ICESat/GLAS Status at NSIDC Melinda Marquis NSIDC Product Team Lead, AMSR-E and GLAS GLAS Science Team Meeting Oct , 2005

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Outline Progress (since last meeting, June 2-3, 2005) Ingested and started distributing Release-22 data Distribution stats Published Chris Shuman’s maps Began subsetting Began “BORG” table (Product-quality information about various ops periods) Submitted Fall AGU abstract Plans Release 23 Release 24 DEM FAQ about multiple releases for users’ benefit #21

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Release 22 Data Release 22 Data: GLA01, (available July 21, 2005) GLA02, (available Aug. 22, 2005) Temporal coverage: to (Laser 3A)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Various Releases:

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Dist. Stats from start of mission (via Data Pool)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Dist. Stats from start of mission (via Gateway)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Dist. Stats from start of mission (via Gateway +Data Pool) Datatype Total files GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA15 687

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , User Affiliations: # of distinct users by user category through Sept. 30,05 user_type Instances ECS OTHER 22 FOREIGN COMMERCIAL 8 FOREIGN GOVERNMENT 14 FOREIGN OTHER 35 FOREIGN UNIVERSITY 53 NASA 21 OTHER 1 US COMMERCIAL 6 US FEDERAL GOVERNMENT 9 US GENERAL PUBLIC 1 US OTHER 5 US STATE/LOCAL GOVERNMENT 2 US UNIVERSITY 64 Total Result 241 Rebinned Research 138 Commercial 14 Govt 25 Other 64 Total 241 Foreign 110 Domestic 131 Total 241

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Published Chris Shuman’s maps Data summaries page: One elevation map/ops period We also made smaller, optimized images of Chris’ maps to serve from our web site (with links to the full-resolution versions from an ftp server).

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Example: Laser 1 Elevations

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Subsetter published July 25 We provide subsetting for GLA01, We’ve had 24 separate requests, from 18 distinct users. (4 users have made 2 requests; 1 users has made 3.) Within a given “request,” subsetting multiple data types (e.g., GLA06 and GLA12) or subsetting a given data sets into multiple regions is common.

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Subsetting (cont.) Data Type# of Requests for Subsetting GLA014 GLA052 GLA066 GLA071 GLA084 GLA092 GLA101 GLA111 GLA127 GLA134 GLA145 GLA151

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Subsetter: Data available for subsetting GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA GLA Data available for subsetting

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , “BORG” Table Goal is to assimilate the most useful product-quality information, about the multiple operations periods, in one table. Laser transmit energies for the two wavelengths Laser footprint size and shape Pointing accuracies Geolocation accuracies Publish this on NSIDC ICESat/GLAS web site. Also to present as a poster at Fall AGU. Dave Harding has provided lots of info.

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , BORG Table (cont.)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Borg Table (cont.)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , AGU Abstract submitted Authors: Melinda, Dave H., Bob S., Jim Abshire, and the GLAS Instrument and Science Teams Title: Ice, Cloud, and land Elevation Satellite (ICESat) Data Quality Information The Geoscience Laser Altimeter System (GLAS) instrument aboard the Ice, Cloud, and land Elevation (ICESat) satellite launched on 12 January The primary objective of the ICESat mission is to provide global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of the mission are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity. The GLAS instrument has three lasers, each of which 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. The three lasers have been operated one at a time, sequentially throughout the mission. To extend mission life, the current operational mode has included 33-day to 56-day campaigns, several times per year. As of abstract submission, a total of seven operational campaigns have been completed. Multiple releases of the ICESat/GLAS data are now available at the National Snow and Ice Data Center ( Here, we present data quality information for the several operational campaigns. The metadata table includes: Laser transmit energies for the two wavelengths; laser footprint size and shape; and pointing and geolocation accuracies. We also provide up-to-date information about the product release versions for each of the 15 data products.

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Plans Next data release: Rel#23 (elev.) products: GLA06, and 12-15, for Laser 3A period. Will have improved pointing data compared to rel#22 elev products. Bob S. working to understand why pointing correction for rel#23 (Laser 3A) differs from that of Laser 2A period Rel. 24 will contain format and file size changes Subsetter changes (From Kris’s talk, slide #13)  Record lengths have changed for GLA05-15 V5.0 libraries will not work with v4.x data and visa versa – bear this in mind when exporting libraries to run F90 routines

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Plans DEM We’ll review what John DiMarzio has and provide further input (in addition to input from Ted Scambos, Oct. 8) FAQ re: multiple releases Action item from June STM I sent draft to Bob S. June 13 Awaiting Bob’s reply Will this be OBE by Rel#24?

