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[THREDDS #LMM-413857]: spatial aggregation w/NCML

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  • Subject: [THREDDS #LMM-413857]: spatial aggregation w/NCML
  • Date: Mon, 10 Feb 2014 10:04:50 -0700
Hi Roland,

At first pass, it your NcML looks fine.  Without looking at the files, my guess 
would be that the union does not work because each file has its own distinct 
coordinate system, something NcML won't know how to manage.  I'm also guessing 
that the soil characteristic variable has the same name (i.e., soil_acidity or 
soil_moisture), which throws off the union given the different coordinate 
systems.  If this is the case, I don't think that an NcML union will do what 
you want.

However, I'm happy to grab the files and try my hand at it, just point me to a 
server with file access.  Sorry I can't be more helpful, though.

Regards,
  Lansing Madry
  Unidata
  Boulder, Colorado

> Hi folks,
> 
> I was hoping to use NCML to panel together a set of *.nc files. Each file
> contains the same soil characteristic for the same point in time, but for a
> different a US state. The states are non-adjacent in my test case (using
> Alabama, Arkansas, and Arizona).
> 
> I took a whack at it and came up with:
> 
> <dataset name="aggregation of US States AWC" ID="AWCagg" dataType="Grid"
> serviceName="odap" urlPath="AWCagg">
> <netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
> <attribute name="title" type="string" value="Union of US States"/>
> <aggregation type="union">
> <scan
> location="E:/software/apache-tomcat-6.0.39/content/thredds/public/wk_esri/wk_awc/"
> suffix=".nc" />
> </aggregation>
> </netcdf>
> </dataset>
> 
> THREDDS doesn't seem to complain (not seeing anything obvious in the tomcat
> log files) about it and all the services are listed. Problem is that only
> the content from the first file scanned is shown when I look at it via WMS
> (Godiva, ArcCatalog). I'm enough of a noob that I can't really tell whether
> the rest of the services are similarly limited to the first file (Alabama,
> in this case).
> 
> Rich and I took a look at the JIRA tickets for TDD/CDM and didn't see
> anything that looked pending wrt spatial aggregation. Is this possible and
> I'm just mangling things or do I need to start merging my set of
> state-based *.nc into one whopper national file?
> 
> Thanks for any information!
> 
> Roland
> 
> =====================
> Roland Viger, Ph.D.
> Research Geographer
> National Research Program
> U.S. Geological Survey
> 303-541-3075
> address@hidden
> https://profile.usgs.gov/rviger
> =====================
> 
> 


Ticket Details
===================
Ticket ID: LMM-413857
Department: Support THREDDS
Priority: Normal
Status: Open