Wind field inversion technique for scanning wind lidar

The Compact High-Power Shipborne Doppler Wind Lidar (CHiPSDWiL) based on highspectral-resolution technique has been built up at the Ocean University of China for the measurement of the wind field and the properties of the aerosol and clouds in the troposphere. The design of the CHiPSDWiL including the transceiver, the injection seeding, the locking and the frequency measurement will be presented. Preliminary results measured by the CHiPSDWiL are provided.

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A six-beam method to measure turbulence statistics using ground-based wind lidars

Atmospheric Measurement Techniques ◽

10.5194/amt-8-729-2015 ◽

2015 ◽

Vol 8 (2) ◽

pp. 729-740 ◽

Cited By ~ 34

Author(s):

A. Sathe ◽

J. Mann ◽

N. Vasiljevic ◽

G. Lea

Keyword(s):

Radial Velocity ◽

Wind Field ◽

Atmospheric Stability ◽

Random Errors ◽

Turbulence Statistics ◽

Beam Method ◽

Vertical Beam ◽

Wind Lidar ◽

Velocity Variances ◽

Cup Anemometer

Abstract. A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method requires measurement of the radial velocity variances at five equally spaced azimuth angles on the base of a scanning cone and one measurement at the centre of the scanning circle, i.e.using a vertical beam at the same height. The scanning configuration is optimized to minimize the sum of the random errors in the measurement of the second-order moments of the components (u,v, w) of the wind field. We present this method as an alternative to the so-called velocity azimuth display (VAD) method that is routinely used in commercial wind lidars, and which usually results in significant averaging effects of measured turbulence. In the VAD method, the high frequency radial velocity measurements are used instead of their variances. The measurements are performed using a pulsed lidar (WindScanner), and the derived turbulence statistics (using both methods) such as the u and v variances are compared with those obtained from a reference cup anemometer and a wind vane at 89 m height under different atmospheric stabilities. The measurements show that in comparison to the reference cup anemometer, depending on the atmospheric stability and the wind field component, the six-beam method measures between 85 and 101% of the reference turbulence, whereas the VAD method measures between 66 and 87% of the reference turbulence.

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Data Quality Evaluation of Sentinel-1 and GF-3 SAR for Wind Field Inversion

Remote Sensing ◽

10.3390/rs13183723 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3723

Author(s):

Yong Wan ◽

Sheng Guo ◽

Ligang Li ◽

Xiaojun Qu ◽

Yongshou Dai

Keyword(s):

United States ◽

Data Quality ◽

Wind Field ◽

The United States ◽

Band Model ◽

East And West ◽

Sar Data ◽

Better Than ◽

Field Inversion

Synthetic aperture radar (SAR) is an important means to observe the sea surface wind field. Sentinel-1 and GF-3 are located on orbit SAR satellites, but the SAR data quality of these two satellites has not been evaluated and compared at present. This paper mainly studies the data quality of Sentinel-1 and GF-3 SAR satellites used in wind field inversion. In this study, Sentinel-1 SAR data and GF-3 SAR data located in Malacca Strait, Hormuz Strait and the east and west coasts of the United States are selected to invert wind fields using the C-band model 5.N (CMOD5.N). Compared with reanalysis data called ERA5, the root mean squared error (RMSE) of the Sentinel-1 inversion results is 1.66 m/s, 1.37 m/s and 1.49 m/s in three intervals of 0~5 m/s, 5~10 m/s and above 10 m/s, respectively; the RMSE of GF-3 inversion results is 1.63 m/s, 1.45 m/s and 1.87 m/s in three intervals of 0~5 m/s, 5~10 m/s and above 10 m/s, respectively. Based on the data of Sentinel-1 and GF-3 located on the east and west coasts of the United States, CMOD5.N is used to invert the wind field. Compared with the buoy data, the RMSE of the Sentinel-1 inversion results is 1.20 m/s, and the RMSE of the GF-3 inversion results is 1.48 m/s. The results show that both Sentinel-1 SAR data and GF-3 SAR data are suitable for wind field inversion, but the wind field inverted by Sentinel-1 SAR data is slightly better than GF-3 SAR data. When applied to wind field inversion, the data quality of Sentinel-1 SAR is slightly better than the data quality of GF-3 SAR. The SAR data quality of GF-3 has achieved a world-leading level.

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Characterisation of Small-Scale Atmospheric Wind-Field Structures Using Coherent Wind Lidar With Short Pulses

EPJ Web of Conferences ◽

10.1051/epjconf/202023706002 ◽

2020 ◽

Vol 237 ◽

pp. 06002

Author(s):

D. T. Michel ◽

M. Valla ◽

D. Goular ◽

L. Lombard ◽

A. Dolfi-Bouteyre ◽

...

Keyword(s):

Spatial Resolution ◽

Wind Field ◽

Small Scale ◽

Short Pulses ◽

Turbulent Wind ◽

Wind Lidar ◽

Scale Structures ◽

Turbulent Wind Field ◽

Small Scale Structures

A lidar design has been developed at ONERA that uses short square pulses (75 ns) to have a small spatial resolution (22.5 m) and be able to measure small-scale atmospheric wind-field structures. Results show that the system is able to resolve the small-scale structures of vortices and to measure wind field structures of a turbulent wind field down to ~20 m.

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A six-beam method to measure turbulence statistics using ground-based wind lidars

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-10327-2014 ◽

2014 ◽

Vol 7 (10) ◽

pp. 10327-10359 ◽

Cited By ~ 3

Author(s):

A. Sathe ◽

J. Mann ◽

N. Vasiljevic ◽

G. Lea

Keyword(s):

Radial Velocity ◽

Wind Field ◽

Atmospheric Stability ◽

Random Errors ◽

Turbulence Statistics ◽

Beam Method ◽

Vertical Beam ◽

Wind Lidar ◽

Velocity Variances ◽

Cup Anemometer

Abstract. A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method requires measurement of the radial velocity variances at five equally spaced azimuth angles on the base of a scanning cone and one measurement at the center of the scanning circle, i.e.using a vertical beam at the same height. The scanning configuration is optimized to minimize the sum of the random errors in the measurement of the second-order moments of the components (u,v, w) of the wind field. We present this method as an alternative to the so-called velocity azimuth display (VAD) method that is routinely used in commercial wind lidars, and which usually results in significant averaging effects of measured turbulence. In the VAD method, the high frequency radial velocity measurements are used instead of their variances. The measurements are performed using a pulsed lidar (WindScanner), and the derived turbulence statistics (using both methods) such as the u and v variances are compared with those obtained from a reference cup anemometer and a wind vane at 89 m height under different atmospheric stabilities. The measurements show that in comparison to the reference cup anemometer, depending on the atmospheric stability and the wind field component, the six-beam method measures between 85–101% of the reference turbulence, whereas the VAD method measures between 66–87% of the reference turbulence.

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