Low-coherence Doppler lidar technique for satellite remote wind sensing

摘要

Abstract: A clear need exists for improved soundings of theatmospheric state for purposes of weather prediction.In particular, lidar offers the promise of makingdetailed profile measurements from space oftemperature, water vapor, and perhaps most importantly,wind speed and direction. In order to make satelliteDoppler lidar wind measurements both feasible andpractical in the troposphere and lower stratosphere,Doppler measurements using both aerosol and molecularscattered signals will be required. This suggests alidar system operating in the visible or nearultraviolet to exploit the strong molecular scatteringat these wavelengths. Additionally, the hardwareconstraints imposed by spaceborne large aperture opticsmake the use of a non- diffraction limited receivingtelescope or telescopes very attractive. Thiseffectively discourages the possibility of making thistype of measurement from a satellite platform bycoherent detection means. A technique for makingDoppler wind measurements using low-coherence Dopplerlidar will be described and ground-based measurementsdemonstrating the capability will be shown. Thetechnique utilizes high spectral resolution Fabry-Perotinterferometry to measure the small Doppler shift andis equally applicable to aerosol or molecularscattering. In particular, the scalability of this typeof lidar system to full spaceborne use will bediscussed.!15