Balloon-borne laser heterodyne radiometer for measurements of stratospheric trace species

Remote measurements of a key stratospheric radical species, chlorine monoxide, have been made with a recently developed balloon-borne instrument: a laser heterodyne radiometer. The characteristics of this instrument, which facilitate its use for measurement of selected trace species in the stratosphere, are described here. The technique of solar occultation in the IR is used to provide the measurement data. This technique is briefly described to point out the high sensitivity and specificity which can be achieved when using a high spectral resolution instrument such as an IR heterodyne radiometer in this manner.