Re: [ferret_users] DODS data reading

[Peter Cornillon <pcornillon@xxxxxxxxxxx>]

Hi Yogesh,

There may be something wrong with the way that the OPeNDAP (a.k.a.  
DODS) server is returning the metadata. OPeNDAP returns three data  
types to the requesting client, the data itself and two different  
groups of metadata, the dds which provides information about the  
structure of the data, the data type, dimensions of arrays, etc. and  
the das which provides information about the variables themselves, the  
units used, the long name if there is one, etc. From both Matlab and my  
web browser I can access all of these. However when I try to access the  
data set from the OPeNDAP Data Connector, a Java based program designed  
to read and display OPeNDAP accessible data, I get an error when it  
tries to access the das. My guess is that the problem is that what is  
being returned doesn't conform exactly to the OPeNDAP data access  
protocol, but that it is very close and that Matlab and my browser are  
ignoring the slight inconsistency. I have copied James Gallagher on  
this message. He is the technical lead for OPeNDAP and should be able  
to give a more definitive answer.

Peter


On Aug 29, 2005, at 1:29 PM, Ansley Manke wrote:

> HI Yogesh,
> It looks like this may be due to a problem with the way the DODS  
> server is configured. I opened the links you show in my browser and  
> get this message.
>
> "http://g0dug03u.ecs.nasa.gov/dods-bin/nph-dods/datapool/MOAA/ 
> MYD08_M3.004/2003.05.01/MYD08_M3.A2003121.004.2004136064318.hdf? 
> Optical_Depth_Land_And_Ocean_Mean_Mean[0:1:179][0:1:359]"
>
> Error {
>    code = 0;
>    message = "This DODS server does not know how to serve the dataset  
> `/datapool/MOAA/MYD08_M3.004/2003.05.01/MYD08_M3.A2003121.004.'
> It maybe that the server has not been configured for this type of  
> dataset.
> Please double check the URL for errors and, if you think that the URL  
> is
> correct, please contact the  DODS user support coordinator at:  
> support@unidata.ucar.edu";
> };
>
>
> (DODS experts please jump in if there's more to this.)
>
> Ansley
>
> Yogesh K. Tiwari wrote:
>
> > Hello Ferret Users,
> >
> > I am using ferret v5.80 in suse linux.
> >
> > First time I am using DODS data server.
> >
> > I tried to open the MODIS/AQUA-atmosphere (Level3, monthly grided))  
> > aerosol optical depth data kept at the DODS server(after taking the  
> > url from the server) :-
> >
> > !++++++++++++
> > yes? use  
> > "http://g0dug03u.ecs.nasa.gov/dods-bin/nph-dods/datapool/MOAA/ 
> > MYD08_M3.004/2003.05.01/MYD08_M3.A2003121.004.2004136064318
> > .hdf?Optical_Depth_Land_And_Ocean_Mean_Mean[0:1:179][0:1:359]"
> >
> > yes? show data
> >      currently SET data sets:
> >     1>  
> > http://g0dug03u.ecs.nasa.gov/dods-bin/nph-dods/datapool/MOAA/ 
> > MYD08_M3.004/2003.05.01/MYD08_M3.A2003121.004.2004136064318.hd
> > f?Optical_Depth_Land_And_Ocean_Mean_Mean[0:1:179][0:1:359]  (default)
> >  name     title I         J         K         L
> >
> > yes?
> >
> > !+++++++++++++
> >
> > show data in ferret , dosent show any variable.
> >
> > What I am doing wrong ?
> >
> > Should I use another ferret version, other thans v5.8, as Ansley  
> > mentioned recently ?
> >
> > Pls help.
> >
> > Many thanks,
> >
> > Regards,
> > Yogesh
--
 Peter Cornillon
   Graduate School of Oceanography     -  Telephone: (401) 874-6283
      University of Rhode Island                 -               Fax:  
(401) 874-6728
        Narragansett, RI 02882                    -           E-mail:  
pcornillon@gso.uri.edu