Introduction to Landgate and the SCDB

1
Welcome to Landgate
Landgate / 1Spatial Meeting
Spatial Cadastral Database (SCDB)
www.landgate.wa.gov.au
2
Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Landgate

• Statutory Authority commercial powers
• Responsible for Western Australias land and
  property information and provision of
• A secure land titles system the official
  register of land ownership
• Valuation services for the States land and
  property
• Survey information in support of ownership and
  land development - SCDB
• Development of a common platform to improve
  access to a range of government information - SLIP

www.landgate.wa.gov.au
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Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Spatial Cadastral Database - SCDB

• One part of Landgates corporate GIS
• Stores topologically related point, line,
  polygon, angle, azimuth, arc and string data,
  with attribute information for a range of
  cadastral and administrative datasets including
• Surveyed Un-surveyed cadastre
• Unapproved surveys (Lodged Layer)
• Control Marks (from GESMAR)
• Easements
• Surveyed Mining Tenements (Mines data stored in
  SCDB)
• Administrative Boundaries (LGAs, Localities, Port
  Authorties etc)

www.landgate.wa.gov.au
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Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Spatial Cadastral Database - SCDB

• Points, Lines Polygons
• Unique numeric identifiers
• Can have multiple usages
• Various derivations accuracies
• Time stamps for create, modify, retired

www.landgate.wa.gov.au
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SCDB Data Attributes(External Linkage Keys)
Landgate / 1Spatial Meeting
www.landgate.wa.gov.au
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Introduction to Landgateand the SCDB
Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Landgate / 1Spatial Meeting
SCDB Business Drivers

• Daily Maintenance
• Average of 500 new surveys/month
• 70 automatically integrated
• New Topographic Boundary Definitions
• Water marks HWM, LWM, MHWM
• Spatial Upgrade Program
• Replacement of digitized values with surveyed
  dimensions

www.landgate.wa.gov.au
www.landgate.wa.gov.au
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Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Spatial Cadastral Database - SCDB

• Seamless database held in GDA94 coordinates
• Original data captured from digitized cadastral
  map sheets of various scales ( 12K to 1250K)
• 86 of SCDB now upgraded to survey accuracy
• Accuracy of upgraded areas is approximately
• Metro - /-0.25m
• Rural /-2m
• Pastoral - /-10m
• Environment is client/server with data stored in
  Oracle and managed in conjunction with SDE

www.landgate.wa.gov.au
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Introduction to Landgateand the SCDB
Introduction to Landgateand the SCDB
Landgate / 1Spatial Meeting
Landgate / 1Spatial Meeting
SCDB Data Dissemination Formats

• ESRI Shape Files
• SDE
• DGN
• DXF
• DWG
• NORM Files (in-house format)

www.landgate.wa.gov.au
www.landgate.wa.gov.au
9
WALIS PAIG
Landgate / 1Spatial Meeting
Landgate / 1Spatial Meeting
WALIS Positional Accuracy Improvement Group (PAIG)

• PAI issues more evident in 2008
• SLIP highlighted positional difference between
  Landgates SCDB compared to Clients Data
• 12 Core Agencies
• Terms of Reference
• Identification of common SCDB user issues
• Investigation of possible changes to SCDB
  maintenance and data dissemination to better
  assist users
• Investigate integration improvement opportunities
  for fundamental WALIS datasets
• Share ideas, collaborate and raise awareness
  across agencies
• Subgroup Landgate subject experts

www.landgate.wa.gov.au
www.landgate.wa.gov.au
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Spatial CadastralDatabase
Landgate / 1Spatial Meeting

• Cadastral Maintenance
• Approach depends on the area to be updated
• Special Survey Areas
• Least Squares Adjusted Areas
• Digitized Areas
• Spatial Upgrade Program
• Replacement of digitized dimensions with surveyed
  measurements
• Improvement of relative and absolute coordinate
  accuracy by linking to Geodetic Control and Least
  Squares Adjustment
• Program is the primary cause of coordinate shifts
  that concern SCDB data customers
• Will not be completed for 3-4 years

www.landgate.wa.gov.au
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SCDB Spatial UpgradeProgress 1 August 2009
Landgate / 1Spatial Meeting
www.landgate.wa.gov.au
12
Least Squares Adjustment
Landgate / 1Spatial Meeting
Before
Red is adjustment hotspot area. Indicating
errors in the network from possible incorrect
observations angles distances
www.landgate.wa.gov.au
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Least Squares Adjustment
Landgate / 1Spatial Meeting
After
Blue is Least Squares Adjusted (Point Accuracy
Statements approx 0.030 metres)   Other is Image
Digitised  (Point Accuracy Statements 50.0
metres)
www.landgate.wa.gov.au
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Least Squares AdjustmentResults Table
Landgate / 1Spatial Meeting
www.landgate.wa.gov.au