NcML: a new XML representation for netCDF data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: NcML: a new XML representation for netCDF data
• From: Russ Rew <russ@xxxxxxxxxxxxxxxx>
• Date: Mon, 12 Aug 2002 15:16:43 -0600

Hi,

This note is to announce a draft of a new XML representation for
netCDF data:

  http://www.scd.ucar.edu/vets/luca/netcdf

This web page points to the current draft XML schema as well as access
to a prototype application, developed by Luca Cinquini, that permits
entering a URL for a binary netCDF dataset and seeing the resulting
XML representation.

Although this representation can serve a purpose similar to the CDL
notation for netCDF data, providing a human-readable and
machine-parsable specification for the structure of the data,
ultimately we intend additional uses as well:

  - cataloging data holdings resulting from metadata harvesting
  - aggregation of data from multiple local or remote datasets
  - changing or augmenting metadata in existing netCDF datasets
  - support for alternate views of data (renaming components,
    subsetting data, changing structure)
  - declaring derived data

The XML representation provides ways to "factor out" metadata
common to multiple netCDF variables or datasets, which makes it
natural for expressing aggregation.

Please consider this a beta draft of an official XML form for netCDF
data.  We're interested in feedback about anything you see wrong with
this proposal, as well as anything we have left out.

Keep in mind that we want this to be a simple model for any kind of
netCDF data, not just netCDF data that conforms to particular
conventions.  We are planning extensions to represent popular
conventions and to support additional uses.

John Caron
Luca Cinquini
Ethan Davis
Bob Drach
Stefano Nativi
Russ Rew