INTER-AMERICAN WORKSHOP ON ENVIRONMENTAL DATA ACCESS

geoLoc and spOutlier: on-line tools for geocoding and validating biological data

Alexandre Marino () , Fabricio Pavarin (), Sidnei de Souza (), Arthur D. Chapman (biodiv@achapman.org)
Centro de Referência em Informação Ambiental, CRIA - Av. Romeu Tórtima, 388, 13084-520 Campinas, SP, Brasil

Abstract:

These tools have been developed to assist in the process of assigning geographic coordinates to locality descriptions and for error checking and validating geocodes of existing data.

geoLoc: allows a user to determine the geocode and associated error for a locality that is at a fixed distance and direction from a known locality.

The database has approximately 110 thousand names of Brazilian geocoded localities. Searching can be made for complete or partial names and the selection of the State is optional. Besides exhibiting data of the localities found in the database, a map of Brazil is presented showing the points where the localities are found. geoLoc is composed of an algorithm based on Egaz, capable of calculating a coordinate for a predetermined distance and direction. In order to use this tool the user must inform the distance in kilometers and the direction (N, S, E, W, NE, NW, SE or SW) and click on the selected locality (at the associated table). The map will show the points for the localities that were searched, highlighting the selected locality and the calculated point, informing the coordinate and possible error.

spOutlier: this automated tool uses techniques modified from Chapman 1999, to detect outliers in latitude, longitude and altitude.

The system will show possible suspect records in red, both in text and on the accompanying map. Individual records with no suspects occurring in latitude, longitude or altitude will not be shown in text, but are shown in green on the map. Another feature was included to identify possible errors. If the user indicates that the points are "marine" the system will highlight all points that occur inland. The maps are produced dynamically on-line using the web service mapCRIA, that facilitates the development of web applications that require fast map production. It is based on Mapscript (MapServer), SOAP protocol and XML. Both tools were developed using free software.

This development is part of the speciesLink project and is being funded by FAPESP (www.fapesp.br).

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