Dear all

OK, I agree that if it's useful to compare them, then they should be described
in a standardised way.

Why is this *not* a standard error? I suppose that to be described as a
standard error it should be a number you could regard as the standard deviation
of the true value around the stated value. If it's not that, are there other
ways you would use such a number?

Best wishes

Jonathan

----- Forwarded message from John Graybeal <[email protected]> 
-----

> From: John Graybeal <[email protected]>
> Date: Mon, 1 Jul 2013 14:19:30 -0700
> To: [email protected]
> X-Mailer: Apple Mail (2.1508)
> CC: [email protected]
> Subject: Re: [CF-metadata] Fwd:  how to represent a non-standard error
> 
> Yes please, I've wanted the ability to specify something like 
> "error_estimate" for some time too. Even if the calculations are not done in 
> exactly the same way -- they could even be off by an order of magnitude -- 
> being able to compare them is meaningful.  And it's extremely valuable to be 
> able to answer the query "Which variables have error estimates?"
> 
> So if we can some up with a standard way to represent this it will be 
> extremely helpful.
> 
> John
> 
> On Jul 1, 2013, at 13:00, Nan Galbraith <[email protected]> wrote:
> 
> > I think that these are fairly important QC checks for wind and current
> > data, and that they deserve to have standard names to make them
> > more useful. Although the algorithms may differ between instruments,
> > and may even be proprietary, these variables are often the most useful
> > way to provide information about the reliability of the geophysical
> > measurements.
> > 
> > I had asked about the best way to label this parameter for ADCP data
> > several years ago, but I wasn't able to explain why standard_error wasn't
> > appropriate (it's a little outside my field).
> > 
> > Could we use a standard name modifier like 'instrument_error',
> > or even just 'error', to convey the meaning of instrument-provided
> > error information?  That would be much simpler than requesting a
> > name for each instrument type (although I suppose there may be
> > only a handful of those).
> > 
> > Thanks - Nan
> > 
> > On 7/1/13 1:10 PM, Jonathan Gregory wrote:
> >> Dear Randy
> >> 
> >> If it is very product-specific, is it really a geophysical quantity which 
> >> needs
> >> a standard name? I mean, are there data from several sources for this 
> >> quantity
> >> which should be regarded as comparable, and which therefore should have a
> >> common standard name?
> >> 
> >> If the answer is Yes, then I would suggest you propose a standard name 
> >> which
> >> explicit names the algorithm, like e.g. isccp_cloud_area_fraction.
> >> 
> >> Best wishes
> >> 
> >> Jonathan
> >> 
> >> ----- Forwarded message from 
> >> "[email protected]"<[email protected]>  -----
> >> 
> >>> From: "[email protected]"<[email protected]>
> >>> To: [email protected]
> >>> Date: Mon, 1 Jul 2013 08:28:15 -0400
> >>> Subject: [CF-metadata] how to represent a non-standard error
> >>> 
> >>> 
> >>> 
> >>> Folks:   the GOES-R ground system generates a derived motion winds 
> >>> product.
> >>>  Accompaning each wind speed&  direction in the product is the amount of
> >>> error associated withe the vector.  This error is not a standard_error, 
> >>> but
> >>> an error estimate based on a custom algorithm.   Because this is not a
> >>> standard_error, it would seem that using a standard_error standard_name
> >>> modifier would be misleading.   Any thoughts on how to represent this
> >>> product-specific error in the NetCDF file ? (The best idead I could come 
> >>> up
> >>> with so far is to establish an ancillary data relationwhip between the 
> >>> wind
> >>> speed/direction variables and the error variable, and use the error
> >>> variable's long_name to describe the error)     very respectfully,   randy
> >>> _______________________________________________
> >>> CF-metadata mailing list
> >>> [email protected]
> >>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >> 
> >> ----- End forwarded message -----
> >> _______________________________________________
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> >> 
> > 
> > 
> > -- 
> > *******************************************************
> > * Nan Galbraith                        (508) 289-2444 *
> > * Upper Ocean Processes Group            Mail Stop 29 *
> > * Woods Hole Oceanographic Institution                *
> > * Woods Hole, MA 02543                                *
> > *******************************************************
> > 
> > 
> > 
> > _______________________________________________
> > CF-metadata mailing list
> > [email protected]
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> 
> ------------------------------------
> John Graybeal
> Senior Data Manager, Metadata and Semantics
> 
> T +1 (408) 675-5545
> F +1 (408) 616-1626
> skype: graybealski 
> 
> Marinexplore
> 920 Stewart Drive
> Sunnyvale, CA
> 
> 
> 
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