Title

Wangaratta - DEM 

Resource Type

Dataset  

Spatial representation type

Grid  

Horizontal Accuracy

0.3m  

Code

MGA Zone 55 GDA94 

 

Title

ESRI Ascii 

Topic category

• Elevation

Use limitation

Data Vic 

Classification

Limited Distribution  

Description

Proprietary ground classification routines in TerraScan were used to remove any non-ground points and generate an accurate ground surface. Once the ground surface had been generated a manual quality control routine was carried out using aerial imagery, hill shades, cross-sections, and profiles within the TerraSolid software suite to classify the above ground points. The vegetation was auto-classified using the height from ground method. A QA review and manual inspection was completed on a percentage of the classified tiles based on the project size and variability of the terrain. The DEM was created as a one metre cell size raster from LiDAR data classification of 2 (ground) retaining the minimum elevation value of all suitable LAS records in each cell, where no suitable value is present for a given cell the data has been filled in a two step process: 1. Isolated cells with numerous valid adjacent value are filled with a focal mean. 2. Larger gaps are triangulated then rasterized to fill. Using hydrological polygons, manually captured from an intensity raster produced by the same LiDAR data prior to classification, the DEM is processed to the minimum surrounding value where the water appears to be static and minimum transverse value along the length of waterbodies that have apparent flow, refined by an algorithm to have no counterflow along the length of the watercourse. 

Classification

Unclassified