15 μm polarization coherent lidar incorporating time-division multiplexing

Wang, Chong; Xia, Haiyun; Shangguan, Mingjia; Wu, Yuqi; Wang, Lu; Zhao, Lijie; Qiu, Jiawei; Zhang, Renjun

doi:10.1364/oe.25.020663

Cited by 50 publications

(28 citation statements)

References 33 publications

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“…and robust in stability due to the all-fiber configuration. More details of this lidar are described in Wang et al (2017). The key parameters of the CDL are listed in Table 1.…”

Section: Coherent Doppler Wind Lidarmentioning

confidence: 99%

“…Among these instruments, lidar can make measurements alone with sufficient long detection range, multi scanning mode, high temporal/spatial resolution. Recently, a micro-pulse coherent Doppler lidar (CDL) is developed to measure wind field with temporal resolution of 2 s and spatial resolution of 60 m in ABL (Wang et al, 2017). Wave motions such as high frequency GWs can be revealed from the vertical wind measured by this lidar in the whole ABL.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Long-live High Frequency Gravity Wavesin Atmospheric Boundary Layer: Observations and Simulations

Jia¹,

Yuan²,

Wang³

et al. 2019

Preprint

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Abstract. A long-live gravity wave (GW) in atmospheric boundary layer (ABL) during a field experiment in Anqing, China (116&#176;58&#8242;&#8201;E, 30&#176;37&#8242;&#8201;N) is analysed. Persistent GWs over 10 hours with periods ranging from 10 to 30&#8201;min in the ABL within 2&#8201;km height are detected by a coherent Doppler lidar from 4 to 5 in September 2018. The amplitudes of the vertical wind due to these GWs are about 0.15~0.2&#8201;m&#8201;s&#8722;1. The lifetime of the GWs is more than 20 wave cycles. There is no apparent phase progression with altitude. The vertical and zonal perturbations of the GWs are apparent quadrature with vertical perturbations generally leading ahead of zonal ones. Based on experiments and simplified 2-Dimensional Computational Fluid Dynamics (CFD) numerical simulations, a reasonable generation mechanism of this persistent wave is proposed. A westerly low-level jet of ~&#8201;5&#8201;m&#8201;s&#8722;1 exists at the altitude of 1~2&#8201;km in the ABL. The wind shear around the low-level jet lead to the wave generation in the condition of light horizontal wind. Furthermore, a combination of thermal and Doppler ducts occurs in the ABL. Thus, the ducted wave motions are trapped in the ABL with long lifetime.

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“…and robust in stability due to the all-fiber configuration. More details of this lidar are described in Wang et al (2017). The key parameters of the CDL are listed in Table 1.…”

Section: Coherent Doppler Wind Lidarmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Long-live High Frequency Gravity Wavesin Atmospheric Boundary Layer: Observations and Simulations

Jia¹,

Yuan²,

Wang³

et al. 2019

Preprint

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“…Coherent Doppler lidar (CDL) has been developed as a powerful tool for atmospheric wind velocity measurement, [1][2][3][4] aircraft wake-vortex hazard detection, [5][6][7] and wind turbulence measurement 8,9 with high temporal space resolution and high measurement accuracy due to its high carrier-to-noise detecting characteristics. The enabling modules for high-performance CDL system include laser transmitter, [10][11][12] balanced detection, 13,14 and weak-regime wind estimation algorithm.…”

Section: Introductionmentioning

confidence: 99%

“…23 In 2016, Zhai et al 24 developed a 1.5-μm pulsed CDL with variable spatial resolution from 15 to 60 m; its discrepancies with radiosonde observation results were within acceptable limits. In 2017, Wang et al 3 presented a versatile CDL with 0.5-m∕s measurement precision and 6-km detection ability, and its stability was demonstrated by continuous wind detection of the atmospheric boundary layer. According to the Commission for Instruments and Methods of Observation guidebook, 25 the accuracy of high-quality windfinding systems should be maintained in less than wind speed of 1 m∕s and direction of 5-deg level.…”

