Design and performance simulation of 532 nm Rayleigh–Mie Doppler lidar system for 5–50 km wind measurement

2018 ◽  
Vol 412 ◽  
pp. 7-13
Author(s):  
Fahua Shen ◽  
Bangxin Wang ◽  
Wenjuan Shi ◽  
Peng Zhuang ◽  
Chengyun Zhu ◽  
...  
Keyword(s):  
Doppler Lidar ◽  
Lidar System ◽  
Performance Simulation ◽  
Wind Measurement ◽  
And Performance ◽  
532 Nm

scholarly journals Airborne tests of an OAWL Doppler lidar: Results and potential for space deployment

2018 ◽  
Vol 176 ◽  
pp. 02004
Author(s):  
Michael Hardesty ◽  
Sara Tucker ◽  
Sunil Baidar ◽  
Mark Beubien
Keyword(s):  
Instrument Design ◽  
Doppler Lidar ◽  
Atmospheric Models ◽  
Wind Measurement ◽  
Measurement Capability ◽  
Research Aircraft ◽  
Wind Measurements ◽  
Wind Lidar ◽  
532 Nm ◽  
Good Agreement

The 532 nm Green Optical Covariance Wind Lidar (GrOAWL) was flown on a NASA WB-57 research aircraft during the summer of 2016 to validate the instrument design and evaluate wind measurement capability and sensitivity. Comparisons with dropsondes and atmospheric models showed good agreement, demonstrating that a GrOAWL type instrument could provide high-value wind measurements from both airborne and space-based platforms

scholarly journals Aerosol particle depolarization ratio at 1565 nm measured with a Halo Doppler lidar

2020 ◽  
Author(s):  
Ville Vakkari ◽  
Holger Baars ◽  
Stephanie Bohlmann ◽  
Johannes Bühl ◽  
Mika Komppula ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Birch Pollen ◽  
Stream Line ◽  
Doppler Lidar ◽  
Marine Aerosol ◽  
Depolarization Ratio ◽  
Lidar System ◽  
Multi Wavelength ◽  
Linear Depolarization Ratio ◽  
532 Nm

Abstract. Depolarization ratio is a valuable parameter for lidar-based aerosol categorization. Usually, aerosol particle depolarization ratio is determined at relatively short wavelengths of 355 nm and/or 532 nm, but some multi-wavelength studies including longer wavelengths indicate strong spectral dependency. Here, we investigate the capabilities of Halo Photonics Stream Line Doppler lidars to retrieve the particle linear depolarization ratio at 1565 nm wavelength. We utilize collocated measurements with another lidar system, PollyXT at Limassol, Cyprus, and at Kuopio, Finland, to compare the depolarization ratio observed by the two systems. For mineral dust-dominated cases we find typically a little lower depolarization ratio at 1565 nm than at 355 nm and 532 nm. However, for dust mixed with other aerosol we find higher depolarization ratio at 1565 nm. For polluted marine aerosol we find marginally lower depolarization ratio at 1565 nm compared to 355 nm and 532 nm. For mixed spruce and birch pollen we find a little higher depolarization ratio at 1565 nm compared to 532 nm. Overall, we conclude that Halo Doppler lidars can provide particle linear depolarization ratio at 1565 nm wavelength at least in the lowest 2–3 km above ground.

scholarly journals Aerosol particle depolarization ratio at 1565 nm measured with a Halo Doppler lidar

2021 ◽  
Vol 21 (8) ◽  
pp. 5807-5820
Author(s):  
Ville Vakkari ◽  
Holger Baars ◽  
Stephanie Bohlmann ◽  
Johannes Bühl ◽  
Mika Komppula ◽  
...  
Keyword(s):  
Aerosol Particle ◽  
Mineral Dust ◽  
Birch Pollen ◽  
Doppler Lidar ◽  
Marine Aerosol ◽  
Depolarization Ratio ◽  
Lidar System ◽  
Multi Wavelength ◽  
Linear Depolarization Ratio ◽  
532 Nm

Abstract. The depolarization ratio is a valuable parameter for lidar-based aerosol categorization. Usually, the aerosol particle depolarization ratio is determined at relatively short wavelengths of 355 nm and/or 532 nm, but some multi-wavelength studies including longer wavelengths indicate strong spectral dependency. Here, we investigate the capabilities of Halo Photonics StreamLine Doppler lidars to retrieve the particle linear depolarization ratio at the 1565 nm wavelength. We utilize collocated measurements with another lidar system, PollyXT at Limassol, Cyprus, and at Kuopio, Finland, to compare the depolarization ratio observed by the two systems. For mineral-dust-dominated cases we find typically a slightly lower depolarization ratio at 1565 nm than at 355 and 532 nm. However, for dust mixed with other aerosol we find a higher depolarization ratio at 1565 nm. For polluted marine aerosol we find a marginally lower depolarization ratio at 1565 nm compared to 355 and 532 nm. For mixed spruce and birch pollen we find a slightly higher depolarization ratio at 1565 nm compared to 532 nm. Overall, we conclude that Halo Doppler lidars can provide a particle linear depolarization ratio at the 1565 nm wavelength at least in the lowest 2–3 km above ground.

