What is atmospheric correction?

This is a technical term, please refer to:

English name: atmospheric correction

English name: atmospheric correction

Applied discipline: surveying and mapping (first-class discipline); Photogrammetry and Remote Sensing (two disciplines)

Concept: The process of eliminating radiation errors caused by atmospheric scattering in remote sensing images.

All kinds of radiant energy used in remote sensing will interact with the earth's atmosphere-or scatter or absorb, so that the energy will be attenuated and the spectral distribution will be changed. The attenuation of the atmosphere is selective for different wavelengths of light, so the atmosphere has different images for different bands of images. In addition, if the geometric relationship between the sun, the target and the remote sensor is different, and the length of the atmospheric path is different, the pixel gray value of ground objects in different regions of the image is affected by the atmosphere to different degrees, and the pixel gray value of the same ground object is also affected by the atmosphere at different acquisition times. The process of eliminating these atmospheric effects is called atmospheric correction.

Even if the remote sensing system works normally, there are still radiation errors in the obtained data. The two most important environmental attenuation are 1) atmospheric attenuation caused by atmospheric scattering and absorption; 2) Terrain attenuation. However, not all remote sensing applications need atmospheric correction. Whether to correct the atmosphere depends on the problem itself, the history of available remote sensing data types, the amount of atmospheric information currently measured and the accuracy required to extract biophysical information from remote sensing data.