Dear Alison and Maarten,
Thanks for your quick reply.
To be a little more specific, we are not in need of implementing a new standard name.
By "Compound data types", I mean the netCDF-4 user defined data type (
http://www.unidata.ucar.edu/software/netcdf/docs/user_defined_types.html). Using the netcdf-4 format you have support for this data type, but I can not seem to find any information about this subject related to the CF-convention.
Since we have metadata per-variable that changes over time, we were thinking about packing it in a nested structure (compound type). We split up our variable in multiple instances, where each instance could potentially hold a new set of metadata. This could be the case when for example a new data-submitter has taken over the responsibility of reporting data from a specific station or that the instrument-model has changed etc.
So for a given instance of a variable, we could easily have over 100 metadata fields related to stations, data originators, instruments etc.
Basically I have played around creating metadata as compound types, but this does not pass the CF compliance checker (
http://puma.nerc.ac.uk/cgi-bin/cf-checker.pl).
>From my understanding Maarten, you use groups to separate your metadata from your product? I will look more into this.
So I was wondering if there are any plans to allow for this custom data type in future revisions of the CF-convention, or if there are any other approaches that you might suggest regarding this issue.
All the best,
Richard Rud
Atmosphere and Climate Department (ATMOS)
________________________________
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Norwegian Institute for Air Research
PO Box 100, 2027 KJELLER
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E-mail: ror at nilu.no
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________________________________________
Fra: CF-metadata <cf-metadata-bounces at cgd.ucar.edu> p? vegne av Maarten Sneep <maarten.sneep at knmi.nl>
Sendt: 4. juli 2016 18:45
Til: cf-metadata at cgd.ucar.edu
Emne: Re: [CF-metadata] Support for compound data types
On 07/04/2016 12:29 PM, Richard Olav Rud wrote:
> Dear CF community,
>
> We are currently working on exporting our NASA Ames formated data to cf-compliant
> netCDF for our atmospheric composition database.
>
> Since our metadata changes over time, for most of our variables, we were thinking
> about using compound data types.
> Most of our metadata is of little interest to our average user and therefore we would
> avoid listing them as variables. Even so, we are still obligated to present this
> information.
>
> So I am wondering if there any plans in the near future to implement compound data
> types for the CF metadata conventions?
What level of metadata? per-variable or per-granule or even per-dataset? If the
latter (2): take a look at the methods employed for Sentinel 5 precursor.
http://www.tropomi.eu/documents/level-2-products
http://www.tropomi.eu/science/level-2-products
(the first link contains documentation, the second has (pre-launch) sample products).
Best,
Maarten Sneep
--
KNMI
T: 030 2206747
E: maarten.sneep at knmi.nl
R: A2.14
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Received on Wed Jul 06 2016 - 07:08:32 BST
