Technical Description

Property is created through processing property data sourced from Australia’s States and Territories. Source attributes are mapped and standardised to provide a coherent definition across the jurisdictional supplies, with associated geometry being cleaned and processed to output a topologically consistent layer of Australia’s property boundaries at a national scale.

Each property record has a boundary representing the overall coverage of the single property and a Contributor ID which is the jurisdiction’s reference to the property for land valuation and other property purposes. The Contributor ID can be utilised for searches in the relevant jurisdiction’s land valuation system to provide the indicative value of the property for rating purposes.

Property is updated and released regularly and has integrated relationships with other Geoscape Products. Further information regarding attributes, quality, coverage and product release details are outlined below.

Linkages

Property is integrated with the following Geoscape products:

• Cadastre

• G-NAF

• Buildings

The joins used to link to these products are shown below, with attributes used in the joins described.

The property_pid attribute can be used to link to a cadastre_pid in the Cadastre product where a relationship between Property and Cadastre exists. These relationships are represented within the property_cadastre table within the Property product. The three possible relationships between Cadastre and Property are:

• one cadastral parcel is equal to one property

• many cadastral parcels make up one property

• one cadastral parcel contains many properties

Attributes

Contributor ID

The Contributor ID is the property identifier provided by the jurisdiction that is searchable for land valuation and rates purposes. The associated attribute(s) in the jurisdiction source data for each State or Territory are found in the table below.

State	Jurisdiction Value
ACT	TITLE_NUMBER [1]
	BLOCK + “/” + SECTION + “/” + DIVISION_CODE [2]
NSW	PROPID
NT	VOLUME_TYP + “/” + VOLUME_NO + “/” + FOLIO_NO
QLD	PROPERTY_ID
SA	ASSNO_TENSEQNO
TAS	PID
VIC	PFI
WA	VPU_VE_NUMBER

[1]

Derived from the following dataset: ‘ACT_PROPERTY’

[2]

Derived from the following dataset: ‘BLOCKS’

Source

The name of the State or Territory that the property data was sourced from. Base Property The Base Property allows for a simple visualisation of property coverage across all States and Territories without overlapping parcels. Only property parcels which are not contained by another property can be part of the base representation.

Area

The area of each property polygon in square meters, calculated from the feature geometry using an equal area projection. The total area in square meters can be calculated by summing property parcels with a common Property PID.

Data Model

Data Dictionary

property

Attribute	Data Type	Description	Primary Key	Mandatory	10 Character Alias
property_polygon_pid	Character String (15)	Persistent identifier for each property polygon.	Yes	Yes	PR_PLY_PID
property_pid	Character String (15)	Persistent Identifier for the property feature for the life of the property.	No	Yes	PR_PID
contributor_id	Character String (50)	An identifier used to link back to the contributor data where the contributor supplies a persistent identifier.	No	Yes	CNTRB_ID
date_created	Date	The date the record is first introduced to the Geoscape product.	No	Yes	DT_CREATE
date_modified	Date	The latest date that this record has been modified.	No	No	DT_MOD
state	Character String (3)	The abbreviated name of the State or Territory that the property spatially resides within.	No	Yes	STATE
source	Character String (20)	The State or Territory authority that has provided the source data for the property.	No	Yes	SOURCE
base_property	Character String (3)	A ‘Yes’ flag indicates that the parcel is part of the base representation.	No	No	BASE_PROP
area	Number (12,2)	The area in square metres of the polygon.	No	Yes	AREA
geometry	Polygon	The geometry of the polygon.	No	Yes	GEOMETRY

Domain Values

state

Domain Value	Description
ACT	The data is located within the Australian Capital Territory.
NSW	The data is located within the state of New South Wales.
NT	The data is located within the Northern Territory.
OT	The data is located within the Other Territories classification. Other Territories covers the external Australian territories of Cocos (Keeling) Islands, Christmas Island, Jervis Bay and Norfolk Island.
QLD	The data is located within the state of Queensland.
SA	The data is located within the state of South Australia.
TAS	The data is located within the state of Tasmania.
VIC	The data is located within the state of Victoria.
WA	The data is located within the state of Western Australia.

source

Domain Value	Description
ACT	The source data for the record was provided by the Australian Capital Territory Government. Jervis Bay data is sourced from the Australian Capital Territory Government.
NSW	The source data for the record was provided by the New South Wales Government.
NT	The source data for the record was provided by the Northern Territory Government.
OT	The data is located within the Other Territories classification. Other Territories covers the external Australian territories of Cocos (Keeling) Islands, Christmas Island, Jervis Bay and Norfolk Island.
QLD	The source data for the record was provided by the Queensland Government.
SA	The source data for the record was provided by the South Australian Government.
TAS	The source data for the record was provided by the Tasmanian Government.
VIC	The source data for the record was provided by the Victorian Government.
WA	The source data for the record was provided by the Western Australian Government. Cocos (Keeling) Islands and Christmas Island data is sourced from the Western Australian Government.
Geoscape Australia	The data has been created by Geoscape for the purposes of base parcel coverage.

base_property

Domain Value	Description
Yes	The property polygon has been identified as a base property. A base property is not contained by any other property parcel and provides base coverage across each state and territory.
<NULL>	The property parcel has been identified as not being a base property. Property parcels contained by other property parcels will have <NULL> values for this field.

