Cocos (Keeling) Islands GIS
Cocos Island 2011 Digital Elevation Model
Metadata
Dataset
Title Cocos Island 2011 Digital Elevation Model
Custodian Geoscience Australia
Jurisdiction Australia
Description
Abstract The digital elevation model (DEM) grid covers the whole of the Cocos (Keeling) Islands. It was provided by AAM in 1km by 1km tiles which were then joined together using ESRI ArcMap. Each grid cell (1m x 1m) contains the height, in metres, of the ground surface derived from the 2011 LiDAR aerial survey data.
Search Word(s) PHOTOGRAPHY AND IMAGERY Digital Elevation Model
PHOTOGRAPHY AND IMAGERY Raster
PHOTOGRAPHY AND IMAGERY Grid
Geographic Extent Name(s) Cocos (Keeling) Islands Edition 1 2010 1:25000 - Geoscience Australia GEOCAT 70146
Data Currency
Beginning Date 8 August 2011
Ending Date 16 August 2011
Dataset Status
Progress Complete
Maintenance and Update Frequency Not planned
Access
Stored Data Format DIGITAL - TIFF/ECW
Available Format Type DIGITAL - TIFF/ECW
Access Constraint None
Data Quality
Lineage In 2011 AAM was commissioned by the Commonwealth to fly an airborne laser scanning survey of Cocos (Keeling) Islands. The survey was carried out using a fixed wing aircraft between the 8th and 16th of August 2011. All data was captured within approximately 2 hours of low tide (photo frame and tide height table). During this period tides ranged from 0.4m to 1.3m.
AAM classified the raw LiDAR points into ground and non-ground points using a single algorithm across the project area. The raw LiDAR points in the .las format were provided to Geoscience Australia along with 1km by 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 the Cocos (Keeling) Islands. 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 to UTM WGS 84 zone 47s to fit the rest of the Cocos GIS data. Vertical data was collected in the Cocos Keeling Island Height Datum (CKIHD).
Positional Accuracy As a guide, the DEM data is vertically accurate to 15cm and horizontally accurate to 30cm. A control survey was carried out by Whelans. Manual checking and editing was carried out by AAM to improve accuracy. Positional accuracy has been checked by Geoscience Australia and was found to match the ground surface well.
Attribute Accuracy Not Relevant
Logical Consistency Not Relevant
Completeness Complete
Contact Information
Contact Organisation Geoscience Australia
Contact Position Keith Porritt
Mail Address Cnr Jerrabomberra Ave and Hindmarsh Drive
Locality SYMONSTON
State A.C.T
Country Australia
Postcode 2601
Telephone (02) 6249 9479
Facsimile (02) 6249 9971
Electronic Mail Address Keith.Porritt@ga.gov.au
Metadata Date 24-4-2012
Additional Metadata
Projection UTM (GDA94) zone 47s