Hi Sriram,
Welcome to Ferret - There are just a couple things to know about
opening an OPeNDAP file, but basically the magic of OPenDAP is that
once you have the data address it is as if the file is on your local
machine. If
you use your browser to go to the site
http://dods.jpl.nasa.gov/dods-bin/nph-nc/pub/data_collections/woce_v3/
you'll see a directory listing - find the set of files you want - say
topex/data/05_deg and click on any file. You'll see the DODS data
request form (DODS is an older name for OPeNDAP, you will see both
terms used, for example as part of the http address you'll see
/dods-bin/)
From the data request form, copy and paste the Data URL to a Ferret
script, and open the data as follows:
yes? set data
"http://dods.jpl.nasa.gov/dods-bin/nph-nc/pub/data_collections/woce_v3/topex/data/05_deg/ssh05d19921012.nc.gz"
yes? show data
currently SET data sets:
1>
http://dods.jpl.nasa.gov/dods-bin/nph-nc/pub/data_collections/woce_v3/topex/data/05_deg/ssh05d19921012.nc.gz
(default)
name title I J
K L
WOCE_DATE
WOCE date ... ...
... 1:1
WOCE_TIME
WOCE time ... ...
... 1:1
DEPTH depth ... ...
... 1:1
SEA_LEVEL
sea_level 1:720 1:360
... ...
BIN_COUNT
number of data points per bin 1:720 1:360
... ...
The site at AVISO that Peter mentions uses an older DODS Catalog
Aggregation server so that data does not work with current versions of
Ferret. Looking at that site, what you would do is to choose an OPenDAP
link, which takes you to a data directory listing, and then click on
the "Data Request Form" for a given file, which lists the data URL to
use. These URL's unfortunately do not open in Ferret unless you happen
to have an old Ferret, version 5.6 or earlier.
Peter Cornillon wrote:
I'm not a
Ferret so I am probably not the right person to lead Sriram
through this. Can someone else on the list help; he wants to know how
to use an OPeNDAP-accessible data set directly from Ferret? Thanks.
Peter
Begin forwarded message:
From:
Prakya Shree Ram <srprakhya@yahoo.com>
Date: August
12, 2005 12:22:28 AM EDT
To: Peter
Cornillon <pcornillon@gso.uri.edu>
Subject: Re:
[ferret_users] Topex data in NetCDF
Dear Cornillon,
Thanks for your response to my request. I have
recently started using the Ferret and do not know how
to read the data over the directly into Ferret. Can
you please give me some guidence.
Looking forward to your reply.
Regards,
Sriram
--- Peter Cornillon <pcornillon@gso.uri.edu> wrote:
Hi Sririam,
1) You can get gridded T/P SSH data from the MERSEA
site via OPeNDPAP,
i.e., read them over the network directly into
Ferret. They are COARDS
compliant, so Ferret should be able to handle them
with no trouble.
Here's the URL for the MERSEA page that points to
the suite of SSH
products that they provide:
http://www.aviso.oceanobs.com/html/donnees/produits/msla_uk.html
They may have other SSH products as well, their site
is quite extensive
2) Gridded T/P products are also available from the
JPL PO-DAAC via an
OPeNDAP server. The URL for these data is:
http://dods.jpl.nasa.gov/dods-bin/nph-nc/pub/data_collections/woce_v3/
topex/data/05_deg/ or replace the 05 with 10 for 1
degree grids, the 05
is for 1/2 degree grids.
You can find a description of this data set at the
GCMD:
http://gcmd.nasa.gov/KeywordSearch/Metadata.do?
Portal=GCMD&KeywordPath=&EntryId=JPL_OCEANESIP_SSHR_GRID&MetadataView=Br
ief&MetadataType=0
or at:
http://podaac.jpl.nasa.gov:2031/DATASET_DOCS/woce_v3.html
I coudn't find raw T/P records available via
OPeNDAP.
Peter
On Aug 11, 2005, at 6:59 AM, Prakya Shree Ram wrote:
Dear ferreters,
Any idea from where I can get T/P sea surface
height
data is NetCDF format? I need this data from
April-August2001 for all the cycles.
Please give me the web address or else send me the
file if any one has it.
Thanks in advance.
Regards,
Sriram
____________________________________________________
Start your day with Yahoo! - make it your home
page
http://www.yahoo.com/r/hs
--
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
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--
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
|