Re: [thredds] [support] Data Request

• To: "Tolley, Stuart" <st514@xxxxxxxxxxxx>, THREDDS community <thredds@xxxxxxxxxxxxxxxx>
• Subject: Re: [thredds] [support] Data Request
• From: Nathan Potter <ndp@xxxxxxxxxxx>
• Date: Thu, 25 Jan 2018 06:54:35 -0800

Hi Stuart,

Unfortunately I do not have access credentials for any of the OpenID providers 
listed at that site and thus am unable to view that dataset. However from the 
URL I can see that the software that is providing access is not Hyrax, but 
rather the THREDDS Data Server (TDS), the form interface is roughly the same as 
the one the we provide with Hyrax so the documentation link I sent is relevant.

The form utilizes array index based subsetting, not value based subsetting. For 
your request you would need to examine the longitude and latitude arrays to 
determine the indices of the bounding box you wish to subset. This can be done 
quickly by selecting one the coordinate variables (pick for example the 
variable for latitude) by selecting just that in the form and then clicking on 
the “Get ASCII” button. (You may need to do a bit of scripting to find the 
indices of the bounds) Repeat for longitude. Once you can express them as 
start:stride:stop you can select the variable you wish to retrieve (pH for 
example) and plug those index values into the appropriate part of the form. 
Using the form you can then retrieve the results as either an ASCII download or 
as a DAP2 binary object.

The TDS provides several other (possibly more intuitive) ways to request data, 
but I am not entirely familiar with them so I am including the TDS support list 
so that they can chime in and assist you.

Cheers,

Nathan 


> On Jan 25, 2018, at 6:35 AM, Tolley, Stuart <st514@xxxxxxxxxxxx> wrote:
> 
> Hi Nathan,
> 
> This is the URL I am hoping to use: 
> http://esgf-data1.ceda.ac.uk/thredds/dodsC/cmip5.output1.MOHC.HadGEM2-ES.rcp45.mon.ocnBgchem.Omon.r4i1p1.ph.20120110.aggregation.1
> 
> Thank you in advance for any assistance you can provide.
> 
> Regards,
> 
> Stuart
> From: Nathan Potter <ndp@xxxxxxxxxxx>
> Sent: Thursday, January 25, 2018 1:57:48 PM
> To: Tolley, Stuart
> Cc: Nathan Potter; support@xxxxxxxxxxx
> Subject: Re: [support] Data Request
>  
> Hi Stuart,
> 
> You can find more about how to use the form here: 
> https://opendap.github.io/documentation/QuickStart.html#_an_easy_way_using_the_browser_based_opendap_server_dataset_access_form
> 
> I can provide more specific help if you send me the URL of the form page. We 
> provide the software (Hyrax) but many institutions around the world deploy it 
> and I can’t know which dataset you are attempting to access without the URL.
> 
> Sincerely,
> 
> Nathan Potter
> 
> 
> > On Jan 25, 2018, at 3:51 AM, Tolley, Stuart <st514@xxxxxxxxxxxx> wrote:
> > 
> > Dear Sir/Madame,
> > 
> > I am currently trying to download data using your dataset access form, 
> > however I am finding it very difficult to understand. The data I am trying 
> > to access is:
> > 
> > Project= CMIP5
> > model=HadGEM2-es
> > experiment=RCP4.5 
> > The main variable I'm looking for is pH.
> > The specific area I need it in is a region of sea off the British Coastline:
> > Latitude= 51-52
> > Longitude= 1.7-2.55.
> > The time I require if for the year 2050 and 2100.
> > 
> > Could you please help me download this data!
> > 
> > Regards, 
> > 
> > Stuart Tolley
> 
> = = =
> Nathan Potter                        ndp at opendap.org
> OPeNDAP, Inc.                        +1.541.231.3317

= = =
Nathan Potter                        ndp at opendap.org
OPeNDAP, Inc.                        +1.541.231.3317

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