GLA12 GLAS/ICESat L2 Antarctic and Greenland Ice Sheet Altimetry Data Zwally, H., R. Schutz, C. Bentley, J. Bufton, T. Herring, J. Minster, J. Spinhirne, and R. Thomas. GLAS/ICESat L2 Antarctic and Greenland Ice Sheet Altimetry Data 2011-08-11 Boulder, Colorado USA NSIDC: National Snow and Ice Data Center 33 http://nsidc.org/data/gla12.html Technical Contact NSIDC User Services nsidc@nsidc.org 1 303 492-6199 x 1 303 492-2468 x

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA Technical Contact David Hancock David.W.Hancock@nasa.gov

NASA Goddard Space Flight Center

ISIPS Manager

NASA Goddard Space Flight Center

Wallops Flight Facility

Wallops Island, VA

USA

Investigator H. Jay Zwally Jay.Zwally@nasa.gov 1 301 614-5643 1 301 614-5644

NASA/Goddard Space Flight Center

Laboratory for Hydrospheric Processes

NASA/Goddard Space Flight Center

Code 971

Greenbelt MD 20771 USA Investigator H. Jay Zwally Jay.Zwally@nasa.gov 1 301 614-5643 1 301 614-5644

NASA/Goddard Space Flight Center

Laboratory for Hydrospheric Processes

NASA/Goddard Space Flight Center

Code 971

Greenbelt MD 20771 USA Investigator Robert Schutz

University of Texas at Austin

Center for Space Research

GLAS Science Team Lead

University of Texas at Austin

Center for Space Research

Austin TX 78712-1085 USA Investigator Charles Bentley

University of Wisconsin

Dept. of Geology and Geophysics

University of Wisconsin

Madison WI 53706 Investigator Jack Bufton

NASA/Goddard Space Flight Center

Greenbelt MD 20771 Investigator Thomas Herring

Massachusetts Institute of Technology

Cambridge MA 02139 Investigator Jean-Bernard Minster

Scripps Institute of Oceanography

University of California

La Jolla CA 92093 Investigator James Spinhirne

NASA/Goddard Space Flight Center

Greenbelt MD 20771 Investigator Robert Thomas

EG&G

NASA Wallops Flight Facility

Wallops Island VA 23337 EARTH SCIENCE Cryosphere Glaciers/Ice Sheets Glacier Elevation/Ice Sheet Elevation Laser Reflectance EARTH SCIENCE Cryosphere Glaciers/Ice Sheets Glacier Topography/Ice Sheet Topography EARTH SCIENCE Cryosphere Glaciers/Ice Sheets Ice Sheets EARTH SCIENCE Cryosphere Sea Ice Reflectance Laser Reflectance EARTH SCIENCE Oceans Sea Ice Reflectance EARTH SCIENCE Terrestrial Hydrosphere Glaciers/Ice Sheets Glacier Elevation/Ice Sheet Elevation EARTH SCIENCE Terrestrial Hydrosphere Glaciers/Ice Sheets Glacier Topography/Ice Sheet Topography EARTH SCIENCE Terrestrial Hydrosphere Glaciers/Ice Sheets Ice Sheets Elevation Atmospheric Delay Correction DAAC Dem EOSDIS GLA12 GLAS Ice Roughness ICESat Ice Sheet Elevation ISIPS Laser Footprint Laser Pulse NASA Noise Level NSIDC Off-nadir Pointing Direction Peak Amplitude Range Received Energy Received Pulse Gain Signal Saturation Solar Incidence Angle Transmitted Energy Transmitted Gain Waveform Waveform Kurtosis Waveform Peak Waveform Skewness ALTIMETERS GLAS Geoscience Laser Altimeter System ICESAT Ice, Cloud and Land Elevation Satellite SATELLITES 2003-02-20 2009-10-11 complete -86 86 -180 180 GEOGRAPHIC REGION GLOBAL ICESAT Ice, Cloud and Land Elevation Satellite Browse products in PNG graphic format contain quality information; these are available along with corresponding data granules in the Data Pool or EOS Data Gateway. The i_FrameQF quality flag is set to '1' if there is a problem in calculating individual parameters, or the flag is set to '0' if there are no problems. English NASA/GSFC/EOS/EO NSIDC_DAAC NASA DAAC at the National Snow and Ice Data Center http://nsidc.org/daac/index.html Data Center Contact NSIDC User Services nsidc@nsidc.org 1 303 492-6199 1 303 492-2468

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA NSIDC National Snow and Ice Data Center http://nsidc.org Data Center Contact NSIDC User Services nsidc@nsidc.org 1 303 492-6199 1 303 492-2468

