The Phillips Laboratory is developing CO2 laser technology for making long range sensing measurements at multiple wavelengths in the 9 - 11 micron regime. A line selectable CO2 system that operates on both the P and R transitions at 9.6 and 10.6 microns is described. The device characteristics and laboratory calibration procedures designed to insure accurate measurements are discussed. The system is capable of making atmospheric gas measurements using either atmospheric backscatter or topographic reflection. Results of laboratory measurements using an SF6 absorption cell are presented. The techniques for data reduction and post processing are described. Included is the approach taken to perform the data reduction using multiple wavelengths for gas analysis and identification. Results will be used for design of a high power airborne system designed for a variety of military and environmental applications.