Introduction and
Collaboration to Automation
David Bloom, Nelson Rios,
Carol Spencer and SERNEC
Introduction to Collaborative
Georeferencing
Collaborative Distributed
Database Portals for Vertebrates
Success! MaNIS Localities Georeferenced
2001-2004
n = 326k localities (1.4M specimens)
r = 14 localities/hr (point-radius method,hand)
t = 3 yrs (~40 georeferencers, 17 institutions)
Success!
HerpNET Localities Georeferenced: 2003-2009
n = 645k localities (1.8M specimens)
r = 15 localities/hr (point-radius method, some automation)
t = 6 yrs (~110 people, 43 institutions)
Map by Michelle Koo
Success!
ORNIS Localities Georeferenced 2008-2010
n = 267k localities (1.4M specimens), N. American only
r = 30 localities/hr (point-radius method, automated)
t = 2 yrs (~30 georeferencers, 8 institutions)
Scope of the Problem for
Natural History Collections
~2.5 M records
~6 records per locality*
~14 (30 with BG) localities per hour*
~15,500 (7233) years
Obviously there’s still room to improve our
automated methods and collaborations
* based on the MaNIS (ORNIS using BioGeomancer) Projects
Collaborations
MaNIS-HerpNET-ORNIS
► Think of georeferencing as “many-stepped process”
– MHO projects produced a first pass. Then
validation and refinement should be done using
itineries, field notes, collector verification and by
mapping the localities and making these maps
available on-line.
What is a georeference?
A numerical description in a coordinate
system of a place.
Translating Georeferencing
textual locality
descriptions into
coordinates
Or
A numerical
description of a
place that can be
mapped and that
describes the
spatial extent of a
locality and its
associated
uncertainties
What we have:
Localities we can read
ID
1
2
3
4
5
6
7
8
9
Species
Lynx rufus
Pudu puda
Canis lupus
Felis concolor
Lama alpaca
Panthera leo
Sorex lyelli
Orcinus orca
Ursus arctos
Locality
Dawson Rd. N Whitehorse
cerca de Valdivia
20 mi NW Duluth
Pichi Trafúl
near Cuzco
San Diego Zoo
Lyell Canyon, Yosemite
1 mi W San Juan Island
Bear Flat, Haines Junction
What we want:
Localities we can map
“Davis, Yolo County, California”
Coordinates:
38.5463
-121.7425
Coordinates:
38.5463
-121.7425
Horizontal
Geodetic
Datum:
NAD27
Horizontal
Geodetic
Datum:
NAD27
“point method”
What is an useful georeference?
A numerical description of a place that
can be mapped
and that describes the spatial extent of a
locality
and its associated uncertainties.
“Davis, Yolo County, California”
Coordinates:
Coordinates:
38.5486
-121.7542
38.5486
-121.7542
38.545
-121.7394
38.545
-121.7394
Horizontal
Geodetic
Datum:
NAD27
Horizontal
Geodetic
Datum:
NAD27
“bounding-box method”
“Davis, Yolo County, California”
Coordinates:38.5468
38.5468-121.7469
-121.7469
Coordinates:
HorizontalGeodetic
GeodeticDatum:
Datum:NAD27
NAD27
Horizontal
MaximumUncertainty:
Uncertainty:8325
8325mm
Maximum
“point-radius method”
What is an ideal georeference?
A numerical description of a place that
can be mapped
and that describes the spatial extent of a
locality
and its associated uncertainties
as well as all possibilities.
“Davis, Yolo County, California”
“shape method”
“20 mi E Hayfork, California”
“probability method”
Eagle Lake; Warren Co.; Mississippi
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
Geographic Concepts
Geographic Concepts
► 3 fundamental concepts
 Datum
 Coordinate system
 Projections
Geographic Concepts
Geodetic Datum:
defines the position of the origin, scale, shape, and
orientation of a 3-dimensional model of the earth.
Geographic Concepts
Common Datums
NAD27 (North American Datum): system derived from landbased surveys, using Clarke 1886 ellipsoid (Meades Ranch)
NAD83: satellite-based system using the Earth’s center as a
reference point; eventually adopted as GRS80 (Geodetic
Reference System 1980)
WGS84 (World Geodetic System 1984): mathematically refined
GRS80 used by the US military and default for GPS
(Doppler)
For most uses, NAD83, GRS80, WGS84 are equivalent
Geographic Concepts
Coordinate System:
defines the “units of measure” of position with respect to the datum.
Example: latitude and longitude in degrees, minutes, seconds or
UTM coordinates in meters
Geographic Concepts
Geographic Concepts
Geographic Concepts
Projection
What projections do
Tissot’s Indicatrix of distortion - Eric Gaba
What projections do
Tissot’s Indicatrix of distortion - Eric Gaba
Geographic Concepts
► Projections will compromise…
 Area
 Shape
 Scale
 Direction
► Select projection to fit your needs
Projection
Geographic
preserves NS distance
Mercator
preserves shape (terrible for
poles, distorts area)
Projection
Winkel Tripel (NGS solution)
reduced distortion in both area and distance
Projection: Regional
Squat California (Geographic) vs. Equal-Area California (Teale Albers)
Web Mercator Projection
WGS84