National Snow and Ice Data Center

CIRES, 449 UCB

University of Colorado

Boulder CO 80309-0449 USA FTP 104 MB Binary Bae, S. and B.E. Schutz. 2002. Precision attitude determination (PAD). GLAS algorithm theoretical basis document. Version 2.2. Austin, TX: Center for Space Research, University of Texas at Austin. Brenner, A.C., C.R. Bentley, B.M. Csatho, D.J. Harding, M.A. Hofton, J. Minster, L. Roberts, J.L. Saba, R. Schutz, R.H. Thomas, D. Yi, and H.J. Zwally. 2000. Derivation of range and range distributions from laser pulse waveform analysis for surface elevations, roughness, slope, and vegetation heights. Algorithm theoretical basis document. Version 3.0. Greenbelt, MD: Goddard Space Flight Center. Center for Space Research. 'ICESat/GLAS.' January 2002. http://www.csr.utexas.edu/glas/. Davis C.H. and H.J. Zwally. 1993. Geographic and seasonal variations in the surface properties of the ice sheets by satellite radar altimetry. Journal of Glaciology 39:687-697. Earth Science Data and Information System (ESDIS). 1996. EOS Ground System (EGS) Systems and Operations Concept. Greenbelt, MD: Goddard Space Flight Center. Farrell, W.E. 1972. Deformation of the Earth by surface loads. Review of Geophysics and Space Physics 10: 761-797. GLAS Science Team. 2000. Mission Operations Requirement Document (MORD) for the Ice, Cloud and Land Elevation Satellite (ICESat) Mission. Greenbelt, MD: Goddard Space Flight Center. GLAS Science Team. 1997. GLAS Science Requirements. Version 2.01. Greenbelt, MD: Goddard Space Flight Center. Heroux, D. 2000. Progress report on GLAS interface effort with ECS NOSE. Rev. 29 December 2000. Landover, MD: Emergent-IT/Raytheon. Herring, T.A. and K. Quinn. 1999. Atmospheric delay correction to GLAS laser altimeter ranges. GLAS algorithm theoretical basis document. Version 1.0. Lanham, MD: Science Systems and Applications, Inc. Jester, P., and D. Hancock. 2002. The Algorithm Theoretical Basis Document for Level 1A Processing, Version 1.2. Wallops Island, VA: Raytheon ITSS. Jester, P., and J. Lee. 2002. GLAS standard data products specification - level 1. Version 6.0. Wallops Island, VA: Raytheon ITSS. Lee, J. 2002. GSAS user's guide: Version 4.0. Wallops Island, VA: Raytheon ITSS. McGarry, J.F., J. Abshire, X. Sun, J. Saba, A. Brenner, and D. Yi. 2002. GLAS flight science data selection algorithms for the altimeter (1064 nm), Version 4.15. Unpublished report. Rim, H., and B. Schutz. 2002. Precision orbit determination. GLAS algorithm theoretical basis document. Version 2.2. Austin, TX: Center for Space Research, University of Texas at Austin. Schutz, B. 2000. GLAS altimeter post-launch calibration/validation plan. Version 0.99. Austin, TX: Center for Space Research, University of Texas at Austin. Schutz, B. 2002. Laser footprint location (geolocation) and surface profiles. GLAS algorithm theoretical basis document. Version 3.0. Austin, TX: Center for Space Research, University of Texas at Austin. Wahr, J., D. Wingham, and C. Bentley. 2000. A method of combining ICESat and GRACE satellite data to constrain Antarctic mass balance. Journal of Geophysical Research 105(B7):16,279-16,294. Yi, D., J. Minster, and C. Bentley. 1999. Ocean tidal loading corrections. GLAS algorithm theoretical basis document. Version 1.0. Greenbelt, MD: Goddard Space Flight Center. Zwally, H.J., B. Schutz, W. Abdalati, J. Abshire, C. Bentley, A. Brenner, J. Bufton, J. Dezio, D. Hancock, D. Harding, T. Herring, B. Minster, K. Quinn, S. Palm, J. Spinhirne, and R. Thomas. 2002. ICESAT's laser measurements of polar ice, atmosphere, ocean, and land. Journal of Geodynamics 34: 405-445. Zwally, H.J., B. Schutz, D. Hancock, and A. Brenner. 2000. ICESat/GLAS Standard Data Products in HDF and SCF Formats. Version 1.2. Greenbelt, MD: Goddard Space Flight Center. Zwally, H.J., R.A. Bindschadler, A.C. Brenner, T.V. Martin, and R.H. Thomas. 1983. Surface elevation contours of Greenland and Antarctic ice sheets. Journal of Geophysical Research 88(C3):1589-1596.

The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity. GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols. This level-2 altimetry product (GLA12) provides surface elevations for ice sheets. Data also include the laser footprint gelocation and reflectance, as well as geodetic, instrument, and atmospheric corrections for range measurements. Each data granule has an associated browse product that users can quickly view to determine the general quality of the data in the granule. Browse products consist of image plots of key parameters and statistics. Data are in scaled integer binary format, big-endian (Unix) byte order, and are available via FTP.

VIEW PROJECT HOME PAGE http://nsidc.org/data/icesat/index.html ICESat/GLAS Data at NSIDC VIEW PROJECT HOME PAGE http://icesat.gsfc.nasa.gov/ ICESat/GLAS web site at NASA Goddard Space Flight Center VIEW PROJECT HOME PAGE http://glas.wff.nasa.gov/ ICESat/GLAS web site at NASA Wallops Flight Facility VIEW PROJECT HOME PAGE http://www.csr.utexas.edu/glas/ ICESat/GLAS web site at University of Texas VIEW RELATED INFORMATION http://nsidc.org/data/dems/index.html Polar Ice Sheet DEMs and Elevation Data USA/NASA CEOS IDN DIF 9.7 2011-08-11 2013-03-06 Updated Version Summary and Citation authors.