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MEaSUREs Greenland Ice Velocity: Selected Glacier Site Velocity Maps from InSAR

Summary

This data set is part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program. This data set provides maps of glacier outlet areas, some of which have shown profound velocity changes over the MEaSUREs observation period from 2000 to 2011. The data are provided in addition to the ice-sheet-wide data from the related data set, MEaSUREs Greenland Ice Sheet Velocity Map from InSAR Data (NSIDC-0478). The InSAR Selected Glacier Site Velocity Maps are produced from TerraSAR-X (TSX) image pairs collected from January through November 2009, January through December 2010, and January through November 2011.

Data are available via FTP, in 4-byte Institute of Electrical and Electronics Engineers (IEEE) floating point format.

Note: These data are considered provisional pending a review by the MEaSUREs program. Once the data have been reviewed, this statement will be removed from this documentation.

Citing These Data

Literature Citation

The generation of this data set and its scientific interpretation are discussed in the following citation. Please acknowledge the use of this data set by referencing the following citation:

Joughin, I, B. E. Smith, I. M. Howat, T. Scambos, T. Moon. 2010. Greenland Flow Variability from Ice-Sheet-Wide Velocity Mapping. Journal of Glaciology, 56 (197), pp. 415-430. doi:10.3189/002214310792447734.

Data Citation

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

Joughin, I., I. Howat, B. Smith, T. Scambos. 2011. MEaSUREs Greenland Ice Velocity: Selected Glacier Site Velocity Maps from InSAR. Boulder, Colorado, USA: NASA DAAC at the National Snow and Ice Data Center. doi:10.5067/MEASURES/CRYOSPHERE/nsidc-0481.001.

Overview Table

Category Description
Data format 4-byte big-endian Institute of Electrical and Electronics Engineers (IEEE) floating point format
Spatial coverage and resolution The data set contains data for most of the outlet glaciers for the Greenland Ice Sheet. It is organized into 69 study sites.

Southernmost Latitude: 60° N
Northernmost Latitude: 82° N
Westernmost Longitude: 20° W
Easternmost Longitude: 70° W
Temporal coverage and resolution January through November 2009, January through December 2010, and January through November 2011
File naming convention

TSX_E68.80N_26Apr009_07May09.vx
TSX_E68.80N_26Apr009_07May09.vx.geodat

File size File size ranges from 178 bytes to 1.5 MB.
Parameters Glacier surface velocity and measurement errors in meters per year
Procedures for obtaining data Data are available via FTP.

Table of Contents

  1. Contacts and Acknowledgments
  2. Detailed Data Description
  3. Data Access and Tools
  4. Data Acquisition and Processing
  5. References and Related Publications
  6. Document Information

1. Contacts and Acknowledgments

Investigators

Dr. Ian Joughin
University of Washington
Applied Physics Laboratory
1013 NE 40th Street
Box 355640
Seattle, Washington 98105
USA

Dr. Ian Howat
Ohio State University
Byrd Polar Research Center
Scott Hall Room 108
1090 Carmack Road
Columbus, Ohio 43210
USA

Dr. Ben Smith
University of Washington
Polar Science Center Applied Physics Laboratory
University of Washington
Department of Earth and Space Sciences
Seattle, Washington 98195
USA

Dr. Ted Scambos
University of Colorado
Cooperative Institute for Research in Environmental Science
National Snow and Ice Data Center
CIRES, 449 UCB
Boulder, Colorado 80309
USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Acknowledgements

These data were generated through a grant from the NASA MEaSUREs program.

2. Detailed Data Description

Format

Raw Data

Data files are in 4-byte big-endian IEEE floating point format with the same byte ordering used by non-Intel Macs and most workstations, not the standard PC byte order. No-data values are represented by -2.0e9. This may require that the user replace these values before applying analysis tools. There are separate files for velocity x (vx) and velocity y (vy) components. There are also accompanying pseudo-error estimates. Refer to the Error Estimates section, below. Accompanying geodat files provide grid descriptions corresponding to each velocity data file. Table 1 describes the file types.

