Authors / CoAuthors
Unknown
Abstract
Airborne Laser Scanning contains ESRI shapefiles constructed from ground height data points. The heights were obtained from an airborne laser scanning survey conducted by AAM Surveys Pty Ltd. The shapefiles contain surface heights in metres for the eastern half of Christmas Island.
Product Type
dataset
eCat Id
81843
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
2003-01-01T00:00:00
Creation Date
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Purpose
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
In 2000 AAM surveys conducted an airborne laser scanner survey of the eastern portion of Christmas Island. AAM surveys divided the eastern part of the island into 36 2km x 2km grid squares. Geoscience Australia was provided with a set of ground heights in metres, and the GPS location in MGA (GDA94) units of each height, for each of the 36 grids. Geoscience Australia converted each height dataset into a text file and imported each file into Microsoft Access. This height dataset was then exported in dbf format, and imported into Arcview. The databases were then added as event themes into Arcview and converted into shapefiles corresponding to each of the 36 2km x 2km grid squares. Previous versions of CIGIS had produced DEM tiles based on a different grid tile system. The 36 shapefiles were adjusted to align with this previous tile system. This was done by merging shapefiles adjacent in the north-south direction and clipping them according to the extent of the previously used tile. In order to minimize areas of ocean or no data, shapefiles containing less than 30% land within the new 2km x 2km grid were merged with adjacent shapefiles, and then clipped to remove excess areas of ocean or no data. As a result, coastal shapefiles, and inland tiles located at the extent of the airborne laser scanner flight path deviate from the standard 2km x 2km grid tile size. The end result consisted of 27 shapefiles, 17 of which were 2km x 2km.
Parent Information
Extents
[-10.5667, -10.4167, 105.5333, 105.7167]
Reference System
Spatial Resolution
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