Atmospheric Extinction Measurements at Nd-YAG and DF Laser Wavelengths Performed in Conjunction with the JAN Propagation Tests,June-September 1975.

摘要

The NRL Infrared Mobile Optical Radiation Laboratory (IMORL) consisting of various infrared laser sources, large-aperture collimating optics, and precision calibrated infrared detectors and electronics was operated in conjunction with the JAN Baseline Demonstration Laser propagation tests during June-September 1975. The trailer-housed elements of the IMORL unit were deployed so as to use an atmospheric measurement path about 5 km long between the TRW Capistrano Test Site and Camp Pendleton Marine Base. Extensive measurements of atmospheric transmission at several DF laser wavelengths between 3.6 and 4.1 micrometers were obtained as well as measurements at the Nd-YAG laser wavelength of 1.06 micrometers. The optical measurements were supported by meteorological observations near the IMORL transmitter and receiver sites. Atmospheric aerosol distributions were monitored during the experiments, and Mie scattering calculations were performed using the aerosol data and were compared to aerosol extinction values derived from the optical measurements obtained using the 5-km-long path. The water-vapor dependence of molecular absorption for each of the 22 DF laser lines studied was compared to values obtained during earlier experiments at the Cape Canaveral Air Force Station and to theoretical predictions based on a HI-TRAN calculation using a line atlas. The experimental apparatus used (IMORL facility) and the measurements procedures followed are briefly described. The measurement results obtained and their comparisons to theoretical predictions for molecular absorption and aerosol scattering at DF laser wavelengths are presented and discussed. (Author)