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spOutlier
This automated tool uses techniques modified from Chapman 1999, to detect outliers in latitude, longitude and altitude. Cut and paste your data into the box in the format cited using either a comma (,) or space ( ) to separate individual fields.

The output will respond with possible suspect records shown in red, both in text and on the accompanying map. Individual records with no suspects occuring in latititude, 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.

This tool is still experimental, and needs further testing. Any comments, criticisms or suggestions should be sent to the contact@cria.org.br . A paper describing the techniques will be published later in 2004.

Ref. Chapman, A.D. (1999). Quality control and validation of point-sourced environmental resource data pp.409-418 in Lowell, K. and Jaton, A. (eds). Spatial Accuracy Assessment: Land Information Uncertainty in Natural Resources. Chelsea, Michigan: Ann Arbor Press. 455pp

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