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02 June 2008
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 1A

Reprocessed Release-28 data are now available for the Laser 1A time period (20 February 2003 to 21 March 2003) for the products GLA05-GLA09 and GLA12-GLA15. Previously these data were released as 228 in the new file naming convention, but they have now been processed to the highest level of processing at 428. For further information on the differences between the 228 and 428 designations, please see the YXX Release Numbers document.

Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, or contact User Services if you have any questions or for a more complete description.

31 MARCH 2008
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3I

Release-28 data for the Laser 3I time period (02 October 2007 to 05 November 2007) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This is the first public release of Laser 3I data. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, or contact User Services if you have any questions or for a more complete description.

18 OCTOBER 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3C

Release-28 data for the Laser 3C time period (20 May 2005 to 23 June 2005) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This is the first public release of Laser 3C data*, and it is another release of GLAS data with the satellite's attitude in airplane mode. Please contact User Services for a more complete description. *Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information.

25 SEPTEMBER 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3F

Release-28 data for the Laser 3F time period (24 May 2006 to 26 June 2006) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This is the first public release of Laser 3F data*, and it is also the first release of GLAS data with the satellite's attitude in airplane mode. Depending on the time of year, the satellite's attitude is changed from airplane to sailboat to accommodate sun angle changes and for power and thermal stability. Please contact User Services for a more complete description. *Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information.

04 SEPTEMBER 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3H

Release-28 data for the Laser 3H time period (12 March 2007 to 14 April 2007) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This is the first public release of Laser 3H data. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release

9 MAY 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 1

Release-28 data for the Laser 1 time period (20 February 2003 to 21 March 2003) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

24 APRIL 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3G

Release-28 data for the Laser 3G time period (25 October 2006 to 27 November 2006) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

30 MARCH 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 2A

Release-28 data for the Laser 2A time period (25 September 2003 to 18 November 2003) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

17 JANUARY 2007
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3A

Release-28 data for the Laser 3A time period (03 October 2004 to 08 November 2004) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This is the first public release of Laser 3A data for some altimetry products. Release-28 provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

27 DECEMBER 2006
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3B

Release-28 data for the Laser 3B time period (17 February to 24 March 2005) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This release provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

14 NOVEMBER 2006
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 2B

Release-28 data for the Laser 2B time period (17 February to 21 March 2004) are available for all 15 GLAS products (GLA10 and GLA11 coverage to 4 March 2004). This release provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

30 OCTOBER 2006
ADDITIONAL RELEASE-28 DATA AVAILABLE: Laser 3D

Release-28 data for the Laser 3D time period (21 October 2005 to 24 November 2005) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This release provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

16 OCTOBER 2006
RELEASE-28 DATA AVAILABLE: Laser 3E

Release-28 data for the Laser 3E time period (22 February 2006 to 27 March 2006) are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This release provides numerous enhancements, such as improved corrections for saturation effects, improved flags to aid users in data selection, and better descriptions of the altimetry products. See ICESat/GLAS Data Releases for more information, including details about a change in file names with this release.

24 MAY 2006
ADDITIONAL RELEASE-26 DATA AVAILABLE

Release-26 data for the Laser 2A time period (25 September to 18 November 2003) are available for the following products: GLA01 - GLA15. Significant changes to the altimetry products include saturation range corrections for all gains and energies, as well as several changes to the alternate waveform fitting. Several new meteorological parameters were added to the atmospheric products. See ICESat/GLAS Data Releases for more information.

4 MAY 2006
ADDITIONAL RELEASE-26 DATA AVAILABLE

Release-26 data for the Laser 2B time period (17 February to 21 March 2004) are available for the following products: GLA01 - GLA15. Significant changes to the altimetry products include saturation range corrections for all gains and energies, as well as several changes to the alternate waveform fitting. Several new meteorological parameters were added to the atmospheric products. See ICESat/GLAS Data Releases for more information.

17 MARCH 2006
RELEASE-26 PRODUCTS AVAILABLE

Release-26 data are available for the following products: GLA01 - GLA09 and GLA12 - GLA15. This release covers the Laser 3D time period (21 October to 24 November 2005). Significant changes to the altimetry products include a range correction for saturation and several changes to the alternate fit waveforms. Several new MET parameters were added to the atmospheric products. See ICESat/GLAS Data Releases for more information.