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , New (interim) POC at NSIDC Doug Fowler

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Summary We’re distributing rel#22 data We’re providing subsetting We’re looking for DEM We’re looking for rel#23 (GLA06, 12-15) We’re looking for rel#24 (one release with all public data) We’re working on Borg Table

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Backup Slides

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Ted’s Input re: DEM, Oct., 8 I think the best format is an image-like format, with elevations reported as integers (or reals) at each grid node. This is the most-used format for the RAMP DEM of Antarctica. However, it will also be valid and useful for some to report the data in a compressed ascii "lat long elev geoid" table, one line for each grid cell. This second format may be very large (10s of gigabytes) but is easily subsetted upon request. The image-format is more compact, but it does require good geo-spatial handling tools to manipulate. So I think both formats. Other information can be incorporated in ascii 'read me' files and the websites. Antarctica: Polar Stereographic, -71 plane of projection, 0longitude = y axis, WGS84 ellipsoid. That is, identical to RAMP, MOA, and a host of other maps. Greenland: Polar Sterographic, -70 plane of projection, 45longitude = yaxis, WGS84 ellipsoid (NOT TOPEX, NOT Hughes-SSM/I ellipsoids.) This is the emerging US standard for Greenland image maps (e.g., Joughin, Kwok radar maps). The MOG mosaic is also in this projection. I think Terry can provide further corner-point and grid dimension details.

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , FAQ about multiple releases Hi, Bob, At the last GLAS STM, I took an action item to sketch a draft explanation for users explaining why it's so difficult to have just one release of all data. I think if we explain the reason for all the multiple releases, it'll diminish users' frustration caused by the confusion. My draft below is meant only as a starting point from which you can write a more comprehensive explanation. We might post this explanation on any of the following URLs. Let me know if you have a suggestion on where you'd like to see it "Multiple releases of the ICESat/GLAS data are currently available as the science team works to provide the highest possible quality data to the public. Some time periods have been corrected for certain issues, while other time periods haven't had such corrections applied to them (for lack of time as of now, but will be corrected eventually). Various complexities of this mission have occupied the time of the science team and data producers, preventing them for creating one release of data in which all data values have been treated equally. Different laser operating temperatures and different satellite modes (airplane vs. sailboat) are examples of the factors that have varied across the time of the mission. In addition to the various types of corrections applied to the data, the EDG client (the search and order interface at NSIDC via which many users order data) has limitations that mean an additional, older release of data may still be available to the public even though an improved release for certain dates is available also. For instance, Rel#18 data for Fall 2003 (laser 2A) are still available to the public, even though Rel#19 data for those same dates are available: This is because Rel #18 covers two time periods (both Fall 2003 and Spring 2003, during which laser 1 operated). Rel #19 doesn't cover the laser 1 time period (nor does any higher- level public release of data). Thus NSIDC continues to provide public access to Rel #18 data for Spring The EDG client doesn't allow for only certain periods of a given release to be available. In order for NSIDC to provide Rel#18 data for Spring 2003, we must also provide Rel #18 data for Fall Users are urged to use the highest-level release for any given date of data. The table at XXX URL (the Excel table I ed you this morning) provides information about the laser operations during the various campaigns of the ICESat mission." Thanks, Melinda

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Dist. Stats from start of mission (via Data Pool)

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , ICESat: Status of current operations Fifth Release: Jan (Altimetry and Atmospheric) Release-19 for GLA01-15 Sept. 26-Nov. 18, 2003; laser #2A Because rel#19 doesn’t cover laser #1, NSIDC is distributing both rel#18 and rel#19 data Fourth Release: 24 Sept 2004 (Altimetry and Atmospheric) Release-18 for GLA01, 02, Sept Nov 18, 2003; laser #2A Release-18 for GLA08-11 Sept Nov 18, 2003; laser #2A Release-18 for GLA01, 02, 05, 06 &07 Feb. 20-March 20, 2003; laser #1 Release-18 for GLA08 & 09 Feb. 20-March 19, 2003; laser #1 Release-18 for GLA12, 13, 14 & 15 Feb. 20-March 19, 2003; laser #1 Replaces Rel#13, 14 &17 because same temporal coverage GLAS receiver/Optics breadboard telescope. Photo courtesy of NASA/GSFC.

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Rel#12, 13, 14 & 17 No Longer Available First Release: 30 Oct 2003 (Altimetry and Atmospheric) Release-12 for GLA01-15 Mar ; laser#1 Available via EDG and SNOWI Hidden from public upon ingest of Release-18 Second Release: 07 April 2004 (Altimetry) Release-13 for GLA01 Release-14 data for GLA05, GLA06, and GLA12-15 Oct. 15 – Nov ; 33-day sample data set, laser #2A Hidden from public upon ingest of Release-18 Third Release: 19 June 2004 (Atmospheric, 532 nm) Release-17 for GLA02, 07, 08, 09 Atmospheric products GLA02, 07, 08, 09 Oct Nov. 18, 2003; 33-day sample data set, laser #2A Hidden from public upon ingest of Release-18

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Ordering ICESat/GLAS Data from NSIDC Data Pool Search ‘N Order Web Interface (SNOWI) EOS Data Gateway (EDG) Subscription

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Disclaimer

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Release Notes

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Release Info Table

GLAS Science Team Meeting Melinda Marquis, NSIDC DAACOct , Tools Page