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) ________________________________ NILU - Norsk institutt for luftforskning Norwegian Institute for Air Research PO Box 100, 2027 KJELLER Besøk/visit: Instituttveien 18, 2007 Kjeller E-mail: [email protected] www.nilu.no ________________________________________ Fra: CF-metadata <[email protected]> på vegne av Maarten Sneep <[email protected]> Sendt: 4. juli 2016 18:45 Til: [email protected] 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: [email protected] R: A2.14 _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata P Please consider the environment before printing this email and attachments _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
