GCMD

GLAS/ICESat L1A Global Altimetry Data

Entry ID: GLA01

Summary

Abstract: 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.

Level-1A altimetry data (GLA01) include the transmitted and received waveform from the altimeter.

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.

Related URL

Link: VIEW PROJECT HOME PAGE
Description: Official ICESat web site

Link: VIEW RELATED INFORMATION
Description: ICESat/GLAS web site at NSIDC

Link: VIEW RELATED INFORMATION
Description: ICESat/GLAS web site at University of Texas

Link: VIEW RELATED INFORMATION
Description: ICESat/GLAS web site at NASA Goddard Space Flight Center

Link: VIEW RELATED INFORMATION
Description: ICESat/GLAS web site at NASA Wallops Flight Facility

ISO Topic Category

CLIMATOLOGY/METEOROLOGY/ATMOSPHERE

Platform

ICESAT >Ice, Cloud and Land Elevation Satellite [Information]

SATELLITES [Information]

Instrument

ALTIMETERS [Information]

GLAS >Geoscience Laser Altimeter System [Information]

Project

EOSDIS >Earth Observing System Data Information System [Information]

ICESAT >Ice, Cloud and Land Elevation Satellite [Information]

ESIP >Earth Science Information Partners Program [Information]

Quality

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.

Keywords

Altimetry

Backscatter

DAAC

Dem

EOSDIS

GLA01

GLAS

Global Positioning System

GPS

ICESat

ISIPS

Laser Pulse

Lidar

NASA

Noise Level

NSIDC

Off-nadir Pointing Direction

Orbit Number

Precision Attitude Determination

Precision Orbit Determination

Range

Received Energy

Received Pulse Gain

Signal Saturation

Transmitted Energy

Transmitted Gain

Waveform

Waveform Kurtosis

Waveform Skewness

Distribution Media

Distribution_Media: FTP
Distribution_Size: 9 MB per granule
Distribution_Format: scaled integer binary

Personnel

NSIDC USER SERVICES
Role: TECHNICAL CONTACT
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA

DAVID HANCOCK
Role: INVESTIGATOR
Email: David.W.Hancock at nasa.gov
Contact Address:
ISIPS Manager
NASA Goddard Space Flight Center
Wallops Flight Facility
USA
City: Wallops Island
Province or State: VA
Country: USA

H. JAY ZWALLY
Role: INVESTIGATOR
Phone: 301-614-5643
Fax: 301-614-5644
Email: Jay.Zwally at nasa.gov
Contact Address:
Laboratory for Hydrospheric Processes
NASA/Goddard Space Flight Center
Code 614
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA

BOB E. SCHUTZ
Role: INVESTIGATOR
Phone: 512-471-1356
Fax: 512-471-3570
Email: schutz at utcsr.ae.utexas.edu
Contact Address:
GLAS Science Team Lead
University of Texas at Austin
Center for Space Research
City: Austin
Province or State: TX
Postal Code: 78712-1085
Country: USA

CHARLES R. BENTLEY
Role: INVESTIGATOR
Contact Address:
Dept. of Geology and Geophysics
University of Wisconsin
City: Madison
Province or State: WI
Postal Code: 53706
Country: USA

JACK L. BUFTON
Role: INVESTIGATOR
Contact Address:
NASA/Goddard Space Flight Center
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA

THOMAS A. HERRING
Role: INVESTIGATOR
Contact Address:
Massachusetts Institute of Technology
City: Cambridge
Province or State: MA
Postal Code: 02139
Country: USA

JEAN-BERNARD MINSTER
Role: INVESTIGATOR
Contact Address:
Scripps Institute of Oceanography
University of California
City: La Jolla
Province or State: CA
Postal Code: 92093
Country: USA

JAMES D. SPINHIRNE
Role: INVESTIGATOR
Phone: 301-614-6274
Email: James.D.Spinhirne at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Mailstop 613.1
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA

ROBERT H. THOMAS
Role: INVESTIGATOR
Contact Address:
EG&G
NASA Wallops Flight Facility
City: Wallops Island
Province or State: VA
Postal Code: 23337
Country: USA

Publications/References

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.

Creation and Review Dates

SERF Creation Date:
SERF Last Revision Date: