Feature relationships

The Relationship Manager tool maintains two types of relationships between objects:

• Hierarchical (structure-equipment)
• Peer to peer (collections)

With the Relationship Manager tool, you can create, edit, and delete structure-equipment and collection relationships in your data. The Relationship Manager tool is on the Maritime S-57 tab that appears when you add maritime data to the Contents pane.

Hierarchical relationships

Hierarchical relationships have designated structure and equipment features. A structure-equipment relationship is created to relate features comprising a navigational aid. Navigational aids are composed of two basic types of objects: structures and equipment. The structure object is considered the primary feature, and the related equipment are considered the secondary features. A lighted buoy is an example of a structure-equipment relationship. The buoy is the primary structure with various equipment attached to it, such as lights and navigational devices, which are considered secondary features.

To create a structure-equipment relationship between two points, the two point features must share the same x,y location. When line, area, and point geometry type features are grouped into a structure-equipment relationship, they must intersect. There may be more than one secondary feature, but only one primary feature is allowed in a structure-equipment relationship.

The following tables list the allowable structure-equipment feature objects:

Structure feature	Geometry
BCNCAR	Point
BCNISD	Point
BCNLAT	Point
BCNSAW	Point
BCNSPP	Point
BOYCAR	Point
BOYINB	Point
BOYISD	Point
BOYLAT	Point
BOYSAW	Point
BOYSPP	Point
BRIDGE	Point, line, area
BUISGL	Point, area
LITFLT	Point
LITVES	Point
LNDMRK	Point, line, area
MORFAC	Point, line, area
OFSPLF	Point, area
PILPNT	Point
SLCONS	Point, line, area
CRANES	Point, area
FLODOC	Line, area
FORSTC	Point, line, area
FSHFAC	Point, line, area
HULKES	Point, area
PONTON	Line, area
PYLONS	Point, area
SILTNK	Point, area

Equipment feature	Geometry
DAYMAR	Point
LIGHTS	Point
FOGSIG	Point
RADSTA	Point
RDOSTA	Point
RETRFL	Point
RTPBCN	Point
SISTAT	Point
SISTAW	Point
TOPMAR	Point

Peer-to-peer relationships

In peer-to-peer relationships, no feature's existence is dependent on another feature. Collections are considered a type of peer-to-peer relationship and can be grouped into two object classes: aggregations (C_AGGR) or associations (C_ASSO).

Association objects depict at least one feature that, when associated, better represents certain navigational situations. For example, a buoy that marks a wreck can be associated in S-57 to help the mariner see that a danger lies in the area. The buoy is not dependent on the wreck and the wreck is not dependent on the buoy.

Aggregation objects are collections of features that form a higher-level collection object that better describes a system or defines a larger area. For example, an aggregation relationship can be used to form a traffic separation scheme from traffic separation lane parts, boundaries, and so on. In the geodatabase, the collection object is stored in the PLTS_COLLECTIONS table, and its relationships to the features that compose the collection are stored in the PLTS_FREL table.