The data contain the time series totals of SAR derived detrended surface velocities from Livingston Island, as well as GeoTiff files generated from intensity tracking of Synthetic Aperture Radar (SAR) imagery. The images include average annual velocity and ice thickness of King George Island, and average annual velocity, ice thickness, and a digital elevation model of Livingston Island.
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King George and Livingston Islands: Velocities and Digital Elevation Model, Version 1
Geographic Coverage
Spatial Coverage: |
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Spatial Resolution: |
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Temporal Coverage: |
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Temporal Resolution: | Not specified |
Parameter(s): |
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Platform(s) | ALOS |
Sensor(s): | PALSAR |
Data Format(s): |
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Version: | V1 |
Data Contributor(s): | Batuhan Osmanoglu, Regine Hock |
Metadata XML: | View Metadata Record |
Data Citation
As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.
Osmanoglu, B. and R. Hock. 2016. King George and Livingston Islands: Velocities and Digital Elevation Model, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5R49NR1. [Date Accessed].Detailed Data Description
The data contain the time series totals of SAR derived detrended surface velocities from Livingston Island, as well as GeoTiff files generated from intensity tracking of Synthetic Aperture Radar (SAR) imagery. The images include average annual velocity and ice thickness of King George Island, and average annual velocity, ice thickness, and a digital elevation model of Livingston Island.
The data are in Microsoft Excel (.xls) and GeoTiff (.tif) formats.
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0667_hock directory. Within this directory, there are six files. See Table 1 for file names and descriptions.
File Name | Description |
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King_George_Island_average_annual_velocity.tif | Mean surface ice velocity (m/yr) of the ice cap on King George Island, Antarctica, over the period January 2008 to January 2011. Refer to Osmanoglu, et al. (2013) Figure 5a. |
King_George_Island_ice_thickness.tif | Ice thickness (m/yr) of the ice cap on King George Island, Antarctica, calculated as a function of surface velocity according to Rignot et al. (1996). Refer to Osmanoglu, et al. (2013) Figure 5b. |
Livingston_average_annual_velocity.tif | Mean surface ice velocity (m/yr) of the ice cap on Livingston Island, Antarctica, over the period October 2007 to March 2011. Refer to Osmanoglu, et al. (2014) Figure 6a. |
Livingston_ice_thickness.tif | Ice thickness (m/yr) of the ice cap on Livingston Island, Antarctica, calculated as a function surface velocity according to Rignot et al. (1996). Refer to Osmanoglu, et al. (2014) Figure 6b. |
Livingston_combined_dem.tif | Digital elevation model (m asl) of the ice cap on Livingston Island, Antarctica, derived from merging elevation data derived from various sources. Refer to Osmanoglu, et al. (2014) Figure 3. |
Livingston_velocity_timeseries_at_flux_gates.xls | This file contains SAR derived detrended surface velocities (m/yr) and estimated errors averaged over each flux gate of 24 individual tidewater glaciers draining the Livingston Island ice cap. Data are available for 24 periods from October 2007 to January 2011. The file contains 24 data sheets, one for each flux gate in the order of the flux gate numbers given in Osmanoglu et al. (2014). See Figure 1 for a map of the flux gates. Refer to Figure 2 for graphs of the 24 velocities (Figure 7 in Osmanoglu et al. 2014). |
Column | Description |
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Date 1 (MM/DD/YY) | First satellite image acquisition date |
Date 2 (MM/DD/YY) | Second satellite image acquisition date |
Mean velocity (m/yr) | Derived through feature tracking the two SAR images |
Velocity error (m/yr) | Errors in derived surface velocities from feature tracking of PALSAR-1 images |


The size of the .tif files range from 6.6 MB to 11 MB. The Excel file is 98 KB.
Volume of the data set is approximately 47 MB.
Livingston Island's coordinates are 62.75° S and 61.0° W. King George Island is located at 61.75° S and 57.5° W.
Spatial Resolution
The data for Livingston Island have a spatial resolution of 10 m grid spacing, and King George Island's spatial resolution is 50 m.
Data were acquired from 20 October 2007 through 18 March 2012.
The data's parameters are ice sheeet elevation, ice thickness, and ice velocity.
Software and Tools
To view the .tif files, use any GeoTiff viewer software or double-click on the file from the ftp directory. For the .xls file, use Microsoft Excel.
Data Acquisition and Processing
Data Acquisition
Synthetic aperture radar (SAR) data were used to derive surface ice velocities and to compile a new DEM for the Livingston Island ice cap. Data from two sources were included: (1) time series from the PALSAR-1 imaging system on board the Japanese Advanced Land Observing Satellite (ALOS-1) satellite (Rosenqvist et al., 2007) and (2) a bistatic image pair from the TerraSAR-X and TanDEM-X satellite mission (Krieger et al., 2007; Mittermayer et al., 2008).
PALSAR-1 provides L-band (1270 MHz) signals and was operational during 2006–2011. We used two parallel tracks (124 and 125) covering the entire ice cap, which provided a total of 25 images between October 2007 and March 2011. All images were collected in fine-beam single polarization mode. The bistatic TanDEM-X pair was acquired by TerraSAR-X and TanDEM-X satellites simultaneously, generating high quality interferometric data by removing the effects of temporal decorrelation.
Processing Steps
For the velocity data, GAMMA software was used to focus the ALOS PALSAR L1.0 data. An intensity tracking method within the GAMMA software obtained azimuth and range surface velocity estimates per pair to further process the scenes. Later, these data were combined and filtered to reduce noise and improve measurement accuracy. See Osmanoglu, et al. (2013) and Osmanoglue et al.(2014) for further detailed descriptions.
Error Sources
In the .tif files, there are data gaps in some regions.
On board Japan's Advanced Land Observing Satellite (ALOS) satellite, the PALSAR instrument provides enhanced sensor characteristics, including full polarimetry, variable off-nadir viewing, and ScanSAR operations, as well as significantly improved radiometric and geometric performance.
The TanDEM-X (TerraSAR-X add-on for digital elevation measurements) is a spaceborne radar interferometer that is based on two TerraSAR-X radar satellites flying in close formation. The primary objective of the TanDEM-X mission is the generation of a consistent global digital elevation model (DEM).
References and Related Publications
Contacts and Acknowledgments
Dr. Batuhan Osmanoglu
Universities Space Research Association
NASA/GSFC
Mail code 618
Greenbelt, MD 20771 USA
Dr. Regine Hock
Geophysical Institute
University of Alaska
903 Koyukuk Dr.
Fairbanks, AK99775-7320 USA
This research was supported by NSF Division of Polar Programs (PLR) Grant Numbers 1043649.
Document Information
DOCUMENT CREATION DATE
08 February 2016
DOCUMENT REVISION DATE
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