Coordinates in iBase

To plot an entity or link on a map, you need to enter coordinate values in two fields that have been set up for this purpose. Your GIS package will have been configured to interpret the values in these fields so that the data can be plotted in the correct location.

In iBase, you will also be able to store geographic data in a number of formats, which are then converted, either manually when you enter the record or automatically after an import or using a bulk conversion. You can also run coordinate queries.

Types of field

The fields used to contain the coordinate data must be defined as Real Number type fields. They may contain the following types of coordinates:
  • Latitude and Longitude values, entered in decimal degrees
  • Easting/Northing data, entered in meters

These fields will typically be called Latitude and Longitude or X and Y. If you are not sure which fields you need to use, move the pointer over the field name to see its tooltip, or speak to your database administrator.

About converting coordinates to a standard format

When you convert coordinates, they are always converted to decimal degrees of latitude and longitude, using the WGS 1984 datum (a global standard for plotting geographic locations).

To convert coordinates, the entity type requires a Coordinate type field in addition to fields for the latitude and longitude. The Coordinate type field must be directly above the latitude and longitude fields. You enter the coordinates in the Coordinate type field and the coordinates are then automatically converted and displayed in the latitude and longitude field.

The original coordinate value is stored so that it can be searched for, and for audit purposes.

Note: The conversion process will change longitude values greater than 180 to their equivalent negative value in order that they can be plotted correctly.