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Full catalog/ATL04
ATL04·v007·dataset

Laser backscatter profiles of the atmosphere (ICESat-2)

ATLAS/ICESat-2 L2A Normalized Relative Backscatter Profiles V006
land NASA NSIDC_CPRD Level 2A active HDF5
In plain English

What it measures. Vertical profiles of how much of the laser light is scattered back by the atmosphere along the satellite's track, sampled 25 times a second up to about 14 kilometers high in roughly 30-meter steps.

How it's made. Collected by the ATLAS laser instrument on NASA's ICESat-2 satellite, recording the uncalibrated return of its green (532 nm) laser pulses, with calibration values included.

How & where you'd use it. Lets scientists study clouds, aerosols, and thin atmospheric layers like haze and smoke, and supports correcting ICESat-2's main job of measuring ice and land heights.

What's measured

SPECTRAL/ENGINEERING › LIDAR › LIDAR BACKSCATTER

Coverage & cadence

  • Time span2018-10-13 → ongoing
  • Measured byICESat-2 (ATLAS)
  • Processing levelLevel 2A
  • Spatial extent-180, -88, 180, 88
  • FormatsHDF5
  • StatusACTIVE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

ATL04 contains along-track normalized relative backscatter (NRB) profiles of the atmosphere. The product includes full 532 nm (14 km tall) uncalibrated attenuated backscatter profiles at 25 times per second for vertical bins of approximately 30 meters. Calibration coefficient values derived from data between 13.5 and 11 km above the surface are also included. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the ICESat-2 observatory.

Get the data

atl04_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ATL04",
    version="007",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from NSIDC_CPRD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.