How to Use MultiNet GDF
Parent topic: How to Use MultiNet GDF

Index Areas in MultiNet® GDF

See Index Areas earlier in this user guide for a general description of Index Areas.

An Index Area is stored as a simple area feature in the product. The capturing on the database level is composed either out of an Index Area Component (Simple Area Feature) or by one or more other area features (Complex Area Feature).

In the case of a complex feature, the components can be any of the following area types:

Relationships for Index Areas in MultiNet GDF

In MultiNet® GDF formats, the following Relationships are applicable to Index Areas:
RELATIONSHIP RELATIONSHIP CODE
Road Element in Named Area 1003
Ferry Connection in Named Area 1013
Service in Named Area 1014
Center Point of Feature Belonging to Feature 1029
Place Within Place 2400
Address Area Boundary Element 9201
Address Area Boundary Element in Named Area 9202
Built-up Area in Named Area 9203
Administrative Area Replaced by Index Area 9204
Relationships 9204, 1003, 1013, 9201, 9202, 1014 and 9203 describe the presence of features in a Named Area. These are "Feature in Index Area".

Place Within Place Relationship for Index Areas

In the Relationships below, Part 1 of the relationship is the child area, part 2 is the parent area.

Possible Relationship Components for Index Areas

  • Index Area (part 1) within an Index Area (part 2)
  • Index Area (part 1) within an Administrative Area (part 2)
  • Administrative Area (part 1) within an Index Area (part 2)

Relationship Attributes

  • Place within Place Classification. Value 3: "address significant"
IMPORTANT: This order of relationship parts deviates from the convention, used in many other MultiNet® relationships where the "largest" object is the first part of the relationship, and the "smaller" object is the second part. The actual definition, however, is compliant to the ISO GDF 4.0 standard.

Administrative Area Replaced by Index Area

Relationship Components for Index Areas:

  • Administrative Area (part 1) replaced by Index Area (part 2)

IMPORTANT: Part 2 of this relationship has feature category 0 followed by an empty identifier field. This means that the relationship merely indicates that the Administrative Area mentioned in the relationship is not appropriate for Index building and can be left out of the Index. The relationship does not mean that a certain Administrative Area is replaced by a specific Index Area.

Example: An Order 8 Administrative Area has three different Index Areas that cover its surface. There is no possibility to choose one of those Index Areas as the second part of the Area Replaced by Index Area relationship. The relationship only indicates that the Order 8 Administrative Area can be left out of the Index.

Index Areas As They Appear in MultiNet GDF-AS Format

An Index Area is represented by a Simple Area feature with feature code 9200. The attributes are Official Name (mandatory) , Alternative Name (not mandatory) and Index Order (mandatory). The Index Order attribute 9X has values 1 to 10 for Index Order 1 to Index Order 10.
Note: The Index Order is country dependent:
Examples: Belgium has Index Orders 8 and 9; the United Kingdom has Index Orders 7, 8, 9 and 10.

Data Example

Area Feature Record 53 has Area Feature Identifier 399958884, Feature Code 9200 for Index Areas, consisting of 4 faces with face identifiers 60000210, 60094251, 60127826, 60127828 and 1 attributeset with segmented attribute identifier 1997392795.

The Segmented Attribute Record 1997392795 above has the following information:

441997392795 29X 9 ON 6562 0

This record lists two attributes: 9X, which is a direct attribute with value 9, indicating Order 9 Index Area; and the indirect attribute ON with ID 6562 that points to the name record (record type 41) that has the official name of the Index Area:

41 6562 ENGTwo Waters Foot 0

The above record contains the language code (ENG) and the official name (Two Waters Foot).

Section-Crossing Index Areas in MutiNet GDF-AS

Example: An Order 8 Index Area is split over two different GDF-sections with section identifiers:25000150 and 25000157.
Note: The entire GDF record information below is not shown in the examples below.
In section 25000157, the Order 8 Index Area has its GDF area feature record as follows:

53 39996273192001 (with 3 faces)

This shows the identifier (399962731) with feature code 9200 (Index Area) and split indicator (1). The Split indicator shows that this Index Area is split over different sections.

In section 25000150, the Order 8 Index Area has its GDF area feature record as follows::

53 39996273192001 (with 793 faces)

This is the complementary Order 8 Index Area.

An Order 9 Index Area lies completely in Section 25000150. The Order 9 Index Area has its GDF area feature record as follows:

53 39995884592000 (with 19 faces)

The split indicator is 0 which shows that the Order 9 Index Area lies completely in one section.

See also, Dataset and Section Crossing later in this user guide.

Parent topic: How to Use MultiNet GDF