21 DECEMBER 2005
RELEASE-24 PRODUCTS AVAILABLE

As of 21 December 2005, Release-24 data are available for all 15 GLAS products. This release covers the Laser 2A time period (25 September to 18 November 2003) and contains significant improvements to the data quality, as well as changes to the lengths of the files. See ICESat/GLAS Data Releases for more information.

18 NOVEMBER 2005
ONE BILLION MEASUREMENTS MILESTONE

The ICESat mission and the GLAS instrument reached an important milestone when the 1,000,000,000th measurement was made while in orbit, on Friday, 18 November 2005. The previous maximum number of measurements reached in space was approximately 670,000,000, which were pulses emitted by the MOLA-2 Laser on the Mars Global Surveyor mission.

5 OCTOBER 2005
PAPERS FROM GEOPHYSICAL RESEARCH LETTERS NOW AVAILABLE

10 papers from the ICESat Special Section of Geophysical Research Letters are now available. Visit the Geophysical Research Letters Special Section, Results From Ice, Cloud, and land Elevation Satellite (ICESat) Mission, to view the papers online.

29 SEPTEMBER 2005
RELEASE-22 PRODUCTS AVAILABLE FOR SUBSETTING

Release-22 GLA07, GLA08, and GLA09 data are available for subsetting. See the ICESat/GLAS Data Subsetter to request subsets.

22 AUGUST 2005
RELEASE-22 ATMOSPHERIC PRODUCTS AVAILABLE

Release-22 GLA02, GLA07, GLA08, and GLA09 data are available. This release covers 03 October to 08 November 2004 and contains significant improvements to the 532 nm cloud layer detection method. See ICESat/GLAS Data Releases for more information.

21 JULY 2005
RELEASE-22 GLA01 AND GLA05 DATA AVAILABLE

As of 25 July 2005, Release-22 data are available for GLA01 (Level-1A global altimetry) and GLA05 (Level-1B global waveform-based range corrections). This release covers a new time period (03 October to 08 November 2004) and contains significant improvements to the waveform alternate fitting process and to energy/reflectance calculations. See ICESat/GLAS Data Releases for more information.

The new data are currently available through the Data Pool and the EOS Data Gateway (EDG). Also, we have released a new subsetting tool that enables users to spatially subset certain GLAS data products. Subsetting is currently available for the following products:

GLA01.018, GLA01.019, GLA01.022, GLA02.019, GLA05.019, GLA05.022, GLA06.018, GLA06.021, GLA07.019, GLA08.019, GLA09.019, GLA10.019, GLA11.019, GLA12.018, GLA12.021, GLA13.018, GLA13.021, GLA14.018, GLA14.021, GLA15.018, GLA15.021

See Ordering ICESat/GLAS Data Products from NSIDC for order options.

Software tools for visualizing and reading ICESat data have been updated for use with Release-22 data. These programs output the uncompressed waveform values in volts.

The data products GLA02-04 and GLA07-09 will be updated to Release-22, but they are not yet available. NSIDC User Services will notify users when these data are ready, hopefully in the next several weeks.

The GLAS altimetry products (GLA06, 12-15) for the new time period should also be available later in the summer. We will notify you again when these data are available.

27 JUNE 2005
LASER 3C CAMPAIGN SUCCESSFULLY FINISHES

At 01:46 U.S. Eastern Daylight Time (EDT) on 23 June 2005, Laser 3 was successfully commanded to stop fire as planned to complete the Laser 3c operations period. The post stop-fire data shows behavior as expected. GLAS has emitted over 905,000,000 laser shots upon completion of the Laser 3c campaign. The stop-fire energies were approximately 44 mJ (1064 nm) and 2 mJ (532 nm).

The ICESat spacecraft attitude will change by 180° on 30 June 2005. On 08 July 2005, the orbit will transition to the 8-day repeat cycle to facilitate transition into the desired subcycle of the 91-day orbit in preparation for the Laser 3d fall campaign.

23 MAY 2005
LASER 3C CAMPAIGN OFF TO A SUCCESSFUL START

The Laser-3c campaign began on 20 May at approximately 12:35 EDT with laser start fire. Initial assessment showed laser performance was as expected. Further verification occurred about two orbits later when the science data were received.

