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Georeferencing Introduction: Collaboration to Automation. John Wieczorek Museum of Vertebrate Zoology University of California, Berkeley. Georeferencing. Collaborations. Automation. Georeferencing. Collaborations. Automation. What is a georeference?. What is a georeference?.
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Georeferencing Introduction: Collaboration to Automation John Wieczorek Museum of Vertebrate Zoology University of California, Berkeley
Georeferencing Collaborations Automation
Georeferencing Collaborations Automation
What is a georeference? A numerical description of a place that can be mapped.
What is a georeference? A numerical description of a place that can be mapped. In other words…
What we have:Localities we can read ID Species Locality 1 Lynx rufus Dawson Rd. N Whitehorse 2 Pudu puda cerca de Valdivia 3 Canis lupus 20 mi NW Duluth 4 Felis concolor Pichi Trafúl 5 Lama alpaca near Cuzco 6 Panthera leo San Diego Zoo 7 Sorex lyelli Lyell Canyon, Yosemite 8 Orcinus orca 1 mi W San Juan Island 9 Ursus arctos Bear Flat, Haines Junction
Darwin Core Location Terms • higherGeography • waterbody, island, islandGroup • continent, country, countryCode, stateProvince, county, municipality • locality • minimumElevationInMeters, maximumElevationInMeters, minimumDepthInMeters, maximumDepthInMeters
Darwin Core Georeference Terms • decimalLatitude, decimalLongitude • geodeticDatum • coordinateUncertaintyInMeters • coordinatePrecision • pointRadiusSpatialFit • footprintWKT, footprintSRS, footprintSpatialFit • georeferencedBy, georeferenceProtocol • georeferenceSources • georeferenceVerificationStatus • georeferenceRemarks
What is a georeference? A numerical description of a place that can be mapped.
“Davis, Yolo County, California” Coordinates: 38.5463 -121.7425 Horizontal Geodetic Datum: NAD27 “point method”
Data Quality • data have the potential to be used in ways unforeseen when collected. • the value of the data is directly related to the fitness for a variety of uses. • “as data become more accessible many more uses become apparent.” – Chapman 2005 • the MaNIS/HerpNET/ORNIS guidelines follow best practices (Chapman and Wieczorek 2006) to enhance data quality and value
What is an acceptable georeference? A numerical description of a place that can be mappedand that describes the spatial extent of a locality and its associated uncertainties.
“Davis, Yolo County, California” Coordinates: 38.5486 -121.7542 38.545 -121.7394 Horizontal Geodetic Datum: NAD27 “bounding-box method”
“Davis, Yolo County, California” Coordinates: 38.5468 -121.7469 Horizontal Geodetic Datum: NAD27 Maximum Uncertainty: 8325 m “point-radius method”
What is an ideal georeference? A numerical description of a place that can be mappedand that describes the spatial extent of a locality and its associated uncertaintiesas well as possible.
