Hi Roy -
> I was arguing at the start of this thread ...
This first came up in August, 2008:
Subject: Same parameter, different meaning (pressure)
Can (or should) the CF standard differentiate between these
two very different measurements of sea water pressure:
The consensus then was that we should use a single name and infer
the "meaning" of the data from metadata about how the sensor was
mounted.
> ... that an instantaneous single-beam echosounder measurement is the so close to being the same thing as a BPR measurement in tidal mode with waves filtered out (ever looked at echosounder data from an anchored ship?) that they should be called the same thing on the basis that the Standard Name represents the phenomenon and should not describe how it was measured.
>
Exactly; they're comparable when the BPR is processed in a specific
way - and not comparable otherwise. So, does data from the different
modes of a pressure recorder (or data that's been post-processed as you
describe) constitute different physical phenomena, worthy of different
standard names, or not?
It looks like we're sticking with the original decision, and using a single
name, but users will need to come to some agreement on how to
document the sensor mounting and/or post-processing, to provide enough
information to understand the "meaning" of the data.
Cheers - Nan
> ________________________________________
> From: Nan Galbraith [ngalbraith at whoi.edu]
> Sent: 04 February 2010 17:29
> Subject: Re: [CF-metadata] seeking CF name for total water column height
>
> Sea_floor_depth_below_sea_surface seems very appropriate when
> the water depth is measured from the surface.
>
> Some communities need to distinguish this measurement from one
> made from the sea floor. Shipboard water depth measurements in the
> open ocean generally ignore tides and other variations in sea surface
> height, while bottom pressure recorders or other instruments used in
> transport studies are monitoring these differences.
>
> The oceansites project is looking for a way to identify this distinction -
> maybe having 2 "water depth" terms in CF will be the solution, although
> it may not be clear enough (especially since most people seem to think
> these terms are synonyms).
>
> If this has been mentioned, please excuse; I've been on a ship with
> terrible network throughput, and I'm slowly trying to catch up with
> email discussions.
>
> Cheers - Nan
>
>
--
*******************************************************
* Nan Galbraith (508) 289-2444 *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 *
*******************************************************
Received on Mon Feb 08 2010 - 08:09:43 GMT
