Queensland LiDAR data (Inland Towns Stage 2 Project) - Townsville City Council (LGA)  

Authors / CoAuthors

Abstract

These datasets cover approximately 384 sq km over the Towns of Woodstock - Majors Creek in Townsville City and are part of the 2011 Inland Towns Stage 2 LiDAR capture project. This section of the project, undertaken by Fugro Spatial Solutions 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 AHD datum (LiDAR Data Exchange Format where strikes are classified as ground, non-ground or building) - Classified las Ellipsoidal datum (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 - 1 metre Digital Elevation Model (DEM) in ESRI Binary grid - 0.25 metre contours in ESRI Shape

Product Type

dataset

eCat Id

78329

Contact for the resource

Keywords

• Airborne Digital Data

• QLD

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_Internal

Publication Date

2011-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Restrictive GA Licence (please provide TRIM link)

Access - restricted

Use - license

Status

Purpose

Maintenance Information

asNeeded

Topic Category

elevation

Series Information

Lineage

LI_Lineage: ACQUISITION Airborne Laser Scanning (ALS) data was acquired from a fixed wing aircraft over the Towns of Woodstock - Majors Creek between the 10 May 2011 and the 12 may 2011. DATA PROCESSING Fugro Spatial Solutions Pty Ltd aim is to select those points that are part of a clean ground surface, which might not be 100% of the ground hits. This results in a cleaner dataset, without compromising on terrain detail and accuracy. Ground filtering algorithms, tailored for this project, data type and terrain type, are applied to the full dataset. The ground filtered dataset is then visually checked by an operator, and incorrectly classified data is corrected or the ground filtering algorithm is adjusted and then visually checked. For the verification of the ground classifications, intensity imagery is used as a backdrop image. Classified Point Cloud with automatically classified buildings: The full LiDAR point cloud, consisting of ground, automatically classified buildings and vegetation and the rest of the point cloud in LAS file format. Bare_Earth_DEM_1m: A 1m DEM has been generated from the LiDAR ground surface. The method of deriving the height for each grid point is by triangulation between the three nearest LiDAR ground points. Contours: From the model keypoints, triangles are built. At 0.25m intervals in height, points or interpolated points on triangle edges with that same height are being connected using slightly smoothed curved lines. The lines for each height interval are then merged to become the final contours. Note: Returns on water have not been removed from the (classified) point clouds. Gridded datasets have been interpolated across voids (up to 500m in diameter) caused by either no-return due to water bodies, or removal of buildings, vegetation or other above ground features. Contour datasets are interpolated across voids, and contours across waterbodies have not been removed/clipped. All data has been cut into 1km tiles, where the file name prefix corresponds with the Upper Left coordinate of the 1km block. DATA PRESENTATION The data 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. NW_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 - 25 cm 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 SOURCE DATA Acquisition Start Date: 10/05/2011 Acquisition End Date: 12/05/2011 Number of Runs: 37 Flight Direction: Non-Cardinal LASER SYSTEM CHARACTERISTICS Item: Laser System Device Name: Leica ALS50-2 Sensor/Lens serial ID: SN031 IMU Used: IPAS-TC Flying Height: 1400m Side Overlap: 20% Swath Width: 990m Laser return: All returns Laser mode: Multipulse LASER DATA CHARACTERISTICS Characteristic: Description Format: space delimited ASCII, LAS Average Point Specification: 1.09 point/m2 Laser footprint size: 0.32m REFERENCE SYSTEMS Horizontal: Datum: GDA94 Projection: MGA Zone 55 Vertical: Datum: AHD71 Geoid Model: Ausgeoid09_v1.01

Parent Information

Extents

[-19.769595, -19.435357, 146.780443, 147.019052]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

Source Information

To provide highly accurate elevation data for use in risk assessment, the management of natural disasters, infrastructure planning, developing strategies to support climate change, topographic mapping and modelling.