Imaging through the atmosphere: An overview

Atmospheric blur is usually attributed in the remote sensing community to forward scatter of light by aerosols, called the adjacency effect, and in the propagation community to optical turbulence. It is our view that both phenomena contribute to atmospheric blur. In some situations such as lines-of-sight close to the ground turbulence is significant, while in others, such as lines of sight with optical depths on the order of unity or more, aerosol blur is significant. However, in general both types of blur should be considered. Examples are cited in which ignoring aerosol scatter leads to incorrect conclusions or in which ignoring turbulence leads to only partial image correction. Both vertical and horizontal imaging are considered. The purpose of the paper is to emphasize the need for both the remote sensing and propagation communities to consider both aerosol blur and turbulence blur in analyses of experimental results.