Topic category

• Elevation

 

Use limitation

General 

Classification

Unclassified  

 

Description

LiDAR data captured using onboard GPS, IMU and network of ground basestations. Trajectories and laser data corrected initially using the AusGeoid09 and then adjusted to AHD using local PSMs. LiDAR data is classified into multiple ground and non-ground classes. Project model key points classified from Ground class automatically; Vegetation (high, medium and low) classified automatically; Bridges classified manually. Ground points are selected from the laser point cloud through iteratively building a triangulated surface model. The building size gives the starting surface point density and the iteration angle determines how close a point has to be to the surface to be included. Ground point thinning is an iterative process similar to ground point classification. 

 

Classification

Unclassified  

 

Attribute Quality

Positional Accuracy

Conceptual Consistency

Comments

Ground definition in vegetated terrain may contain localized areas with systematic errors or outliers which fall outside this accuracy estimate. Gaps may occur due to diminished returns over water and materials with low laser reflectivity, such as black composite roofing.The definition of the ground may be less accurate in isolated pockets of dissimilar terrain/vegetation combinations. Accuracy of the ground surface under or within dense canopy/vegetation may be reduced. 

Missing Data

Comments

Gaps may occur due to diminished returns over water, under canopy and on materials with low laser reflectivity, such as black composite roofing. 

Excess Data

 

Platform Type

Aerial  

Assembly

Single  

Tile Size

2 km  

 

 

Pulse Mode

Single Pulse 

Scan Rate (Hz)

47Hz  

Scan Frequency (kHz)

70kHz  

Scan Angle (degrees)

15degrees  

Footprint Size (m)

0.30000001m  

Point Density Actual (pts/m2)

2.03999996points/m2  

Point Spacing Actual (pts/m)

0.69999999points/m2  

Ellipsoid Provided

1 

Ellipsoid Vertical Datum

GRS80 Ellipsoidal (ITRF2005)  

Ellipsoid Format

LAS 1.3  

Geoid Vertical Datum

AUSGEOID09  

Environmental Conditions

1. Cloud and fog free between the aircraft and the ground. 2. Floodplain/wetland data must be captured during times of base-flow and outside of significant surface inundation due to natural events and /or regulated environmental flows. 3. Flights should not be undertaken during periods of heavy smoke haze. 

Class Level

2 

Classification

Class Level	Class 0 - Unclassified	Class 1 - Default	Class 2 - Ground	Class 3 - Low Vegetation	Class 4 - Medium Vegetation	Class 5 - High Vegetation	Class 6 - Buildings/Structures	Class 7 - Low/High Points	Class 8 - Model Key Points	Class 9- Water	Class 10 - Bridge	Class 12 - Flightline Overlap Points
2	0	1	1	1	1	1	1	0	1	1	1	1