Contacts

 

Identifiers and Keywords

ANZLIC Id

ANZVI0008101194 

Topic category

• Elevation

 

Resource Constraints

Use limitation

General 

Classification

Unclassified  

 

Other Dataset Details

Format

LAS 1.3, Waveform Packets 

 

Spatial

Spatial representation type

Point Cloud  

Reference system identifier

MGA Zone 54 GDA94

 

Resolution

Horizontal Accuracy

0.3m  

Vertical Accuracy

0.1m  

 

Quality

Conceptual Consistency

Accuracy of the ground surface under dense canopy may be reduced due to diminished returns. Laser accuracy at swath edges may be reduced. Classification algorithms have been tailored for common terrain/vegetation combinations across the project area. Classification accuracy and ground definition may be less accurate in uncommon or mixed terrain/vegetation/land use combinations. The Riegl Q1560 LiDAR sensor is an extremely sensitive system and also contains a unique functionality with ¿multi-time-around¿ technology. The combination of these two factors increases the number of high/low outliers compared to other LiDAR sensors. 

Missing Data

Gaps may occur due to the multi-time-around technology of the Reigl Q1560 LiDAR Sensor, or from diminished returns over water, under canopy and on materials with low laser reflectivity, such as black roofing, swimming pools. 

 

Lineage

Description

LiDAR was acquired over the project area. An instrument calibration issue was encountered with the LiDAR system during initial pre-processing. The issue was caused by an internal calibration error between channel 1 and channel 2. It manifested itself by producing a fluctuating, vertical, misalignment between both channels in the range of 0.05 - 0.20m (relative accuracy). It was resolved by an internal calibration correction (provided by sensor manufacturer) being applied to all flights of LiDAR data in this project. The acquired LiDAR strikes were transformed into an ellipsoid point cloud using a solution obtained from the onboard IMU and GPS and Victorian CORS network. The point cloud was then adjusted to AHD using AusGeoid09. Checks against an network of surveyed ground control resulted in further general and local adjustments where required. Reduction of the LiDAR data proceeded without any significant problems. Laser returns were classified into ground and non ground classes using a single algorithm tailored to the project before further automatic classification was performed to differentiate non ground features into their respective classes. Following this, manual checking and editing was undertaken to improve the classification of the ground class. 

 

Acquisition Date

Begin date

2016-01-09 

End date

2016-01-10 

 

Instrument

Name

Riegl Q1560 

Type

LIDAR 

Platform Type

Aerial 

 

Acquisition Data (Common)

Status

complete  

Assembly

Single  

Tile Size

2 km  

 

Point Cloud Details

Pulse Mode

Multi Pulse 

Scan Rate (Hz)

102Hz  

Scan Frequency (kHz)

400kHz  

Scan Angle (degrees)

60degrees  

Footprint Size (m)

0.25m  

Point Density Actual (pts/m2)

4points/m2  

Point Spacing Actual (pts/m)

0.5points/m2  

Ellipsoid Provided

1 

Ellipsoid Vertical Datum

GRS80 Ellipsoidal (ITRF2005)  

Ellipsoid Format

LAS 1.2  

Geoid Vertical Datum

AUSGEOID09  

Additional Adjustments

Ground data in this volume has been compared to 364 test points obtained by field survey and assumed to be error-free. The test points were distributed in 4 groups across the mapping area and located on open clear ground. Comparison of the field test points with elevations interpolated from measured data resulted in the mean difference for Horsham (-0.918m) being removed from the data. 

Class Level

2 

Classification Accuracy

98 

Classification

Class Level	Classification Accuracy	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	98	1	1	1	1	1	1	1	1	1	1	1	0

 

Aerial Survey Details

Runs

10 

Run Orientation

N-S  

Swath Width

1480 

Side Overlap

33 

Forward Overlap

60 

Flying Height Unit

agl metre  

Flight Height

1400 

 

About the Metadata Record

Metadata identifier

302e50db-1644-5c82-8c36-3f155641fce7

Resource Type

Dataset  

Date info ( Revision )

2023-03-22T00:22:23

Standard Name

ISO 19115-3:2018 

Profile Name

DELWP Profile 

Profile Version

Version 1 

Profile Date

2019-05-24  

 

Metadata Constraints

Classification

Unclassified