THREDDS aggregation capability
Roy Mendelssohn
Roy.Mendelssohn at noaa.gov
Tue Jun 20 18:51:15 MDT 2006
Take a look at the utility ConvertTable, it may help you do some of
the conversion or other code:
http://coastwatch.pfel.noaa.gov/coastwatch/ConvertTable.html
-Roy M.
At 11:10 AM -0600 6/20/06, Ethan Davis wrote:
>Hi Ben,
>
>As is, the THREDDS Data Server (TDS) will not be able to serve your
>ascii data files through a service that provides subsetting. Three
>possible solutions come to mind:
>
>1) The OPeNDAP FreeForm server can be used to read ASCII files. I'm
>not sure how easy it would be to write a FreeForm description for
>your data files. But that might be worth looking into.
>
>2) You mentioned this one. Convert the ascii to netCDF and use
>either the TDS or the OPeNDAP netCDF server to serve the data.
>
>3) The TDS uses the netCDF-java library to read the data files it is
>serving. The netCDF-java library has a framework for allowing it to
>read non-netCDF files. You could write some code to allow the
>netCDF-java library to read these data files.
>
>That's all I can think of. Perhaps others on the lists have other suggestions.
>
>Ethan
>
>Ben Burford wrote:
>>Hello Roy, Jose, Ethan and All,
>>
>>Thanks very much for your help.
>>
>>The project that I'm working on is CEOP (http://www.ceop.net/) and we are re
>>ceiving this data from 10 major data centers internationally (NCEP, UK Met O
>>ffice, ECPC, ECMWF, BMRC, JMA, Epson Meteo Centre (EMC), GLDAS, GMAO and CPT
>>EC). Right now I want to focus on 2, NCEP and UK Met Office (UKMO). I thin
>>k I can get the NCEP data in netCDF and I'll send more information on this l
>>ater.
>>
>>It turns out that the UKMO data is not in NetCDF and it may be a while befor
>>e we have the tool for converting the ascii data to netCDF, so I
>>would like to ask you to tell me if we can work with the UKMO data
>>in ascii.
>>
>>A sample file is attached along with some documentation on the format of the
>> data. Remember, this is time series data at a grid point (derived from glo
>>bal gridded NWP model output data).
>>
>>There is one file per day, with a 36 hour forecast beginning at 12Z. This 3
>>6 hour forecast produced values on a 3 hourly interval, so, in each file the
>>re are 13 data values per variable (i.e. 12Z+00 12Z+03 12Z+06 12Z+09 12Z
>>+12 12Z+15 12Z+18 12Z+21 12Z+24 12Z+27 12Z+30 12Z+33 12Z+36). The d
>>ata is space separated.
>>
>>Following is an example of a file name: UKMO_ST_FC_12Z_lin_MUL_1.txt. As yo
>>u can see the date/time is not given in the file name. This file begins at:
>> 20021001 12Z. The final digit in the file name (in this case its 1) gives
>> the record number, so this digit would go from 1 to 365 for the
>>first year of data.
>>
>>There is a detailed description of the format in the attached file, but I'll
>> summarize the format as follows:
>>1. Header information (date/time/lat/lon/elevation/etc.)
>>
>>2. Values for surface variables
>>This section contains the 13 data values for 41 variables at a
>>single level (e.g. surface) (referred to as "single level data" in
>>the file). Each line contains some information (e.g. variable
>>name) followed by 13 data values. The following example is one
>>line of 13 time series data values for TotSW do
>>wn TOA.
>>
>>128 TotSW down TOA W/m2 3 7.445994e+02
>>5.875879e+02 1.083438e+02 0.000000e+00 0.000000e+00
>>0.000000e+00 1.670333e+01 4.2427
>>90e+02 7.375867e+02 5.797017e+02 1.035093e+02 0.000000e+00 0.000000e+00
>>
>>
>>3. Values for variables at pressure levels
>>This section contains the 13 time series data values (per pressure level) fo
>>r 8 variables at 18 pressure levels. Each line contains the
>>pressure level followed by 13 time series data values at one
>>pressure level. The following
>> example is one line of data for 13 times of temperature data values at pres
>>sure =1000:
>>
>>1000.0 2.891250e+02 2.896250e+02 2.895000e+02 2.890000e+02 2.88375
>>0e+02 2.875000e+02 2.866250e+02 2.860000e+02 2.895000e+02
>>2.907500e+02 2.903750e+02 2.892500e+02 2.876250e+02
>>
>>
>>4. Values for variables at model levels (height in meters)
>>This sections contains the 13 time series data values (per model
>>level) for the 11 variables at 38 model levels. Each line contains
>>the level number (1
>> to 38), the height in meters, followed by the 13 time series data values fo
>>r one variable at one model level. The following example is one line of dat
>>a for 13 times of temperature data values at model level 1, height of 19.9 m
>>eters:
>>
>> 1 19.9 2.903750e+02 2.908750e+02 2.907500e+02 2.890000e+02 2.8662
>>50e+02 2.840000e+02 2.818750e+02 2.852500e+02 2.908750e+02 2.920000e+02
>> 2.908750e+02 2.871250e+02 2.851250e+02
>>
>>
>>Any possibility of putting this data on a THREDDS (or OPeNDAP, or
>>whatever) server and then being able to extract a subset of the
>>data (e.g. 12Z+15 to 1
>>2Z+36) from each file and then concatenating this into a continuous time ser
>>ies? If its not possible to do the variables at pressure or model levels, w
>>ould it be possible to at least do this for the variables at "single level d
>>ata"?
>>
>>Thanks again for your help.
>>
>>Ben
>>
>--
>Ethan R. Davis Telephone: (303) 497-8155
>Software Engineer Fax: (303) 497-8690
>UCAR Unidata Program Center E-mail: edavis at ucar.edu
>P.O. Box 3000
>Boulder, CO 80307-3000 http://www.unidata.ucar.edu/
>---------------------------------------------------------------------------
--
**********************
"The contents of this message do not reflect any position of the U.S.
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097
e-mail: Roy.Mendelssohn at noaa.gov (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/
"Old age and treachery will overcome youth and skill."
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