This table contains one row for every analyzed observation of a location (from SWERB_LOC_DATA).

For a variety of reasons, a GPS point may be collected many meters away from the actual noted location. Because of this, the database does not implement rules that require an observation's GPS coordinates to be within a particular number of meters from the location's SWERB_GW_LOC_DATA.XYSource. Presumably, this means that mistakes that the observers occasionally make go undetected when added to Babase. To help address this problem, a data manager performs periodic analyses of the data and determines scores of "confidence" in the accuracy of the noted location. For further information about these analyses, please consult your local Babase scientist. The SWERB_LOC_DATA_CONFIDENCES table records those confidence scores, and notes the nearest SWERB_GWS.Loc whose coordinates (from SWERB_GW_LOC_DATA.XYSource) are nearest to the related SWERB_DATA.XYLoc and whose SWERB_GWS.Type matches that of the related SWERB_LOC_DATA.Loc.

To determine confidence in a particular observation and to calculate which Loc is nearest, the manager must have a set of "known" or "reference" coordinates. Because of this, the Nearest_Loc should be a Loc value from SWERB_GW_LOC_DATA. The system will return a warning when this is not so -- when a Nearest_Loc value is not a SWERB_GW_LOC_DATA.Loc value.

The Nearest_Loc must have existed when the observation was made. That is, an observation's related SWERB_DEPARTS_DATA.Date must be between the Nearest_Loc's related SWERB_GWS.Start and Finish (inclusive).