Multi-Wavelength Lidar

Abstract

Multi-wavelength LIDARs have been intensively researched and developed over the last decade, owing to their high potential in monitoring of environment and air pollution. The abbreviation LIDAR (Light Detection And Ranging) is now often used to describe many different devices for remote sensing. In the present paper this term is used to describe a device for remote detection and analysis of possible gaseous impurities (pollutants) in air. In light of the fact that the proposed method is based on the absorption in atmosphere of a fixed laser beam with mirror or topographic object at its remote end, a more exact term would be “laser remote spectrometer”.Most published developments are based on the so-called frequency agile scheme, when a laser is tuned over its oscillating lines sequentially, one line per pulse. Simultaneous generation of many laser lines presents serious advantages in real atmosphere, providing a tool to overcome difficulties from atmospheric turbulence and, in principle, and dramatically improving measurement accuracy. Results of several years’ research, with the aim of creation this new type of LIDAR, are presented in this paper.