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At least 163 records · Page 9

WFIP3 Lidar / Raw Data

This dataset contains raw data from the ANL scanning Doppler lidar, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Scanning Lidar / Raw Data

This dataset contains raw data from the UND scanning Doppler lidar, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Lidar / Raw Data

This dataset contains raw data from the UND scanning Doppler lidar, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Lidar / Raw Data

This dataset contains raw data from the UND scanning Doppler lidar, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Lidar / Processed Data

This dataset contains processed, standardized data from the UND scanning Doppler lidar at WFIP3's BARG site, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Lidar / Processed Data

This dataset contains processed, standardized data from the UND scanning Doppler lidar at WFIP3's BARG site, consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

NANT Site - Lidar / Processed Data Reformatted

This dataset contains standardized data from the PNNL scanning Doppler lidar (S/N 184), consisting of range- and time-resolved measurements of radial velocity, attenuated backscatter, intensity, and spectral width. We note that the beam azimuth angles are NOT referenced to true north.

17 WIND ENERGY↗

Evaluation of coupled wind-wave model simulations of offshore winds in the Mid-Atlantic Bight using lidar-equipped buoys.

From 2014 to 2017, two Department of Energy buoys equipped with Doppler lidar were deployed off the U.S. East Coast to provide long term measurements of hub-height wind speed in the marine environment. In this study, we performed simulations of selected cases from the deployment using a 5-km configuration of the Weather Research and Forecasting (WRF) model, to see if simulated hub height speeds could produce closer agreement with the observations than existing reanalysis products. For each case we performed two additional simulations: one in which marine surface roughness height was one-way coupled to forecast wave parameters from a standalone WaveWatch III (WW3) simulation, and another in which WRF and WW3 were two-way coupled using the Coupled-Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) framework. It was found that all the 5-km WRF simulations improved 90-m wind speed statistics for the tropical cyclone case of 08 May 2015 and the cold frontal case of 25 Mar 2016, but not the nor-easter of 18 Jan 2016. The impact of wave coupling on buoy-level (4 m) wind speed was modest and case dependent, but when present, the impact was typically seen at 90 m as well, being as large as 10% in stable conditions. One-way wave coupling consistently reduced wind speeds, improving biases for 25 Mar 2016 but worsening them for 08 May 2015. Two-way wave coupling mitigated these negative biases, improved wave field representation and statistics, and mostly improved 4-m wind field correlation coefficients, at least at the VA buoy, largely due to greater self-consistency between wind and wave fields.

54 ENVIRONMENTAL SCIENCES↗

Rolling Meadows Golf Course - CLAMPS 1 Lidar / Reviewed Data

This dataset contains data from the CLAMPS 1 Halo Photonics StreamLine Doppler Lidar at the Rolling Meadows Golf Course site. CLAMPS 1 deployed during fall-winter 2022 (10/3/22-12/27/23) and summer-fall 2023 (6/16/23-10/1/23).

17 WIND ENERGY↗

High-fidelity retrieval from instantaneous line-of-sight returns of nacelle-mounted lidar including supervised machine learning

Abstract. Wind turbine applications that leverage nacelle-mounted Doppler lidar are hampered by several sources of uncertainty in the lidar measurement, affecting both bias and random errors. Two problems encountered especially for nacelle-mounted lidar are solid interference due to intersection of the line of sight with solid objects behind, within, or in front of the measurement volume and spectral noise due primarily to limited photon capture. These two uncertainties, especially that due to solid interference, can be reduced with high-fidelity retrieval techniques (i.e., including both quality assurance/quality control and subsequent parameter estimation). Our work compares three such techniques, including conventional thresholding, advanced filtering, and a novel application of supervised machine learning with ensemble neural networks, based on their ability to reduce uncertainty introduced by the two observed nonideal spectral features while keeping data availability high. The approach leverages data from a field experiment involving a continuous-wave (CW) SpinnerLidar from the Technical University of Denmark (DTU) that provided scans of a wide range of flows both unwaked and waked by a field turbine. Independent measurements from an adjacent meteorological tower within the sampling volume permit experimental validation of the instantaneous velocity uncertainty remaining after retrieval that stems from solid interference and strong spectral noise, which is a validation that has not been performed previously. All three methods perform similarly for non-interfered returns, but the advanced filtering and machine learning techniques perform better when solid interference is present, which allows them to produce overall standard deviations of error between 0.2 and 0.3 m s−1, or a 1 %–22 % improvement versus the conventional thresholding technique, over the rotor height for the unwaked cases. Between the two improved techniques, the advanced filtering produces 3.5 % higher overall data availability, while the machine learning offers a faster runtime (i.e., ∼ 1 s to evaluate) that is therefore more commensurate with the requirements of real-time turbine control. The retrieval techniques are described in terms of application to CW lidar, though they are also relevant to pulsed lidar. Previous work by the authors (Brown and Herges, 2020) explored a novel attempt to quantify uncertainty in the output of a high-fidelity lidar retrieval technique using simulated lidar returns; this article provides true uncertainty quantification versus independent measurement and does so for three techniques rather than one.

47 OTHER INSTRUMENTATION↗

Turbulence dissipation rate estimated from lidar observations during the LAPSE-RATE field campaign

The International Society for Atmospheric Research using Remotely-piloted Aircraft (ISARRA) hosted a flight week in July 2018 to demonstrate unmanned aircraft systems' (UASs) capabilities in sampling the atmospheric boundary layer. This week-long experiment was called the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. Numerous remotely piloted aircraft and ground-based instruments were deployed with the objective of capturing meso- and microscale phenomena in the atmospheric boundary layer. The University of Oklahoma deployed one Halo Streamline lidar, and the University of Colorado Boulder deployed two WindCube lidars. In this paper, we use data collected from these Doppler lidars to estimate turbulence dissipation rate throughout the campaign. We observe large temporal variability of turbulence dissipation close to the surface with the WindCube lidars that is not detected by the Halo Streamline. However, the Halo lidar enables estimating dissipation rate within the whole boundary layer, where a diurnal variability emerges. We also find a higher correspondence in turbulence dissipation between the WindCube lidars, which are not co-located, compared to the Halo and WindCube lidar that are co-located, suggesting a significant influence of measurement volume on the retrieved values of dissipation rate.

WIND ENERGY↗