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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
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Once you have logged in, you will be able to click and download files via a Web browser. There are also options for downloading via a command line or client. For more detailed instructions, please see Options Available for Bulk Downloading Data from HTTPS with Earthdata Login. Earthdata Search: This application allows you to search, visualize, and access data across thousands of Earth science data sets. Additional customization services are available for select data sets, including subsetting, reformatting, and reprojection. |
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].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
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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
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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
