Title

Vicmap Elevation LiDAR DEMs Collection 

Alternate title

VICMAP ELEVATION LiDAR DEMs Collection 

Purpose

The Vicmap LiDAR DEMs collection contains high accuracy and detailed ground surface model datasets designed for many and varied applications including: use as terrain surfaces in 3D and digital twin environments, flood modelling, river channel and land surface cnage detection, mine shaft mapping, coastal inundation modelling and general landscape and landuse suitability anlayses. 

Supplemental Information

Relationship to other Datasets: ANZVI0803002639 Related Documents: Please see Vicmap Elevation LiDAR DEMs Collection product description for more detailed information on this product. This can be found on the Vicmap Elevation Webpage. https://www.land.vic.gov.au/maps-and-spatial/spatial-data/vicmap-catalogue 

Status

Completed  

Code

28355 

Maintenance and update frequency

Irregular  

Title

Ranging from ESRII ASCII Grid to Cloud Optimised GeoTIF 

Topic category

• Elevation
• Environment
• Geoscientific information

Use limitation

Vicmap Elevation LiDAR DEMs are subject to licensed use. Data Access License Agreements (DALA) are used to provide the terms and conditions of use, including license fees determined by the coverage and extent of the data purchased. Commercial use licenses may also be negotiated with businesses wishing to become a licensed Value-Added Reseller (VAR) or licensed Data Service Provider (DSP). VARs and DSPs offer data ordering and sale services for Vicmap LIDAR DEM datasets. VARs and DSPs offer data ordering and sale services for Vicmap LIDAR DEM datasets. 

Classification

Unclassified  

Statement

Dataset Source: Vicmap LiDAR DEMs derive from LiDAR survey projects undertaken through the States Coordinated Imagery Program (CIP). LiDAR surveys are conducted on behalf of the State by commercial aerial survey companies that have qualified for the relevant State services panels. Acquisition planning is driven by purchase partner investment in the CIP program and is implemented in an on-demand basis. Aerial survey most often occurs as a single project achievable within one flying season by a single commercial supplier. As investment and funding allows, larger capture programs may occur that span multiple flying seasons and require multiple commercial suppliers to complete. LiDAR survey within Victoria is achievable throughout the whole calendar year, however most data capture has been conducted during the spring, summer, and autumn seasons (November through to May). Dataset Originality: Primary 

Description

Collection Method: Aerial LiDAR Survey 

Description

Vicmap LiDAR DEMs are constructed from LiDAR points classified as ground. The model defines a bare earth ground surface and is devoid of trees and human-made structures. In summary terms, the DEM generation approach employs a Point to TIN and TIN to Raster process with Natural Neighbour interpolation. The surface models exclude road and rail bridges as well as major culverts. If these features were incorrectly classified as LiDAR ground points and automatically included in the DEM, they are subsequently edited out of the model in a manner that ensures the underlaying terrain is continuous and not left as a gap or void in the surface. 

Classification

Unclassified  

Attribute Quality

Comments

As the LiDAR DEMs represent the bare earth ground surface, the attribution of the dataset is reflected in the vertical elevation values of the dataset. In this sense, the attribute accuracy is commensurate with the vertical accuracy of the surface which ranges between +/- 10cm RMSE and +/- 50cm RMSE for different datasets in the collection. Vicmap Elevation LiDAR DEMs are most correct when used in their native datums and projections. Transforming and reprojecting DEMs may alter and reduce the fidelity of the elevation values for the transformed or reprojected coordinate. 

Positional Accuracy

Comments

Horizontal Accuracy is greater than or equal to +/- 30cm RMSE All LiDAR surveys from which the LiDAR DEM datasets are derived are rated at +/-30cm RMSE horizontal accuracy. Greater horizontal accuracies are now achievable and have been demonstrated in the more recent LiDAR surveys that have contributed LiDAR DEM datasets. Vertical Accuracy ranges between +/- 10cm RMSE and +/- 50cm RMSE Vertical accuracy has historically been a commonly varied LiDAR survey specification. Within the LiDAR DEMs collection, vertical accuracy ranges from +/-50cm RMSE for some of the older datasets to +/-10cm for later datasets. The increase in vertical accuracy is due to improved sensor technology as well as better positioning and aerial survey inertial management technology. 

Conceptual Consistency

Comments

The LiDAR DEM datasets are all consistent in their data representation of AHD. As described, variations exist in resolution and vertical accuracy. Additionally, there will be variation in the degree to which older datasets have been hydro flattened and bridges treated, as surface modelling improvements have evolved over time. 

Missing Data

Comments

The collection covers approximately 60% of the land area of Victoria and approximately 99% of the populated areas. As an expanding collection, coverage continues to grow in temporal and spatial terms as new datasets are added. Completeness Verification: Each dataset in the collection has been verified for conformity with the vertical accuracy specifications for the LiDAR survey under which the data collected. Vertical accuracy requirements vary between projects from +/-10cm RMSE to +/-50cm RMSE. 

Excess Data

Comments

LiDAR DEM datasets in the collection represent the bare earth surface as the only data class. Bridges do not form part of ground surface and are excluded from the DEM datasets. DEM resolution varies between datasets from 5m to 50cm.