Hi Rod,
I would treat easting and northing as latitude and longitude, but not following strictly the definition in Darwin Core. There is actually value in being able to have the easting (longitude) separate from the northing (latitude) if the source has them separated. It makes it that much less ambiguous to interpret. I would also have that full tuple as in the example you gave (18M 166624 9840350) along with "UTM" in verbatimCoordinateSystem, and a datum or something similar in verbatimSRS. We want more information, not less, when it comes time to try to turn this all into more readily usable information (decimalLatitude, decimalLongitude, geodeticDatum, coordinateUncertaintyInMeters). All of this verbatim separation arose from the heyday of massive collaborative georeferencing in MaNIS, HerpNET, and ORNIS where we were able to take good advantage of whatever information the source had, and that is why verbatimCoordinateSystem is part of the offerings, to help with tha parsing problem if the original source is known.
In short, I wouldn't have it any other way than the way it is done with TTU. It actually allows use to extract more information correctly rather than less. Parsing is a mess, but it is a mess anyway. It takes me about 25 steps to parse the variations I see in verbatim coordinates in VertNet. but it is worth it.
Now, to get back to TTU and upgrade their venerable migrator and see how things look afterwords. We appreciate the careful eye and the quality feedback reports to Github on TTU's behalf.
Cheers,
John
On Mon, Feb 9, 2015 at 8:50 AM, Roderic Page Roderic.Page@glasgow.ac.uk wrote:
Hi Dag,
Gack, this is where things get messy. I wouldn’t treat easting and northing as latitude and longitude (although they are obviously related). When I write code to parse verbatim latitude and longitude the last thing I expect is easting and northing (it’s hard enough already given the various ways people write lats and longs). There seems to be enough ambiguity here to really mess things up, as indeed they have for the TTU dataset.
Regards
Rod
Roderic Page Professor of Taxonomy Institute of Biodiversity, Animal Health and Comparative Medicine College of Medical, Veterinary and Life Sciences Graham Kerr Building University of Glasgow Glasgow G12 8QQ, UK
Email: Roderic.Page@glasgow.ac.uk Tel: +44 141 330 4778 Skype: rdmpage Facebook: http://www.facebook.com/rdmpage LinkedIn: http://uk.linkedin.com/in/rdmpage Twitter: http://twitter.com/rdmpage Blog: http://iphylo.blogspot.com ORCID: http://orcid.org/0000-0002-7101-9767 Citations: http://scholar.google.co.uk/citations?hl=en&user=4Z5WABAAAAAJ ResearchGate https://www.researchgate.net/profile/Roderic_Page
On 9 Feb 2015, at 11:41, Dag Endresen dag.endresen@gmail.com wrote:
Hi Rod,
I have assumed that the purpose of the dwc:verbatimCoordinates term is to allow for reporting coordinates originally recorded as one single tuple such as the MGRS (Military Grid Reference System).
While original source coordinates that do have two tuples such as UTM would use dwc:verbatimLongitude (for the Easting or X coordinate tuple) and dwc:verbatimLatitude (for the Northing or Y coordinate tuple).
Regards Dag
On 9 February 2015 at 11:57, Roderic Page Roderic.Page@glasgow.ac.uk wrote:
Hi John,
So, if I understand you correctly, you would have hoped that TTU would have output something like this:
“dwc:verbatimCoordinates” : “18M 166624 9840350”
rather than put the easting and northing into verbatimLatitude and verbatimLongitude.