Release-22 data from laser 3a are expected to be released in July 2005. This release will cover 03 October to 08 November 2004 with the following changes:

20 APRIL 2005
RELEASE-21 ELEVATION PRODUCTS RELEASED

Release-21 data are available for GLA06 and GLA12-15. This release contains the following improvements. (No product format changes were implemented.)

See Ordering ICESat/GLAS Products from NSIDC for important disclaimer information and ordering options.

22 MARCH 2005
NEW ANIMATIONS OF ATMOSPHERIC MEASUREMENTS FROM ICESAT/GLAS

See Animations of ICESat/GLAS Atmospheric Measurements for visualizations of GLA07 attenuated, calibrated backscatter data over India and Africa. These 37 MB MGEG files are suitable for users with high-speed Internet access.

04 FEBRUARY 2005
NEW VERSIONS OF TOOLS AVAILABLE

A new version of the GLAS Visualizer is available with improved features and plotting capabilities. The most anticipated new feature is that users without Interactive Data Language (IDL) can run the Visualizer with the free "IDL Virtual Machine," available from Research Systems, Inc..

A new version of the NSIDC GLAS Altimetry elevation extractor Tool (NGAT) (ngat-0.3.tar.gz) is also available.

18 JANUARY 2005
RELEASE-19 PRODUCTS AVAILABLE

Release-19 data products from GLAS laser 2A are available from NSIDC starting 18 January 2005. GLA01 will initially be available; other products will follow throughout the week. Data span 25 September to 18 November 2003. Release-19 offers improved sea ice roughness calculations in GLA13, corrected energy computation, improved aerosol and cloud discrimination and layer detection, and many other product enhancements. See ICESat/GLAS Data Releases for a summary of changes and known limitations with Release-19, and visit Ordering ICESat/GLAS Products from NSIDC for important disclaimer information and ordering options.

18 OCTOBER 2004
GLAS LASER 3 TEMPERATURE INCREASE

On 18 October, the process to raise the GLAS laser 3 temperature by approximately 2.2° C began and finished on 19 October. As of 20 October, the laser 3 temperature was steady at 16.0°C, the desired temperature. At this point, the 1064 nm energy was 66.7 mJ and the 532 nm energy was 5.07 mJ. The CRS image (in the LRS) and the beam quality showed a marginal improvement. Since all indications are that the laser health is nominal at this temperature and with some marginal improvement in green, it was decided to remain at this temperature for the remainder of this campaign. An around-the-world scan is scheduled for 22 October to help assess any changes in pointing.

ICESat operations continue to be nominal.

24 SEPTEMBER 2004
RELEASE-18 DATA AVAILABLE

Release-18 data are available for all 15 ICESat/GLAS products, covering 16 October to 18 November 2003. Notable improvements include better ground height detection in GLA09 and multiple scattering corrections to extinction and optical depth calculations in GLA10 and GLA11. See ICESat/GLAS Data Releases for a summary of changes and known limitations with Release-18, or visit Ordering ICESat/GLAS Products from NSIDC for important disclaimer information and ordering options.

23 SEPTEMBER 2004
SUBSCRIPTIONS AVAILABLE AS AN ORDERING OPTION

Users can now request subscriptions for AMSR-E, ICESat/GLAS, MODIS, and NISE data. This option is convenient if you require new data for a specific region on a daily or other repeating basis, but you do not want to actively search and order data files each time. Based on your preference, NSIDC will either "push" new data to your local server via File Transfer Protocol (FTP) or will stage data on our FTP site for you to pull. Please see Data Subscription Requests for more information.

26 AUGUST 2004
NEW AND IMPROVED ATMOSPHERIC PRODUCTS TO BECOME AVAILABLE IN EARLY SEPTEMBER

Although Release-17 atmospheric products are currently available, a number of improvements to GLA09, GLA10 and GLA11 will be incorporated in Release-18, expected to be available around 10 September 2004. These include improved ground height detection (GLA09) and multiple scattering correction to extinction and optical depth calculations (GLA10-11). Users may consider waiting until September to order data, to ensure better quality Release-18 data.

