We are not helping the data providers if we suggest that they publish in a way that is not usable, re-usable to downstream research. In fact, you/we are doing the data providers a disservice by suggesting that they do not need to do so. If indeed we do, then the data brokers, whether GBIF, Manis, Ornis, Vertnet, etc, have the responsibility to ensure that the data can be transformed into standard reference systems. Given the investment already made in these data improvement tools, I can't quite see why these rather simple geospatial transformations aren't extant. If we can't support the geo: namespace, then I'm starting to believe that we deserve the perception in various research/development communities that these data are not particularly useful.
Verbatim geo-temporal information is fine, and DWC is honest with this representation. Let's just make sure we accompany with standard reference systems resolved appropriately. If you have a a lat/long coordinate pair associated with an unknown datum and an uncertainty measure of your pleasure, then you can also represent it as some WGS84 based feature.
On Aug 9, 2010, at 10:47 AM, John Wieczorek wrote:
The reason is simple, we want to help data publishers. It doesn't help data publishers if they can't publish what they have - it would mean there is no room for data improvement tools. That would be sad. Worse, most people haven't a clue what a datum is, or how it can ruin your whole day (or life, in at least one sad case of a crashed helicopter in Patagonia). Given this naiveté, people would simply put whatever geographic coordinates they have into geo:lat/lon and no one would have any way to know that they are incorrect.
Note that Darwin Core offers data publishers options to publish event information with year, month, day, startDayOfYear, endDayOfYear, and verbatimEventDate in addition to eventDate and eventTime - same philosophy.
On Mon, Aug 9, 2010 at 7:26 AM, Javier de la Torre jatorre@gmail.com wrote: I am not sure I understand why we can not set DWC fields to conform to WGS84 and then use what everybody else is using.
For example in eventDate DWC conforms to ISO 8601, why dont we do the same for location... it would allow to simplify it quite a lot and be more compliant with other standards-existing apps, etc.
Just an idea.
Javier de la Torre www.vizzuality.com
On Aug 9, 2010, at 4:13 PM, John Wieczorek wrote:
The partially good news is that if enough information (dwc:geodeticDatum) is given in a Darwin Core-based record, geo:lat/ lon can be determined from it. More disturbing to me is that anyone would think geo:lat/lon alone is sufficient for any application, as it carries no notion of uncertainty and therefore fitness for use. Add dwc:coordinateUncertaintyInMeters (or even dwc:coordinatePrecision if you must) to the mix and I would be much happier.
On Sun, Aug 8, 2010 at 11:26 PM, Garry.Jolley-Rogers@csiro.au wrote: Hi Jim, Thanks. Had this aside to read in detail later. I think John is right... As same value with different constraints mean different interpretations are possible and seems to be the key thing. How are the values to be interpreted.
G
-----Original Message----- From: Jim Croft [mailto:jim.croft@gmail.com] Sent: Monday, 9 August 2010 4:12 PM To: Alexander, Paul (PI, Black Mountain); Harvey, Paul.W (PI, Black Mountain); Jolley-Rogers, Garry (PI, Black Mountain); Cawsey, Margaret (CES, Crace); Greg Whitbread Cc: tuco@berkeley.edu Subject: Fwd: [tdwg-tag] time and space namespaces in Darwin Core
Did you catch this thread on tdwg-tag? It is an almost exact mirror of the conversations we have be having in the taxon profile space, but involving the specimen locational data.
From John's comments it would appear he is not prepared to accept
the geo: and dwc: lat/long as 'exact match' because, although they are the same values, they have different constraints (or more precisely one one has a constraint and one doesn't).
I wouldn't have picked it but this looks like a case for 'closematch'.
jim
---------- Forwarded message ---------- From: John Wieczorek tuco@berkeley.edu Date: Mon, Aug 9, 2010 at 3:56 AM Subject: Re: [tdwg-tag] time and space namespaces in Darwin Core To: joel sachs jsachs@csee.umbc.edu Cc: tdwg-bioblitz@googlegroups.com, tdwg-tag@lists.tdwg.org
There is actually no equivalency between dwc:decimalLatitude and geo:lat because geo:lat is specified to represent the latitude in the WGS84 spatial reference system and dwc:decimalLatitude has no such such restriction.
On Fri, Aug 6, 2010 at 10:08 AM, joel sachs jsachs@csee.umbc.edu wrote:
On Fri, 6 Aug 2010, Hilmar Lapp wrote:
Shouldn't the RDF for DwC link DwC:lat to geo:lat (using some
subtype
or better yet equivalency relation)? And shouldn't hence Linked
Data
browsers be able to use DwC:lat in the same way as geo:lat?
Yes. But no Linked Data browser I'm aware of applies owl:equivalentProperty assetions before rendering the data. (In
fact, most
do no reasoning at all.) I agree that, whatever our default
display,
it should include the appropriate mapping statements, either via an rdfs:seeAlso or similar link, or directly in the document.
Joel.
-hilmarOn Aug 6, 2010, at 11:01 AM, joel sachs wrote:
All,
When representing observation records in RDF, there are
advantages
to using Dublin Core and Geo (http://www.w3.org/2003/01/geo/ wgs84_pos#) namespaces where possible. For example, if we use DC:date, and geo:lat, geo:long, instead of DwC:eventDate, DwC:lat, and
DwC:long,
then Linked Data browsers can automatically map the records,
plot
them on a timeline, etc.
My question is: What are the disadvantages to doing this? (For example, is this going to break someone's DwC validator?)
Thanks - Joel.
--
: Hilmar Lapp -:- Durham, NC -:- informatics.nescent.org :
Jim Croft ~ jim.croft@gmail.com ~ +61-2-62509499 ~ http://www.google.com/profiles/jim.croft 'A civilized society is one which tolerates eccentricity to the point of doubtful sanity.'
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