Table 1. File Description
Filename Description
TSX_E62.70N_23Apr09_04May09.vx
TSX_E62.70N_23Apr09_04May09.vy
Velocity products in 4-byte IEEE floating point format
TSX_E62.70N_23Apr09_04May09.vx.geodat
TSX_E62.70N_23Apr09_04May09.vy.geodat
Grid description files in .geodat format
TSX_E62.70N_23Apr09_04May09.ex
TSX_E62.70N_23Apr09_04May09.ey
Error values (1 sigma standard deviation)
TSX_E62.70N_23Apr09_04May09.meta Metadata file in ASCII text format

 

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/nsidc0481_MEASURES_greenland_V01/ directory. This directory is divided into subdirectories based on the grid location, and then based on the type of data (TSX), and date of acquisition. Grid names and locations are provided under Spatial Coverage below.

File Naming Convention

Files are named according to the following convention and as described in Table 2:

Source_grid_startdate_enddate.xx

Where:

Table 2. File Naming Convention
Variable Description
Source Data Source
  • TSX: TerraSAR-X
grid

Grid is defined by the following:

  • E, W, or S: East, West, or South Coast
  • Latitude in degrees, minutes
startdate Beginning date of data collection (DDMMMYY)
enddate End date of data collection (DDMMMYY)
xx File extension
  • vx: velocity x values
  • vy: velocity y values
  • ex: error x values
  • ey: error y values
  • geodat: file extension for location data files

Example: TSX_E61.70N_23Apr09_04May09.vx is the displacement vector in X for the glacier on the East Coast of Greenland at 61.70°N, based on TerraSAR-X measurements from 23 April 2009 to 4 May 2009.

File Size

File size ranges from 178 bytes to 1.5 MB.

Spatial Coverage

Table 3 details the grid name and locations, glaciers included in the grid, and dates for the available TSX data. The spatial coverage map below shows the locations of all the grids on a map of Greenland. Data are not available for all grids shown on the map.

 

