Wind Field Characterization from the Trajectories of Small Balloons

Wilkerson, Thomas D.; Marchant, Alan; Apedaile, T.

doi:10.1175/jtech-d-11-00081.1

Cited by 5 publications

(4 citation statements)

References 28 publications

(21 reference statements)

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“…The purpose of these additional measurements was to observe how wind and temperature profiles evolved from within the canyon to the exit during typical events. A novel new wind profiling system (ValidWind) developed at Utah State University (Wilkerson et al 2012) that automatically tracks pilot balloons using a laser range finder was tested during several IOPs inside the canyon (INVW) in the vicinity of the INSONDE and INLDR. During IOP4 this instrument collected wind profiles continuously during the entire night.…”

Section: Topography Observations and Synoptic Conditionsmentioning

confidence: 99%

Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah

Chrust

Whiteman

Hoch

2013

Journal of Applied Meteorology and Climatology

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Thermally driven valley-exit jets were investigated at Utah's Weber Canyon, a main tributary of the Great Salt Lake basin. An intensive measurement campaign during July-September 2010 supplemented longerterm measurements to characterize the wind and temperature structure in the vicinity of the canyon exit. Exit jets at Weber Canyon are most frequent in late summer or early fall. Strong low-level-wind jets formed at the canyon exit on 75 of 90 nights (83%) during the measurement campaign, with the best-developed winds forming during synoptically undisturbed, clear-sky periods. Winds inside the canyon consisted of a weak down-valley flow layer that occupied most of the 1000-m depth of the canyon. The flow was observed to descend, thin, and accelerate at the valley exit, producing winds that were typically 2.5 times as strong but much more shallow than those inside the canyon. Maximum nighttime jet-axis wind speeds of 15-20 m s 21 are typically found about 80-120 m above the ground at the canyon exit on clear undisturbed nights in the late summer and fall. The jets form 1-3 h after sunset, approach a near-steady state during the late night, and continue until 5-6 h after sunrise, although slowly losing speed after sunrise. The jet is a local modification at the canyon exit of the thermally driven down-valley flow. Its continuation after sunrise is thought to be caused by the nighttime buildup and persistence of a cold-air pool in the Morgan Basin at the east end of the canyon. The potential for utilizing the exit jet for wind power generation is discussed.

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Section: Topography Observations and Synoptic Conditionsmentioning

confidence: 99%

Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah

Chrust

Whiteman

Hoch

2013

Journal of Applied Meteorology and Climatology

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“…Currently, hydrogen balloon tracking, anemometer, Doppler lidar, wind profiler radar, and Doppler radar (Stith et al 2018;Liu et al 2019) are the major approaches for wind field measurement. Due to the low cost and simple operation, hydrogen balloon is widely used for wind profile measurement and it is also taken as a benchmark to calibrate other velocity measuring sensors (Stith et al 2018;Wilkerson et al 2012;Rider and Armendariz 1966). For the hydrogen balloon observation method, there are two types of balloon tracking approaches, say, the optical theodolite observation of pilot balloon and the remote sensing of the balloon, which carries the GNSS and radiosonde sensors.…”

Section: Introductionmentioning

confidence: 99%

“…The single-theodolite method measures the elevation and azimuth angles of the hydrogen balloon at a series of time samples, and then obtains the wind velocity and direction through some basic algebraic calculations by assuming that the rising velocity is constant (Thyer 1962). This method is convenient and easy to be implemented, and it plays an important role in the meteorological community (Wilkerson et al 2012;Tuononen et al 2017;Noh et al 2021;Ha et al 2018;Sun and Xu 2021;Zheng et al 2021).…”

Section: Introductionmentioning

confidence: 99%

An Accurate Wind Retrieval Method Based on Observing Hydrogen Balloons with Multi-Theodolite Measurements

Zhou

Gao

Wang

et al. 2022

Journal of Atmospheric and Oceanic Technology

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The hydrogen balloon is widely used for wind sensing by tracking it with optical theodolites. The traditional theodolite observation (single- and double-theodolite) methods assume that the balloon is a perfect tracer of the background wind and it rises with a constant speed during the whole observation period, but these assumptions may not hold well in complex wind circumstances. In this paper, an accurate wind field retrieval method based on multi-theodolite measurement is proposed. The extended Kalman filter algorithm is used to filter the angle data observed by the theodolites in order to accurately estimate the trajectory of the balloon, and the motion equation is used to correct the velocity difference between the background wind and the balloon. As a result, not only the horizontal velocity but also the vertical velocity can be accurately retrieved by this method. Numerical simulation and field experiments show that the multi-theodolite observation method excels the traditional single-theodolite method, and the velocity errors can be reduced by even more than 40% in comparison with the single-theodolite method for complex wind cases. Significanace Statement In the meteorological community, hydrogen balloon tracking is a widely used wind retrieval method, but the accuracy is limited, especially under complex wind conditions. In this paper, a new method based on tracking the hydrogen balloon with multi-theodolite is proposed, which uses the extended Kalman filter and the motion equation to get an accurate estimation of the balloon’s velocity and fix the inertia effect of balloon, respectively. Simulation and field experiment show that the new method can reduce the velocity error by more than 40% compared with the traditional method.

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“…Wilkerson [4] is one example method for validation of such a LIDAR retrieval system. Comparisons with tracking systems are not comprehensive, nor are comparisons with anemometers, but they are a place to start and would lead to a better understanding of system performance.…”

Section: Introductionmentioning

confidence: 99%

Four Methods for LIDAR Retrieval of Microscale Wind Fields

Howard

Naini

2012

Remote Sensing

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This paper evaluates four wind retrieval methods for micro-scale meteorology applications with volume and time resolution in the order of 30 m 3 and 5 s. Wind field vectors are estimated using sequential time-lapse volume images of aerosol density fluctuations. Suitably designed mono-static scanning backscatter LIDAR systems, which are sensitive to atmospheric density aerosol fluctuations, are expected to be ideal for this purpose. An important application is wind farm siting and evaluation. In this case, it is necessary to look at the complicated region between the earth's surface and the boundary layer, where wind can be turbulent and fractal scaling from millimeter to kilometer. The methods are demonstrated using first a simple randomized moving hard target, and then with a physics based stochastic space-time dynamic turbulence model. In the latter case the actual vector wind field is known, allowing complete space-time error analysis. Two of the methods, the semblance method and the spatio-temporal method, are found to be most suitable for wind field estimation.

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Wind Field Characterization from the Trajectories of Small Balloons

Cited by 5 publications

References 28 publications

Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah

Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah

An Accurate Wind Retrieval Method Based on Observing Hydrogen Balloons with Multi-Theodolite Measurements

Four Methods for LIDAR Retrieval of Microscale Wind Fields

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