OpenAltimetry

Discover and visualize altimetry data across the globe

About

NASA’s OpenAltimetry (OA) is a free and powerful map-based data visualization and discovery tool for exploring surface elevation profiles from ICESat and ICESat-2 satellite mission altimetry data. With OA, users can explore how different types of surface heights have changed across the Earth over time. You can also easily download the data without the need for any special software or scripts; all you need is a web browser. 

Data availability 

OA’s ICESat-2 elevation data include observations from 2018 to present. The data show multiple photon beams, one day at a time, and users can easily select different dates and overlay MODIS cloud cover data. Types of altimetry data include: 

  • Land ice height  
  • Sea ice height  
  • Land and vegetation height  
  • Sea ice freeboard  
  • Ocean surface height  
  • Inland water surface  

Users can also interact with GLAH06 Global Elevation Data from the ICESat satellite mission. ICESat is the predecessor to ICESat-2 and collected data from 2003 through early 2010. 

About the data

ICESat-2 data

ATL03 | ATLAS/ICESat-2 L2A Global Geolocated Photon Data

This data set (ATL03) contains height above the WGS 84 ellipsoid (ITRF2014 reference frame), latitude, longitude, and time for all photons downlinked by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory. The ATL03 product was designed to be a single source for all photon data and ancillary information needed by higher-level ATLAS/ICESat-2 products. As such, it also includes spacecraft and instrument parameters and ancillary data not explicitly required for ATL03.
https://doi.org/10.5067/ATLAS/ATL03.006

 

ATL06 | ATLAS/ICESat-2 L3A Land Ice Height

This data set (ATL06) provides geolocated, land-ice surface heights (above the WGS 84 ellipsoid, ITRF2014 reference frame), plus ancillary parameters that can be used to interpret and assess the quality of the height estimates. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
https://doi.org/10.5067/ATLAS/ATL06.006

ATL07 | ATLAS/ICESat-2 L3A Sea Ice Height

The data set (ATL07) contains along-track heights for sea ice and open water leads (at varying length scales) relative to the WGS84 ellipsoid (ITRF2014 reference frame) after adjustment for geoidal and tidal variations, and inverted barometer effects. Height statistics and apparent reflectance are also provided. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
https://doi.org/10.5067/ATLAS/ATL07.006

ATL08 | ATLAS/ICESat-2 L3A Land and Vegetation Height

This data set (ATL08) contains along-track heights above the WGS84 ellipsoid (ITRF2014 reference frame) for the ground and canopy surfaces. The canopy and ground surfaces are processed in fixed 100 m data segments, which typically contain more than 100 signal photons. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
Data DOI

ATL10 | ATLAS/ICESat-2 L3A Sea Ice Freeboard

This data set (ATL10) contains estimates of sea ice freeboard, calculated using three different approaches. Sea ice leads used to establish the reference sea surface and descriptive statistics used in the height estimates are also provided. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
https://doi.org/10.5067/ATLAS/ATL10.006

ATL12 | ATLAS/ICESat-2 L3A Ocean Surface Height

This data set (ATL12) contains along-track sea surface heights at variable length scales over cloud-free regions. Estimates of height distributions, surface roughness, surface slope, and apparent reflectance are also provided. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
https://doi.org/10.5067/ATLAS/ATL12.006

ATL13 | ATLAS/ICESat-2 L3A Inland Water Surface Height

This data set (ATL13) contains along-track water surface heights and descriptive statistics for inland water bodies. Water bodies include lakes, reservoirs, bays, and estuaries. Descriptive statistics include along-track surface slope (where data permit), mean and standard deviation, subsurface signal (532 nm) attenuation, wave height, and coarse depth to bottom topography.
https://doi.org/10.5067/ATLAS/ATL13.006

ICESat data

GLAH06 | GLAS/ICESat L1B Global Elevation Data (HDF5), Version 34

GLAH06 Level-1B Global Elevation is a product that is analogous to the geodetic data records distributed for radar altimetry missions. It contains elevations previously corrected for tides, atmospheric delays, and surface characteristics within the footprint. Elevation is calculated using the ice sheet parameterization. Additional information allows the user to calculate an elevation based on land, sea ice, or ocean algorithms. Each data granule has an associated browse product.

https://doi.org/10.5067/ICESAT/GLAS/DATA109

About the missions

ICESat

Mission status: Complete

Time range: 2003 to early 2010

ICESat data available from OpenAltimetry are the 15 Level-1 and Level-2 data products from the Geoscience Laser Altimeter System (GLAS) instrument that was aboard the NASA Ice, Cloud, and land Elevation (ICESat) satellite and distributed by NSIDC. Launched on 12 January 2003 the ICESat's science mission ended after seven years in orbit and 18 laser-operations campaigns.

The main objective of the GLAS instrument was to measure ice sheet elevations and changes in elevation through time. Secondary objectives included measurement of cloud and aerosol height profiles, land elevation and vegetation cover, and sea ice thickness.

ICESat-2

Mission status: Active

Time range: 2013 to present

The ICESat-2 mission collects altimetry data of the Earth's surface. The sole instrument on ICESat-2 is the Advanced Topographic Laser Altimeter System (ATLAS) instrument that measures ice sheet elevation change and sea ice thickness, while also generating an estimate of global vegetation biomass. ICESat-2 continues the important observations of ice-sheet elevation change, sea-ice freeboard, and vegetation canopy height begun by ICESat. ICESat-2 data observations begin in 2013 and extend to the present.

Have questions?

OA has become a NASA Earth science application maintained and supported by the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC). For assistance with OA, contact NSIDC User Services with questions and user-support requests. 

OA history

OA started as an Advancing Collaborative Connections for Earth System Science (ACCESS) Program-funded collaboration between Scripps Institution of Oceanography, San Diego Supercomputer Center at the University of California San Diego, National Snow and Ice Data Center, and EarthScope Consortium (formerly @UNAVCO).