absorption différentielle de la lumière laser

CONT: DIAL Techniques. DIAL (Differential Absorption of Laser Light) uses a two or more wavelength LIDAR to examine the absorption of a pollutant. By subtracting the effect from the non-absorbed wavelength, the system can be made specific to a certain pollutant. DIAL systems have been used for remotely measuring SO[subscript 2] but at the present time sensitivity is low requiring tens to hundreds of parts per million concentrations.