----- Original Message -----Actually this might be somewhat different than DODS. The
From: "Daniel Holloway" <address@hidden>
To: <address@hidden>
Sent: Wednesday, June 19, 2002 1:34 PM
Subject: Reprsenting OGC services in a THREDDS catalog> dimensions. To make a long story short, all a WMS/WCS
> client really needs is the layer name corresponding to a
> particular collection/dataset to properly access the datafile
> with that service (assuming the client app interacts with the
> server to determine the sample dims, etc.) (Dataset #1
> in the example)
>
> However, if you want to insure that a particular datafile is
> accessed by the WMS/WCS service, without requiring the
> client to figure out the sample dimensions necessary
> to access that particular datafile, then you would need to
> add the minimal set of sample dimensions necessary to
> uniquely identify the granule in the particular WMS/WCS
> server. (Dataset #2 in the example)I would say that this situation is analogous to DODS, in the sense that you
specify a dataset in the catalog, which can be further decomposed from
within the protocol, or as an explicit catalog entry.
No, I'm stating that the dataset (.i.e., file) is available through WMS/WCS
Because urlPath is required on the access element, I hadnt thought of doing
what you do in Example 1:<dataset name="QS_XWGRD3_2002001.20020041637.Z" serviceName="DODS"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041637.
Z">
<access serviceName="FTP"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041637.
Z"/>
<access serviceName="WCS" urlPath=""/>
<access serviceName="WMS" urlPath=""/>
</dataset>Since you are assuming I think that a blank urlPath means "use the one in
the dataset element". If this was allowed, then the meaning would be:The dataset is available through WCS and WMS, as
"http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl/pub/ocean_wind/quikscat/L3/
data/2002/QS_XWGRD3_2002001.20020041637.Z"
The URL you list above is not a valid WMS/WCS request.
The minimum information an OGC WMS/WCS client needs is the layer
name, and path to the service. The responsibility to identify
the specific
datafile from the WMS/WCS server is the client's responsibility, and
it's
not obvious that a client could make that distinction without knowing
the mapping of the sample dimensions within the repository.
Yes, I noticed that mistake as well.
though DODS as"http://dods.jpl.nasa.gov/dods-bin/nph-dods/pub/ocean_wind/quikscat/L3/data/
2002/QS_XWGRD3_2002001.20020041637.Z"and through FTP as
"http://podaac.jpl.nasa.gov/pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2
002001.20020041637.Z"(shouldnt protocol type be ftp ?)
I had thought of doing it this way:<service name="OGC-DODS" serviceType="Compound" base="">
<service name="DODS" serviceType="DODS"
base="http://dods.jpl.nasa.gov/dods-bin/nph-dods/"/>
<service name="WCS" serviceType="WCS"
base=http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl/>
<service name="WMS" serviceType="WMS"
base="http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl"/>
</service><dataset name="myName" serviceName="OGC-DODS"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041637.
Z">
<access serviceName="FTP"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041637.
Z"/>
</dataset>
I think this works best, though you would have to move the WMS/WCS
or maybe even<service name="OGC-DODS-FTP" serviceType="Compound" base="">
<service name="DODS" serviceType="DODS"
base="http://dods.jpl.nasa.gov/dods-bin/nph-dods/"/>
<service name="FTP" serviceType="FTP" base="http://podaac.jpl.nasa.gov/"/>
<service name="WCS" serviceType="WCS"
base=http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl/>
<service name="WMS" serviceType="WMS"
base="http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl"/>
</service><dataset name="myName" serviceName="OGC-DODS-FTP"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041637.
Z" />
No you don't use the urlPath from the dataset at all for WMS/WCS access.
-------------
For example 2:<dataset name="myName" serviceName="DODS"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041638.
Z">
<access serviceName="FTP"
urlPath="pub/ocean_wind/quikscat/L3/data/2002/QS_XWGRD3_2002001.20020041638.
Z"/>
<access serviceName="WCS"
urlPath="?SERVICE=WCS&REQUEST=GetCoverage&TIME=2002-01-02&LAYER=QuikScat-Lev
el3"/>
<access serviceName="WMS"
urlPath="?SERVICE=WMS&REQUEST=GetMap&TIME=2002-01-02&LAYER=QuikScat-Level3"/
>
</dataset>I assume you mean (for WCS, WMS) use the urlPath from the dataset, and
append, so the URL is"http://seablade.jpl.nasa.gov/cgi-bin/esip/de.pl/pub/ocean_wind/quikscat/L3/
data/2002/QS_XWGRD3_2002001.20020041637.Z?SERVICE=WCS&REQUEST=GetCoverage&TI
ME=2002-01-02&LAYER=QuikScat-Level3"??
The sample dimension and layer name is equivalent to the filename in
the WMS/WCS domain.
Layer=QuikScat-Level3,Time=2002-01-02 ==> pub/.../QS_XWGRD3...637.Z
This discussion might lead us to how you envision an OGC
client using a THREDDS catalog. It might be possible for
a WMS/WCS
client to be developed which will access THREDDS catalogs but I
don't see that happening immediately. The real benefit
from that
community would be for the OGC Catalogs to be able to discover
WMS/WCS layers advertised by THREDDS catalogs. Actually
I'm not sure of the state of development of the catalog effort in
OGC Map services, we should get some input from the OGC client
developers on how useful the information in THREDDS is to
that community.
Dan