Infrared transmission measurement in the atmosphere

With the purpose of establishing a model for the IR extinction of atmospheric aerosols in relation to weather parameters, we have performed measurements with a transmissometer and meteorological sensors. A CO2-lidar is used to measure aerosol extinction at 106 microns in slant paths in order to investigate the altitude dependence of the extinction. The beam from a pulsed TEA-laser is emitted into the atmosphere and backscattered radiation is detected. The signal is digitized and used as input in a computer program to solve the lidar equation. The extinction coefficient vs range or altitude is obtained. The principle and characteristic properties of the two instruments are described and examples of obtained results are presented.