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Quick Reference: http://rs.tdwg.org/dwc/terms/index.htm#Location Geographic TermsA good reference for place names is the Getty Thesaurus of Geographic Names (TGN), which can be found at http://www.getty.edu/research/conducting_research/vocabularies/tgn/. Administrative boundary files can be obtained from the Global Administrative Areas (GADM) data set at http://biogeo.berkeley.edu/gadm/. continentQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#continent Standard continents and their codes can be found at http://en.wikipedia.org/wiki/List_of_countries_by_continent_(data_file). countryCodeQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#countryCode The official list of ISO 3166-1-alpha-2 country codes can be found at http://www.iso.org/iso/english_country_names_and_code_elements. Verbatim Coordinate TermsThe terms beginning with verbatim are meant to capture the original record of the coordinates of the Location. verbatimCoordinates is meant to capture coordinates that have not or cannot be separated into the verbatimLatitude and verbatimLongitude. If the coordinates can be separated, they should be, since there is less chance to misinterpret the content. The verbatimCoordinateSystem and the verbatimSRS both refer to the values in verbatimLatitude and verbatimLongitude, or to the value in verbatimCoordinates. verbatimLatitude, verbatimLongitudeQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#verbatimLatitude Quick Reference: http://rs.tdwg.org/dwc/terms/index.htm#verbatimLongitude These terms are meant to capture the original coordinates for the Location in their original format. If possible, these coordinates should also be translated into the combination of decimalLatitude, decimalLongitude, geodeticDatum, and coordinateUncertaintyInMeters, but only if you really know what you are doing - coordinate transformations can be challenging. Use these two verbatim fields to capture coordinates in systems such as UTM, providing the spatial reference system for them in the verbatimSRS. If the original spatial information is an area (for example, a grid cell or a protected area polygon), use the footprintWKT and the footprintSRS to capture the complete area information. verbatimCoordinateSystemQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#verbatimCoordinateSystem The verbatimCoordinateSystem term is meant to help with the interpretation of the values given in verbatimLatitude and verbatimLongitude, or verbatimCoordinates. The recommended controlled vocabulary includes:
UTM refers to Universal Transverse Mercator. CRTM refers to Costa Rica Transverse Mercator. For verbatim coordinates given in degrees, or degrees and minutes, use "degrees minutes seconds". verbatimSRSQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#verbatimSRS This term refers only to the values given in verbatimLatitude and verbatimLongitude, or verbatimCoordinates, but the recommended best practice is the same as for geodeticDatum, below. Georeference TermsFurther detailed explanations of the terms associated with georeferences (spatial descriptions of place using points, circles, lines, polygons, etc.) can be found in the Guide to Best Practices for Georeferencing http://www.gbif.org/prog/digit/Georeferencing. decimalLatitude, decimalLongitudeQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#decimalLatitude Quick Reference: http://rs.tdwg.org/dwc/terms/index.htm#decimalLongitude decimalLatitude and decimalLongitude are always in decimal degrees. The Spatial Reference System for these coordinates must be given in the geodeticDatum term. Other types of original coordinates, such as UTM, should be given in one or both of the following combinations: verbatimLatitude, verbatimLongitude, verbatimSRS or footprintWKT, footprintSRS geodeticDatumQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#geodeticDatum Ideally one should use a standard European Petroleum Survey Group (EPSG) code to a Spatial Reference System as a value for this term. The recommended controlled vocabulary is to use a value consisting of the string "EPSG:" followed by a valid EPSG code corresponding to the spatial reference system used for the geographic coordinates in the terms decimalLatitude and decimalLongitude. A good resource for determining the EPSG code from the Datum name can be found at http://spatialreference.org/. Some common EPSG codes and the Datums they use can be found in the following table:
If you don't know the details of the SRS, then it is permissible to provide the name or code of the geodetic datum for the decimalLatitude and decimalLongitude coordinates. Sometimes this information is not on the original source (such as a map), while an ellipsoid name is given. In this case, provide the name of the ellipsoid. If the spatial reference system, datum, or ellipsoid are not known, use the value "unknown" for this term. A good reference for datum and ellipsoid names is http://www.colorado.edu/geography/gcraft/notes/datum/edlist.html georeferenceProtocolQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#georeferenceProtocol It is recommended to give a citation (publication or URL) to the resource describing the methods used to determine the georeference (coordinates AND uncertainty, or footprint). Good resources on methods include:
georeferenceVerificationStatusQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#georeferenceVerificationStatus The recommended controlled vocabulary includes:
The data contributor is the agent who participated in the Event that produced the Location. Verification by the contributor means that the georeference as recorded is correct and as specific as it can be based on the contributor's personal knowledge of the event and location. The data custodian is the agent responsible for the management of the primary source of the record. Verification by the data custodian means that the georeference as recorded is correct and as specific as it can be based on the all of the resources at the disposal of the agent (field notes, maps, labels) in the absence of verification by the contributor. All other georeferences, those produced without consulting all existing primary sources, should be "unverified". footprintSRSQuick Reference: http://rs.tdwg.org/dwc/terms/index.htm#footprintSRS The specification for constructing Spatial Reference Systems in WKT can be found at http://geoapi.sourceforge.net/2.0/javadoc/org/opengis/referencing/doc-files/WKT.html. Following are some example WKT renditions of common Spatial Reference Systems: WGS84 GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.0174532925199433]] NAD27 GEOGCS["NAD27",DATUM["NORTH_AMERICAN_DATUM_1927",SPHEROID["CLARKE 1866",6378206.4,294.9786982138982]],PRIMEM["Greenwich",0],UNIT["Degree",0.01745329251994283]] | |||||||||||||||
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