Intersection table representing the resolution of a many to many relationship.

spatial_object_s (FSK, M: CHAR VARYING(19))
spatial_object_t (M: CHAR VARYING(16))
earth_model_s (FSK, M: CHAR VARYING(19))

earth_model.spatial_object
Indicates the population of spatial representations which comprise this earth model.
spatial_object.earth_model
Indicates various earth models which include this spatial representation.
spatial_object_s: Implements a foreign key to a row in one of the tables projected from entity spatial_object depending on the value of the next column (See below).
spatial_object_t: Defines the name of the referenced table. Possible values are defined in @spatial_object.
earth_model_s: Defines a foreign key to table earth_model.