Re: [thredds] Access a "latest dataset" as a netCDF file in THREDDS

• To: Filipe Freire <filipe.r.freire@xxxxxxxxxxx>
• Subject: Re: [thredds] Access a "latest dataset" as a netCDF file in THREDDS
• From: Sean Arms <sarms@xxxxxxxx>
• Date: Thu, 25 Feb 2016 11:42:00 -0700

Greetings Filipe,

Currently, this isn't possible with THREDDS. The latest resolver dataset
isn't actually a dataset, it is a webservice that returns a thredds catalog
which contains the latest available dataset. The other services, such as
oepndap or wms, work on datasets only, not other webservices.

There are libraries out there that can use the resolver service and return
the correct WMS url. For example, in Python you can use the Unidata library
Siphon [1] and do the following to get the latest WMS access url from the
GFS 0.25 degree forecast model output:

----

from siphon.catalog import get_latest_access_url

latest_wms_url = get_latest_access_url("
http://thredds.ucar.edu/thredds/catalog/grib/NCEP/GFS/Global_0p25deg/catalog.xml";,
"WMS")

print(latest_wms_url)
http://thredds.ucar.edu/thredds/wms/grib/NCEP/GFS/Global_0p25deg/GFS_Global_0p25deg_20160225_1200.grib2

----

Cheers,

Sean

[1] https://github.com/unidata/siphon


On Fri, Feb 12, 2016 at 10:51 AM, Filipe Freire <filipe.r.freire@xxxxxxxxxxx
> wrote:

> Hello everyone,
> I'm Filipe and I have a question regarding the "Latest" resolver dataset.
> Currently I can make a datasetScan and in it return a "latest.xml" catalog
> with a direct dataset inside that is the most recent dataset.
>
> *http://host/thredds/catalog/some_folder/latest.xml?dataset=...data_20160201.nc
> <http://host/thredds/catalog/some_folder/latest.xml?dataset=...data_20160201.nc>*
>
> The problem is, when I access that dataset through opendap, wms, etc., the
> dataset's filename is the one that shows up in the URL path, and not a
> dataset name like "latest.nc".
>
> Example:
> *http://host/thredds/dodsC/some_folder/data_20160201.nc.html
> <http://host/thredds/dodsC/some_folder/data_20160201.nc.html>*
> *http://host/thredds/wms/some_folder/data_20160201.nc.html?service=WMS&version=1.3.0&request=GetCapabilities
> <http://host/thredds/wms/some_folder/data_20160201.nc.html?service=WMS&version=1.3.0&request=GetCapabilities>*
>
> And actually I need something like:
> *http://host/thredds/dodsC/some_folder/latest.nc.html
> <http://host/thredds/dodsC/some_folder/latest.nc.html>*
> *
> http://host/thredds/wms/some_folder/latest.nc.html?service=WMS&version=1.3.0&request=GetCapabilities
> <http://host/thredds/wms/some_folder/latest.nc.html?service=WMS&version=1.3.0&request=GetCapabilities>*
>
> Could you kindly point me how I can achieve this in THREDDS?
> Thanks in advance,
> Filipe Freire
>
>
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• References:
  • [thredds] Access a "latest dataset" as a netCDF file in THREDDS
    • From: Filipe Freire