Presentation on theme: "Georeferencing: Collaboration and Automation John Wieczorek 1 Reed Beaman 2 1 Museum of Vertebrate Zoology University of California, Berkeley 2 Center."— Presentation transcript:
Georeferencing: Collaboration and Automation John Wieczorek 1 Reed Beaman 2 1 Museum of Vertebrate Zoology University of California, Berkeley 2 Center for Biodiversity Research University of Kansas
Caveat: Im going to over-simplify everything. Warning: Apertem os Cintos Fasten your seat belts
What is georeferencing?
Georeferencing is the expression of a terrestrial spatial description in coordinates within a frame of reference
Terrestrial Spatial Descriptions: Bakersfield 10 mi E (by air) Bakersfield 5 mi from Bakersfield 2 mi E and 1.5 mi N of Bakersfield 13 mi E (by road) Bakersfield 10.2 mi E of Bakersfield E of Bakersfield T29S R29E Sec.34
Coordinate Systems decimal degrees degrees minutes seconds N, W degrees, decimal minutes N, W UTM Zone 11S E N Innumerable other grid-based systems
Frames of Reference Australian Geodetic 1984 Japanese Geodetic Datum 2000 North American Datum 1983 South American 1969 World Geodetic System 1984 Geodetic Datums … over 100 others
Why is the datum important?
What is an ideal georeference? I propose that it is a shape, with a frame of reference, which exactly describes the spatial extent of a terrestrial location. The answer depends on the questions you want to address. The Shape Method
Davis, Yolo County, California
Is this method currently practical? Requires sophisticated software to capture these data. Requires database capabilities beyond the scope of many collections Requires baseline digital data that are neither freely, nor globally available. The remedy is costly.
What is practical? Describe spatial extent using elements that can be captured and stored by anyone using current technology.
One possible solution Describe the locality using one set of coordinates, the datum, and a bounding radius. The Point-Radius Method
Davis, Yolo County, California
Coordinates: Horizontal Geodetic Datum: NAD27 Maximum Error Distance: 8325 m
Advantages This remedy is relatively inexpensive. Describes the locality in a minimal element set. Obviates the need for investment in new technology. Establishes a maximum spatial scale of the locality. Does enable spatial visualization and a broad range of analytical applications
Disadvantages The remedy will remain just as costly as before. This solution does not contribute toward the ideal solution. There may be future applications for spatial footprints that cannot be met by the data produced by the Point-Radius Method.
Who is georeferencing? Who isnt, and why not?
Who is georeferencing? MaNIS – 17 mammal collections; institutions in Canada, Mexico and the United States; global holdings; 1.4M specimens; 284k localities; 3 years; started Sep HerpNet – 37 North American herpetological collections; global holdings; ca. 3M specimens; 5 years; first georeferencing North and Central American localities; starts 2003.
How are we georeferencing?
Advantages Reduces overall cost of supplies – no duplication Expands the pool of resources – geographic expertise and reference material Increases georeferencing rates – economy of scale Promotes standardization – methods Increases skills in a community Increases exposure and awareness inside and outside of a community
Disadvantages Vulnerable to procrastinators, cheaters, and numbskulls. Can distance georeferencing process from useful primary resources (e.g., field notes). Introduces time sensitivity to the georeferencing process Requires project-level management
One way to improve upon the georeferencing process will be to collaborate with a distributed query mechanism already in place.
Reed will talk about another way we hope to improve the georeferencing process.
Special Thanks CONABIO Bell Museum Kansas State University San Diego Natural History Museum A. Townsend Peterson 1 1 University of Kansas Natural History Museum