With TerraExplorer, the client application can use a different coordinate system from that of the terrain database. The ICoordServices61 interface provides a set of methods for reprojecting given coordinates between different coordinate systems. Use the SourceCoordinateSystem() property to define the coordinate system your application uses. Once a coordinate system has been set by a client, every coordinate used by the client is converted from the source coordinate system used by the client to the terrain coordinate system. Also, any coordinate returned from TerraExplorer (e.g., INavigate61.GetPosition()) is converted from the coordinate system of the terrain, to the client coordinate system.
TerraExplorer also provides a number of service methods to perform advanced geographic-related tasks like converting units to metric value, calculating distances and angles between points. These methods are especially useful when working with globe databases, where the units are in degrees, but work for any database.