Single-particle laser Doppler anemometry at 155 µm

Harris, Michael; Pearson, Guy N.; Ridley, Kevin D.; Karlsson, Christer J.; Olsson, F.; Letalick, Dietmar

doi:10.1364/ao.40.000969

Cited by 15 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the period of the field study the wind direction changed as depicted in Figure 4 The The power spectral density (PSD) at a particular Doppler frequency corresponding to the raindrop's projected fall velocity is shown as a time series in Figure 5 (b) and it follows a Gaussian function of time (coincident with the findings from [15]) since the transverse intensity profile of the laser beam follows a Gaussian function. In this case, the drop seems to be away from the focus or it is falling slowly, so it takes several milliseconds for it to cross the beam.…”

Section: Sonic Anemometer Datamentioning

confidence: 81%

Improved wind speed estimation and rain quantification with continuous-wave wind lidar

Jin

Angelou

Mann

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The presence of raindrops has an adverse impact on the line-of-sight wind speed measurement of Doppler lidars. Here, we propose a method to improve the accuracy of wind speed estimation through a filtering process on rapidly sampled (3000 Hz) lidar data. For this purpose, we conducted a field study at the Risø campus of the Technical University of Denmark using a ground-based, continuous-wave Doppler lidar. Data was acquired during a three-hour period with rain. We propose that we can differentiate between the rain and aerosol back-scattering signals by assessing the maximum of the noise-normalized Doppler spectra. To reduce the influence of rain of the velocity signal, we filter away the Doppler spectra where the maximum is larger than a given threshold. The comparison between the raw and the filtered lidar data with sonic anemometer measurements acquired at the same location, shows that we can effectively remove rain signals and improve the measurement accuracy of a Doppler lidar. However, this method is not applicable when the back-scattering of aerosols and rain are characterized by the same statistics.

show abstract

Section: Sonic Anemometer Datamentioning

confidence: 81%

Improved wind speed estimation and rain quantification with continuous-wave wind lidar

Jin

Angelou

Mann

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…Harris et al [32] draw fresh attention to the possibilities for single-particle lidar anemometry and to the need to consider different fluctuation statistics because the probe volume varies dramatically; they do not consider time series analysis, chirp behaviour, or spectral moment estimation in detail.…”

Section: Simulation Of Multiple Scatterers In a Lidar Beammentioning

confidence: 99%

Coherent Focused Lidars for Doppler Sensing of Aerosols and Wind

Hill¹

2018

Remote Sensing

View full text Add to dashboard Cite

Many coherent lidars are used today with aerosol targets for detailed studies of e.g., local wind speed and turbulence. Fibre-optic lidars operating near 1.5 µm dominate the wind energy market, with hundreds now installed worldwide. Here, we review some of the beam/target physics for these lidars and discuss practical problems. In a monostatic Doppler lidar with matched local oscillator and transmit beams, focusing of the beam gives rise to a spatial sensitivity along the beam direction that depends on the inverse of beam area; for Gaussian beams, this sensitivity follows a Lorentzian function. At short range, the associated probe volume can be extremely small and contain very few scatterers; we describe predictions and simulations for few-scatterer and multi-scatterer sensing. We review the single-particle mode (SPM) and volume mode (VM) modelling of Frehlich et al. and some numerical modelling of lidar detector time series and statistics. Interesting behaviour may be observed from a modern coherent lidar used at short ranges (e.g., in a wind tunnel) and/or with weak aerosol seeding. We also review some problems (and solutions) for Doppler-sign-insensitive lidars.

show abstract

“…16) On the other hand, an interesting event in signal statistics of a CW-CDL has been discovered. It is called single-particle detection, [17][18][19] in which only a single particle exists in the focal volume. In this detection state, an intensity of a detected signal becomes deterministic since there is no interference from echoes.…”

Section: Introductionmentioning

confidence: 99%

Investigation of single-particle detection of continuous-wave coherent Doppler lidar: theoretical feasibility and performance comparison with multiple-particle detection state

Kameyama

2024

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Single-particle detection with a continuous-waves coherent Doppler lidar (CW-CDL) is an interesting event. Even though some experimental results have been shown in past literatures as evidence of single-particle detection, these results have not been verified from theoretical point of view. Here, performance of a CW-CDL with the single-particle detection is investigated. Examples of single-particle detection which have been reported in the past literatures are verified by using theoretical simulation. Further, comparison on signal detection ability between single- and multiple- particle cases is additionally performed theoretically.

show abstract

Single-particle laser Doppler anemometry at 155 µm

Cited by 15 publications

References 8 publications

Improved wind speed estimation and rain quantification with continuous-wave wind lidar

Improved wind speed estimation and rain quantification with continuous-wave wind lidar

Coherent Focused Lidars for Doppler Sensing of Aerosols and Wind

Investigation of single-particle detection of continuous-wave coherent Doppler lidar: theoretical feasibility and performance comparison with multiple-particle detection state

Contact Info

Product

Resources

About