05 AUGUST 2004
ICESAT REVERTING TO 8-DAY ORBIT

To acquire the necessary 91-day orbit phasing, the ICESat orbit will transition to the 8-day repeat orbit approximately 05 August 2004, 02:00 UTC. Spacecraft operations will continue in the 8-day repeat (no laser operations) until sometime in early September. The transition back to the 91-day orbit will be made approximately two weeks before the laser is turned on, to achieve the required phasing.

19 JUNE 2004
IMPROVED ICESAT/GLAS ATMOSPHERIC DATA NOW AVAILABLE

New and improved ICESat/GLAS Release-17 atmospheric data (GLA02, GLA07-09) are now available for the following time period:

Start Date: 16 October 2003
Stop Date: 18 November 2003

These data now include protection for floating point exceptions, corrections to science software documentation, and improved Quality Assurance Products (QAPs) and browse products. Atmospheric products now have substantially improved PBL height retrieval (GLA08), improved cloud layer detection from 1064 channel, and a new time-dependent calibration for 1064 nm. Data are available through the EOS Data Gateway (EDG) and NSIDC Data Pool.

21 MAY 2004
ALTIMETRY CORRECTION NOTICE

Release-12 and -14 ICESat/GLAS geoid height data (i_gdHt) were referenced to the WGS-84 ellipsoid in a tide-free system. In future releases of ICESat/GLAS data, geoid height will be referenced to the TOPEX/Poseidon ellipsoid in a mean-tide system. See Correcting the ICESat/GLAS Geoid Height (i_gdHt) for an IDL program that corrects geoid height values from Release-12 and -14 altimetry data so that the resulting values are referenced to the TOPEX/Poseidon ellipsoid in a mean-tide system.

17 MAY 2004
ICESAT BEGINS FIRST OPERATIONAL PERIOD IN 2004

Laser 2 on ICESat's GLAS instrument was again successfully commanded to turn on 17 May at 4:38 pm EST. Please see the official ICESat site for more details.

NSIDC RELEASES NEW IDL READERS

The NSIDC GLAS Altimetry elevation extractor Tool (NGAT) extracts elevation and geoid data from GLAS altimetry products (GLA06 and GLA12-15) and outputs latitude, longitude, elevation, and geoid in ASCII columns. The NGAT runs under IDL (6.0 or greater) or the free IDL Virtual Machine (IDLVM) available from Research Systems Inc. Please review the readme file included with this IDL-based tool for instructions.

ANNOUNCEMENT: WORKSHOP ON EOS SNOW AND ICE PRODUCTS

The First Workshop on Earth Observing System (EOS) Snow and Ice Products will be held near Goddard Space Flight Center in Greenbelt, Maryland, on 16-17 November 2004. The intent of the workshop is to bring together current and potential users of EOS snow and ice standard products from the Moderate-Resolution Imaging Spectroradiometer (MODIS), Advanced Microwave Scanning Radiometer - EOS (AMSR-E), Ice, Cloud and land Elevation Satellite (ICESat), Enhanced Thematic Mapper Plus (ETM+), and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors. The themes of the workshop center on the snow and ice products, including validation results; integration of EOS snow and ice products into models; production of climate data records; and the discussion of improvements to data access and availability. Presentations by data producers will be made, and demonstrations dealing with the acquisition and use of the products will be provided by the National Snow and Ice Data Center (NSIDC) and the Goddard Distributed Active Archive Centers (DAACs). All users of EOS data are invited to present posters on their snow- and ice-related results. There will be ample time during the workshop for discussions relative to the workshop themes. If interested, please contact Dorothy Hall at NASA/GSFC or Marilyn Kaminski at NSIDC .

07 APRIL 2004
NEW AND IMPROVED ICESAT/GLAS ALTIMETRY DATA NOW AVAILABLE

New and improved ICESat/GLAS altimetry data are now available from the National Snow and Ice Data Center (NSIDC). As of 07 April 2004, Release-13 data are available for GLA01 (level-1a altimetry), and Release-14 data are available for GLA05 (level-1b waveform corrections), GLA06 (level-1b elevation), and GLA12-15 (level-2 ice sheet, sea ice, land surface, and ocean altimetry) for the following time period:

Start Date: 15 October 2003
Stop Date: 18 November 2003 (19 November for GLA01)

These new versions of data have significantly improved calibration. Improvements continue and will be reflected in future data releases. New software tools for visualizing ICESat data and for extracting the data from binary into ASCII format are also provided. Data are available through the EOS Data Gateway (EDG) and the NSIDC Data Pool.

