Both passive and active remote monitoring instruments, using discretely tunable infrared gas lasers and heterodyne receivers, have been used for measurements of ozone and other trace constituents in the atmosphere. A ground-based, solar heterodyne radiometer has been used in discrete spectral regions near 9.5 pm to measure altitude profiles of ozone in both the troposphere and stratosphere. Results indicate that this technique shows promise in providing calibration points for earth orbiting ozone measurement instruments. An airborne laser absorption spectrometer has been used to measure tropospheric ozone in two series of flights during the winter and spring of 1977, and these operations will be described here. Plans are also in progress to fly a balloon-borne heterodyne radiometer during the fall of 1977 in order to measure stratospheric trace species.