A Simplified Fuel Cell Model for System Analysis and Performance Simulation

2020 ◽  
Author(s):  
Ziliang ZHAO ◽  
Jing Du ◽  
Honghui ZHAO ◽  
Dechao XU ◽  
Lucheng QU ◽  
...  
Keyword(s):  
Fuel Cell ◽  
System Analysis ◽  
Cell Model ◽  
Performance Simulation ◽  
And Performance

Modeling and Performance Simulation of MIMO Channel in THz Communication

2020 ◽  
Author(s):  
Haohui Hong ◽  
Jingcheng Zhao ◽  
Tao Hong ◽  
Tao Tang ◽  
Mingming Lv
Keyword(s):  
Mimo Channel ◽  
Performance Simulation ◽  
And Performance

Development of a mobile Doppler lidar system for wind and temperature measurements at 30–70 km

2017 ◽  
Vol 188 ◽  
pp. 52-59 ◽  
Author(s):  
Zhaoai Yan ◽  
Xiong Hu ◽  
Wenjie Guo ◽  
Shangyong Guo ◽  
Yongqiang Cheng ◽  
...  
Keyword(s):  
Temperature Measurements ◽  
Doppler Lidar ◽  
Lidar System

Low tropospheric wind measurement with Mie Doppler Lidar

2008 ◽  
Vol 15 (4) ◽  
pp. 204-209 ◽  
Author(s):  
Fahua Shen ◽  
Hyunki Cha ◽  
Dongsong Sun ◽  
Dukhyeon Kim ◽  
Sung Ok Kwon
Keyword(s):  
Doppler Lidar ◽  
Wind Measurement ◽  
Tropospheric Wind

Automatic Parametric Modeling From Non-Feature Based Designs for Additive Manufacturing

2021 ◽  
Author(s):  
Xinyi Xiao ◽  
Byeong-Min Roh
Keyword(s):  
Additive Manufacturing ◽  
3D Models ◽  
Parametric Modeling ◽  
Parametric Models ◽  
Performance Simulation ◽  
Cad Modeling ◽  
3D Cad ◽  
Feature Based ◽  
And Performance ◽  
The Given

Abstract The integration of Topology optimization (TO) and Generative Design (GD) with additive manufacturing (AM) is becoming advent methods to lightweight parts while maintaining performance under the same loading conditions. However, these models from TO or GD are not in a form that they can be easily edited in a 3D CAD modeling system. These geometries are generally in a form with no surface/plane information, thus having non-editable features. Direct fabricate these non-feature-based designs and their inherent characteristics would lead to non-desired part qualities in terms of shape, GD&T, and mechanical properties. Current commercial software always requires a significant amount of manual work by experienced CAD users to generate a feature-based CAD model from non-feature-based designs for AM and performance simulation. This paper presents fully automated shaping algorithms for building parametric feature-based 3D models from non-feature-based designs for AM. Starting from automatically decomposing the given geometry into “formable” volumes, which is defined as a sweeping feature in the CAD modeling system, each decomposed volume will be described with 2D profiles and sweeping directions for modeling. The Boolean of modeled components will be the final parametric shape. The volumetric difference between the final parametric form and the original geometry is also provided to prove the effectiveness and efficiency of this automatic shaping methodology. Besides, the performance of the parametric models is being simulated to testify the functionality.

scholarly journals LIDAR BATHYMETRIC EVALUATION BASED ON SCATTERING CLASSIFICATION ALGORITHM

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 97-103
Author(s):  
J. Gao ◽  
G. Q. Zhou ◽  
H. Y. Wang ◽  
X. Zhou ◽  
Y. X. Mu ◽  
...  
Keyword(s):  
Attenuation Coefficient ◽  
Classification Algorithm ◽  
Airborne Lidar ◽  
Discrimination Factor ◽  
Actual Situation ◽  
Particle Scattering ◽  
Lidar System ◽  
Scattering Intensity ◽  
Diffuse Attenuation Coefficient ◽  
532 Nm

Abstract. The evaluation of the bathymetric capability of traditional airborne lidar system is mostly based on the formula of bathymetric capability by evaluating the diffuse attenuation coefficient (Kd). This method is derived form the assumption that the reflectance of sediment is fixed. In this study ,however,the reflectance of sediment is not fixed. Therefore, this study improves the ability of bathymetric formula, and proposes a particle scattering classification algorithm to obtain the transmissivity value. The algorithm filters the scattering modes of particles by scattering discrimination factor (q), and obtains the transmissivity values by using the scattering intensity formulas. Experiments show that, when the transmissivity is in the range of 0–1 and the average values of Kd(532 nm) are 0.1150 m−1, 0.0894 m−1 and 0.0903 m−1 in January, June and October respectively, accordingly, the bathymetric capabilities are 0–44 m, 0–61.5 m and 0–52.5 m, respectively. Compared with the original bathymetric method, these results show that the maximum bathymetric value has measured by the improved bathymetric capability formula and scattering classification algorithm has decreased under the influence of the change of sediment reflectance, and the result is more consistent with the actual situation and more accurate.

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