This data set includes airborne altimetry collected over the catchment and main trunk of Thwaites Glacier, one of Antarctica's most active ice streams.
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Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica, Version 1
Geographic Coverage
Spatial Coverage: |
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---|---|
Spatial Resolution: | Not Specified |
Temporal Coverage: |
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Temporal Resolution: | Not specified |
Parameter(s): |
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Platform(s) | AIRCRAFT, FIELD SURVEYS |
Sensor(s): | ALTIMETERS, GPS, INS |
Data Format(s): |
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Version: | V1 |
Data Contributor(s): | Duncan Young, Scott Kempf, Donald Blankenship, John Holt, David Morse |
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.
Young, D. A., S. D. Kempf, D. D. Blankenship, J. W. Holt, and D. L. Morse. 2008. Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5HD7SK8. [Date Accessed].Detailed Data Description
This data set includes airborne altimetry collected over the catchment and main trunk of Thwaites Glacier, one of Antarctica's most active ice streams. The airborne altimetry comprises 35,000 line-kilometers sampled at 20 meters along track. The full data set has an internal error of ±20 cm; a primary subset has an error of ±8 cm. We find a +20 cm bias with Geoscience Laser Altimeter System data over a flat interior region. These data will serve as an additional temporal reference for the evolution of Thwaites Glacier surface, as well as aid the construction of future high resolution Digital Elevation Models (DEM).
Space delimited ASCII with ten columns; 43 Mb after gzip compression.
Time(J2000 seconds)
Longitude
Latitude
ps71 meters eastings
ps71 northings
elevation (WGS-84)
Project
System
Transect
Quality Flag
Project indicates the project flown; most of these lines were THW; Unplanned transit flights fell under ASE1. System indicates the onboard acquisition system used; this is SJB0 for all of this data. Transect is the name of the flown line; normally all three terms are used to designate a flight line to maintain uniqueness among all seasons.
File name
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File Size
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Description
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---|---|---|
.dbase.gz |
43 MB | compressed file |
.txt |
161 MB | space-delimited ASCII |
161 MB ASCII
43 MB after gzip compression
Thwaites Glacier, Smith Glacier and Haynes Glacier, West Antarctica
Southernmost Latitude: 80 S
Northernmost Latitude: 75 S
Westernmost Longitude: 95 W
Easternmost Longitude: 130 W
Spatial Resolution
1 cm resolution in elevation, 20 meters along track
Collection period: 10 December 2004 through 29 January 2005 (Summer only)
Ice sheet elevation
Parameter Description
Ice sheet elevation via laser altimetry
Sample Data Record
Time(J2000 seconds)
|
Longitude
|
Latitude
|
ps71 meters eastings
|
ps71 northings
|
Elevation (WGS-84)
|
Project
|
System
|
Transect
|
Quality Flag
|
---|---|---|---|---|---|---|---|---|---|
157472167.727700
|
-124.793463
|
-76.072357
|
-1248629.329000
|
-867608.728800
|
2184.409372
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472168.020600
|
-124.793730
|
-76.072517
|
-1248610.745000
|
-867604.463600
|
2184.638830
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472168.312200
|
-124.794007
|
-76.072676
|
-1248592.173000
|
-867600.505700
|
2184.631137
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472168.603500
|
-124.794287
|
-76.072833
|
-1248573.759000
|
-867596.735300
|
2184.690533
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472168.892800
|
-124.794545
|
-76.072990
|
-1248555.635000
|
-867592.475200
|
2184.857183
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472169.181900
|
-124.794771
|
-76.073149
|
-1248537.813000
|
-867587.396600
|
2184.900682
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472169.471000
|
-124.795006
|
-76.073307
|
-1248519.964000
|
-867582.591300
|
2184.871665
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472169.761600
|
-124.795253
|
-76.073466
|
-1248501.800000
|
-867577.967100
|
2185.149318
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472170.052400
|
-124.795530
|
-76.073626
|
-1248483.190000
|
-867573.967300
|
2185.194623
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
157472170.341700
|
-124.795796
|
-76.073787
|
-1248464.514000
|
-867569.589200
|
2185.277740
|
THW
|
SJB0
|
X03a
|
PRIMARY
|
Software and Tools
The Quality Flag (either 'PRIMARY' or 'SECONDARY') indicates whether the root mean square (RMS) crossovers values of the data was low enough to allow it to influence other data during leveling, or whether it should attempt to level to other data.
Data Acquisition and Processing
A Riegl LD90-3HiP nadir pointing distance ranger, sampling at 3.5 Hz, was used to collect the range data; K&RS, a differential dual carrier phase method, and kinematic GIPSY, a single receiver dual carrier phase method, was used to reduce the GPS positioning at 2 Hz and 1 Hz respectively. Trimble 5700 and Ashtech Z-Surveyor receivers on both the aircraft and at the bases were used for GPS acquisition. A Litton 92 ring laser gyro inertial navigation system (INS) provided attitude data, with a quoted angular resolution of 0.05˚.
These data were collected on a DHC-8 Twin Otter flown out of camps in the Pine Island Glacier Catchment and on the Ross-Amundsen Sea Divide in 2004-05. Typical line spacing was 15 kilometers. The aircraft typical ground speed was 70 meters per second.
Error Sources
Data gaps are due to clouds, excessively rough terrain (i.e. crevasses, rock) and poor GPS solutions. Lines lacking at least three cross overs were dropped as quality assessment was difficult. These data have not been tide corrected.
References and Related Publications
Contacts and Acknowledgments
Investigator(s)
Duncan A.Young
University of Texas at Austin
Jackson School of Geosciences, Institute for Geophysics
J.J. Pickle Research Campus Bldg. 196
10100 Burnet Road (R2200)
Austin, TX 78758-4445 USA
Scott D. Kempf
University of Texas at Austin
Jackson School of Geosciences, Institute for Geophysics
J.J. Pickle Research Campus Bldg. 196
10100 Burnet Road (R2200)
Austin, TX 78758-4445 USA
Donald D. Blankenship
University of Texas at Austin
Jackson School of Geosciences, Institute for Geophysics
J.J. Pickle Research Campus Bldg. 196
10100 Burnet Road (R2200)
Austin, TX 78758-4445 USA
John W. Holt
University of Texas at Austin
Jackson School of Geosciences, Institute for Geophysics
J.J. Pickle Research Campus Bldg. 196
10100 Burnet Road (R2200)
Austin, TX 78758-4445 USA
David L. Morse
University of Texas at Austin
Jackson School of Geosciences, Institute for Geophysics
J.J. Pickle Research Campus Bldg. 196
10100 Burnet Road (R2200)
Austin, TX 78758-4445 USA
This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0230197 awarded to John Holt, Donald Blankenship and David Morse, OPP grant 0636724 awarded to Blankenship and Holt, the G. Unger Vetlesen Foundation and the Jackson School of Geosciences.
Document Information
Document Creation Date
March 2008
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