Re: netCDF to XML

>To: "Russ Rew" <address@hidden>
>Subject: netCDF to XML
>Date: Mon, 15 Mar 1999 10:26:57 +1000
>Organization: Research & Development, Geoterrex-Dighem Pty Limited, AUSTRALIA
>Keywords: 199903150327.UAA24865

Hi Dr. Wolfgram,

> Geoterrex-Dighem is the largest airborne geophysical survey contractor for
> the mining industry with offices and operations all over the world. Detailed
> information on us can be found at http://www.geoterrex.com
> 
> We have started an initiative to establish an Airborne Geophysical Data
> Exchange AGDE) standard and we are looking seriously at netCDF as the
> platform for this definition.
> 
> One of the major issues during this development is the upgrade path to XML.
> We would like to get a realistic idea of the importance that Unidata is
> attaching to the tasks that you have specified in your "to do" list (as
> posted on your website):
> 
> (1) design XML conventions and DTD for representing netCDF data, IDD data
> products, decoded data products
> 
> (2) design and implement a netCDFtoXML utility analogous to ncdump to dump
> netCDF data in XML form instead of CDL
> 
> (3) design and implement XMLtonetCDF to reverse the process of netCDFtoXML
> 
> It would be great to get an idea about the timeframe for your development.
> Also, any further comments would be appreciated.

We haven't actually started any of the XML work yet.  Only one other
netCDF users has shown any interest in XML, so it hasn't been high on
our priority list.  I'm the one here who is most interested in this,
but when I last looked at it, it was not clear to me when to use XML
attributes versus XML elements, for example

   <dimension name=level size=10 />

versus

   <dimension>
       <name>level</name>
       <size>10</size>
   </dimension>

I put the project aside until I could learn enough about XML to
understand the tradeoffs between these two different forms of XML
representation and whether we should  try to specify a DTD for
netCDF.  That's still the status of this project.

By now, there may be much better resources than the XML specification
for learning about XML, which is what I was trying to work from
earlier.  With all the XML support in things like Sun's Project X and
the IBM XML stuff available, this may be a good time to create
something like this.

I'm afraid I still can't give you any firm time frame for this, but at
least one other user is looking into netCDF/XML issues may have made
some progress, Jim Secan <address@hidden> from Northwest Research
Associates.  I'm CC:ing him on this reply, in case he's gotten further ...

--Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu