A spectral optical flow method for determining velocities from digital imagery

We present a method for determining surface flows from solar images based upon optical flow techniques. We apply the method to sets of images obtained by a variety of solar imagers to assess its performance. The {\tt opflow3d} procedure is shown to extract accurate velocity estimates when provided perfect test data and quickly generates results consistent with completely distinct methods when applied on global scales. We also validate it in detail by comparing it to an established method when applied to high-resolution datasets and find that it provides comparable results without the need to tune, filter or otherwise preprocess the images before its application.Comment: 12 pages, 5 figures. Submitted to Earth Science Informatic

Three-component laser Doppler velocimeter measurements in a juncture flow

A single-axis, five-beam, three-component laser velocimeter (LV) system was used in a major experiment. Satisfactory results were obtained with the LV system in the juncture flow. Limited optical access to the tunnel proved to be a problem for the three component LV system in determining the third component

The task adaptation method for determining the optical flow problem of interactive objects recognition in real time

In this paper, we solved the problem of determining the optical flow as a stationary image and a real-time video stream. Unlike conventional methods of calculation, the problem of the module integrated vision determines the optical flow in Unity3D interactive environment to obtain real time data. The carried out testing and approbation of data presented an image processing algorithm, an experiment, the results obtained by the optical flow

An assessment of warm fog: Nucleation, control, and recommended research

A state-of-the-art survey is given of warm fog research which has been performed up to, and including, 1974. Topics covered are nucleation, growth, coalescence, fog structures and visibility, effects of surface films, drop size spectrum, optical properties, instrumentation, liquid water content, condensation nuclei. Included is a summary of all reported fog modification experiments. Additional data is provided on air flow, turbulence, a summary of recommendations on instruments to be developed for determining turbulence, air flow, etc., as well as recommendations of various fog research tasks which should be performed for a better understanding of fog microphysics

"Determining optical flow": a retrospective

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30981/1/0000654.pd

Программная реализация обратного композиционного алгоритма Гаусса-Ньютона в задаче определения перемещений на изображениях поверхности материалов

Выпускная квалификационная работа содержит 64 с., 10 рис., 3 табл., 17 источников, 2 прил. Ключевые слова: оптический поток, бикубическая интерполяция, многопоточность, обратный композиционный алгоритм Гаусса-Ньютона, быстрое преобразование Фурье, взаимная корреляция, цифровая обработка изображений. Объектом исследования является задача определения перемещений на поверхностях материалов. Цель работы – исследование и программная реализация метода определения векторов смещений. В процессе исследования были изучены и проанализированы существующие методики вычисления оптического потока, а также методы интерполяции на субпиксельном смещении. В результате исследования был реализован алгоритм для нахождения векторов смещений, а также разработана и реализована его параллельная версия.Final qualifying work contains 64 c., 10 Fig., 3 Tab., 17 Sources, 2 adj. Keywords: optical flow, bicubic interpolation, multithreading, inverse compositio Gauss-Newton algorithm, a fast Fourier transform, cross-correlation, digital image processing. The object of investigation is the problem of determining the movement of materials on surfaces. Objective - Research and software implementation of the method for determining displacement vectors. The study was reviewed and analyzed existing methods of calculating the optical flow, and interpolation methods at the subpixel displacement. The study was implemented an algorithm for determining the displacement vectors, as well as developed and implemented its parallel version. Scope: engineering, motion detection on a series of images, material

The roles of jets: CF, CCSN, PN, CEE, GEE, ILOT

I review the roles of jet-inflated bubbles in determining the evolution of different astrophysical objects. I discuss astrophysical systems where jets are known to inflate bubbles (cooling flow [CF] clusters; young galaxies; intermediate luminosity optical transients [ILOTs]; bipolar planetary nebulae [PNe]), and systems that are speculated to have jet-inflated bubbles (core collapse supernovae [CCSNe]; common envelope evolution [CEE]; grazing envelope evolution [GEE]). The jets in many of these cases act through a negative jet feedback mechanism (JFM). I discuss the outcomes when the JFM fizzle, or does not work at all. According to this perspective, some very interesting and energetic events owe their existence to the failure of the JFM, including stellar black holes, gamma ray bursts, and type Ia supernovae.Comment: 4 pages. To appear in the proceedings of "Physics of Evolved Stars 2015 - A conference dedicated to the memory of Olivier Chesneau

Line spread instrumentation for propagation measurements

A line spread device capable of yielding direct measure of a laser beam's line spread function (LSF) was developed and employed in propagation tests conducted in a wind tunnel to examine optimal acoustical suppression techniques for laser cavities exposed to simulated aircraft aerodynamic environments. Measurements were made on various aerodynamic fences and cavity air injection techniques that effect the LSF of a propagating laser. Using the quiescent tunnel as a control, the relative effect of each technique on laser beam quality was determined. The optical instrument employed enabled the comparison of relative beam intensity for each fence or mass injection. It was found that fence height had little effect on beam quality but fence porosity had a marked effect, i.e., 58% porosity alleviated cavity resonance and degraded the beam the least. Mass injection had little effect on the beam LSF. The use of a direct LSF measuring device proved to be a viable means of determining aerodynamic seeing qualities of flow fields