Hello, (Apologies if this has been covered way back in the e-mail traffic, or I've misuderstood.)
I'm a bit confused as to the use of these grid_mapping parameters with vertical coordinates - do we need new grid_mapping_names? I'm thinking, for example, of linking a geoid specification to a vertical "altitude" coordinate. Thanks, David ---- Original message from Jonathan Gregory (12PM 11 Mar 14) > Date: Tue, 11 Mar 2014 12:59:21 +0000 > From: Jonathan Gregory <j.m.greg...@reading.ac.uk> > To: cf-metadata@cgd.ucar.edu > User-Agent: Mutt/1.5.21 (2010-09-15) > Subject: Re: [CF-metadata] Vertical datums (again) > > Dear Rich > > Thanks for keeping this going. > > > In CF, we have some of these parameters of the vertical coordinate > > system specified with the "units" and "positive" attributes. And we > > already have "add_offset" that could be used for the vertical shift. > > > > So that just leaves the geoid-based "Vertical Datum" or spheroid-based > > "Datum", where the spheroid can be specified with parameters. > > In the agreed trac ticket 80 > https://cf-pcmdi.llnl.gov/trac/ticket/80 > we added several more attributes to grid mapping to describe reference > surfaces in ways analogous to CRS WKT. We already have attributes to name > and specify the reference ellipsoid (spheroid). As far as I can see, we need > only to add an attribute of geoid_name to Appendix F to identify the geoid. > Would that meet your requirement? Earlier discussions implied that CRS WKT > does not have a way to name the geoid specifically. > > Best wishes > > Jonathan > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- David Hassell National Centre for Atmospheric Science (NCAS) Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, U.K. Tel : +44 118 3785613 E-mail: d.c.hass...@reading.ac.uk _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata