Abstract

The performance of IR sensors and particularly the attainable detection range against targets depends to a large extent on the atmospheric transmission. With the aim to provide data for the calculation of IR transmission in connection with test and evaluation of airborne IR sensors we perform measurements with a lidar. Backscatter from aerosols is measured at two wavelengths, 355 nm and 1.54 μm. Statistical analysis of data from earlier measurements with a ground based transmissometer (ref) has shown that values of the aerosol extinction coefficient at 0.55 and 1.7 μm can be combined to calculate the coefficient for thermal IR with fairly good accuracy. We therefore conclude that lidar returns at two different wavelengths, as obtained in our lidar, may provide data for the calculation of IR transmission at higher altitudes.

© 1998 IEEE