The WALIS Cadastre Review Technical Working Group started in mid 2005 on request from the WALIS Council. Their TOR includes identifying and quantifying issues users have with digital cadastre and to investigate means of implementing changes to the maintenance and dissemination of cadastral data to better meet user needs.

From issues identified and progressed by the WALIS Cadastre Review Technical Working, the need for a Referential Topology Working Group became evident.  In 2008 the WALIS Spatial Management Group proposed that such a working group be officially formed, now known as the Positional Accuracy Improvement Group (PAIG).

Referential Topology is used to more accurately model the world and maintain orientation integrity between objects.  The concept of aligning datasets through rules and links has been around for many years and has been referred to as either; referential topology, boundary linkage, topologically structured or dynamic vertical topology to name a few.

The WALIS Positional Accuracy Improvement Group (PAIG) members are seeking ways to better automate the up-dating of datasets that are co-incident geographically and that are collectively affected when one of the datasets is altered. Some agencies have already invested much effort in automated software solutions. The WALIS Positional Accuracy Improvement Group (PAIG) also looks at the processes for updating, maintaining and disseminating land cadastre to be better aligned with users needs.

Please complete the survey if you would like to provide information on how your agency deals with positional accuracy improvement of agency data in relationship to Landgate Spatial Cadastral Database (SCDB) and what you require from SCDB to improve alignment issues. Any comments and requests can be e-mailed to jenny.smith@walis.wa.gov.au

A Referential Topology Workshop was held early 2009 and the WALIS Positional Accuracy Improvement Group (PAIG) got underway.

 January – April 2009

A Referential Topology Workshop was held on 29 April 2009. The workshop was hosted and facilitated by WALIS and Landgate. 25 People attended from 6 key agencies.

Presentations on referential topology issues within agency work areas were given by Landgate, Department for Planning & Infrastructure, Local Government and the Water Corporation.

Group discussions centered on Spatial upgrade, Shared Line Usage and a Fit for Purpose Dataset.

May – July 2009

The Positional Accuracy Improvement Group (PAIG) is meeting on 8 July 2009 to follow up on the outcomes of the workshop. Department of Planning and Water Corporation have submitted position papers outlining agency issues and requirements pertaining to cadastral data. This information will be used to determine commonalities between agency business needs and how internal business processes can be improved to accommodate referential topology difficulties. The preliminarily review will be discussed at the July meeting.

Department of Planning gave an update on the Land Boundary Linkage Project.

On 17 July, Dr Lesley Arnold presented on Maintaining Boundary Relationships within Spatial Databases at the SSSI conference.

August – September 2009

A meeting is scheduled for 9 September from 9-11 at Landgate, in Midland.

The PAIG Terms of Reference will be discussed.

October – December 2009

A PAIG meeting is scheduled for 4 November from 9-11 at Landgate, in Midland

Landgate gave a presentation on linking the Department of Planning R-Codes to Landgate Cadastral Data by using the centroid of the polygon. Read the proposal and view the presentation.

The SCDB Spatial Upgrade status index can be found on the Landgate Corporate Website

WALIS, Landgate and 1Spatial met on 14 October to discuss Radius Align and Radius Studio software that can be used to produce shift vector files, build business rules to check for non conformance and apply automated action to fix anomalies. WALIS and Landgate provided a presentation on PAIG, SCDB and alignment concerns.

January – April 2010

The PAIG meeting is scheduled for 3 February form 9:30 at Landgate in Midland

May – June 2010

The PAIG meeting is scheduled for 5 may form 9:30 at Landgate in Midland

July – August 2010

The PAIG meeting is scheduled for 7 July form 9:30 at Landgate in Midland

September – October 2010

The PAIG meeting is scheduled for 8 September form 9:30 at Landgate in Midland

November – December 2010

The PAIG meeting is scheduled for 3 November form 9:30 at Landgate in Midland