Table 3. Site Locations and Data Availability
Grid Name
(Center Latitude)
Lower Left Coordinate
(Lat °N - Lon °W)
Glaciers Included in Grid
2009 TSX Data
Available for Download
2010 TSX Data
Available for Download
2011 TSX Data
Available for Download
E61.70N 61.3903 - 43.7671
  • Anoritup Kangerdlua
  • Nappassorssuaq
February
July
September
November
April/May
July
August/September
November
Apr-30-2011 to May-11-2011
Aug-29-2011 to Sep-20-2011
Jul-05-2011 to Jul-27-2011
Nov-14-2011 to Nov-25-2011
E62.10N 61.801 - 43.2149
  • Puisortuq North
  • Puisortuq South
N/A N/A Mar-12-2011 to Mar-23-2011
E62.55N 62.2422 - 43.6371
  • Mogens
  • Tingmjarmiut
February
April/May
July
August
September
November
February
May
July
September
November
Apr-20-2011 to May-01-2011
Aug-30-2011 to Sep-21-2011
Feb-13-2011 to Feb-24-2011
Jul-06-2011 to Jul-17-2011
Nov-26-2011 to Dec-07-2011
E63.00N 62.7212 - 43.5332
  • Heimdal
February
April/May
July
August
September
November
February
April/May
July
September
November
Apr-20-2011 to May-01-2011
Aug-30-2011 to Sep-21-2011
Feb-02-2011 to Feb-13-2011
Jul-06-2011 to Jul-17-2011
Nov-15-2011 to Nov-26-2011
E63.35N 63.0911 - 42.5656
  • Thrym
  • Sehested
  • Skinefaxe
February
April/May
July
August
September
November
January/February
April/May
July
September
November
Apr-26-2011 to May-07-2011
Aug-03-2011 to Aug-25-2011
Feb-08-2011 to Feb-19-2011
Jul-12-2011 to Aug-03-2011
Nov-21-2011 to Dec-02-2011
E63.85N 63.5620 - 42.4419
  • Bernstorf
February
April/May
July
August
September
November
February
April/May
July
September
November
Apr-20-2011 to May-01-2011
Aug-30-2011 to Sep-21-2011
Feb-02-2011 to Feb-13-2011
Jul-06-2011 to Jul-17-2011
Nov-15-2011 to Nov-26-2011
E64.35N 64.0768 - 42.2688
  • Gyldenslove
January/February
April/May
July
August
September
November
January/February
April/May
July
August/September
November/December
Apr-25-2011 to May-06-2011
Aug-24-2011 to Sep-15-2011
Jul-11-2011 to Jul-22-2011
Jul-22-2011 to Aug-24-2011
Nov-20-2011 to Dec-01-2011
E64.65N 64.3291 - 41.7539
  • Fridtjof
N/A N/A Mar-08-2011 to Mar-19-2011
E65.10N 64.7987 - 41.8569
  • Koge Bugt
January/February
April/May
July
August
September
November
February
April/May
July
September
November
Apr-20-2011 to May-01-2011
Aug-30-2011 to Sep-10-2011
Feb-13-2011 to Feb-24-2011
Jul-06-2011 to Jul-17-2011
Nov-15-2011 to Nov-26-2011
E65.55N 65.2242 - 40.5156
  • Ikertivaq
  • Pamiatig
February
April/May
July
August
September
November
January/February
April/May
July
August/September
November
Aug-03-2011 to Aug-25-2011
Aug-25-2011 to Sep-05-2011
Dec-02-2011 to Dec-24-2011
Feb-08-2011 to Feb-19-2011
Jul-12-2011 to Aug-03-2011
E66.50N 66.1973 - 39.1116
  • Fenris
  • Helheim
January/February
April/May
July
August
September
November
December
April/May
July
September
November
Aug-09-2011 to Aug-20-2011
Jul-07-2011 to Jul-18-2011
Jun-04-2011 to Jun-15-2011
Mar-08-2011 to Mar-19-2011
Nov-16-2011 to Nov-27-2011
E66.60N 66.4197 - 37.4122
  • Midgard
  • Midgard Nord
N/A November
November/December
Aug-09-2011 to Aug-31-2011
Aug-31-2011 to Sep-11-2011
Jul-29-2011 to Aug-09-2011
May-02-2011 to May-13-2011
Nov-16-2011 to Nov-27-2011
E67.55N 67.2762 - 34.9643
  • Nordre Parallel Gletscher
  • Nordre
January/February
April/May
July
August
September
November
February
April/May
July
August/September
November
Apr-22-2011 to May-03-2011
Aug-21-2011 to Sep-12-2011
Feb-15-2011 to Mar-09-2011
Jul-08-2011 to Jul-19-2011
Nov-17-2011 to Nov-28-2011
E68.80N 68.4663 - 34.3672
  • Kangerdlugssuaq
  • Nordfjord
January/February
April/May
June
August
September
November
Decemer
April/May
July/August
September
November
Aug-21-2011 to Sep-01-2011
Jul-08-2011 to Jul-30-2011
Jun-05-2011 to Jun-16-2011
Mar-09-2011 to Mar-20-2011
Nov-17-2011 to Nov-28-2011
E71.75N 71.4887 - 30.9758
  • Daugaard-Jensen
N/A N/A Mar-12-2011 to Mar-23-2011
Mar-27-2011 to Apr-07-2011
Mar-28-2011 to Apr-08-2011
E78.90N 78.7017 - 24.0968
  • Zach
N/A N/A Feb-25-2011 to Mar-08-2011
Mar-30-2011 to Apr-10-2011
E79.40N 79.190 - 24.0779
  • Fjorden
N/A N/A Mar-03-2011 to Mar-14-2011
E81.35N 81.1300 - 30.0074
  • Hagan
N/A N/A Mar-27-2011 to Apr-07-2011
E81.45N 81.196 - 34.6273
  • Acad
N/A N/A Mar-08-2011 to Mar-19-2011
W64.25N 63.9263 - 49.8721
  • Kangia
  • Qamanarssup
February
April/May
August
September
November
February
April/May
August/September
November
