Laser Altimeter Based on Random Code Phase Modulation and Heterodyne Detection

Yang, Fu; He, Yabai; Chen, Weibiao; Zhan, Yufeng

doi:10.1109/lpt.2014.2356333

Cited by 10 publications

(2 citation statements)

References 17 publications

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“…The schematic of the system is shown in Fig.1. [4] FOC: fiber optic coupler; EOPM: electro-optic phase modulator; AOM: acousto-optic modulator; OC: optical circulator; BD: Balance detector; ADC: dual channel AD capture card; AWG: Arbitrary waveform generator; ETC: external trigger circuit…”

Section: The Lidar Systemmentioning

confidence: 99%

Research on a Wind Lidar Without Blind Zone Based on the Technologies of Pseudo Random Code Phase Modulation and Heterodyne Detection

2020

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In this measurement method, a wind lidar system with no blind zone based on the technologies of heterodyne detection and pseudorandom code phase modulation is proposed. The simulation results show the feasibility of the method. 15m range resolution and 7.75cm/s line of sight (LOS) wind velocity resolution can be achieved from 0 m to 300m, when the laser transmitted power is 2mW, the transmitted pulse length is 100us, the receiving telescope aperture is 2cm, and an accumulation times of 10. The simulation results also show the positive effect of the transmitted pulse length.

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Section: The Lidar Systemmentioning

confidence: 99%

Research on a Wind Lidar Without Blind Zone Based on the Technologies of Pseudo Random Code Phase Modulation and Heterodyne Detection

2020

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“…Recently, the pulse coding technology used in communication has been adopted in optical fiber sensing [17,18], ranging lidar [19], and radar [20]. By using the appropriate pulse coding algorithm, one cannot only improve the performance of the lidar by increasing the f rep , but also enhance the spatial resolution without distance ambiguity.…”

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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Comparison among Silicon modulators based on Free-Carrier Plasma Dispersion Effect

Pérez-Galacho

Marris‐Morini

Cassan

et al. 2015

2015 17th International Conference on Transparent Optical Networks (ICTON)

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Laser Altimeter Based on Random Code Phase Modulation and Heterodyne Detection

Cited by 10 publications

References 17 publications

Research on a Wind Lidar Without Blind Zone Based on the Technologies of Pseudo Random Code Phase Modulation and Heterodyne Detection

Research on a Wind Lidar Without Blind Zone Based on the Technologies of Pseudo Random Code Phase Modulation and Heterodyne Detection

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

Comparison among Silicon modulators based on Free-Carrier Plasma Dispersion Effect

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