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Global Change Master Directory (GCMD)
Amery Ice Shelf velocity time series from Landsat images
Entry ID: AAD_Ant_AIS_vel_series


Summary
Abstract: A time series of ice velocity values have been derived by analysis of LandSat-7 ETM+ images for the Lambert Glacier and Amery Ice Shelf system.

The analysis technique uses feature tracking in pairs of Landsat-7 ETM+ images. This process uses surface features that persist with time and move with the ice as tracers of the ice motion. The displacement of these features over the time interval between acquisition of the two images in a pair is determined by image correlation. The analysis is made at regular increments across and along the images, to produce a regular grid of values. The derived values are filtered and validated according to set of a prior constraints for the flow in a local region and the statistics of a set of velocity values within a window. The images have been projected onto a common reference system, and spliced together in order to produce a seamless set of velocity values.

Horizontal components of strain rate are derived from the velocity data using a set of derivative operators in a least-squares solution of an over-constrained set of equations, which uses all velocity values within a computation window. This procedure effectively produces a set of average velocity and strain rate values and accounts for much of the noise in the individual velocity observations. Values of the local longitudinal, transverse and shear strain rate components are derived by rotation of the cartesian values to the local flow direction. The procedure is described in Young and Hyland (2002).

This metadata record has been derived from work performed under the auspices of ASAC project 3067 (ASAC_3067).

Related URL
Link: View Related Information
Description: Download point for the data


Link: View Related Information
Description: Public information for ASAC project 3067


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

Geographic Coverage
 N: -73.0 S: -75.0  E: 70.0  W: 62.0

Data Set Citation
Dataset Creator: Young, N.W.
Dataset Title: Amery Ice Shelf velocity time series from Landsat images
Dataset Series Name: CAASM Metadata
Dataset Release Date: 2017-07-04
Dataset Publisher: Australian Antarctic Data Centre
Version: 1
Online Resource: https://data.aad.gov.au/metadata/records/AAD_Ant_AIS_vel_series


Temporal Coverage
Start Date: 1999-01-01
Stop Date: 2006-12-31


Location Keywords
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Data Resolution
Latitude Resolution: 25 Metre(s)
Longitude Resolution: 25 Metre(s)


Science Keywords
CRYOSPHERE >GLACIERS/ICE SHEETS    [Definition]
CRYOSPHERE >GLACIERS/ICE SHEETS >GLACIER MOTION/ICE SHEET MOTION    [Definition]


Platform
LANDSAT    [Information]
LANDSAT-7    [Information]
SATELLITES    [Information]


Instrument
ETM+ >Enhanced Thematic Mapper Plus    [Information]
TM >Thematic Mapper    [Information]


Quality
Position coordinates are accurate to better than +/- 50 m from nominal location accuracy of the satellite image products and be validation against Ground Control Points

Velocity components have an accuracy which varies between data sets. It is dependent on the accuracy of the feature displacement (typically +/- 8 m), registration accuracy of an image pair (typically around 20 m), and the time increment between image acquisitions (typically one or more years).


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=AAD_Ant_... when using these data.


Keywords
Amery Ice Shelf
Lambert Glacier
Ice Velocity
Landsat 7


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: 20 kb
Distribution_Format: NetCDF files
Fees: free


Personnel
NEAL W YOUNG
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Contact Address:
ACE CRC AND AUSTRALIAN ANTARCTIC DIVISION
Private Bag 80
City: Hobart
Province or State: Tasmania
Postal Code: 7001
Country: Australia


Extended Metadata Properties
(Click to view more)

Creation and Review Dates
DIF Creation Date: 2008-07-20
Last DIF Revision Date: 2019-04-02



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