Regards
Rod
Roderic Page Professor of Taxonomy Institute of Biodiversity, Animal Health and Comparative Medicine College of Medical, Veterinary and Life Sciences Graham Kerr Building University of Glasgow Glasgow G12 8QQ, UK
Email: Roderic.Page@glasgow.ac.uk Tel: +44 141 330 4778 Skype: rdmpage Facebook: http://www.facebook.com/rdmpage LinkedIn: http://uk.linkedin.com/in/rdmpage Twitter: http://twitter.com/rdmpage Blog: http://iphylo.blogspot.com ORCID: http://orcid.org/0000-0002-7101-9767 Citations: http://scholar.google.co.uk/citations?hl=en&user=4Z5WABAAAAAJ ResearchGate https://www.researchgate.net/profile/Roderic_Page
On 8 Feb 2015, at 20:22, John Wieczorek tuco@berkeley.edu wrote:
Hi Rod,
The verbatimLatitude, verbatimLongitude, and verbatimCoordinates were all intended to be able to capture the original coordinates used at the source, where decimalLatitude and decimalLongitude, with geodeticDatum, were meant to contain the the easy to act on global system (UTMs do not cover the entire planet, for example). The verbatimCoordinate term's definition shows that this was the intent, but verbatimLatitude and verbatimLongitude do not. When we get the examples separated from the term definitions, it should be easier to make this clear.
Cheers,
John
On Sat, Feb 7, 2015 at 2:36 PM, Dag Endresen dag.endresen@gmail.com wrote:
Hi Rod,
At least in Norway, it is very common for the GBIF node to receive (only) Easting and Northing of UTM zones 32V to 36W. For many datasets we will on routine automatically make the conversion to decimal degrees (and WGS84) at the node before these datasets are published to the GBIF portal. When people download occurrences from the Norwegian "GBIF portal", Artskart, my impression is that the UTM 32V (and the 33V) Easting and Northing coordinate format is actually more popular than the decimal degree format - this is because the geographic data layers for Norway more often are made available in the UTM format (most often 32V or 33V) [1]. And yes, this continued present day official use of such a wide variety of coordinate formats frustrates me too... The historic use reported with the verbatim terms, is of course difficult to do anything with...
I assume that Easting and Northing coordinates are both valid and very common values (and not only in Norway) for the Darwin Core verbatim coordinate terms (dwc:verbatimLatitude and dwc:verbatimLongitude or dwc:verbatimCoordinates), but of course only at all useful when accompanied by the respective dwc:verbatimCoordinateSystem and dwc:verbatimSRS also reported. (And that the dwc:decimalLatitude and dwc:decimalLongitude correctly reported in WGS84 should preferably also always be there). I believe that Darwin Core is already fine with respect to terms to report geographic coordinates. If at all any additions are useful, I believe that identifying and recommending terms from more specialized geographic vocabularies and ontologies might be much more useful than adding any new dwc:Location terms to Darwin Core. In fact, most of the dwc:Location terms might perhaps preferably be replaced by terms from the geography community... such as perhaps [2] and [3] (as a start).
[1] https://dagendresen.wordpress.com/2013/11/22/convert-coordinate-srs/ [2] http://www.w3.org/2003/01/geo/wgs84_pos# [3] http://www.geonames.org/ontology/documentation.html
Regards Dag
On 7 February 2015 at 13:02, Roderic Page Roderic.Page@glasgow.ac.uk wrote:
Pardon my ignorance, but has there ever been a discussion of easting and northing values in regards to Darwin Core? AFAIK the current standard doesn’t mention them. The reason I’m asking is that I’ve just come across some VerbatimLatitude and VerbatimLongitude values in a dataset that is aggregated by VertNet (and hence GBIF) where (after some head scratching) I realised that the verbatim values were actually Easting and Northing (which I didn’t know existed until yesterday). Details are here: https://github.com/ttu-vertnet/ttu-mammals/issues/11
I’m guessing this isn’t a terribly common way to record location information, but it looks like in this case the lack of support for this type of data has resulted in somebody trying to shoehorn them into VerbatimLatitude and VerbatimLongitude, resulting in values which are uninterpretable to aggregators further up the chain.
Regards
Rod
-- Dag Endresen, Ph.D. Private email: dag.endresen@gmail.com Work email: dag.endresen@nhm.uio.no Mobile: +47 4061 2982 _______________________________________________ tdwg-content mailing list tdwg-content@lists.tdwg.org http://lists.tdwg.org/mailman/listinfo/tdwg-content
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