Atmospheric correction
Atmospheric correction is the process of adjusting images taken by satellite or airborne sensors to remove distortions caused by the atmosphere. These distortions—mainly due to the scattering and absorption of sunlight by particles and gases—can affect how accurately the sensor captures the true reflectance of the Earth's surface.
In remote sensing, atmospheric effects can significantly alter the spectral characteristics of the radiation detected by sensors. This occurs because light must pass through the atmosphere twice—first as sunlight traveling to the Earth's surface, and again as reflected light returning to the sensor—undergoing both absorption and scattering along the way. These distortions can affect the accuracy of surface reflectance measurements and are typically corrected through a range of physical and statistical methods.
Examples of atmospheric correction methods
| Sensor | Approach |
| MSS | band-to-band regression |
| MSS | all-band spectral covariance |
| airborne MSS | band-to-band regression |
| AVHRR | iterative estimation |
| MSS, TM | DOS with exponential scattering model |
| TM | DOS with exponential scattering model, downwelling atmospheric radiance measurements |
| TM | pixel-by-pixel tasseled cap haze parameter |
| AVHRR | DOS, NDVI, AVHRR band 3 |
| airborne TMS, Landsat TM | ground and airborne solar measurements, atmospheric modeling code |
| TM | comparison of ten DOS and atmospheric modeling code variations with field data |
| TM | dark target, modeling code |
| TM | atmospheric modeling code, region histogram matching |
| TM | DOS with estimated atmospheric transmittance |
| TM | dark target, atmospheric modeling code |
| TM, ETM+ | empirical line method, single target, ground measurements |
| TM | water reservoirs, comparison of 7 methods for 12 dates |
| AVHRR | 2-band PCT used to separate aerosol components |