Authors / CoAuthors
Unknown
Abstract
The 2011 digital elevation model (DEM) grid covers the whole of the Christmas Island. It was provided by AAM in 1km by 1km ESRI grid tiles which were then joined together using ESRI ArcMap. Each grid cell (1m by 1m) contains the height in metres of the ground surface derived from the 2011 LiDAR aerial survey data.
Product Type
dataset
eCat Id
81820
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- DEM topographic
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- AU-ACT
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2012-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
In 2011 AAM was commissioned by the Commonwealth to fly an airborne laser scanning survey (LiDAR) of Christmas Island. The survey was carried out using a fixed wing aircraft between the 24th and 26th of August 2011. All data was captured within approximately 2 hours of low tide. During this period tides ranged from 0.5m to 1.2m (photo frame and tide height table). AAM classified the raw LiDAR points into the following classes using a single algorithm across the project area: 0 Unclassified - Created, never classified 1 Default - Unclassified 2 Ground - Bare ground 3 Low vegetation - 0  0.3m (essentially sensor noise) 4 Medium vegetation - 0.3  2m 5 High vegetation - 2m > 6 Buildings, structures - Buildings, houses, sheds, silos etc. 7 Low / high points - Spurious high/low point returns (unusable) 8 Model key points - Reserved for Â`model key points only 9 Water - Any point in water 10 Bridge - Any bridge or overpass 11 not used - Reserved for future definition 12 Overlap points - Flight line overlap points The raw LiDAR points in the .las format were provided to Geoscience Australia along with 1km ESRI grid tiles generated by interpolation from the points. The tiles were then joined to create a DEM (TIFF) that covers the full extent of Christmas Island. Each cell, 1m x 1m, in the grid contains the height in metres of the ground surface. As a guide, the DEM data is vertically accurate to 15cm and horizontally accurate to 30cm. For a detailed description of the survey accuracy see the AAM Survey Report. The DEM grid file was generated in GDA94 and has been converted by Geoscience to UTM WGS 84 zone 48s using ArcGIS to fit the rest of the CIGIS data. Vertical data was collected in the Christmas Island Height Datum (CIHD).
Parent Information
Extents
[-10.5667, -10.4167, 105.5333, 105.7167]
Reference System
GDA94 (EPSG:4283)
Spatial Resolution
Service Information
Associations
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