Application of the Lidar to Air Pollution Measurements

Abstract

An urgent need exists for a technique of rapid and economical measurement of vertical profiles of atmospheric particulate concentration. It is shown in this paper that the lidar, or optical radar, is capable of meeting this need. The first part of the paper presents the physical basis of the technique wherein equations based on the Mie scattering theory and the radar equation are derived which permit quantitative calculation of the particulate concentration, turbidity index, and horizontal visibility from the lidar data as functions of height. The remainder of the paper is devoted to a brief description of an operational lidar system, some examples of results obtained with it, and an evaluation of its performance during six months of use. A subsequent paper will present some detailed case studies of pollution episodes in the Chicago Metropolitan area.