Incoherent Doppler lidar using two wavelengths for wind measurement

Nagasawa, Chikao; Shibata, Yasukuni; Abo, Makoto; Nagai, Tomohiro; Uchino, Osamu

doi:10.1117/12.417066

Cited by 5 publications

(2 citation statements)

References 16 publications

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“…The other is direct detection lidar (DDL). Various instruments, such as the Fabry-Perot interferometer (FPI) [5][6][7][8][9][10], iodine absorption filter [11,12], Fizeau interferometer [13], and Mach-Zehnder interferometer [14] have been chosen theoretically and experimentally to transform the Doppler shift into an irradiance variation, and the estimate of the frequency change can be accomplished by processing the detected signals. There are usually two leading implementations of the DDL when an FPI is used as the frequency discriminator.…”

Section: Introductionmentioning

confidence: 99%

Fabry-Perot interferometer based Mie Doppler lidar for low tropospheric wind observation

et al. 2007

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Similar in principle to recent implementations of a lidar system at 355 nm [Opt. Lett. 25, 1231 (2000), Appl. Opt. 44, 6023 (2005)], an incoherent-detection Mie Doppler wind lidar at 1064 nm was developed and deployed in 2005 [Opt. Rev. 12, 409 (2005)] for wind measurements in the low troposphere, taking advantage of aerosol scattering for signal enhancement. We present a number of improvements made to the original 1064 nm system to increase its robustness for long-period operation. These include a multimode fiber for receiving the reference signal, a mode scrambler to allow uniform illumination over the Fabry-Perot interferometer, and a fast scannable Fabry-Perot interferometer for calibration and for the determination of outgoing laser frequency during the wind observation. With these improvements in stability, the standard deviation of peak transmission and FWHM of the Fabry-Perot interferometer was determined to be 0.49% and 0.36%, respectively. The lidar wind measurements were validated within a dynamic range of +/-40 m/s. Comparison experiments with both wind profiler radar and Vaisala wiresonde show good agreement with expected observation error. An example of 24 h continuous observations of wind field and aerosol backscatter coefficients in the boundary layer with 1 min and 30 m temporal and spatial resolution and 3 m/s tolerated wind velocity error is presented and fully demonstrates the stability and robustness of this lidar.

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Section: Introductionmentioning

confidence: 99%

Fabry-Perot interferometer based Mie Doppler lidar for low tropospheric wind observation

et al. 2007

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“…Coherent lidar measures the Doppler shift by beating the backscattered signal with light from a continuous-wave local oscillator laser, which often resolves the narrowband aerosol and cloud return and is commonly used for relatively small velocity detection. 3 The theory of direct-detection Doppler wind lidar was first described and realized by BenedettiMichelangeli et al 4 Various kinds of instruments, such as Fabry-Perot interferometer (FPI), [5][6][7][8][9][10] iodine absorption filter, 11,12 Fizeau interferometer, 13 and Mach-Zehnder interferometer, 14 have been chosen to discriminate the Doppler shift from the spectrally broadband Rayleigh-Brillouin return of molecules and spectrally narrowband Mie backscatter return of aerosol or cloud particles. The Doppler shift determination for direct detection has two typical implementations: edge technique and fringe-imaging technique.…”

Section: Introductionmentioning

confidence: 99%

Analysis on wind retrieval methods for Rayleigh Doppler lidar

et al. 2013

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Abstract. A modification method is described for Rayleigh Doppler lidar wind retrieval. Compared to the double-edge theory of Korb et al. [Appl. Opt. 38, 432 (1999)] and the retrieval algorithm of Chanin et al. [Geophys. Res. Lett. 16, 1273(1989], it has a greater sensitivity. The signal-to-noise ratio of the energy monitor channel is involved in error estimation. When the splitting ratio of the two signal channels is 1.2, which usually happened during wind detection, it will improve the measurement accuracy by about 1% at 30 km altitude for a Doppler shift of 250 MHz (44 m∕s). Stabilities of retrieval methods, i.e., errors caused by the spectrum width deviation including laser pulse, Rayleigh backscatter, and filter transmission curve are first discussed. The proposed method increases the resultant precision by about 15% at 30-km altitude assuming an 8-MHz deviation in full width at half maximum of the Fabry-Perot interferometer. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Direct-detection Doppler wind measurements with a Cabannes–Mie lidar: A Comparison between iodine vapor filter and Fabry–Perot interferometer methods

et al. 2007

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Atmospheric line-of-sight (LOS) wind measurement by means of incoherent Cabannes-Mie lidar with three frequency analyzers with nearly the same maximum transmission of ~80% that could be fielded at different wavelengths is analytically considered. These frequency analyzers are (a) a double-edge Fabry-Perot interferometer (FPI) at 1064 nm (IR-FPI), (b) a double-edge Fabry-Perot interferometer at 355 nm (UV-FPI), and (c) an iodine vapor filter (IVF) at 532 nm with two different methods, using either one absorption edge, single edge (se-IVF), or both absorption edges, double edge (de-IVF). The effect of the backscattered aerosol mixing ratio, R(b), defined as the ratio of the aerosol volume backscatter coefficient to molecular volume backscatter coefficient, on LOS wind uncertainty is discussed. Assuming a known aerosol mixing ratio, R(b), and 100,000 photons owing to Cabannes scattering to the receiver, in shot-noise-limited detection without sky background, the LOS wind uncertainty of the UV-FPI in the aerosol-free air (R(b)=0), is lower by ~16% than that of de-IVF, which has the lowest uncertainty for R(b) between 0.02 and 0.08; for R(b)>0.08, the IR-FPI yielded the lowest wind uncertainty. The wind uncertainty for se-IVF is always higher than that of de-IVF, but by less than a factor of 2 under all aerosol conditions, if the split between the reference and measurement channels is optimized. The design flexibility, which allows the desensitization of either aerosol or molecular scattering, exists only with the FPI system, leading to the common practice of using IR-FPI for the planetary boundary layer and using UV-FPI for higher altitudes. Without this design flexibility, there is little choice but to use a single wavelength IVF system at 532 nm for all atmospheric altitudes.

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Incoherent Doppler lidar using two wavelengths for wind measurement

Cited by 5 publications

References 16 publications

Fabry-Perot interferometer based Mie Doppler lidar for low tropospheric wind observation

Fabry-Perot interferometer based Mie Doppler lidar for low tropospheric wind observation

Analysis on wind retrieval methods for Rayleigh Doppler lidar

Direct-detection Doppler wind measurements with a Cabannes–Mie lidar: A Comparison between iodine vapor filter and Fabry–Perot interferometer methods

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