SLIP Technology Uses OGC® Standards to Create One Access Point for Land Information in Western Australia

SLIP Technology Uses OGC® Standards to Create One Access Point for Land Information in Western Australia

Landgate contributed the following write-up about SLIP, a network that provides access to 1200 WMS and WFS layers. If your organization uses OGC Standards and has a story to tell, particularly including why it uses OGC Standards and any "Lessons Learned," please contact <editor at opengeospatial dot org>. Tina Cary, Editor

In Western Australia (WA), approximately 1900 people per month are now logging on to the Shared Land Information Platform (SLIP) to access more than 20 gigabytes of land information maintained by many government departments. By so doing, users eliminate having to visit and deal with the multiple agencies otherwise needed to gather this information.

Nineteen Government agencies and two private organizations are currently connected to the SLIP network, bringing together and making available some 200 vector spatial datasets and over 1000 imagery datasets that in the past resided in isolated systems. Registered users (registration is free) need only a PC, a supported browser (see https://www2.landgate.wa.gov.au/slip/portal/home/tech-requirements.html ) and software that supports OGC standards to connect to SLIP and directly to the source data hosted and maintained by the custodian agency.

The SLIP initiative stems from the Western Australian Government e-initiative and recommendation of the Functional Review Committee in 2003 to develop a common information framework that would allow agencies to make available and share their information online. Western Australia Land Information System (WALIS) contracted OGC Australia to study needs, requirements, etc., and develop a reference architecture for SLIP based on open standards and specifications, so that SLIP would produce a ‘connected government', reduce capital expenditure, avoid duplication of services and make information readily available to government agencies, businesses and citizens from just one place.

SLIP has these objectives:

• Simplify access to the government's valuable collections of land and geographic information;

• Improve the efficiency of government business processes and enable better decision-making;

• Promote better integration across government; and

• Facilitate the development of new applications to meet the changing requirements of the general community and business.

Landgate, Western Australia's land and property information agency, is the lead agency for SLIP's development. In 2004, Landgate initiated the SLIP Program to build the technical infrastructure and establish focus groups. Landgate also initiated the subsequent SLIP Implementation Plan with a strong focus on consultation, because it recognized that success is just as dependant on engaging people as overcoming technological challenges. In fact the success of SLIP so far is largely due to the enormous collaborative effort by a number of Western Australian Government agencies.

Four lead agencies were appointed to share responsibility for SLIP's implementation, which extended the sense of ownership of the project. This is another significant contributing factor towards SLIP's success to date. Each lead agency focuses on one of four areas :

• Emergency Management led by the Fire and Emergency Services Authority - using land information to improve public safety, reduce reaction times for emergency services and help save lives.

• Natural Resource Management led by the Department of Agriculture and Food - delivering mapping and data to regional groups and agencies to support conservation, land management and sustainable development.

• An electronic Land Development Process (eLDP) led by the Department for Planning and Infrastructure - designed to dramatically reduce the time needed for subdivision approvals compared to the old paper-based system and make the process for obtaining statutory approvals more transparent.

• Interest Enquiry led by Landgate - a one-stop Interest Enquiry within SLIP that links all relevant datasets to provide a simple, quick way of determining all parties with an interest or say over how a particular parcel of land may be used.

All lead agencies are Perth-based although SLIP's technology can be adapted to provide Australia-wide and even international opportunities.

Landgate was also responsible for the development of the SLIP Enabler which is the technical infrastructure that made possible the network of connected spatial datasets owned by multiple organizations. Landgate appointed consultants CA (Pacific) Pty Ltd to develop, design and implement the enabling framework together with their partners Amristar and Ross Logic.

All four focus areas utilize the SLIP Enabler to access and combine information, even though each area has been built to individual specifications (see Figure 1).

Figure 1 - SLIP Concept

SLIP's enabling infrastructure is installed at each agency's site to directly interface with each data store. Having the enabling technology onsite allows agencies to update their information simultaneously with any amendments to their systems. The information is streamed through to the central portal at Landgate via SLIP to provide users with access to real-time data.

The SLIP Enabler is set apart from similar solutions because of its ability to connect directly to information in a variety of ways to meet each data custodian's technical and business needs, while maintaining central control of the securing and access tiers. A representation of the physical architecture is shown in Figure 2.

Figure 2 SLIP Enabler - Physical Architecture

This original design allows data custodians to retain full control of their information behind best-of-breed security practices and design. A virtual private network allows a small central team to manage the external infrastructure. This means that that contributing agencies can deliver a service to an extended customer base without having to expend resources to build internal infrastructure.

The design of the SLIP Enabler included a decision to adopt a Services Oriented Architecture to maximize the re-use of components, to position SLIP for integration with other services, and to use open standards. This ensured broad interoperability and provided a foundation that will extend data capabilities into the future.

The architecture is consistent with the OpenGIS® reference model and extends the model to introduce capabilities to address security - an important consideration in the SLIP context. It includes the groundbreaking secure delivery tier that enables users to source data directly from custodial agencies. A functional overview of the architecture is shown in Figure 3.

Figure 3 SLIP Enabler - Functional Overview

The Global Spatial Data Infrastructure Association has asked that the SLIP Enabler architecture and collaboration model be included within its Cookbook which profiles best-practice systems.

SLIP utilizes Open Geospatial Consortium (OGC) standards for interoperability between spatial software and the data disseminated by the Enabler: It also includes an integrated metadata catalogue, a web-based map viewer, and security and management services.

SLIP's data services have been tested on ESRI products, MapInfo, GeoMedia and Google Earth, and have been designed to meet these OGC specifications:

• Web Map Service (WMS) version 1.1.1

• Web Feature Service (WFS) version 1.0

The WMS is used to produce dynamic maps of spatially referenced data extracted from geographic information. The OGC standard defines a ‘map' to be a portrayal of geographic information as a digital image file suitable for display on a computer screen. A WMS map is not itself the spatial data; the maps are rendered in a pictorial format such as PNG, GIF, TIFF or JPEG.

The WFS allows users to retrieve geospatial data encoded in Geography Markup Language (GML) which fully describes points and metadata for features. GML data can be used for display or querying purposes.

The spatial software components used within SLIP include MapServer, GeoServer and PostGIS databases running on the Red Hat Linux operating system, with SLIP connected to a variety of data sources including ArcSDE, Oracle Spatial and GeoMedia.

In late 2006, the responsibility for managing SLIP's governance for projects and production systems transferred to the Western Australian Land Information Services (WALIS). The transference included the integration of WALIS into Landgate.

In August 2007, SLIP was launched to government agencies. The number of data custodians continued to increase along with the number of datasets, data services, and complementary business applications.

In February 2008, the SLIP Developers Program was launched. The program provides specialized online and technical support to WA organizations that are developing applications for use with SLIP services. The program has a dual function to improve application support for OGC services and to extend the sales team for SLIP services.

SLIP will be formally launched to industry in September 2008, building on a program that encourages the involvement of commercial developers of spatial and business applications.

New focus areas have been identified for development including community health and marine information. Further areas will be identified during 2008.

The development and partnership possibilities are endless, including a great opportunity for future public/private partnering and the development of further commercial applications as the scope of SLIP increases. Protocols have been developed for private sector involvement.

The next steps include the ongoing acquisition of more datasets and commercial applications.

This project shows that the ability and willingness of government agencies to work together and embrace change yields success.

SLIP is found at https://www2.landgate.wa.gov.au/slip/portal/home/home.html