Low-coherence Doppler lidar technique for satellite remote wind sensing,

摘要

Abstract: A clear need exists for improved soundings of the atmospheric state for purposes of weather prediction. In particular, lidar offers the promise of making detailed profile measurements from space of temperature, water vapor, and perhaps most importantly, wind speed and direction. In order to make satellite Doppler lidar wind measurements both feasible and practical in the troposphere and lower stratosphere, Doppler measurements using both aerosol and molecular scattered signals will be required. This suggests a lidar system operating in the visible or near ultraviolet to exploit the strong molecular scattering at these wavelengths. Additionally, the hardware constraints imposed by spaceborne large aperture optics make the use of a non- diffraction limited receiving telescope or telescopes very attractive. This effectively discourages the possibility of making this type of measurement from a satellite platform by coherent detection means. A technique for making Doppler wind measurements using low-coherence Doppler lidar will be described and ground-based measurements demonstrating the capability will be shown. The technique utilizes high spectral resolution Fabry-Perot interferometry to measure the small Doppler shift and is equally applicable to aerosol or molecular scattering. In particular, the scalability of this type of lidar system to full spaceborne use will be discussed.!15