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Data Set ID: 

ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 4

This data set (ATL09) contains calibrated, attenuated backscatter profiles, layer integrated attenuated backscatter, and other parameters including cloud layer height and atmospheric characteristics obtained from the data. 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.

There is a more recent version of these data.

Version Summary: 

Changes for this version include:

  • Erroneous blowing snow detection was fixed by using an updated ANC30 (NOAA snow/ice maps) file.
  • Added new control parameters demtol1 and demtold2 and low-rate segment_id.
  • Modified blow_snow to accommodate the new surface signal changes.
  • Replaced DDA constant layer_sep with the new constant min_layer_sep.
  • Changed values for phi_ocean, asl_cal_factor and snow_age
  • Changed the low rate blowing snow implementation to select the profiles used based on wind speed and proper relation to the time of low-rate data.
  • Fixed the computation error in total column optical depth to take the cosine of tilt_angle in radians rather than degrees.
  • Implemented surface returns based on density, a replacement algorithm for Cloud/Aerosol Determination and detected ground as a layer when computing density algorithm cloud layer confidence
  • Improved the algorithm that removes ground surface from cloud layers.
  • Added 400 shots to the theoretical background equation.
  • Removed unused constant grd_search_width and added new constant min_layer_sep.
  • Remove references to GMTED in dem_h and dem_flag.
Data Format(s):
  • HDF5
Spatial Coverage:
N: 90, 
S: -90, 
E: 180, 
W: -180
Spatial Resolution:
  • 280 m
Temporal Coverage:
  • 13 October 2018 to 15 July 2021
Temporal Resolution91 dayMetadata XML:View Metadata Record
Data Contributor(s):Steve Palm, Yeukui Yang, Ute Herzfeld, David Hancock, Kristine Barbieri, et al

Geographic Coverage

No access options.

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Palm, S. P., Y. Yang, U. C. Herzfeld, D. Hancock, K. A. Barbieri, J. Wimert, and the ICESat-2 Science Team. 2021. ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 4. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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