[CF-metadata] CF Specification of Vertical Datums

From: Jeff deLaBeaujardiere <Jeff.deLaBeaujardiere>
Date: Tue, 05 Apr 2011 16:54:17 -0400

Hello-

We are using the following vertical datum identifiers in the IOOS (Integrated
Ocean Observing System) program. Two are URNs in the OGC namespace (from the
EPSG database); the others are currently in the experimental 'x-noaa'
namespace but we would like to transition them to an 'ioos' namespace.

Vertical datum URNs:

North Am. Vert. Datum (NAVD88) urn:ogc:def:datum:epsg::5103
Free surface of water urn:ogc:def:datum:epsg::5113
Mean Sea Level (MSL) urn:x-noaa:def:datum:noaa::MSL
Intl Great Lakes Datum (IGLD) urn:x-noaa:def:datum:noaa::IGLD
Mean High Water (MHW) urn:x-noaa:def:datum:noaa::MHW
Mean Lower Low Water (MLLW) urn:x-noaa:def:datum:noaa::MLLW
Station Datum (STND) urn:x-noaa:def:datum:noaa::STND

Regards,
Jeff DLB

--
Jeff de La Beaujardi?re, PhD
U.S. National Oceanic and Atmospheric Administration (NOAA)
Sr Systems Architect, Integrated Ocean Observing System (IOOS) Program Office
1100 Wayne Ave #1225, Silver Spring MD 20910 USA
+1 301 427 2427
Jeff.deLaBeaujardiere at noaa.gov
On 2011-04-05 15:38, Justin R. Davis wrote:
>
> Does anyone have any specific examples/recommended approaches of how to
> specify vertical datums in CF-Compliant NetCDF? I don't see any definitive
> explanation of how to do this in any of the documentation.  I also see where
> people have asked this question in the past, but there never appears to be a
> final recommended approach.
>
> Specifically, I'm trying to make sure that its clear that the "z" (bathy/topo)
> and "eta" (water level) are being expressed relative to either NGVD29 or
> NAVD88...currently the "CF Standard Names" for "sea_surface_height*" mention
> only mean water level, geoid or ellipsoid...none of which are really the same
> as NGVD29/NAVD88...and the "depth" standard name has no other variants which
> look appropriate.
>
> Previous discussion on this topic include approaches of creating a new
> standard names (e.g. water_surface_height_above_reference_datum), adding a new
> piece of metadata (e.g. reference=NAVD88)...but none of these have made it
> into the "CF standard name" document or the CF v1.x Conventions.
>
> Is there a specific recommended approach? If not, is someone working
> on this?
>
> thx,
>
> jrd
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Justin R. Davis, Ph.D.
> davis at coastal.ufl.edu
> Research Assistant Scientist
> Department of Civil and Coastal Engineering
> 365 Weil Hall / P.O. Box 116580
> University of Florida
> Gainesville, FL 32611-6580
>
> Office: 352-392-9537 x1528, Weil Hall Room #551
>
>
>
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Received on Tue Apr 05 2011 - 14:54:17 BST