Database Manual

Oak Ridges Moraine Groundwater Program

Appendix G.14

G.14 Population of coordinates

Coordinates are found in D_LOCATION within the fields LOC_COORD_EASTING and LOC_COORD_NORTHING. These are in UTMz17-NAD83 projection and datum (the system default). If not populated (i.e. they are NULL) the original coordinates are found in LOC_COORD_EASTING_OUOM and LOC_COORD_NORTHING_OUOM with the original projection/datum referenced as a reference code (to R_LOC_COORD_OUOM_CODE).

The view ‘CHK_D_LOC_Coords_Not_Assigned’ extracts the *_OUOM coordinates from D_LOCATION where the QA code is not ‘117’. It also includes the projection and datum information. If NULL or invalid values are represented here by the coordinate columns, the QA code should be immediately changed in D_LOCATION_QA to ‘117’ (storing the original value in QA_COORD_CONFIDENCE_CODE_ORIG; a comment can be included, in QA_COORD_COMMENT, as well).

If the coordinates are not in system units (i.e. UTMz17, NAD83) they should be exported and converted (remember to keep the LOC_ID as part of the export to relate-back the converted coordinates). Otherwise, the coordinates can be copied directly to LOC_COORD_EASTING and LOC_COORD_NORTHING.