[CF-metadata] New CoordinateType: Spectral?

From: Jonathan Gregory <j.m.gregory>
Date: Thu, 11 Apr 2013 20:45:06 +0100

Dear Randy

> With the growing interest in the CF conventions around the world by the
> satellite CF data producer and user communities coupled with the ubiquitous
> nature of wavelength-based satellite CF data sets, does it make sense to
> add a paragraph to Section 4 Coordinate Types to discuss Spectral
> Coordinates ?

As Roy pointed out, "spectral" is a word with several meanings.

In principle it should not be necessary add anything, because CF already
permits coordinate variables in any quantity. However, perhaps this is not
stated clearly enough. My suggestion would be

* Delete the sentence, "Coordinate types other than latitude, longitude,
vertical, and time are allowed" at the start of the third para of section 4.

* Insert new text at the start of the section:

  The commonest use of coordinate variables is to locate the data in space and
  time, but coordinates may be provided for any other continuous geophysical
  quantity (e.g. density, temperature, radiation wavelength, zenith angle of
  radiance, sea surface wave frequency) or discrete category (see Section 4.5,
  "Discrete axis", e.g. area type, model level number, ensemble member number)
  on which the data variable depends.

continuing with the existing text, "Four types of coordinates ...".

Would that help?

Cheers

Jonathan
Received on Thu Apr 11 2013 - 13:45:06 BST