“Davis, Yolo County, California” “shape method”
“20 mi E Hayfork, California” “probability method”
Method Comparison point easy to produce no data quality bounding-box simple spatial queries difficult quality assessment point-radius easy quality assessment difficult spatial queries shape accurate representation complex, uniform probability accurate representation complex, non-uniform
MaNIS/HerpNET/ORNIS (MHO) Guidelines http://manisnet.org/GeorefGuide.html • uses point-radius representation of georeferences • circle encompasses all sources of uncertainty about the location • methodology formalizes assumptions, algorithms, and documentation standards that promote reproducible results • methods are universally applicable
Darwin Core Georeference Terms • decimalLatitude, decimalLongitude • geodeticDatum • coordinateUncertaintyInMeters • coordinatePrecision • pointRadiusSpatialFit • footprintWKT, footprintSRS, footprintSpatialFit • georeferencedBy, georeferenceProtocol • georeferenceSources • georeferenceVerificationStatus • georeferenceRemarks
Georeferencing Collaborations Automation
Collaborative Distributed Databases for Vertebrates
MaNIS Localities Georeferenced n = 326k localities (1.4M specimens) r = 14 localities/hr (point-radius method) t = 3 yrs (~40 georeferencers)
ORNIS Localities Georeferenced n = 267k localities (1.4M specimens) r = 30 localities/hr (point-radius method) t = 2 yrs (~30 georeferencers)
Scope of the Problem for Natural History Collections ~2.5 Giga-records
Scope of the Problem for Natural History Collections ~2.5 Giga-records ~6 records per locality* ~14 localities per hour* * based on the MaNIS Project
Scope of the Problem for Natural History Collections ~2.5 Giga-records ~6 records per locality* ~14 localities per hour* ~15,500 years * based on the MaNIS Project
Scope of the Problem for Natural History Collections ~2.5 Giga-records ~6 records per locality* ~14 (30) localities per hour* ~15,500 (7233) years * based on the MaNIS (ORNIS) Project
Georeferencing Collaborations Automation
Automation Combining the Best in Georeferencing GeoLocate DIVA-GIS BioGeomancer Classic MaNIS Georeferencing Calculator
Geographical Concepts: • Geodetic Datum: defines the position of the origin, scale, shape, and orientation of a 3-dimensional model of the earth. Example: WGS84. • Coordinate System: defines the “units of measure” of position with respect to the datum. Example: latitude, longitude in degrees, minutes, seconds
Map Projections: • mathematical transformations of the 3-D model of the surface of the earth onto a 2-D map. • there are many (e.g., conical, cylindrical, azimuthal) - they all suffer from distortions (area, shape, distance, or direction), but some preserve areas or distances. • When measuring distances on paper maps, use an equal distance projection, if available, otherwise understand the implications.
GeoreferencingConcepts • Named place: a place of reference in a locality description. Example: “Davis” in “5 mi N of Davis” • Areal extent:the geographic area covered by a named place (feature). Example: the area inside the boundaries of a town. • Linear extent:the distance from the geographic center to the furthest point of the areal extent of a named place.
Georeferencing Concepts • Offset: the distance from a named place. Example: “5 mi” in “5 mi NE of Beatty”. • Heading: the direction from a named place. Example: “NE” in “5 mi NE of Beatty”.
Georeferencing Concepts • coordinateUncertaintyInMeters:“The horizontal distance (in meters) from the given decimalLatitude and decimalLongitude describing the smallest circle containing the whole of the Location. Leave the value empty if the uncertainty is unknown, cannot be estimated, or is not applicable (because there are no coordinates). Zero is not a valid value for this term.” (from Darwin Core) • Maximum Error Distance: same as coordinateUncertaintyInMeters, except the units are the same is in the locality description, not necessarily meters.
Scale Uncertainty (ft) Uncertainty (m) 1:1,200 3.3 ft 1.0 m 1:2,400 6.7 ft 2.0 m 1:4,800 13.3 ft 4.1 m 1:10,000 27.8 ft 8.5 m 1:12,000 33.3 ft 10.2 m 1:24,000 40.0 ft 12.2 m 1:25,000 41.8 ft 12.8 m 1:63,360 106 ft 32.2 m 1:100,000 167 ft 50.9 m 1:250,000 417 ft 127 m Sources of uncertainty: 20° 30’ N 112° 36’ W • Coordinate Uncertainty • Map scale • The extent of the locality • GPS accuracy • Unknown datum • Imprecision in direction measurements • Imprecision in distance measurements (1km vs. 1.1 km)
Georeferencing Calculator Example • Locality: 0.5 km N of Little mermaid, Copenhagen, DK • Start with original coordinates for the mermaid: 55° 41' 34.18" N 12° 35' 56.73" E • Then use the Georeferencing Error Calculator to determine the final coordinates AND the uncertainty.
Georeferencing Error Calculator: 0.5 km N of Little mermaid, Copenhagen, DK 55° 41' 34.18" N 12° 35' 56.73" E
Georeferencing Templates Capture georeferences in database or spreadsheet (we will use an Excel template for examples)