Apr-29-2011 to May-10-2011
Aug-28-2011 to Sep-08-2011
Jul-15-2011 to Jul-26-2011
Jul-26-2011 to Aug-28-2011
Nov-13-2011 to Nov-24-2011
W67.05N 66.7183 - 50.3192
  • Russell
March
July/August
September
November
February
April/May
May
June
June/July
July
August
August/September
October/November
November
Aug-17-2011 to Aug-28-2011
Jul-15-2011 to Aug-06-2011
Jul-26-2011 to Aug-17-2011
Mar-16-2011 to May-10-2011
Nov-13-2011 to Nov-24-2011
W69.10N 68.7418 - 50.4126
  • Alangordliup
  • Jakobshavn
  • Torssukatak
January/February
April/May
July
August
September
November
February
April/May
July
August/September
September
November/December
Apr-12-2011 to Apr-23-2011
Apr-24-2011 to May-05-2011
Aug-02-2011 to Aug-13-2011
Aug-23-2011 to Sep-03-2011
Aug-23-2011 to Sep-14-2011
Feb-06-2011 to Feb-28-2011
Feb-16-2011 to Mar-10-2011
Jul-21-2011 to Aug-01-2011
Nov-18-2011 to Nov-29-2011
Nov-19-2011 to Nov-30-2011
W69.95 69.6356 - 50.6122
  • Kangilerngata
  • Kujatdleq
  • Torsukatat
N/A N/A Mar-27-2011 to Apr-07-2011
W70.55N 70.2285 - 50.9177
  • Lille
  • Sermilik
  • Kangigdleq
  • Store
March
June
June/July
August
September
November
February
May
October/November
November
Apr-29-2011 to May-10-2011
Jul-15-2011 to Jul-26-2011
Nov-13-2011 to Nov-24-2011
W71.65N 71.3100 - 51.8327
  • Kangerdlugssup
  • Rink
January/February
April/May
July
August
September
November
April/May
July
August/September
November/December
Apr-24-2011 to May-05-2011
Aug-23-2011 to Sep-14-2011
Nov-19-2011 to Nov-30-2011
W72.90N 72.5829 - 54.8293
  • Alangorssup Sermia
  • Upernavik
February
April/May
July
September
November
April/May
July
August/September
November
Apr-30-2011 to May-11-2011
Aug-29-2011 to Sep-20-2011
Feb-01-2011 to Feb-12-2011
Jul-05-2011 to Jul-16-2011
Nov-14-2011 to Nov-25-2011
W73.45N 73.1520 - 55.6912
  • Kakivfat
  • Giesecke
  • Nutarmiut
  • Tuvssaq
N/A N/A Mar-11-2011 to Mar-22-2011
W73.75N 73.1520 - 55.6912
  • Comell
  • Sugarloaf
  • Ussing
N/A N/A Mar-05-2011 to Mar-16-2011
W74.50N 74.1506 - 56.4843
  • Cornel
  • Alison
  • Igdlulik
February
April/May
July
September
April/May
July
August/September
November
Apr-30-2011 to May-22-2011
Aug-29-2011 to Sep-20-2011
Feb-01-2011 to Feb-12-2011
Jul-05-2011 to Jul-16-2011
Nov-14-2011 to Nov-25-2011
W74.95N 74.5750 - 57.6463
  • Hays
  • Kjers
  • Jensen
January/February
April/May
July
April/May
July
August/September
November/December
Apr-24-2011 to May-05-2011
Feb-17-2011 to Feb-28-2011
Jul-10-2011 to Aug-01-2011
Nov-19-2011 to Nov-30-2011
W75.50N 75.1264 - 58.5281
  • Dietrichsons
  • Steenstrup
  • Sverdrups
February
April/May
July
September
February
April/May
July
September
November
Apr-20-2011 to May-01-2011
Feb-13-2011 to Feb-24-2011
Jul-06-2011 to Jul-17-2011
Nov-15-2011 to Nov-26-2011
W75.85N 75.4736 - 59.2722
  • South of Nansen
  • Nansen
  • Nordenskiold
N/A N/A Mar-01-2011 to Mar-23-2011
W76.10N 75.7205 - 60.0987
  • Kong Oscar
  • Nordenskiold
  • Nutarmiut
February
April/May
July
September
April/May
July
November
Aug-29-2011 to Sep-09-2011
Feb-01-2011 to Feb-12-2011
Jul-05-2011 to Jul-16-2011
May-11-2011 to May-22-2011
Nov-14-2011 to Nov-25-2011
W76.25N 75.9067 - 61.2365
  • Balgoni
  • Docker
  • Fisher
  • Igssuarssuit
  • Leven
N/A N/A Feb-28-2011 to Mar-11-2011
W76.35N 75.7416 - 63.3988
  • Mohn
  • Gade
  • Meteor
  • Yngvar Nielson
N/A N/A Feb-27-2011 to Mar-10-2011
Mar-04-2011 to Mar-15-2011
W76.40N 76.0579 - 65.9643
  • Savigssuaq Helland
  • Sidebriks
N/A N/A Feb-26-2011 to Mar-09-2011
W76.45N 76.1084 - 67.6907
  • Dedodes
  • Harald Moltke
N/A N/A Feb-25-2011 to Mar-08-2011
W77.55N 77.0728 - 66.2296
  • Leidy
  • Mane
  • Heilprin
  • Mellville
  • Tracy
N/A N/A Mar-05-2011 to Mar-27-2011
W79.75N 79.3702 - 65.1597
  • Humboldt
N/A N/A Mar-15-2011 to Mar-26-2011
W80.75N 79.9328 - 61.5545
  • Petermann
N/A N/A Nov-09-2010 to Nov-20-2010
Nov-20-2010 to Dec-01-2010
W81.25N 80.9256 - 51.3505
  • Ryder
N/A N/A Mar-14-2011 to Mar-25-2011
S44.84W 61.0923 - 45.3465
  • Kiagtut
  • Qorqup
N/A N/A Mar-01-2011 to Mar-23-2011
S45.43W 61.2196 - 45.8994
  • Eqalorutsit Kangigdlit Sermia
N/A N/A Feb-24-2011 to Mar-29-2011
Mar-29-2011 to Apr-20-2011
S46.31W 60.9232 - 467807
  • Eqalorutsit Kangigdlit Sermia West
N/A N/A Dec-14-2010 to Jan-05-2011
S46.91W 60.8876 - 47.3303
  • Qaleragdlit
  • Naujat
  • Sermilik
N/A N/A Dec-07-2010 to Dec-18-2010


