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Global Change Master Directory (GCMD)
Heard Island - Ground Control Point Identification on 4 satellite images
Entry ID: heard_satimage_control


Summary
Abstract: Ground control points were captured in the field as described in the metadata record "Global change, biodiversity and conservation in terrestrial and coastal ecosystems on Heard and McDonald Islands [ASAC_1181]". The aim of this project was to identify the control points on various satellite images (AADC Image IDs 253, 267, 446 and 447) to determine image coordinates for the control points. These would then allow the satellite image to be adjusted to the ground control. There is a shapefile for each image with the features in the shapefile moved to the corresponding image location. Attributes in the shapefile include image coordinates (UTM43) and control point coordinates.

Related URL
Link: View Related Information
Description: Download point for the dastaset - shapefiles and readme


Link: View Related Information
Description: Citation reference for this metadata record and dataset

Parent DIF
This description is a member of a collection. The collection is described in
ASAC_1181


Geographic Coverage
 N: -52.95 S: -53.05  E: 73.41  W: 73.23

Data Set Citation
Dataset Creator: Brolsma, H.
Dataset Title: Heard Island - Ground Control Point Identification on 4 satellite images
Dataset Series Name: CAASM Metadata
Dataset Release Date: 2009-05-22
Dataset Publisher: Australian Antarctic Data Centre
Version: 1
Online Resource: https://data.aad.gov.au/metadata/records/heard_satimage_control


Temporal Coverage
Start Date: 2003-01-17
Stop Date: 2005-02-09


Location Keywords
OCEAN > SOUTHERN OCEAN
GEOGRAPHIC REGION > POLAR
OCEAN > SOUTHERN OCEAN > HEARD AND MCDONALD ISLANDS


Data Resolution
Latitude Resolution: 1 Metre(s)
Longitude Resolution: 1 Metre(s)


Science Keywords
BIOSPHERE >VEGETATION >FOREST COMPOSITION/VEGETATION STRUCTURE    [Definition]
BIOSPHERE >VEGETATION    [Definition]
HUMAN DIMENSIONS >BOUNDARIES >BOUNDARY SURVEYS    [Definition]
SPECTRAL/ENGINEERING >VISIBLE WAVELENGTHS >VISIBLE IMAGERY    [Definition]


Platform
SATELLITES    [Information]


Instrument
GPS >Global Positioning System    [Information]
GPS RECEIVERS    [Information]


Quality
Ground control points were captured in the field by Dr Jenny Scott using differential GPS as described in
"Global change, biodiversity and conservation in terrestrial and coastal ecosystems on Heard and McDonald Islands [ASAC_1181]".

David Smith of the AAD Data Centre provided a shapefile called control_pts_UTM43 which had been exported from the differentially corrected GPS data.

Two fields were added to the attribute table - UTM43_X and UTM43_Y, these were populated with the X and Y coordinates of the points in the UTM zone 43S projection of the shapefile.
One copy of the shapefile was created for each image set:
Control2005_07 shapefile was adjusted to AADC Image ID 446
Control2005_09 shapefile was adjusted to AADC Image ID 447
Control2004 shapefile was adjusted to AADC Image IDs 266 and 267
Control2003 shapefile was adjusted to AADC Image ID 253

The control points were identified on various satellite images (AADC Image IDs 253, 267, 446 and 447).
Points were initially moved on the 2003 image, as this had been used in the field and the points marked on a 1:5000 hardcopy.
The Description field in the attribute table, plus memory of the point's location in the field, plus the hardcopy, were relied on for accurate point location.
The fact that Dr Scott did both the work plus the fieldwork was an important factor in achieving maximum accuracy.
The most convenient working scale for positioning the points was 1:1900 (anything larger became too pixelated), with a larger scale used occasionally to check actual distance measurements.

Fields added to the attribute tables of the four new shapefiles:

'Moved' field (integer)

0 Point not moved
1 Point moved

'Comments' field (text)

Moved.
Not moved, obscured by cloud.
Not moved, not on image.

'Confidence' field (integer)

0 Point not moved
1 Point moved. Moderate accuracy due to deep shadow, haze, variations between images, or difficulty in pinpointing exact location (accuracy probably within 2-3 m).
2 Point moved. Greatest accuracy (probably within 1-2 m or less).

Image_No field
The AADC image number from which the control point was identified

Platform field
The satellite platform used to capture the image

Capt_date field
The date the image was captured

Image_X field
The X coordinate of the moved control point feature in the corresponding image coordinate system

Image_Y field
The Y coordinate of the moved control point feature in the corresponding image coordinate system

UTM43_X field
The original X coordinate of the control point before it was moved

UTM43_Y field
The original Y coordinate of the control point before it was moved


Access Constraints
These data are publicly available for download from the provided URL.


Use Constraints
This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=heard_sa... when using these data.


Keywords
Ground Control
Satellites


Data Set Progress
COMPLETE


Originating Center
Australian Antarctic Division


Data Center
Australian Antarctic Data Centre, Australia    [Information]
Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: metadata at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia



Distribution
Distribution_Media: HTTP
Distribution_Size: 585 kb
Distribution_Format: shapefiules, pdf, text
Fees: free


Personnel
HENK BROLSMA
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


Extended Metadata Properties
(Click to view more)

Creation and Review Dates
DIF Creation Date: 2009-05-22
Last DIF Revision Date: 2019-04-08



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