Andrea,
The DS_Series adds lots of baggage to the system so I would suggest using it only when definitely required. The case you describe, a map made up of tiles, might be more easily described as a single dataset with multiple sources in the DQ_DataQuality section. Each tile is a source that has it's own citation and, more importantly, it's own extent (the extent of the tile). I think that is all you need.
BTW, we are working with many datasets like this and are exploring a practice of naming the extent referenced in MD_DataInformation as fileidentifier.boundingExtent. An extent with this name would be understood to be the complete extent for a dataset and would be the one cross-walked to standards that only allow one extent (i.e. FGDC) and searched first. More detailed extents could be included with appropriate names.
In NOAA, the NOS Physical Oceanographic Real-Time System PORTS® <http://tidesandcurrents.noaa.gov/ports.html> is a decision support tool that improves the safety and efficiency of maritime commerce and coastal resource management through the integration of real-time environmental observations, forecasts and other geospatial information from a number of important commercial ports in the United States. These ports are in disjoint regions from Tampa to Anchorage along the east and west coasts of the United States. The map attached shows these regions as small red boxes which were extracted from the NOSA database for the PORTS observing system. The large box is the bounding lat/lon box of the entire collection. The XML for this case looks like the snippet included below.
Hope this seems reasonable. Please let me know if you have questions,
Ted
<gmd:extent>
<gmd:EX_Extent uuid="gov.noaa.nosa:NOS-PORTS.boundingExtent'">
<gmd:description><gco:CharacterString>gov.noaa.nosa:NOS-PORTS.boundingExtent</gco:CharacterString></gmd:description>
<gmd:geographicElement>
<gmd:EX_GeographicBoundingBox>
<gmd:westBoundLongitude><gco:Decimal>-151.3959</gco:Decimal></gmd:westBoundLongitude>
<gmd:eastBoundLongitude><gco:Decimal>-71.1818</gco:Decimal></gmd:eastBoundLongitude>
<gmd:southBoundLatitude><gco:Decimal>27.5697</gco:Decimal></gmd:southBoundLatitude>
<gmd:northBoundLatitude><gco:Decimal>61.2255</gco:Decimal></gmd:northBoundLatitude>
</gmd:EX_GeographicBoundingBox>
</gmd:geographicElement>
</gmd:EX_Extent>
</gmd:extent>
<gmd:extent>
<gmd:EX_Extent uuid="Anchorage PORTS">
<gmd:description><gco:CharacterString>Anchorage PORTS</gco:CharacterString></gmd:description>
<gmd:geographicElement>
<gmd:EX_GeographicBoundingBox>
<gmd:westBoundLongitude><gco:Decimal>-151.3959</gco:Decimal></gmd:westBoundLongitude>
<gmd:eastBoundLongitude><gco:Decimal>-149.8981</gco:Decimal></gmd:eastBoundLongitude>
<gmd:southBoundLatitude><gco:Decimal>60.6845</gco:Decimal></gmd:southBoundLatitude>
<gmd:northBoundLatitude><gco:Decimal>61.2255</gco:Decimal></gmd:northBoundLatitude>
</gmd:EX_GeographicBoundingBox>
</gmd:geographicElement>
</gmd:EX_Extent>
</gmd:extent>
<gmd:extent>
<gmd:EX_Extent uuid="Chesapeake Bay PORTS">
<gmd:description><gco:CharacterString>Chesapeake Bay PORTS</gco:CharacterString></gmd:description>
<gmd:geographicElement>
<gmd:EX_GeographicBoundingBox>
<gmd:westBoundLongitude><gco:Decimal>-77.0208</gco:Decimal></gmd:westBoundLongitude>
<gmd:eastBoundLongitude><gco:Decimal>-75.5631</gco:Decimal></gmd:eastBoundLongitude>
<gmd:southBoundLatitude><gco:Decimal>36.7793</gco:Decimal></gmd:southBoundLatitude>
<gmd:northBoundLatitude><gco:Decimal>39.5619</gco:Decimal></gmd:northBoundLatitude>
</gmd:EX_GeographicBoundingBox>
</gmd:geographicElement>
</gmd:EX_Extent>
</gmd:extent>
...
--
==== Ted Habermann ===========================
Enterprise Data Systems Group Leader
NOAA, National Geophysical Data Center
V: 303.497.6472 F: 303.497.6513
"If you want to go quickly, go alone.
If you want to go far, go together"
Old Proverb
==== Ted.Habermann@anonymised.com ==================
(attachments)
