ABSTRACT
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.
ABSTRACT
A blackbody heterodyne radiometer using a widely tunable PbSnSe-diode laser as the local oscillator (LO) achieved signal-to-noise performance that was an order of magnitude better than previously reported and only a factor of 2.5 below that obtained with a CO(2)-laser LO. The diode laser system performance was within a factor of 6 of an ideal radiometer. High-resolution blackbody heterodyne absorption spectra of ethylene at 10.6 microm were obtained with a 0.4-sec post-detection integration time by tuning the diode LO in a closed-cycle cryogenic cooler.
