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Collaboration and Automation

发布时间:2013-11-21 14:07:59  

Georeferencing:

Collaboration and Automation

John Wieczorek1

Reed Beaman2

1Museum of Vertebrate Zoology

University of California, Berkeley

2Center for Biodiversity Research

University of Kansas

Caveat:

I’m 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:

?

?

?

?

?

?

?Bakersfield10 mi E (by air) Bakersfield5 mi from Bakersfield2 mi E and 1.5 mi N of Bakersfield13 mi E (by road) Bakersfield10.2 mi E of BakersfieldE of Bakersfield T29S R29E Sec.34

Coordinates

?Points (have no spatial footprint)?Shapes (have bounded footprint)

Polygons

Multipolygons

Coordinate Systems?decimal degrees

35.3733 -119.0178

?degrees minutes seconds

35 22 23.88 N, 119 1 4.08 W

?degrees, decimal minutes

35 22.398 N, 119 1.068 W

?UTM

Zone 11S 316695E 3916111N

?Innumerable other grid-based systems

Frames of Reference

Geodetic Datums

?Australian Geodetic 1984?Japanese Geodetic Datum 2000

?North American Datum 1983?South American 1969??World Geodetic System 1984… over 100 others

Why is the datum important?

What is an idealgeoreference?

The answer depends on the questions you want to address.

I propose that it is a shape, with a frame of reference, which exactly describes the spatial extent of a terrestrial location.“The Shape Method”

“Davis, Yolo County, California”

“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 ispractical?

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”

“Davis, Yolo County, California”Coordinates: 35.32443 -119.32343Horizontal Geodetic Datum: NAD27Maximum Error Distance: 8325 m

Advantages

?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 applicationsThis remedy is relatively inexpensive.

Disadvantages

?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.

The remedy will remain just as costly as before.

Who is georeferencing?

Who isn’t, and why not?

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 UniversitySan Diego Natural History Museum

A. Townsend Peterson11University of Kansas Natural History Museum

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