Queensland LiDAR data (South East Queensland Project) - Ipswich City Council (LGA)  

Authors / CoAuthors

Grove, R.

Abstract

These datasets cover all of Ipswich City and are part of the 2009 South East Queensland LiDAR capture project. This project, undertaken by AAM Hatch Pty Ltd on behalf of the Queensland Government captured highly accurate elevation data using LiDAR technology. Available dataset formats (in 1 kilometre tiles) are: - Classified las (LiDAR Data Exchange Format where strikes are classified as ground, non-ground or building) - 1 metre Digital Elevation Model (DEM) in ASCII xyz - 1 metre Digital Elevation Model (DEM) in ESRI ASCII grid - 0.25 metre contours in ESRI Shape

Product Type

dataset

eCat Id

75941

Contact for the resource

Keywords

• Airborne Digital Data

• AU-QLD

Australian and New Zealand Standard Research Classification (ANZSRC)

• Surface Processes

• Published_Internal

Publication Date

2010-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Special, MOU, etc.

Access - restricted

Use - license

Status

Purpose

Maintenance Information

unknown

Topic Category

elevation

Series Information

Lineage

LI_Lineage: ACQUISITION Airborne Laser Scanning (ALS) data was acquired for the SEQ Area from a fixed wing aircraft. Acquisition over tidal areas was undertaken within +/- 2 hours of low tide. DATA PROCESSING Laser strikes were classified into ground and non-ground points using a single algorithm across the project area. Manual checking and editing of the data classification further improved the quality of the terrain model. FURTHER PROCESSING Thinned Ground: Thinned ground points have been derived by removing superfluous points not contributing to the definition of the ground surface. Buildings: Building points have been classified using an automatic algorithm tailored for the project area. No manual checking of building points has been undertaken. There may be occurences of non-ground strikes being incorrectly classified as buildings and conversely building strikes remaining classified as non-ground. Non-ground: Non-ground points have been filtered by removing points within 0.2m of the ground surface to reduce incidence surface 'noise'. Points classified as non-ground may include laser strikes on the surface of water bodies. Contours: Contours have been generated automatically from a smoothed triangulated ground model and visually checked for completeness and logical consistency. Some cartographic license has been applied in areas where laser points were not captured. Original contours supplied by the contractor have been generalised to reduce file size with no discernable difference in shape. The Point-Remove tool in ARCGIS from ESRI is used to perform this task. The maximum allowable offset in the simplification tolerance is set to 0.1 metre. DEM: An ArcGIS 9.2 Terain model was created from the LiDAR ground points and interpolated coastal boundaries, from which tiled ESRI grids and ASCII xyz files were generated. DATA PRESENTATION The data provided on this volume has been supplied in accordance with a specification agreed with the primary client. The data is delivered in 1 km tiles to ensure file sizes and point counts. per file are manageable. FILE SIZES AND NAMES Data is provided in tiles 1km by 1km to the following file naming convention: eg. 426000_6983000_1k_1m_DEM.xyz 426000 - coordinate easting of north west tile corner. 6983000 - coordinate northing of north west tile corner _1km - tile dimensions, eg 1km x 1km _1m_DEM - Digital Elevation model with 1m grid spacing _Cont - 0.25m contours .xyz - space delimited ASCII format .las - laser strikes -classified in accordance with ASPRS V1.1 LAS file standards- various point class levels. DEM_ESRI.asc - ESRI ASCII Grid format LAS format is a binary format and cannot be listed. LAS file point classifications levels are formatted to comply with ASPRS Standard LiDAR Point Classes. 2 Ground 6 Building 8 Model Key-point (mass point) 10 Non-ground

Parent Information

Extents

[0.0, 0.0, 0.0, 0.0]

Reference System

GDA94 / MGA zone 56 (EPSG:28356)

Spatial Resolution

Service Information

Associations

Downloads and Links

Source Information

These datasets cover all of Ipswich City and are part of the 2009 South East Queensland LiDAR capture project. This project, undertaken by AAM Hatch Pty Ltd on behalf of the Queensland Government captured highly accurate elevation data using LiDAR technology. Available dataset formats (in 1 kilometre tiles) are: - Classified las (LiDAR Data Exchange Format where strikes are classified as ground, non-ground or building) - 1 metre Digital Elevation Model (DEM) in ASCII xyz - 1 metre Digital Elevation Model (DEM) in ESRI ASCII grid - 0.25 metre contours in ESRI Shape