A method is described for directly measuring atmospheric winds in the 20–120-km altitude interval from a spacecraft. The principle of operation of the wind sensor is the measurement of the Doppler shift between the spectral absorption lines of a gas in a cell within the instrument and the thermal emission lines of the same gas in the atmosphere. The wind measurements are to be made with a spacecraft-borne gas correlation spectrometer viewing the limb of the atmosphere. The measurement of the wind-induced Doppler shift between the two spectra, and thence the magnitude of the wind itself, is accomplished by phase modulating the incoming thermal radiation (equivalent to frequency modulation) by means of an electrooptically active crystal to determine the frequency shift required to reestablish exact correlation between the lines in the cell and the lines from the atmosphere. Results of numerical simulations of the wind-sensor performance are presented showing the noise-equivalent-wind to be between 1 and 5 m/sec over most of the stratosphere and mesosphere.
© 1983 Optical Society of America
Daniel J. McCleese and Jack S. Margolis, "Remote sensing of stratospheric and mesospheric winds by gas correlation electrooptic phase-modulation spectroscopy," Appl. Opt. 22, 2528-2534 (1983)