ITT ANGEL Spectroscopic Lidar

Dr. Todd Lines
Department of Physics
Brigham Young University Idaho

Light Detection And Ranging (Lidar) was born shortly after the invention of the laser. Simple lidar systems operate like radar systems using time-of-flight measurements to locate objects or make distance measurements.

DIfferential Absorption Lidar (DiAL) goes beyond the simple time-of-flight measurements by incorporating understanding of the absorption characteristics of gasses in the lidar equation.

ITT Industries has produced the first commercial DiAL-based lidar system. The instrument, called the Airborne Natural Gas Emission Lidar (ANGEL), is designed to be sensitive to methane in the atmosphere for pipeline leak detection. The physics and design considerations of this instrument are discussed in this presentation. The experimental proof-of-concept is discussed. The need for statistical signal processing of the lidar return is also covered and a description of the ANGEL algorithm is given.

Current work at BYU-I will be briefly discussed.