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Note the contents of this wiki are under active revision and may change often.


As applied to natural history collections data, georeferencing is the process of determining geographic coordinates (typically latitude and longitude) from a textually described locality description. Measurements of uncertainty associated in the form of a radius from the determined point or a polygon encompassing the maximum possible extent of a locality description are usually included in the georeferencing process.

Geographic Concepts Related to Georeferencing

It is not uncommon for georeferencing to involve numerous resources from various sources using differing scale and geographic systems. Ensuring an accurate and reliable result in georeferencing requires a basic understanding of the following concepts.

Geodetic datum

A model of the earth used for geodetic calculations. A geodetic datum describes the size, shape, origin, and orientation of a coordinate system for mapping the surface of the earth.

Coordinate System

A system used to denote direct or relative positions by coordinates; Examples of two-dimensional coordinate systems are Latitude/Longitude and Universal Transverse Mercator (UTM)

Geographic Coordinate System

The net or graticule of lines of latitude (parallels) numbered 0° to 90° north and south of the equator, and lines of longitude (meridians) numbered 0° to180° east and west of the international zero meridian of Greenwich, used to define locations on the Earth's surface (disregarding elevation) with the aid of angular measure (degrees, minutes and seconds of arc).


A projection is a representation of the earth's three-dimensional surface as a flat two-dimensional surface. This normally involves a mathematical model (of which there are many) that transforms the locations of features on the earth's surface to locations on a two- dimensional surface. Such representations distort one or more parameters of the earth's surface such as distance, area, shape, or direction.

Georeference Best Practices

Guide to Best Practices for Georeferencing for a - Chapman, A.D. and J. Wieczorek (eds). 2006
Georeferencing Quick Reference Guide version 2012-10-08. John Wieczorek, David Bloom, Heather Constable, Janet Fang, Michelle Koo, Carol Spencer, Kristina Yamamoto

Georeferencing Videos
Videos have been made and posted on Vimeo that focus on skills needed and software useful for georeferencing locality data from natural history museum specimens. Some videos were captured during a workshop - in front of a live audience. Others were planned and produced to cover a specific georeferencing topic. Videos captured at workshops are helpful for workshop participants to review or share with others in order to talk about the content and plan their own georeferencing workshops. The Power Point presentations and materials used in the live presentations are available at or The scripted videos are designed for individuals to teach themselves the material - or point others to, who would like to master this material.

Georeferencing Community Protocols and Workflows

  1. See also the earlier section on Georeferencing Best Practices.
  2. Georeferencing using the Arthropod Easy Capture Database system: A comprehensive guide, by Danielle Pace, Project Assistant, TTD-TCN.
    From the Tri-trophic TCN - This guide presents a comprehensive look at the best practices for the georeferencing process, solutions for common problems, Frequently Asked Questions, and sources for more information.
    Software: GEOLocate, Arthropod Easy Capture, Google, Google Maps
  3. Georeferencing Guide by Shannon Asencio, Canadian Museum of Nature.
    From the Macrofungi Collection Consortium TCN
    Software: GEOLocate, Symbiota
  4. Georeferencing Procedure Outline by Michael Yost, Denver Botanic Gardens.
    Update from the Macrofungi Collection Consortium (MaCC)
    Software: GEOLocate, Symbiota
    1. Blog Post: Georeferencing Guidelines - Community Examples, by Michael Yost, MaCC Project Assistant
  5. Georeferencing: The Polygon Method (pdf) (doc version) by Michael, Yost, Denver Botanic Gardens
    1. Blog Post: Georeferencing: The Polygon Method, by Michael Yost, MaCC Project Assistant
  6. MVZ and iDigBio GWG Guide for Recording Localities in Field Notes
    This guide details best practices for what locality information to write down when collecting and observing in the field. It includes a section designed just-so to fit in your field notebooks. Happy Collecting, and you'll be even happier still, with robust locality information and great georeferences.
  7. A locality worksheet used in the Division of Invertebrate Paleontology at the Yale Peabody Museum
  8. A quick start guide to using the GEOLocate collaborative portal, complete with screenshots

