Southern Murray Darling Basin (SMDB) LiDAR Project 2001  

Authors / CoAuthors

Abstract

This suite of products contains topographical relief generated from raw LiDAR data and covers the Southern extent of the Murray Darling Basin within the proximity of the Murray River. LiDAR (Light Detection and Ranging) is an airborne remote sensing technique for rapid collection of terrain data. The sensor used for this LiDAR project collected XYZ and Intensity data for 2 returns, first and last (ground) return by bouncing a pulse from the aircraft to the surface that enables the height and intensity values to be calculated. Height data within the first and last return raw LiDAR data was processed into 1m pixel DEMs. The intensity data with the first return raw LiDAR data was processed into a 1m pixel intensity image. The 1m cell size products, due to their large file sizes, are stored as 2km by 2km tiles to help facilitate data management and processing. The complete study area, covering 1.7million hectares, contains 5,288 of these tiles. All the above derived products were initially created as value added products by the Land Information Group (LIG), of the Department of Sustainability and Environment (DSE), Victoria. This acquisition was commissioned by Murray Darling Basin Commission (MDBC) and participating Consortium members including: Barmah Millewa Forum Murray Irrigation Limited, NSW Department of Infrastructure, Planning and Natural Resources - Deniliquin North Central Catchment Management Authority (CMA) Department of Urban Affairs and Planning, NSW Goulburn Broken CMA, Vic North East CMA, Vic

Product Type

dataset

eCat Id

81943

Contact for the resource

Keywords

• Airborne Digital Data

• NSWVIC

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_Internal

Publication Date

2014-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Special, MOU, etc.

Access - restricted

Use - license

Status

Purpose

Maintenance Information

asNeeded

Topic Category

elevation

Series Information

Lineage

The 1m, 10m, first and last return products have all been derived from raw LiDAR data (XYZ Intensity ASCII's) collected by the Southern Murray Darling Basin Commission. (see metadata for Southern Murray Darling Basin LiDAR Project Raw Data for more information). The DEM and intensity products have been created by converting the ASCII files to a point coverage. A TIN is then generated from the points and converted to a DEM. Due to the size and quantity of data being processed a 2km x 2km tile index system was used to process all data (first and last return) for both the 1m and 10m pixel products. The DEM products have been created with a 1m pixel in the first instance, then the raw data reprocessed to create 10m pixel DEMs. Positional Accuracy Within 0.5m Horizontal Attribute Accuracy N/A Vertical Accuracy Project specifications: 0.15m - Deductive estimate from aerial surveys with 0.11 - 0.16m vertical accuracy at 68% confidence level. A thorough accuracy assessment project was undertaken to test the accuracy against known heights (feature survey) at 5 selected study sites based on the National Standards for Spatial Data Accuracy methodology The results are summarised below. Tested accuracy of SMDB LiDAR Project for 1m DEM is: 0.1688m at the 68% confidence level (1sigma) 0.3308m at the 95% confidence level (2sigma) Logical Consistency The consistency of the DEMs is mainly conditioned by the consistency of the input data set (raw LiDAR data). Errors within the raw data will have an impact on the resultant DEM. Consistency during processing for 1m and 10m DEMs and Intensity, included ensuring that there was sufficient buffering to minimise 'edge effects' between 2km x 2km tiles when they are mosaiced to create a seamless terrain model. Completeness 1m and 10m DEMs have been created for the whole Southern Murray Darling Basin study area, though owing to errors during the data capture process, there are sections of some 2km x 2km tiles where the DEM generation has not been entirely successful in terms of creating continuous terrain. Errors such as swathe overlaps (possibly due to calibration errors between flight paths), missing data (insufficient pulses returning to the recording device or errors during data capture) and 'waves' (possibly owing to turbulence) cause visible artefacts in the terrain model. These errors can only be rectified through future LiDAR data capture flights over the study area. NEDF Metadata Acquisition Start Date: Sunday, 7 February 2010 Acquisition End Date: Sunday, 7 February 2010 Sensor: LiDAR Device Name: N/A Flying Height (AGL): 2000 INS/IMU Used: Unknown Number of Runs: UNK Number of Cross Runs: UNK Swath Width: UNK Flight Direction: UNK Swath (side) Overlap: UNK Horizontal Datum: GDA94 Vertical Datum: AHD71 - AusGeoid98 Map Projection: MGA55 Description of Aerotriangulation Process Used: N/A Description of Rectification Process Used: N/A Spatial Accuracy Horizontal: 0.5 Spatial Accuracy Vertical: 0.168 Average Point Spacing (per/sqm): 0.1 Laser Return Types: Unknown Data Thinning: 0 Laser Footprint Size: 0 Calibration certification (Manufacturer/Cert. Company): N/A Limitations of the Data: N/A Surface Type: Mixed Product Type: Mass Points Classification Type: C1 Grid Resolution: 1 Distribution Format: LAS Processing/Derivation Lineage: The 1m, 10m, first and last return products have all been derived from raw LiDAR data WMS: N/A?

Parent Information

Extents

[-36.350012, -19.732842, 142.703161, 147.515415]

Reference System

GDA94 / MGA zone 55 (EPSG:28355)

Spatial Resolution

Service Information

Associations

Downloads and Links

Source Information

This suite of products contains topographical relief generated from raw LiDAR data and covers the Southern extent of the Murray Darling Basin within the proximity of the Murray River. LiDAR (Light Detection and Ranging) is an airborne remote sensing technique for rapid collection of terrain data. The sensor used for this LiDAR project collected XYZ and Intensity data for 2 returns, first and last (ground) return by bouncing a pulse from the aircraft to the surface that enables the height and intensity values to be calculated. Height data within the first and last return raw LiDAR data was processed into 1m pixel DEMs. The intensity data with the first return raw LiDAR data was processed into a 1m pixel intensity image. The 1m cell size products, due to their large file sizes, are stored as 2km by 2km tiles to help facilitate data management and processing. The complete study area, covering 1.7million hectares, contains 5,288 of these tiles. All the above derived products were initially created as value added products by the Land Information Group (LIG), of the Department of Sustainability and Environment (DSE), Victoria. This acquisition was commissioned by Murray Darling Basin Commission (MDBC) and participating Consortium members including: Barmah Millewa Forum Murray Irrigation Limited, NSW Department of Infrastructure, Planning and Natural Resources ¿ Deniliquin North Central Catchment Management Authority (CMA) Department of Urban Affairs and Planning, NSW Goulburn Broken CMA, Vic North East CMA, Vic