05 MARCH 2004
ICESAT REFERENCE ORBIT GROUND TRACKS

New information is available about the ICESat 8-day and 91-day reference orbits, along with binary files containing the geodetic latitude and longitude location of the reference orbit ground tracks and Fortran and IDL programs to ingest these data files.

12 FEBRUARY 2004
VISUALIZATION SOFTWARE AVAILABLE TO READ ICESAT/GLAS DATA

The following links provide access to software on NSIDC's FTP site. Please be sure to view the respective README files for instructions on installing and/or running the programs.

IDL visualizer (183 MB GZIP file): Read data from an ICESat/GLAS file and view graphical summaries of variables. Included in the Unix tar file is a comprehensive user manual with instructions on installing and running the visualizer.

IDL readers: Read data from an ICESat/GLAS file and print all the variables in ASCII format.

Fortran 90 readers: This set of programs reads the data products and prints the parameters in integer format except for the flags, which are printed in hex. These are sample codes to help users develop their own applications. There is a separate program for each product type ("read_glaxx_file") where xx is the product number. All the source codes, makefiles, and executables are in the same directory. The programs are written in Fortan 90 and developed in a HP/UX 11.x runtime environment. A relatively modern Fortran 90 compiler is required.

31 OCTOBER 2003
ICESat/GLAS PRODUCTS PUBLICLY AVAILABLE!

Preliminary versions of all ICESat/GLAS products are now available from the National Snow and Ice Data Center (NSIDC) through the Earth Observing System Data Gateway. Please see Preliminary ICESat/GLAS Data for more information regarding these data, their limitations, orbital tracks, and ordering information.

25 SEPTEMBER 2003
ICESat MISSION STATUS

Today, ICESat resumed measurements of the Earth's polar ice sheets, clouds, mountains, and forests with the second of its three lasers. To date, the science and engineering data sent from the satellite indicates that all is well as ICESat begins its second major period of ice, cloud, and land elevation data acquisition. The mission had been "on hold" during several months of engineering review into the cause of an anomaly affecting the first laser on ICESat's instrument GLAS. NASA will issue a report shortly on the reason for the anomaly. ICESat was launched 12 January 2003, on a Boeing Delta II rocket from Vandenberg Air Force Base, Calif. On 20 February, GLAS Laser 1 was activated and on 29 March, Laser 1 unexpectedly stopped working after providing about 36 days of data. More details on the mission and its scientific and technical achievements will be available when ICESat scientists and engineers convene a special session on ICESat, on 10 December at the 2003 Fall Meeting of the American Geophysical Union in San Francisco.

8 OCTOBER 2003
ICESAT/GLAS ARTICLES ON SPACE.COM

See the articles An Icy Dilemna and Beware the Space Lasers!, which highlight ICESat/GLAS.

30 SEPTEMBER 2003
SWGD DATA ACCESS/USABILITY WORKSHOP ANNOUNCED

The Earth Observing System (EOS) Science Working Group on Data (SWGD) is announcing a workshop scheduled for 5-6 November 2003, in Greenbelt, MD, USA. This workshop will include panel and breakout discussions by users describing their objectives, type of data they need, access to data, and barriers encountered and overcome. Please visit the SWGD's workshop announcement for more information.

27 MARCH 2003
ARTICLE ABOUT ICESat on INTERNATIONAL LASER RANGING SERVICE WEB SITE

Read the ICESat article on the ILRS Web site.

21 FEBRUARY 2003
GLAS LASER TURNED ON

Members of the ICESat/GLAS science community achieved a major milestone as the laser was activated over Svalbard at 15:18 MST, 20 February 2003. The firing was confirmed with data from the GLAS laser reference system. The laser is close to the boresight, allowing preliminary data to be collected. For more information, please visit the official ICESat site.

12 JANUARY 2003
ICESAT LAUNCHES SUCCESSFULLY

The Ice, Cloud and land Elevation Satellite (ICESat) was successfully launched Sunday, January 12, from Vandenberg Air Force Base. See the official NASA press release.

Page last updated: 06/25/08