Hi Jonathan:
The range for the data variable is not error/uncertainty.
Rather, the data variable is one of a set of data variables needed to define the current environmental conditions at a location.
The specific data variable is an energy band with an upper and lower limit where the energy band is dynamic, and a function of the current environmental conditions.
When you say ...
"a possibility would be new modifiers to indicate the lower and upper bounds."
This is the most applicable possibility of those you listed. (I think you are suggesting using the existing ancillary variable convention construct).
One other point worth making is that the data set only needs to contain the upper and lower bounds, and not any data value (e.g. midpoint) in the range.
very respectfully,
randy
Randy C. Horne (rhorne at excaliburlabs.com)
Principal Engineer, Excalibur Laboratories Inc.
voice & fax: (321) 952-5100
url:
http://www.excaliburlabs.com
---------- Original Message ----------------------------------
From: Jonathan Gregory <j.m.gregory at reading.ac.uk>
Date: Wed, 19 Sep 2012 16:17:57 +0100
>Dear Randy
>
>> We have a type of product we are generating where the data value is not precisely known?only a range between two values.
>>
>> Cells / boundary variables would work, but according to appendix A, they are to be used for coordinate variables only.
>>
>> Is there a CF compliant approach to handling this ?
>
>If the range can be described by a standard error on the value, then you could
>use the standard_error modifier of the standard_name (Appendix C). If it can't
>be described that way, a possibility would be new modifiers to indicate the
>lower and upper bounds. If the bounds could be characterised as particular
>percentiles, another possibility would be to introduce coordinate variable of
>cumulative probability; I have a memory of this being discussed in another
>context. I don't think there is currently a way to do it.
>
>Cheers
>
>Jonathan
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..............End of Message ...............................-->
Received on Wed Sep 19 2012 - 09:48:43 BST
