Landsat 9 Atmospheric Correction

  • Released Monday, March 22, 2021
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Landsat collects light in visible and infrared wavelengths. Sunlight reflects off Earth’s surface, and scientists identify the land cover based on which wavelengths are reflected strongly or weakly.

But sunlight is also reflected by particles in the atmosphere, which distorts the data and can lead to what looks like a haze in the imagery. Using basic principles of physics, and knowing the meteorological conditions, scientists can determine the effects of the scattering and absorption as light passes through the atmosphere. This atmospheric correction is essential to determining exactly how much of each wavelength reflected of the features of the surface, and having quantifiable data.

The videos below show different examples of atmospheric scattering which need to be accounted for when doing atmospheric correction of satellite data. In these cases, it is for observations over water. The resulting atmospheric corrections are part of the process for the new Landsat Aquatic Reflectance data product.

Landsat’s highly calibrated data products, free to download and use, are making detailed Earth-observation data more accessible to users and bringing a greater benefit to society.

Light from the sun reflects off Earth's surface, and is collected by the satellite.

Some of the reflected sunlight gets scattered by molecules in the atmosphere on the way to the satellite, lessening the signal received.

Close-up view of reflected light being scattered on the way to the satellite, removing it from data collection.

Sometimes light that never made it to the surface gets scattered by molecules in the atmosphere, and gets sent into the satellite, adding a false signal.

Close-up view of sunlight being scattered into the satellite, adding signal that is not from the surface of Earth.

Sometimes light is scattered in a downward direction, causing it to reflect off the target spot and up into the satellite. This causes extra signal to be collected at the satellite.

Close-up view of light being scattered, forcing it downward to hit the surface target and get reflected up into the satellite.

Credits

Please give credit for this item to:
NASA's Goddard Space Flight Center Conceptual Image Lab

This page was originally published on Monday, March 22, 2021.
This page was last updated on Wednesday, May 3, 2023 at 1:44 PM EDT.

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