DF Laser Propagation Analysis.

Abstract : Investigations in support of the NRL effort to obtain a field verified model of the atmospheric absorption of DF laser radiation are reported. New absorption line parameters have been extracted from spectroscopic data in the DF laser region. A simple analytic model has been developed for each DF laser line. The model allows the laser transmission to be simply calculated for any arbitrary temperature or humidity. The coefficients for this model are periodically updated by SAI, and the last set of coefficients is included in the report. Included also are plots of the functional dependence of DF laser transmission on temperature and humidity, and tables of the data used to obtain the coefficients. The atmospheric molecular transmission has been calculated and plotted for all wavelengths in the DF laser region (3.57 - 4.03 micrometers) and in the CO laser region (4.55 - 5.26 micrometers). (Author)