GDF-AS

Product Records

Unlike Shapefile, OSL and GDF-AR formats, GDF-AS-formatted data contains all Features, Attributes and Relationships in a single file of many different records. GDF files may be delivered as an entire Dataset (Country) in one file, or partitioned by "Sections" in single or multiple files (A Section is created out of one or more Administrative Areas. See Administrative Areas in this user guide for an overview.). A MultiNet^® GDF-AS "Volume" contains one or more Sections. A collection of Volumes is referred to as an "Album." The hierarchy and order of the GDF-AS records in *.gdf files is generally organized as shown below:

Volume Header Record
	Dataset Records
		Section Header Records
			Layer Header Records
				Data Records
Volume Termination Record

See the Record Organization of GDF-AS Files in the GDF-AS Formats section of this user guide for a complete listing of records displayed as a hierarchy.

List of Records - GDF-AS

The list of records below is ordered as they appear in MultiNet^® data.

See also Notes on the Order of Records in the GDF-AS Format section of this user guide.

See record names under the Record Name column in the table below to find the matching records in the MultiNet^® ASCII Sequential (GDF-AS) Format Specifications document for the record definitions for each file.

Table 1. List of Records - GDF-AS
RECORD TYPE	RECORD NAME	RECORD IDENTIFIER
Volume Header Record	Volume Header Record	01
Comment Record*	Comment Record	99
Dataset Header Record	Dataset Identification Subrecord	0201
Dataset Header Record	Dataset Main Title Subrecord	0202
Dataset Header Record	Dataset Contents Subrecord	0206
Dataset Header Record	Field Definition Record	03
Dataset Header Record	Record Definition Record	04
Dataset Header Record	Attribute Definition Record	05
Dataset Header Record	Feature Definition Record	07
Dataset Header Record	Relationship Definition Record	09
Dataset Header Record	Administrative Structure Definition Record	10
Dataset Header Record	Default Attribute Record	15
Dataset Header Record	Attribute Value Definition Record	18
Dataset Header Record	Datum & Ellipsoid Record	61
Dataset Header Record	Earth Magnetic Field Record	66
Section Header Record	Section Identification Subrecord	1601
Layer Header Record	Section Border Subrecord	1607
Data Record	Layer Header Record	17
Data Record	Coordinate Record	23
Data Record	Node Record	25
Data Record	Edge Record	24
Data Record	Face Record	29
Data Record	Point Feature Record	51
Data Record	Line Feature Record	52
Data Record	Area Feature Record	53
Data Record	Complex Feature Record	54
Data Record	Name Record	41
Data Record	Segmented Attribute Record	44
Data Record	Conversion Record	46
Data Record	Relationship Record	50
Data Record	Time Domain Record	45
Data Record	Object Reference Record	83
Volume Termination Record	Volume Termination Record	90

* A Comment Record (99) cannot be inserted between two physical records belonging to one logical record. Comment Records containing free text are allowed to be written anywhere else in the GDF-AS file between the Volume Header Record (01) and the Volume Termination Record (90).

See also Notes on Order of Records in the GDF-AS Format section of this user guide.

Data Model - GDF-AS

Below is the data model for the Data Records in GDF-AS format:

Data Record Relations

Figure: GDF-AS Data Records Model

Data Record Field Pointers - GDF-AS

In the Pointer Fields figure below:

an open dot ° indicates a field where the identifier is assigned;
a full black dot ● indicates a field used to refer to another record.

Figure: Pointer Fields and Their Role in the Records