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[THREDDS #JER-551961]: Time Series Aggregation Question



Dominic:

You cant use TDS opendap to do coordinate space subsetting, only the netcdf 
subset service (ncss, and WCS and WMS do that.

John

> The catalog file I'm using aggregates the files, but the request for a
> subset of data must specify a range of elements rather than a range of time
> in the URL. Is there a service (perhaps OPeNDAP) that allows URL time
> parameters and calculates the corresponding elements server side?
> 
> According to this document, it is possible to use condition parameters in
> the URL when the variables are contained in a sequence structure:
> http://docs.opendap.org/index.php/QuickStart#Sequence_Data
> 
> Would this be a suitable solution? Would it be possible to rearrange the
> variables into a sequence structure using NCML in the configurable catalog
> file? How would I go about doing this?
> 
> Thanks in advance,
> Dom
> 
> address@hidden> wrote:
> 
> > I found it here:
> > https://www.unidata.ucar.edu/software/thredds/current/tds/reference/NetcdfSubsetServiceReference.html#Temporal
> >
> > Maybe this is for Netcdf Subset Service? Thanks for the response!
> >
> > Cheers,
> > Dom
> >
> > Dominic Fuller-Rowell -- Supervised by William Denig
> > Associate NOAA/NGDC/STPD [Boulder Facility]
> > 325 Broadway St.
> > Boulder, CO 80305-3328  USA
> >
> >
> > Tel:   (303) 497-6900
> > Cell:  (303) 587-8671
> > address@hidden <address@hidden>
> >
> >
> > address@hidden> wrote:
> >
> >> Hi Dominic:
> >>
> >> where did you get this syntax:
> >>
> >> >
> >> http://localhost:8080/thredds/dodsC/GOES_magneto/GOES_magneto_2014_03.nc.ascii?BY_1&time_start=2014-03-29T12:00:00Z&time_end=2014-03-30T12:00:00Z
> >>
> >> ??
> >>
> >> its not standard opendap.
> >>
> >> John
> >>
> >> > THREDDS support,
> >> >
> >> > I'm a student intern at the Solar and Terrestrial Physics division of
> >> > NGDC/NOAA and I have been tasked with evaluating the feasibility of
> >> using
> >> > TDS to serve a GOES NetCDF data set. I have set up the catalog file to
> >> > aggregate a month of day files, but I was hoping I could get some advise
> >> > regarding the best method for aggregating time series data.
> >> >
> >> > The issue I'm having is with the use of start_time and end_time
> >> parameters
> >> > in the url. For example:
> >> >
> >> >
> >> http://localhost:8080/thredds/dodsC/GOES_magneto/GOES_magneto_2014_03.nc.ascii?BY_1&time_start=2014-03-29T12:00:00Z&time_end=2014-03-30T12:00:00Z
> >> >
> >> > This url returns ascii csv for the entire month of March rather than
> >> just
> >> > 3/29 through 3/30.
> >> >
> >> > I'm currently using TDS version 4.3, JDK 1.8, and Tomcat 8.0.5. The
> >> NetCDF
> >> > files are being aggregated along the "record" dimension and the
> >> "time_tag"
> >> > variable with units "milliseconds since 1970-01-01 00:00:00.0 UTC". The
> >> > "time_tag" variable is being renamed "record" to match the dimension
> >> name
> >> > as required by TDS. I have attached my catalog.xml file and an example
> >> of a
> >> > NetCDF file can be found here:
> >> >
> >> >
> >> http://satdat.ngdc.noaa.gov/sem/goes/data/new_full/2014/03/goes15/netcdf/g15_magneto_512ms_20140301_20140301.nc
> >> >
> >> > I think the problem might be that the file's metadata doesn't comply
> >> > exactly with CF metadata conventions. If this is the case, how would the
> >> > metadata need to change in order for TDS to recognize the aggregation
> >> > dimension as time and allow the use of time parameters in the url? Could
> >> > these changes be made in the catalog file via NcML? If these files are
> >> not
> >> > cut out for time series aggregation, then what conventions would you
> >> > suggest for future data sets to make this sort of aggregation feasible?
> >> >
> >> > Any advice or guidance would be appreciated.
> >> >
> >> > Thanks in advance,
> >> > Dominic Fuller-Rowell
> >> >
> >> >
> >> > Dominic Fuller-Rowell -- Supervised by William Denig
> >> > Associate NOAA/NGDC/STPD [Boulder Facility]
> >> > 325 Broadway St.
> >> > Boulder, CO 80305-3328  USA
> >> >
> >> >
> >> > Tel:   (303) 497-6900
> >> > Cell:  (303) 587-8671
> >> > address@hidden <address@hidden>
> >> >
> >> >
> >>
> >> Ticket Details
> >> ===================
> >> Ticket ID: JER-551961
> >> Department: Support THREDDS
> >> Priority: Normal
> >> Status: Open
> >>
> >>
> >
> 
> 


Ticket Details
===================
Ticket ID: JER-551961
Department: Support THREDDS
Priority: High
Status: Closed