[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[THREDDS #VMY-667165]: Exposing resolution metadata to THREDDS



Hi Heejoon,

> This is Heejoon from IU LEAD team.
>
> We are now trying to use additional metadata existing inside of the data
> file for example resolution metadata about NAM file.
> 
> I am just wondering how is thredds extracting file metadata and if it would
> be possible to  easily crack and open the files and expose the additional
> metadata to the THREDDS,
> 
> we could easily get them by crosswalking mechanism we use now.
> 
> So, could you look at this and let us know? Our first priority parameter is
> resolution parameter for NAM file.

Are you running your own THREDDS Data Server (TDS) or are you looking at:

1) http://motherlode.ucar.edu:8080/thredds/catalog.html, or
2) http://lead.unidata.ucar.edu:8080/thredds/catalog.html?

In general, the TDS doesn't support any automated extraction of metadata from 
datasets. All the metadata that ends up in THREDDS catalogs is either added by 
hand to the configuration catalogs or extracted from the file names (according 
to information in the config catalogs).

We do have a few tools that can be used to crack open particular files, extract 
things like a list of variables contained in the file, and output XML that can 
be inserted into the config catalogs.

On the motherlode and LEAD TDS, most metadata has been added to homogeneous 
collections of data (like the NAM CONUS 80km dataset [*]) rather than 
individual files. Where it is added for individual files, like the time 
coverage for an individual file (see todays 00Z run of NAM CONUS 80km data 
[**]), the information iss extracted from the file name rather than any 
information inside the data file.

In the case of the NAM data, each homogeneous collection should have consistent 
resolution in time and horizontal directions. Though that is only in the 
projection plane not necessarily latitude/longitude. In the vertical, the 
resolution may differ between parameters.

What kind of resolution are you interested in?

Ethan

[*] NAM CONUS 80km data - 
http://motherlode.ucar.edu:8080/thredds/catalog/fmrc/NCEP/NAM/CONUS_80km/catalog.html?dataset=fmrc/NCEP/NAM/CONUS_80km

[**] NAM CONUS 80km, 23 Feb 00Z run -  
http://motherlode.ucar.edu:8080/thredds/catalog/fmrc/NCEP/NAM/CONUS_80km/files/catalog.html?dataset=fmrc/NCEP/NAM/CONUS_80km/files/NAM_CONUS_80km_20090223_0000.grib1

Ticket Details
===================
Ticket ID: VMY-667165
Department: Support THREDDS
Priority: Normal
Status: Open


NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.