ICESatGLAS Tools at NSIDC Melinda Marquis NSIDC Product

ICESat/GLAS Tools at NSIDC Melinda Marquis NSIDC Product Team Lead, AMSR-E and GLAS Feb. 16, 2005 1 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

Outline: ICESat/GLAS Tools IDL Visualizer NSIDC GLAS Altimetry elevation extractor Tool (NGAT) IDL Readers Fortran 90 Readers IDL Ellipsoid Conversion tool ICESat/GLAS Subsetter GLAS Tools Page at http: //nsidc. org/data/icesat/tools. html GLAS on ICESat. Graphic is courtesy of Ball Aerospace. 2 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

IDL Visualizer §Reads data from an ICESat/GLAS file and views graphical summaries of variables. §A quick-start tutorial is available on-line to help users get started viewing ICESat/GLAS data. §SCF responded to NSIDC’s request that this package be made to work with the free IDL Virtual Machine (Jan. 2005). §Developed by the GLAS SCF. 3 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

IDL Visualizer 4 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

IDL Visualizer 5 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

NSIDC GLAS Altimetry elevation extractor Tool (NGAT) §Extracts elevation and geoid data from GLAS altimetry products (GLA 06 and GLA 12 -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. §Developed by NSIDC (Matt Savoie). 6 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

NSIDC GLAS Altimetry elevation extractor Tool (NGAT) Record No. Date Time Lat. (deg. ) 372402615 03/07/2004 00: 31: 01. 540 372402615 03/07/2004 00: 31: 01. 565 372402615 03/07/2004 00: 31: 01. 590 372402615 03/07/2004 00: 31: 01. 615 372402615 03/07/2004 00: 31: 01. 640 372402615 03/07/2004 00: 31: 01. 665 7 Long. (deg. ) 61. 775047 213. 540418 61. 776580 213. 539815 61. 778114 213. 539224 61. 779650 213. 538645 61. 781187 213. 538080 61. 782726 213. 537528 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005 Elevation (m) 562. 026 561. 983 562. 099 562. 267 562. 097 562. 012 Geoid (m) 18. 440000 18. 434615 18. 429231 18. 423846 18. 418462 18. 413077

IDL Readers §Read data from an ICESat/GLAS file and prints all the variables in ASCII format. §The readers run under IDL (6. 0 or greater) or the free IDL Virtual Machine (IDLVM) available from Research Systems, Inc. §Developed by the GLAS SCF. 8 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

IDL Readers 9 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

Fortran 90 Readers §This set of programs reads data from an ICESat/GLAS file and prints all the variables in ASCII format (identical output as IDL reader). §This is sample code 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. 10 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

Fortran 90 Readers §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. §Runs on only HP/UX and some Sun platforms. §Developed by the GLAS SCF. 11 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

IDL Ellipsoid Conversion tool • Converts between the ICESat/GLAS and WGS-84 ellipsoids. • ICESat/GLAS geolocated products are given in terms of geodetic latitude, longitude, and height (elevation) above the TOPEX/Poseidon ellipsoid. • Three programs convert latitudes and elevations between the WGS-84 and the TOPEX/Poseidon ellipsoids. • Developed by NSIDC (Terry Haran). 12 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

ICESat/GLAS Subsetter §User enters bounding coordinates and temporal range of interest in a web form on NSIDC’s site. §NSIDC provides the spatially subsetted data. §Developed by NSIDC (Matt Savoie), in conjunction with the GLAS SCF. §NSIDC uses our r. SCF (with code dev’d by main SCF) to perform subsetting. 13 Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

Summary • NSIDC has worked with the ICESat/GLAS science team, SCF and SIPS to provide needed tools to the broad user community. § Readers § Visualization tools § Subsetter • This collaborative effort benefits users and facilitates use of the ICESat/GLAS data. • Thanks go to the science team, SCF, SIPS and NSIDC programmers and staff: 14 Jay Zwally John Di. Marzio Matt Savoie David Hancock Kris Barbieri Terry Haran Anita Brenner Jeff Guerber Siri Jodha Singh Khalsa Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005

GLAS Data Products 15 Short. Name Longname Received # of Granules Ingested GLA 01 L 1 A Global Altimetry Data X 206 GLA 02 L 1 A Global Atmosphere Data X 26 GLA 03 L 1 A Global Engineering Data X 22 GLA 04 L 1 A Global Laser Pointing Data X 22 GLA 05 L 1 B Global Waveform-based Range Corrections X 95 GLA 06 L 1 B Global Elevation Data X 131 GLA 07 L 1 B Global Backscatter Data X 6 GLA 08 L 2 Global PBL & Elevated Aerosol Layer Heights X 3 GLA 09 L 2 Global Cloud Heights for Multi-layer Clouds X 3 GLA 10 L 2 Global Aerosol Vertical Structure Data X 2 GLA 11 L 2 Global Thin Cloud/Aerosol Optical Depths Data X 2 GLA 12 L 2 Global Antarctic & Greenland Ice Sheet Alt. X 2 GLA 13 L 2 Sea Ice Altimetry Data X 2 GLA 14 L 2 Global Land Surface Altimetry Data X 2 GLA 15 L 2 Ocean Altimetry Data X 2 GLA 16 is not fully developed Polar DAAC Advisory Group Melinda Marquis, NSIDC DAAC Feb. 16, 2005