[thredds] geospaticalCoverage metadata information

[Ethan Davis]

Hi Roland,

Looking again ...

>> Roland Schweitzer wrote:
>>>
>>> I create an aggregation with these files and include the following 
>>> in a <metadata> element.
>>>
>>> <geospatialCoverage>
>>>                                                 <northsouth>
>>>                                                         
>>> <start>-90</start>
>>>                                                         <size>73</size>
>>>                                                         
>>> <resolution>2.5</resolution>
>>>                                                         
>>> <units>degrees_north</units>
>>>                                                 </northsouth>
>>>                                                 <eastwest>
>>>                                                         
>>> <start>0</start>
>>>                                                         
>>> <size>144</size>
>>>                                                         
>>> <resolution>2.5</resolution>
>>>                                                         
>>> <units>degrees_east</units>
>>>                                                 </eastwest>
>>>  </geospatialCoverage>
>>>
>>> When I look at the HTML of the THREDDS catalog using TDS 
>>> (Implementation-Version: 3.16.32) I get this:
>>>
>>>
>>>       GeospatialCoverage:
>>>
>>>     * / Longitude: / 0.0 to 144.0 Resolution=2.5 degrees_east
>>>     * / Latitude: / -90.0 to -17.0 Resolution=2.5 degrees_north
>>>
>>> Have I misinterpreted the documentation, is this a bug in TDS, or what?

... I think it is a misinterpretation of the documentation.

The range is defined using the start and size (extent) of the range, so 
the range is [start, start+size]. The range is then output using the 
start and end values of the range: [start, end]. So, a start of -90 and 
size of 73 result in [-90, -17].

This one is pretty easy to get tripped up on as start/end seems more 
natural, certainly for me anyway. Let me know if we could clarify our 
documentation somewhere.

Hope this helps,

Ethan

-- 
Ethan R. Davis                                Telephone: (303) 497-8155
Software Engineer                             Fax:       (303) 497-8690
UCAR Unidata Program Center                   E-mail:    edavis at ucar.edu
P.O. Box 3000
Boulder, CO  80307-3000                       http://www.unidata.ucar.edu/
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