National Digital Elevation Model

The ANZLIC AusDEM workshop was held in Perth on 7 August 2007 with around 50 people attending. The WALIS Marine Group had, in advance of the workshop, prepared the following statement and recommendation which was put to the workshop attendees at the start of the day:

Direct observations of the Earth's surface, both onshore and offshore, are important for decision-making by government and industry, impacting on social, environmental and economic decision-making. Onshore, complete national coverage exists for material properties (e.g., Landsat) and topography (e.g., 9-second DEM, 3-second and 1-second SRTM). In addition, there are continual improvements in direct spectral and topographic observation at  project- and regional-scale across the country. Offshore, there is no single directly observed dataset of seabed topography or material, although there is some project-scale or local area data of high quality. This situation contrasts markedly with the situation onshore.

In terms of DEMs, the WALIS Marine Group sees the absence of complete national offshore coverage as the single most significant impediment to development, conservation and emergency planning. To address this we are proposing that the States, Territory and Commonwealth:

1.   Acquire complete low/medium-resolution coverage of accessible WA Coastal Waters (3-nautical mile limit). This would probably rely on boat based sidescan/multibeam sonar and would take up to three years to complete but would leave nearshore areas unmapped.

2.   Complete selected high-resolution surveys of the coastal zone (+HWM to -20metre depth) in areas where conservation and development issues are pressing. This may rely more on LIDAR and would be ongoing.

To achieve these goals will rely on all governments committing to a national approach and providing resources. The WALIS Marine Group, representing all WA state agencies with an interest in a positive outcome, is seeking broad support for the coastal and offshore areas of Australia to receive the highest priority in the development of a national DEM.

Outcomes:

Technical and Administrative Framework for a National Digital Elevation Model

(DEM)

Seven regional AuzDEM workshops were conducted by ANZLIC in July and August 2007.

All workshops have been well attended – with over 300 attendees – most identifying themselves as users of digital elevation data. There is wide spread support for a national approach now through shared responsibility and coordinated resourcing. A wide range of issues have been raised but certain trends are common:

· Develop and apply national standards for elevation data and access.

· Need for a common vertical datum to be used in new (and where possible existing) elevation datasets

· Better ability to find and access elevation datasets, using a virtual data repository and a one-stop portal;

· Close data gap along the coast between existing land and sea datasets.

· Leadership is needed to quickly develop a national framework, with broad agreement to the facilitation role by ANLIC and standards framework by ICSM.

· Develop a clearing house to enable cost sharing in data acquisition, documentation and access to elevation data.

· Need to sort out IP issues and develop relevant DRM structure to encourage access and use of elevation data.

· Need to optimise investment (especially funds from Australian Government programs), reduce costs, develop budgets and obtain funding for improving elevation data.

 Other issues discussed in relation to the DEM included:

· need for more emphasis to be given to data access and licensing issues;

· impact of data quality upgrade on all jurisdictions of tying data together, eg. roads;

· CRCSI undertaking a pilot project of integrating bathymetry to land (should be available within next 2 months);

· Need to more actively involve Water.

The DEM business plan will evolve as the workshops progress and the needs analysispaper will be discussed at the national workshop sponsored by the Australian Academies of Science in September.

Workshop Agenda   Communication Plan   Business Plan    Workshop Pack    Workshop Questionnaire

ANZLIC – the Spatial Information Council, with the support of the Australian Greenhouse Office and Geoscience Australia, is sponsoring development of a nationally coordinated DEM.

A key element of the project is to obtain stakeholder support and engagement. A number of steps will be taken to achieve this aim. These steps include:

1. Development of a Business Plan, setting out the intent and potential form of a nationally coordinated DEM, identifying key stakeholders and a preliminary review of existing usage of DEM in Australia.
2. Use the Business Plan to inform discussion about the need for and form of a nationally coordinated DEM.
3. Develop a User Needs Analysis through direct contact with key stakeholders around Australia and research of international trends.
4. Develop an Implementation Plan using the User Needs Analysis and feedback from stakeholders on issues such as governance arrangements, funding and technical standards.
5. Develop and gain agreement on use of applicable data standards and access arrangements such as licensing.

The Project Team (ANZLIC, AGO, GA and CRCSI) will meet at least fortnightly during the course of the project to approve project activities, review draft documents and assess progress. A consultant, Paul Kelly, has been appointed to provide resources to the project team during the project.

Key Message

“Preparing for the high-resolution future of digital elevation models in Australia.”

Specific points:

·         There is increased interest in use of the third dimension (think Google Earth).

·         New and emerging technologies provide an opportunity to operate at scales not feasible even a decade ago.

·         There are major gaps in terrain and bathymetric data of higher resolutions across Australia.

·         The technologies exist to acquire all of Australia at the highest vertical accuracy of 30 cm. What constrain us from doing so is cost (estimated in the hundreds of millions of dollars) and the capacity to acquire and process the volume of information at such a scale.  The cost, limited capability and acceptability of variable resolutions leads to a conclusion that a nested approach where datasets of various resolutions are placed within a contiguous framework will be most suited for a wide range of uses at both national and local levels.

·         Existing and future elevation data of differing resolutions need to be integrated to achieve this continuity.

·         There is strong interest in a national approach.

·         A national approach would potentially yield benefits in improved consistency, contiguity and cost efficiencies in the acquisition and use of elevation data.

·         An option is to produce a national framework with a single nested product with accuracies and resolutions in any region designed specifically for that purpose and application.

·         This is a way of raising profile of the third dimension and attracting investment in better digital elevation models.

·         A study of the future needs of users is being conducted and the benefits of a national approach need to be clearly enunciated by stakeholders

For more information regarding this workshop please contact Karen Barns on 9273 7093 or karen.barns@walis.wa.gov.au

Jurisdictional Workshop Schedule