Update Frequency

Property is continuously updated and released with the most up to date data available on a monthly schedule.

Data Quality

Positional Accuracy

Property has been created by combining land valuation/rates information with Cadastre. To achieve a single property representation a union of multiple Cadastre boundaries happens during production. This will preserve the outer boundaries accuracies as supplied by the jurisdiction. Geoscape makes minor changes only where they are required to create valid features described in Property Geometry Validity.

Coordinates Referencing the GDA2020 Datum

Spatial features referencing the GDA2020 datum are produced using a coordinate transformation from the GDA94 datum using the following parameters.

shift_x = 0.06155,

shift_y = -0.01087,

shift_z = -0.04019,

rotate_x = -0.0394924,

rotate_y = -0.0327221,

rotate_z = -0.0328979,

scale_adjust = -0.009994

Property Geometry Validity

Property geometry is validated to ensure polygons are a valid representation and free of self-intersection. Issues being detected and resolved include spikes, bow ties, duplicate vertices, null geometries, multipart geometries, and self-contacts. Minor overlaps are also resolved where a property has a Base Property of ‘Yes’. Overlapping polygons will persist in the product as they can be valid geometries representing the jurisdictions intent.

Polygon orientation conforms to the following specifications:

• OGC Simple Feature Access Specification v1.2.1 [Section - 6.1.11.1]

• The GeoJSON Specification RFC7946 [Section 3.1.6 dot point 4]

This means the polygon outer boundary will be counter clockwise and the inner boundary will be clockwise for file formats that support the above standards.

Further Comments

Property has been processed to assure all polygons are stored as single part features to improve capability with a range of software applications. Due to this there is duplication of the Property PID and Contributor ID information.

Extent/Geographic Description

The spatial coverage of Property includes Australia’s land mass and surrounding offshore islands.

The Bounding Box for this data is as follows:

• North bounding latitude: -8˚

• South bounding latitude: -45˚

• East bounding longitude: 155˚

• West bounding longitude: 112˚

A detailed description of the coverage for each State and Territory is provided in the table below.

Spatial Reference System

GDA94

Horizontal Datum: The Geocentric Datum of Australia 1994 (GDA94) is the target horizontal datum.

Coordinate System: Geographic Coordinate System Geocentric Datum of Australia 1994 (GDA94).

GDA2020

Horizontal Datum: The Geocentric Datum of Australia 2020 (GDA2020) is the target horizontal datum.

Coordinate System: Geographic Coordinate System Geocentric Datum of Australia 2020 (GDA2020).

Delivery Format

Property is provided at a National and State/Territory level, depending on the file format selected. The data is made available in the File Geodatabase, GeoJSON, ESRI Shapefile and MapInfo TAB formats described below.

Format	National	State/Territory
File Geodatabase	Yes	Yes
GeoJSON	Yes	Yes
ESRI Shapefile		Yes
MapInfo TAB		Yes

File Geodatabase

Format name

File Geodatabase – ESRI™

Specification

This format includes files with the following extensions: *.gdb

ESRI File Geodatabase Technical Description. Follow this link: http://desktop.arcgis.com/en/desktop/latest/manage-data/administer-file-gdbs/file-geodatabases.htm

Language

English

GeoJSON

Format name

GeoJSON

Specification

This format includes files with the following extensions: *.geojson

GeoJSON specification: https://tools.ietf.org/html/rfc7946

Language

English

Note

The GeoJSON specification states that the coordinate reference system for all GeoJSON coordinates is: “a geographic coordinate reference system, using the World Geodetic System 1984 (WGS 84) datum, with longitude and latitude units of decimal degrees” Cadastre will be provided with coordinates using the datum selected for download (GDA94/GDA2020) with longitude and latitude units of decimal degrees.

JSON

Format name

JSON

Specification

This format includes files with the following extensions: *.json

JSON specification: https://www.json.org/json-en.html

Language

English

ESRI Shapefile

Format name

Shape – ESRI™

Specification

This format includes files with the following extensions: *.shp, *.shx, *.dbf

ESRI Shapefile Technical Description, an ESRI White Paper, July 1998. Follow this link: https://www.esri.com/library/whitepapers/pdfs/shapefile.pdf

Language

English

MapInfo TAB

Format name

TAB – MapInfo Professional™

Specification

This format includes files with the following extensions: *.tab, *.dat, *.id, *.map

The MapInfo TAB format is a popular geospatial vector data format for geographic information systems software. It is developed and regulated by MapInfo as a proprietary format. TAB files support geospatial standards such as Open GIS, the OGC, ISO, W3C and others.

Language

English

Product Versioning

Property versioning is managed through incrementing when there is a change to the product schema or a significant change in data population, these are described further below:

• A schema change can affect a major or minor increment to the versioning. Additive changes (changes that won’t break customers’ ability to work with the data) will be incremented with a minor version increment, an example is the addition of a new attribute. Removal of attributes or changing the structure of the Property schema will enact a major change to identify that this requires the attention of all customers and partners.

• Where a significant geography of Australia either has a new population of data for an attribute or is populated from a much higher quality source a minor increment will be applied to the product version.

Therefore, Property versioning will not increment with every data update, published releases will have a name e.g. ‘May 2021’ and will reference a version of the Property product e.g. ‘1.0’.