[gradsusr] xdfopen via opendap (developed from re Re: sdfopen with opendap file)

[James T. Potemra]

Takaya:

I don't think that the template option works with data via OPeNDAP, only on
local files. The data provider needs to aggregate the data on the server
side
of things. Otherwise, you will have to write your script to loop through
all the
files.

You are also welcome to get the Pathfinder SST from our site,
http://apdrc.soest.hawaii.edu.
The exact URL is:

http://apdrc.soest.hawaii.edu:80/dods/public_data/satellite_product/AVHRR/avhrr_mon

for the monthly values (and these are aggregated).

Jim

Namba Takaya wrote:
> Dear Sir
>
> I tried to read the HDF file of pathfinder monthly sst via opendap
>
> Fortunately I could read the sst data by xdfopen and data descriptor
> file(bsst.ctl) as bellow,
> Then I tried to develop using % of DSET in the data descriptor file.
> Then I have a problem explained below and could you tell me how to
> solve the problem?
>
> Best Regards, Takaya Namba
>
> bsst.ctl (data descriptor file)
>
> DSET
> http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/1985/198501.s04m1pfv50-bsst-16b.hdf
> options yrev
> ***DSET
> http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/%y4/%y4%m2.s04m1pfv50-bsst-16b.hdf
> TITLE This is a sample
> UNDEF 99999.0
> YDEF lat 4096 LINEAR -90 0.043945
> XDEF lon 8192 LINEAR -180 0.043945
> ***TDEF time 1 linear 00:00z1! 5JAN1985 1mo
> VARS 1:
> bsst=>bsst 1 99 surface temperature
> ENDVARS
>
>
> However, I would like to use
> DSET
> http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/%y4/%y4%m2.s04m1pfv50-bsst-16b.hdf
> instead of
> DSET
> http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/1985/198501.s04m1pfv50-bsst-16b.hdf.
> Because I would like to do all the thirty years from jan 1988 to 2009.
>
> I added the line in the bsst.ctl
> TDEF time 1 linear 00:00z15JAN1985 1mo
> and then
> grads -cl batch-opendap.gs.
>
> However, the error comes like below,
>
> Error: nc_open failed to open file
> http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/%y4/%y4%m2.s04m1pfv50-bsst-16b.hdf
> NetCDF: DAP server error
> gadsdf: Couldn't i! ngest SDF metadata.
> SDF Descriptor file bsst.ctl was not suc cessfully opened & parsed.
>
> I understand that I could not replace /%y4/%y4%m2 with /1985/198501 by
> the data descriptor file.
> Could you tell me how can I replace by the proper descriptor file as I
> expected?
>
> (batch-opendap.gs grads script file)
> 'set gxout shaded'
> 'xdfopen bsst.ctl'
> 'q file'
> say result
> 'set lat 10 50'
> 'set lon 120 170'
> 'set T 1'
> 'set Z 1'
> 'd bsst'
> 'cbar'
> 'quit'
>
>
> dncdump -h
> "http://data.nodc.noaa.gov/opendap/pathfinder/Version5.0/Monthly/1985/198501.s04m1pfv50-bsst-16b.hdf"
>
> is as below,
>
> netcdf 198501.s04m1pfv50-bsst-16b { // format variant: 64bit
> dimensions:
> lat = 4096 ;
> &n! bsp; lon = 8192 ;
> variables:
> short bsst(lat, lon) ;
> bsst:dsp_PixelType = 1b ;
> bsst:dsp_PixelSize = 2b ;
> bsst:dsp_Flag = 0s ;
> bsst:dsp_nBits = 16s ;
> bsst:dsp_LineSize = 0 ;
> bsst:dsp_cal_name = "Temperature" ;
> bsst:units = "Temp" ;
> bsst:dsp_cal_eqnNumber = 2s ;
> bsst:dsp_cal_CoeffsLeng! th = 8s ;
> &n bsp; bsst:dsp_cal_coeffs = 0.075f, -3.f ;
> bsst:scale_factor = 0.075f ;
> bsst:add_off = -3.f ;
>
>
>
>
>
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