Specialized Georeferencing Tools


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The GEOLocate project is an effort to develop software and services for translating textual locality descriptions associated with biodiversity collections data into geographic coordinates. In addition to the automated processing of locality descriptions, GEOLocate provides an interface by which users can georeference records one by one or in batches from files, visualize and correct calculated coordinates, and determine polygonal error descriptions.
GEOLocate also now includes a Collaborative Georeferencing client, a mechanism whereby groups of users can form communities to collaboratively georeference and verify a shared dataset. Verification and correction of the computer generated geographic coordinates is accomplished using the GEOLocate desktop and/or web application. GEOLocate allows users to login to their communities, retrieve and visualize results, make any necessary corrections, provide additional comments, define errors as polygons, and save the results back to the shared dataset. The verified results of georeferencing can then be downloaded via the portal’s data management interface for re-import to the parent database.
Click here for further information

Georeferencing Calculator

The Georeferencing Calculator can be found here. It was created as a tool to aid in the georeferencing of descriptive localities such as those found in museum-based natural history collections. It was specifically designed for the Mammal Networked Information System (MaNIS) Project and has been adopted as well by HerpNet and ORNIS. The application makes calculations using the methods described in the Georeferencing Guidelines


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The BioGeomancer Project is a worldwide collaboration of natural history and geospatial data experts. The primary goal of the project is to maximize the quality and quantity of biodiversity data that can be mapped in support of scientific research, planning, conservation, and management. The project promotes discussion, manages geospatial data and data standards, and develops software tools in support of this mission.
Some portions of this site are down, including the Workbench, but if you'd like to learn more about the BioGeomancer workbench click here

Natural History Databases with Integrated Georeferencing Capabilities

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Arctos’ multidisciplinary collection management information system integrates access to diverse types of collections (botany, entomology, herpetology, mammalogy , ornithology, paleontology, parasitology) and data, including specimen records, observations, tissues, endoparasites and ectoparasites, stomach contents, fieldnotes and other documents, and media such as images, audio recordings, and video. Arctos provides solutions to managing and integrating collections data with object tracking (via barcodes or RFID tags), transactions (loans, borrows, accessions, permits), geospatial information (coordinates and descriptive data), agents (people and organizations), and usage (publications, projects, and citations).

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Selected Online Resources & Tools

*A more inclusive list can be found at herpnet*
A comprehensive site covering the basics of georeferencing as well as providing useful links to resources and guidelines.
This document is a list of locality types based on Georeferencing guidelines (Chapman, A.D. and J. Wieczorek (eds). 2006), as well as providing what is considered the best for georeferencing and finding the extent and error for each type of locality.
Provides geographic and administrative divisions, in addition to historical information related to many countries.
The USGS has put together an interactive site utilizing its historical topographic map collection. Users can simply type in a location and the site will guide you to a place. Human and geologic activity change sites, borders, boundaries, landscapes and the power of this site is that it allows the user to explore a location by comparing maps created at different dates. The user can slide the transparency on maps to compare layers, or drag/drop to re-order maps.



TTT1: The First iDigBio GWG Train the Trainers Workshop: Expanding the Biodiversity Natural History Collections Georeferencing Community October 8 - 12, 2012

TTT2: The Second iDigBio GWG Train the Trainers Workshop We're Expanding the Biodiversity Natural History Collections Georeferencing Community - Again, August 12 - 16, 2013

Need Georeferencers? Need Trainers?

Workshops Done by TTT1 and TTT2 Participants

The following trainees have gone on to do one or more workshops on their own. We look forward to more updates on everyone's progress to get this massive amount of data georeferenced!

Hannah Braeme, Liath Appleton, Una Farrell, Rita Velez, Margaret Landis, Jessica Utrup, Jennifer Zaspel, Ryan Moraski, Angelika Nelson, Dmitry Dimitriev, Dorothy Allard, Shannon Asencio, Stephen Gottschalk

How can you help? Watch this page to see the updates as they are posted by the community or join our working group!

Follow the working group discussion and participate in the conversation at

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