Two-dimensional remote air-pollution monitoring via tomography

Computerized tomography is proposed as a means of mapping two-dimensional air pollutant concentrations over an area that may contain several sources of pollution. Measurements would be conducted using a single tunable laser source to generate a number of secondary light sources around the perimeter of a circle, analogous to X rays in conventional computerized medical tomography, the radiation from which is measured by a series of detectors. Examples of the mapping of a 2-km diameter area with a 10-m depth resolution and a 10-km radius circle with a spatial resolution of 100 m are used to illustrate that the power requirements (3.0 and 25 W, respectively) are orders of magnitude lower than those of a depth-resolved differential absorption measurement, and are well within the capabilities of state-of-the-art lasers.