taken me so long to start posting the wcsplus mailing
list (particularly as I was in on some of the very early discussions on
WCS 1.0+) - my (poor) excuse is a combination of holiday, incompetence
(my initial subscription to the mailing list failed) and other work
commitments.

Part of those work commitment was the production of a draft interface
specification for a WCS which will be built on top of "Visual Weather"
(a software package developed by a company called IBL), which will
become the future Met Office forecaster workstation system. As this is
being developed by IBL, as an enhancement to their software, I'm afraid
it will not be open source, but the interface specification is open, and
the process of drafting this has thrown up a number of issues that I
think should be of interest to this forum.=20

The draft WCS interface specification that I provided to IBL was based
on WCS 1.0, as it needed to be provided now (before the WCS 1.0+
specification has been developed), but I (like others) found that there
were a number of areas, where I had to make design decision that
potentially reduce interoperability. Where this was the case, I looked
initially to follow the approach taken for a WMS that has already been
produced for Visual Weather by IBL (to our specification), to the
THREDDS WCS (which we have been doing some evaluation work on) and to
the early ideas for the WCS 1.0+ spec.=20

Since then, I have also had a look at some of the DEW WCS information
that Adit and Jon have posted, and what struck me is the large number of
areas where the THREDDS WCS, the DEWS WCS and the Visual Weather WCS (as
I will call it) adopt either fundamentally different approaches, or at
least different conventions. A few examples are:
- Treatment of the 3 (related) time parameters that can be used to
characterise a model forecast (i.e. Model Run ('analysis time'),
validity time and forecast period (only 2 of which are required to
uniquely fix a coverage, but which 2 are preferable depends on the
client application or user);
- Handling of coordinate reference systems (e.g. horizontal only or 3d);
- Vertical levels as part of the Domain Set (e.g. BBOX) or the Range Set
(a PARAMETER);
- PARAMETER names use to define the Range Set;
- and even, the name for a CF-compliant NetCDF3 file for the returned
format!
(and probably many more)

I feel that some elements of these can and should be tackled directly as
part of a WCS 1.0+ specification, but others should probably form part
of an application profile for the FES community.

Any thoughts on this?

I will post separately on some of the specific areas, rather than make
this posting too long.

Regards,
Bruce
--
Bruce Wright  IT Architect
Met Office  FitzRoy Road Exeter EX1 3PB United Kingdom
Tel: +44 (0)1392 886481  Fax: 0870 9005050=20
E-mail: bruce.wright@xxxxxxxxxxxxxxxx http://www.metoffice.gov.uk