N: 90 S: -90 E: 180 W: -180
TABLE OF CONTENTS
Description
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.
Version Description
A new parameter was added to the equation used to compute blowing snow. The algorithm detects blowing snow at two rates (25 Hz and 1 Hz), however, the optimal threshold for low rate detection was found to be different (lower) than for high rate detection. The new parameter (lr_bsnow_fac) adjusts the low rate detection threshold and improves retrievals. The new parameter's nominal value of 0.5 is adjustable; Low-rate blowing snow height (profile_[x]/low_rate/bsnow_h) is now computed as defined in the ATBD for ATL04; The value for the high rate blowing snow threshold constant (bs_thresh_scale) was changed from 10.0 to 20.0 to reduce blowing snow detections; A new parameter for blowing snow intensity (profile_[x]/high_rate/bsnow_intensity) was added, defined as the average scattering ratio within the blowing snow layer multiplied by the 10 m level wind speed; ATL09 was updated to accommodate the new pass-through constant (alpha) added to ATL04; The single scaling constant phi, used to define a threshold in the apparent surface reflectance (ASR) cloud detection algorithm, was replaced by two constants, phi_land and phi_ocean. These new scaling parameters allow for different thresholds over land and ocean to address analyses that indicate the algorithm was reporting too many clouds over land and too few over ocean; Areas masked out in ATL04 due to dense clouds were not being properly masked out in ATL09. This bug was corrected; The cloud_det_layer_thick parameter was removed.
Product Summary
Platforms
Instruments
Spatial Extent
Spatial Resolution
280 Meters
Spatial Reference System(s)
WGS 84 (EPSG:4326)
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
ORBIT
Temporal Extent
2018-10-13 to 2020-11-11
Temporal Resolution
91 Day
Concept ID
C4115898164-NSIDC_CPRD
Data State
DEPRECATED
Number of Files/Granules
0
Processing Level
3
Published
Science Keywords
Cloud Properties
,
Lidar Backscatter
Citation
Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.
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Citation Copied
Palm, S., Yang, Y., Herzfeld, U., Hancock, D., Barbieri, K., Wimert, J., & the ICESat-2 Science Team. (2020). ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 3 [Dataset]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/ATLAS/ATL09.003 Date Accessed: 2026-08-01
Palm, S., Yang, Y., Herzfeld, U., Hancock, D., Barbieri, K., Wimert, J., & the ICESat-2 Science Team. (2020). ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 3 [Dataset]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/ATLAS/ATL09.003 Date Accessed: 2026-08-01
Palm, Steve, et al. “ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 3.” NASA National Snow and Ice Data Center Distributed Active Archive Center, 2020, https://doi.org/10.5067/ATLAS/ATL09.003. Date Accessed: 2026-08-01
TABLE OF CONTENTS
Documents
USER'S GUIDE
ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)
DATA PRODUCT SPECIFICATION
Publications Citing This Dataset
Filters
| Title | Year Sort ascending | Author | Topic |
|---|---|---|---|
| Detection and Height Measurement of Tenuous Clouds and Blowing Snow in ICESat2 ATLAS Data | Herzfeld, Ute, Hayes, Adam, Palm, Stephen, Hancock, David, Vaughan, Mark, Barbieri, Kristine | Lidar Backscatter, Cloud Properties | |
| OnOrbit Radiometric Performance on ICESat2 | Gibbons, Aimee, Neumann, Thomas, Hancock, David, Harbeck, Kaitlin, Lee, Jeffrey | Terrain Elevation, Glacier Elevation/Ice Sheet Elevation, Cloud Properties, Lidar Backscatter, Sensor Characteristics |
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