Re: [thredds] aggregating GFS data, problem with accumulated

• To: thredds@xxxxxxxxxxxxxxxx
• Subject: Re: [thredds] aggregating GFS data, problem with accumulated
• From: John Caron <caron@xxxxxxxxxxxxxxxx>
• Date: Thu, 06 Jun 2013 11:37:47 -0600

Hi Hein:

What you are seeing is the limitations of aggregations. In this case, there are 
3 different time coordinates in the collection, but NcML aggregation can only 
aggregate on one of them.

You want to use feature collections instead. Replace your entire <dataset> 
element with something like:

      <featureCollection name="myCollectionName" featureType="GRIB" 
path="grib/NCEP/GFS/etc">

        <collection 
spec="/pub/data/nccf/com/gfs/prod/gfs.2013060600/gfs\.t00z\.pgrb2f..$"
                    dateFormatMark="#prod/gfs.#yyyyMMddHH"  />

      </featureCollection>


you have to get the regexp right to pick out the files you need (rather than 
just enumerate them as in ncml):

  spec="/pub/data/nccf/com/gfs/prod/gfs.2013060600/gfs\.t00z\.pgrb2f..$

means all the files starting with 
"/pub/data/nccf/com/gfs/prod/gfs.2013060600/gfs.t00z.pgrb2f"

and then the last two chars can be anything "..$"

Usually need to get a $ terminator in order to exclude the gbx9 and ncx index 
files.


See

  
http://www.unidata.ucar.edu/projects/THREDDS/tech/tds4.3/reference/collections/FeatureCollections.html

for more details.

John

On 6/6/2013 3:30 AM, Hein Zelle wrote:
> Dear John,
> 
> attached to this email is a complete ncml file that we place next to
> the data files.  The data files themselves are too big to upload, but
> they are standard gfs grib2 files, you can find them at
> 
> ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.2013060600
> 
> (that's for this morning, modify the date as needed)
> The files are the grib2 files at 0.5 degree, e.g.  gfs.t00z.pgrb2bf30
> (50 mb each).
> 
> The previous snippet of ncml I sent should also work, you'll have to modify
> the paths to the correct folder of course.  A variable to check is for
> example
> 
> Total_precipitation_surface_3_Hour_Accumulation
> 
> These should have multiple time steps, but I get only 1 time step (the
> first, for the +03 forecast). The +00 analysis doesn't contain the
> precipitation fields.  Any variable with an accumulation or averaging
> interval exhibits the problem.
> 
> 
> Kind regards,
>       Hein Zelle
> 
> 
> 
> 
> _______________________________________________
> thredds mailing list
> thredds@xxxxxxxxxxxxxxxx
> For list information or to unsubscribe,  visit: 
> http://www.unidata.ucar.edu/mailing_lists/
> 

• References:
  • Re: [thredds] aggregating GFS data, problem with accumulated
    • From: Hein Zelle