Annotating Uncertainty in Geospatial and Environmental Data

The Geography Markup Language (GML) - the existing standard for encoding geospatial data - has no mechanism for annotating such data with uncertainty. To address this issue while supporting the geospatial community´s existing data and service standards, the authors extend GML to enable uncertainty markup. They demonstrate this extension´s use with some common geospatial data types and Web services. The result is a robust capability to share error information while maintaining compatibility with existing geospatial data clients.