Section: Introductionmentioning

confidence: 99%

Performance validation on an all-fiber 1.54-μm pulsed coherent Doppler lidar for wind-profile measurement

et al. 2020

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Performance validation on an all-fiber 1.54-μm pulsed coherent Doppler lidar for wind-profile measurement,"Abstract. The characteristics and capability of a homemade all-fiber 1.54-μm pulsed coherent Doppler lidar (CDL) were validated in field experiments by comparing the detection results with a collocated lidar and sounding balloons. With the range gate of 30 m and temporal resolution of 16 s at velocity-azimuth display mode, the detection capability of the CDL ranged from 0.1 to 5 km, and the time sequence and height position of this CDL were calibrated by the collocated lidar. In the intercomparison experiments with sounding balloons, the discrepancy of 30-s averaged measurement results of horizontal wind speed and wind direction was nearly 0.7 m∕s and 5.3 deg, respectively. The good agreement achieved in such a short averaged time period was a convincing case of intercomparison experiments between CDL and sounding balloon. The CDL system demonstrated good reliability and operational stability in field experiments.

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“…The spatial and temporal resolution are 19.2 m and 2 s, respectively. This noncoding CDWL is upgraded from our previous system [24].…”

mentioning

confidence: 99%

Meter-scale spatial-resolution-coherent Doppler wind lidar based on Golay coding

Wang¹,

Xia²,

Wu³

et al. 2019

Opt. Lett.

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Generally, the pulse duration of a coherent Doppler wind lidar (CDWL) is shortened to minimize the spatial resolution at the sacrifice of carrier-to-noise ratio, since the peak power of a laser source is limited by the stimulated Brillouin scattering or other nonlinear optical phenomena. To solve this problem, an all-fiber CDWL incorporating Golay coding is proposed and demonstrated. Given the peak power of the laser pulse, the Golay coding method can improve the measuring precision by improving the pulse repetition frequency of the outgoing laser. In the experiment, the Golay coding implementation is optimized by normalizing the intensity of every single pulse of the outgoing laser with a closed-loop feedback, achieving a spatial resolution of 6 m and a temporal resolution of 2 s with a maximum detection range of 552 m. The wind profile in line of sight and the result derived from another noncoding CDWL show good agreement.Doppler wind lidar (DWL) with an all-fiber structure is developed rapidly due to its inherited characteristics, such as high spatial/temporal resolution, high precision, large dynamic range, strong immunity to electromagnetic (EM) interference, and its stability in harsh environments. DWL has been used widely in different applications and scientific researches, such as aviation safety, air force operation in a carrier, wind power generation, and forecast of extreme weather events. Although DWL is mature and commercially available, minimizing the spatial resolution is still a great challenge [1][2][3][4][5][6][7].In order to improve the aviation safety and optimize the aerodynamic design of an aircraft, the impact of small-scale turbulence on aircraft is receiving increasing attention. Aircraft vortex and wakes have also become a serious limitation in managing the efficiency and capacity of airports [8]. The wingspan of the aircraft is about tens of meters. In such a scale, to study and estimate the dynamic influence of the surrounding atmospheric environment (small-scale turbulence, aircraft vortex, and wakes) on the aircraft, DWL with meter-scale spatial resolution is highly demanded.The spatial resolution (ΔR) of a lidar based on the timeof-flight method is defined as ΔR cΔT ∕2, where ΔT is the duration [full width at half-maximum (FWHM)] of the transmitted laser pulse. c is the speed of light in the atmosphere. The lidar equation is used to describe the relationship between the backscatter signal, transmitted laser, and atmosphere, and it is defined as [9]where P s R is the power of the backscatter signal at a distance of R, E T is the energy of a single laser pulse, η T is the transmitter optical efficiency, η R is the receiver optical efficiency, and T is the single-pass transmittance of laser in atmosphere. β is the aerosol backscattering coefficient, and A r is the effective area of the telescope. In principle, the following three problems limit the spatial resolution improvement of a lidar:(1) In coherent Doppler wind lidar (CDWL), the carrierto-noise ratio (CNR) is proportional to ΔT ...

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15 μm polarization coherent lidar incorporating time-division multiplexing

Cited by 50 publications

References 33 publications

Long-live High Frequency Gravity Wavesin Atmospheric Boundary Layer: Observations and Simulations

Long-live High Frequency Gravity Wavesin Atmospheric Boundary Layer: Observations and Simulations

Performance validation on an all-fiber 1.54-μm pulsed coherent Doppler lidar for wind-profile measurement

Meter-scale spatial-resolution-coherent Doppler wind lidar based on Golay coding

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