Bob Simons wrote:
Thank you for your email.
John Caron wrote:
Hi Bob:
Bob Simons wrote:
In the Unidata Observation Dataset Conventions, under the heading
"Identifying the Coordinate Variables", it says "Each observation
must have a latitude, longitude, altitude, and time coordinate value
associated with it."
Just to be clear, this first quote is under the larger heading
"Conventions used by ALL Observation Datasets" (my emphasis). So perhaps
it is incorrect and should be removed from the document or modified.
I think its a true statement, you just have to understand that "associate" can
be done in different ways.
The spec covers 2 cases:
A PointObsDataset will have the lat, lon, etc in the observation.
A StationObsDataset will have the lat, lon, etc in the station. Since
the station is associated wwith the obs, the lat, lon, etc are
asociates withe the obs.
Under the heading "Station Observation datasets", it says "The
latitude, longitude, and altitude variables must all be station
variables".
I am confused. It seems like the first quote indicates these
variables should use the observationDimension, but the second
indicates they should use the stationDimension. Which is it?
In some ways I see that it would be nice to have the information in
both places (although that violates standard database design
standards), but you can't have two variables with the same name.
You can certainly put them in both places, obviously using a
different name. Some other data providers need that. The adapter code
will only use one of them, but they should be identical, so it doesnt
matter.
BTW, Im working on reading in dods sequences into the Point/Station
ObsDataset framework. Hope to have it working by the end of the week,
at least for some cases. If you have any test cases, send them to me.
As I can't make .nc files with sequences, I have no test files for you.
Which brings up the question: what types of files (of any type) can be
served as sequences by OPeNDAP?
It depends on the opendap server. theres a lot of them, eg check out
http://www.epic.noaa.gov/epic/software/dapper/
I may eventually make TDS serve sequences using netcdf with "Unidata Observation
Dataset Conventions". Im still investigating, though.
Roy gave me two url's to work with for reading in sequences:
http://oceanwatch.pfeg.noaa.gov:8081/dods/GLOBEC/GLOBEC_MOC1?abund_m3,lat,long
and
http://oceanwatch.pfeg.noaa.gov:8081/dods/GLOBEC/GLOBEC_vpt?stn_id&unique()
thanks!
Sincerely,
Bob Simons
Satellite Data Product Manager
Environmental Research Division
NOAA Southwest Fisheries Science Center
1352 Lighthouse Ave
Pacific Grove, CA 93950-2079
(831)658-3205
bob.simons@xxxxxxxx
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Sincerely,
Bob Simons
Satellite Data Product Manager
Environmental Research Division
NOAA Southwest Fisheries Science Center
1352 Lighthouse Ave
Pacific Grove, CA 93950-2079
(831)658-3205
bob.simons@xxxxxxxx
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