Spatial Resolution

100 meter

Spatial Coverage Map

locator map
Figure 1. This map shows the locations of grids on a map of Greenland. Data
are not available for all grids shown on map. Eventually data will be available for
more of the sites.
High Resolution Image.

Projection

Data are provided in subregions of a standard polar stereographic grid with a standard latitude of 70° N and rotation angle of -45° (sometimes specified as a longitude of 45° E). With this convention, the x-axis extends south from the North Pole along the 45° E meridian.

Location information is provided by the geodat files, in the following format:

Note. The origin specifies the polar stereographic coordinates for the center of the lower left pixel, the first sample in the file. This specification using the middle of the reference pixel is different than some GeoTIFF and other formats where the reference coordinates are specified for outer corner of the reference pixel.

Sample Geodat file:

# 2
;
;Image size (pixels) nx ny
;
600 720
;
;Pixel size (m) deltaX deltaY
;
100.000000 100.000000
;
;Origin, lower left corner (km) Xo Yo
;
457.000000 -2319.000000
&

Temporal Coverage

TSX data span January 2009 through November 2011.

Parameter or Variable

The vx and vy files yield values of velocity in meters per year, in the x and y directions defined by the polar stereographic grid. The velocities are true values and not subject to the distance distortions present in a polar stereographic grid. In some areas small holes have been filled via interpolation. Interpolated values are identifiable as the locations where there is velocity data but no error estimate. Radar-derived velocities are determined using a combination of conventional InSAR and speckle tracking techniques (Joughin, 2002).

Error Estimates

Error estimates are included for all non-interpolated radar-derived velocity vectors, in the files TSX_E62.70N_23Apr09_04May09.ex and TSX_E62.70N_23Apr09_04May09.ey. These estimates include the statistical uncertainty associated with the phase and speckle tracking error. Formal errors agree reasonably well with errors determined by comparison with GPS data (Joughin, 2002). These estimates, however, underestimate true uncertainty in several ways and as such should be used more as an indication of relative quality rather than absolute error.

See Joughin, 2002 for more detail on errors and how they are computed.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

Total volume is 2.6 GB.

Software and Tools

The data can be read using a variety of software. The following are sample codes for use in Matlab or IDL.

Reading data with Matlab

The following routines will read the data in Matlab.

