L Field
The location field holds four values: latitude, longitude, altitude and precision.
During import, the number of values must be 2, 3 or 4.
The two first values are always the latitude and longitude.
If a third value is provided, it is the precision and the values order is: latitude – longitude– precision.
If four values are provided, their order must be latitude – longitude – altitude – precision.
The latitude value should be in the range [-90°, 90°].
The longitude value should be in the range [-180°, 180°].
The altitude value can be any real number, in meters.
The precision value can be any positive real number, in kilometers.
The Merge with existing data option is unused.