Title

Greater Melbourne LiDAR - Point Cloud 

Resource Type

Dataset  

Spatial representation type

Point Cloud  

Horizontal Accuracy

0.2m  

Code

MGA Zone 55 GDA2020 

 

Title

Other 

Topic category

• Elevation

Use limitation

General 

Classification

Unclassified  

Description

The IMU and post processed airborne GPS logs were used to generate the LiDAR point cloud from the waveform instrument data. Raw LiDAR swaths were levelled to establish internal consistency, merged and 1km x 1km tiles in LAS v1.2 format were created. An automatic classification algorithm was applied in TerraScan software to produce an initial classification of ground (2) and unclassified (1). High and low noise points were automatically classified and allocated to class 7. The ground classification was improved manually by visually scanning the ground surface and reassigning points from ground to unclassified to remove spikes and by assigning unclassified points to ground where the ground surface lacked sufficient detail to describe the terrain (i.e. large TIN triangles). The classification of ground points was to the ICSM level 2 standard (98% accuracy with respect to ground points). On completion of the ground classification automatic algorithms were used to classify unclassified points to low vegetation (3), medium vegetation (4), high vegetation (5), buildings (6), water (9) and bridge (10). Ground points were confirmed and retained. The classification accuracy was not measured empirically. Upon successful classification, the dataset was converted from ellipsoidal to orthometric using AusGeoid09, and tiles were regenerated to 1km x 1km and LAS v1.4. 

Classification

Unclassified