% This function reads a standard mosaiced velocity data
% set and returns arrays with the data and the geodat info.
%
function [vx,vy,xd]= readvelocity(rootname)
%
% Get geodat info
%
xd=readgeodat(strcat(rootname,'.vx.geodat'));
%
% Vx component
%
fid = fopen(strcat(rootname,'.vx'),'r','ieee-be');
[vx,count]=fread(fid,[xd(1,1) xd(1,2)],'float32');
fclose(fid);
%
% Vy component
%
fid = fopen(strcat(rootname,'.vy'),'r','ieee-be');
[vy,count]=fread(fid,[xd(1,1) xd(1,2)],'float32');
fclose(fid);

%
% Read a geodat file
%
function xgeo=readgeodat(filein)
fid = fopen(filein,'r');
xgeo=zeros(3,2);
i=1;
while ~feof(fid),
  line=fgets(fid);
  [A,count]=sscanf(line,'%f %f',[1 2]);
  if(count == 2)
     xgeo(i,:)=A;
     i=i+1;
  end
end
fclose(fid);=

Reading data with IDL

The following code fragment can be used to write a complete program to read the data with IDL.

;
; Similar to matlab program
;
get_lun,lun
openr,lun,filename
buffer=fltarr(xs)
image=fltarr(xs,ys)
for i=0,ys-1 do begin
   readu,lun,buffer
   buffer=swap_endian(buffer,/swap_if_little_endian)  ; This is needed on a PC
   image(*,i) = buffer
endfor

Related Data Collections

4. Data Acquisition and Processing

Theory of Measurements

The velocity maps in this data set were created using SAR data from the TerraSAR-X satellite. The methods included a combination of speckle tracking and conventional interferometry. For more detail, please see Joughin. 2002.

Sensor or Instrument Description

Synthetic Aperture Radar (SAR) data were obtained from the TerraSAR-X satellite.

5. References and Related Publications

Ahn, Y. and I. Howat. 2011. Efficient Automated Glacier Surface Velocity Measurement From Repeat Images Using Multi-Image/Multichip and Null Exclusion Feature Tracking. IEEE Transactions on Geoscience and Remote Sensing Vol. 49, No. 8. doi:10.1109/TGRS.2011.2114891.

Howat, I. M., J. E. Box, Y. Ahn, A. Herrington, E. M. McFadden. 2010. Seasonal Variability in the Dynamics of Marine-Terminating Outlet Glaciers in Greenland.Journal of Glaciology, 56(198), pp. 601-613. doi:10.3189/002214310793146232.

Joughin, I. 2002. Ice-Sheet Velocity Mapping: A Combined Interferometric and Speckle-Tracking Approach. Annals of Glaciology 34: 195-201. doi:10.3189/172756402781817978.

Joughin, I., W. Abdalati, and M. Fahnestock. 2004. Large fluctuations in speed on Greenland's Jakobshavn Isbræ glacier. Nature,Vol. 432: 608-610.

Joughin, I., B. Smith, I. M. Howat, T. Scambos, and T. Moon. 2010. Greenland Flow Variability from Ice-Sheet-Wide Velocity Mapping. Journal of Glaciology, 56 (197), pp. 415-430, doi: 10.3189/002214310792447734.

Joughin, I., R. Kwok, and M. Fahnestock, 1996. Estimation of Ice Sheet Motion Using Satellite Radar Interferometry: Method and Error Analysis with Application to Humboldt Glacier, Greenland. Journal of Glaciology 42(142) pp 564-575.

The following related Web sites provide additional information on MEaSUREs data and related data sets:

Table 4. Related Documents
Document Description URL
MEaSUREs Data Web site NSIDC data Web site http://nsidc.org/data/measures/
NASA MEaSUREs Web site NASA Measures Projects Web site http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 5. Acronyms and Abbreviations
Acronym Description
FTP File Transfer Protocol
IDL Interactive Data Language
MEaSUREs Making Earth System Data Records for Use in Research Environments
NSIDC National Snow and Ice Data Center
SAR Synthetic Aperture Radar
TSX TerraSAR-X
URL Uniform Resource Locator

Document Creation Date

19 May 2011

Document Revision Date

8 March 2012

Document URL

http://nsidc.org/data/docs/measures/nsidc0481_joughin/index.html