[CF-metadata] Default datum for latitude and longitude?

From: Jonathan Blower <j.d.blower>
Date: Mon, 19 Apr 2010 15:43:49 +0100

Hi all,

The CF conventions define a means to specify the datum used in certain
map projections
(http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.ht
ml#grid-mappings-and-projections). In the (common) case of a data file
containing latitude and longitude axes, but no explicit datum
specification, which datum should be assumed? Spherical Earth? WGS84?

The horizontal error resulting from use of an incorrect datum can be
significant for high-resolution and/or local dataset (hundreds of
metres).

Cheers, Jon

--
Dr Jon Blower
Technical Director, Reading e-Science Centre
Environmental Systems Science Centre
University of Reading
Harry Pitt Building, 3 Earley Gate
Reading RG6 6AL. UK
Tel: +44 (0)118 378 5213
Fax: +44 (0)118 378 6413
j.d.blower at reading.ac.uk
http://www.nerc-essc.ac.uk/People/Staff/Blower_J.htm

Received on Mon Apr 19 2010 - 08:43:49 BST