For a list of known issues with this product, see the Known Issues document under the Technical References tab.
Data Set ID: 
ATL04

ATLAS/ICESat-2 L2A Normalized Relative Backscatter Profiles, Version 5

ATL04 contains along-track normalized relative backscatter profiles of the atmosphere. The product includes full 532 nm (14 km) uncalibrated attenuated backscatter profiles at 25 times per second for vertical bins of approximately 30 meters. Calibration coefficient values derived from data within the polar regions are also included. 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.

This is the most recent version of these data.

Version Summary: 

Changes for this version include:

  • Reading dem_h and dem_flag from ANC39 rather than input ANC06 and ANC28 files for processing efficiency.
  • Changed dead time correction algorithm used to correct the surface signal magnitude. This should improve the accuracy of the surface_sig parameter and the too small winter time values over Antarctica..
  • Added the podppd_flag parameter to ATL04. The podppd_flag provides identification of ATLAS data in nominal geolocation quality status or a degraded quality. podppd_flag=0 means geolocation is in reference ground track pointing with normal quality. podppd_flag=4 means geolocation is in around-the-world can or ocean scan with normal quality. Other values are degraded quality. This enables detection of ocean scans and other geolocation problems.
  • Fixed a some bugs including an added constant dtime_max as maximum dead time correction, set Fill Value to 127 for cloud_fold_flag, added checks on beam elevation off by 15 degrees, and added a check on negative dead time correction factor.
  • For consistency a list of constants was updated to match the SIPS overrides. See the user guide or ATBD for more details.

COMPREHENSIVE Level of Service

Data: Data integrity and usability verified; data customization services available for select data

Documentation: Key metadata and comprehensive user guide available

User Support: Assistance with data access and usage; guidance on use of data in tools and data customization services

See All Level of Service Details

Parameter(s):
  • LIDAR > LIDAR BACKSCATTER
Data Format(s):
  • HDF5
Spatial Coverage:
N: 90, 
S: -90, 
E: 180, 
W: -180
Platform(s):ICESat-2
Spatial Resolution:
  • 280 m
Sensor(s):ATLAS
Temporal Coverage:
  • 13 October 2018
Version(s):V5
Temporal Resolution91 dayMetadata XML:View Metadata Record
Data Contributor(s):Steve Palm, Yeukui Yang, Ute Herzfeld, David Hancock, Kristine Barbieri, et al

Geographic Coverage

Other Access Options

Other Access Options

Close

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 L2A Normalized Relative Backscatter Profiles, Version 5. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/ATLAS/ATL04.005. [Date Accessed].

It appears your Web browser is not configured to display PDF files. Download adobe Acrobat or click here to download the PDF file.

How To

Programmatic Data Access Guide
Data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system or through our Application Programming Interface (API). Our API offers you the ability to order data using specific temporal and spatial filters... read more
ICESat, IceBridge, and ICESat-2: A primer on data access across the three missions
This guide will provide an overview of the altimetry measurements and data sets across the missions, as well as a guide for accessing the data through NASA Earthdata Search and programmatically using an Application Programming Interface (API). Overview The NASA ICESat, Operation IceBridge, and... read more
Explore, Access, and Customize ICESat-2 data at the NASA NSIDC DAAC
This webinar introduces the ICESat-2 mission and shows you how to explore, access and customize ICESat-2 data with the OpenAltimetry application, using NSIDC DAAC tools, and shows you how to subset, reformat and analyze the data using Python. This webinar was originally presented on July 23, 2019... read more
Search, order, and customize NSIDC DAAC data with NASA Earthdata Search
NASA Earthdata Search is a map-based interface where a user can search for Earth science data, filter results based on spatial and temporal constraints, and order data with customizations including re-formatting, re-projecting, and spatial and parameter subsetting. Thousands of Earth science data... read more
Filter and order from a data set web page
Many NSIDC data set web pages provide the ability to search and filter data with spatial and temporal contstraints using a map-based interface. This article outlines how to order NSIDC DAAC data using advanced searching and filtering.  Step 1: Go to a data set web page This article will use the... read more
How do I convert an HDF5/HDF-EOS5 file into binary format?
To convert HDF5 files into binary format you will need to use the h5dump utility, which is part of the HDF5 distribution available from the HDF Group. How you install HDF5 depends on your operating system. Full instructions for installing and using h5dump on Mac/Unix and... read more

FAQ

What subsetting and reformatting services are available for ICESat-2 data?
The following table describes the subsetting and reformatting services that are currently available for ICESat-2 data via the NASA Earthdata Search tool, along with ... read more