About the GVS
What is the GVS?
Project Development
Source Code
Funding
What is the GVS?
The Geocoordinate Validation Service (GVS) is a tool for the detection of errors in geographic coordinates. In addition to basic checks (such as ensuring that the submitted coordinate points are valid decimal geocoordinates and alerting users to points located in the ocean), the main purpose of the GVS is to detect and flag points which are likely centroids of political divisions (such as countries or states) or geographic units (such as islands)—as opposed to accurate geocoordinates such as those obtained from a GPS-enabled device. In biodiversity science, georeferenced organismal observations based on centroids are generally too inaccurate to be useful for most types of research, in particular species distribution modeling. It is therefore extremely important that such sources of error be detected and excluded prior to analysis. The GVS detects three types of commonly-used centroids: the geometric center of mass (using PostGIS function ST_Centroid), point-on-surface (ST_PointOnSurface), and bounding box (ST_Centroid plus ST_Envelope).
In addition to basic error validation and centroid detection, the GVS also returns the country plus first- and second-level administrative divisions (plus their GADM identifiers) in which each point is located. This information can be used as part of an additional validation that checks if the declared political division (which typically accompanies biological observations from herbarium and museum specimens) matches the actual political division in which the point is located (as detected by the GVS). The GVS also calculates the inherent uncertainty due to the number of decimal places used in the verbatim coordinates.
Project Development
The GVS was developed by the Botanical Information and Ecology Network (BIEN) as a data validation tool for the BIEN botanical observation database.
Project conception and direction
Brad Boyle at University of Arizona
Brian Maitner at University of South Florida, St. Petersburg
Dan Park at Purdue University
Brian Enquist at University of Arizona
Application development & Source
Brad Boyle: GVS database, search engine, and API.
Brian Maitner: RCDS R package.
Rethvick Sriram Yugendra Babu: GVSweb React/Node.js user interface.
Source Code
Source code for all GVS components is publicly available from the following repositories:
GVS Search Engine, Database, and API: https://github.com/ojalaquellueva/gvs
RCDS R package: https://github.com/EnquistLab/RCDS
GVS web user interface: https://github.com/EnquistLab/GVSweb
Funding
Funding provided by the National Science Foundation Harnessing the Data Revolution Grant HDR 1934790 to Brian J. Enquist. Ongoing support from the National Center for Ecological Analysis and Synthesis (NCEAS) at University of California, Santa Barbara.