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1
Carlsson, Andreas. "Vindjämförelse mellan VAD-algoritm och FMCW-radar." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 1998. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392767.
Повний текст джерелаАнотація:
I denna undersökning som mestadels koncentrerat sig på VAD-algoritmen och dess fördelar och nackdelar har till att börja med två för algoritmen särdeles viktiga parametrar undersökts. Totala antalet VAD-cirklar respektive andelen av dessa som i slutänden ger en vind som resultat har direkt studerats som en funktion av tiden och samtidigt indirekt mot de synoptiska väderförhållanden som rådde vid tidpunkten i fråga. Som en andra del av arbetet utfördes en mestadels relativ jämförelse där två till viss del olika radaralgoritmer jämfördes i samband med olika vädersituationer och olika tider på dygnet. Vad det gäller totala antalet cirklar visade sig en god korrelation mot det storskaliga vädret vilket främst kunde ses i samband med frontpassager medan ingen typ av regelbunden dygnsvariation kunde ses. Andelen cirklar som i slutänden gav godkänd vind som resultat visade istället en starkt regelbunden dygnskorrelation medan enbart en ytterst svag korrelation med vädret kunde ses. Den följande jämförelsen visade på två intressanta resultat i samband med natt- respektive dagmätningar samt mätningar utförda vid två högtryckssituationer. Den första jämförelsen visade på en markant större skillnad i mätresultat i samband med nattliga mätningar än vid mätningar i liknande vädersituationer utförda dagtid. Sammankopplat med resultatet som gavs i samband med andelen resultatgivande cirklar antyder detta att VAD-algoritmen i samband med nattliga mätningar ger ett relativt inkorrekt resultat. Ett andra intressant resultat gavs i det visade sig finnas en signifikant skillnad i resultaten vid de jämförelsen mellan resultaten från mätningarna utförda vid de två ovan angivna högtryckssituationerna.
2
James, Curtis Neal. "Radar observations of orographic precipitation /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/10082.
Повний текст джерела
3
May, Peter T. "VHF radar studies of the troposphere /." Title page, contents and summary only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phm4666.pdf.
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4
MacKinnon, Andrew David. "VHF Boundary Layer Radar and RASS." Title page, abstract and table of contents, 2001. http://hdl.handle.net/2440/37807.
Повний текст джерелаАнотація:
This thesis describes the refinements, modifications and additions to a prototype Very High Frequency (VHF) Boundary Layer (BL) Spaced Antenna (SA) radar initially installed at the University of Adelaide's Buckland Park field site in 1997. Previous radar observations of the lowest few kilometres of the atmosphere, in particular the Atmospheric Boundary Layer, have used Ultra-High Frequency (UHF) radars. Unlike VHF radars, UHF radars are extremely sensitive to hydro-meteors and have difficulty in distinguishing clear-air echoes from precipitation returns. The advantages and requirements of using a VHF radar to observe the lowest heights is discussed in conjunction with some of the limitations. The successful operation of the system over long periods has enabled in-depth investigation of the performance of the system in a variety of conditions and locations. Observations were made from as low as 300m and as high as 8 km, dependent upon conditions. Comparisons between the radar and alternative wind measuring devices were carried out and examined. The antenna system of the radar is a critical component which was analysed in depth and subsequently re-designed. Through the use of numerical models and mea- surements, evaluation of different designs was accomplished. Further calibration of the remaining components of the full system has enabled estimations of the absolute received power. Additional parameters which can be derived with a calibrated radar were compared with values obtained by other authors, giving favourable results. Full Correlation Analysis (FCA) is the predominant technique used in this work. A brief discussion of the background theory and parameters which can be measured is described. A simple one-dimensional model was developed and combined with a 'radar backscatter model' to investigate potential sources of errors in the parameters determined using FCA with the VHF Boundary Layer Radar. In particular, underes- timations in the wind velocity were examined. The integration of a Radio Acoustic Sounding System (RASS) to obtain tempera- ture profiles is discussed. The theory of RASS measurements including the limitations and considerations which are required for the VHF BL radar are given. The difficulties encountered trying to implement such a system and the subsequent success using a Stratospheric Tropospheric (ST) Profiler in place of the BL radar is presented. Taken as a whole this thesis shows the success of the VHF BL to obtain mea- surements from as low as 300m. The validation of this prototype radar provides an alternative and, in certain situations, a superior device with which to study the lower troposphere.Thesis (Ph.D.)--Department of Physics and Mathematical Physics, 2001.
5
Duncan, Mike R. (Mike Ross). "The universal multifractal nature of radar echo fluctuations." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41364.
Повний текст джерелаАнотація:
The intensity returns obtained by a radar from precipitation are well known to fluctuate violently in space and time. We present a systematic study of the resolution dependence time series with overlapping time resolutions spanning 10 orders of magnitude (0.77 ms to 4 months), of the fluctuating radar echo from precipitation. The results undermine the current assumptions of homogeneity of rainfield at scales smaller than the radar resolution, due to Marshall and Hitschfeld (1953), by showing that the only length scales identifiable in the time series are those of the radar pulse volume, the wavelength, and a very small inner scale of the order of millimeters. An analysis of the multiscaling nature of the time series of echo fluctuations reveals multiscaling behaviour at scales down to the resolution or pulse volume scale. Since there are no a priori scales in the rainfield we proceed to model the fluctuating radar echo by assuming a multiscaling model of rainfield variability which extends to sub-resolution scales. A systematic analysis of the statistical behaviour of computed reflectivities from this variability gives a full statistical description of reflectivity originating from multiscaling variability, and solves the scalar multifractal radar observer's problem. Computation of time series of reflectivities from a time-space representation of this variability reveals quantitative and qualitative behaviours consistent with those of observed echo fluctuation time series. We conclude that a multiscaling model of the rainfield which extends to the smallest scales of the rainfield is consistent with observation.
6
Kazempour, Alireza. "Meteorological studies of cut-off lows over Australia with a VHF radar /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phk2361.pdf.
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7
Carlsson, Andreas. "A comparison between wind measurements with doppler weather radar and rawinds." Thesis, Uppsala universitet, Meteorologiska institutionen, 1996. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392766.
Повний текст джерелаАнотація:
Comparisons between wind measurement with doppler weather radar and wind measurement with rawinds in different weather situations is done. The study is made in a statistical way with some comparable parameters as outcome. The importance of the weather and different weather situation’s effect on the results are discussed, both in form of the winds accuracy and the probability of getting any wind at all as outcome. The study shows that wind measurement with doppler radar at lower elevations not has so good accuracy, but it becomes better the higher up we measure. At the same time will we lose a lot of the measurements at higher levels by the reason that the reflected power is weakened very fast with the distance the transmitted ray travel. The doppler effect is explained and the by SMHI used routine for wind measurement with radar is described. At the end of the work are some problems and disadvantages with the radar measurements and the used method discussed.
8
Leon, David C. "Observations of drizzle cells in marine stratocumulus." Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1212794291&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Повний текст джерела
9
Cáceres, León Richard Humberto. "Impacto de la asimilación radar en el pronóstico de precipitación a muy corto plazo usando el modelo WRF." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/665103.
Повний текст джерелаАнотація:
El propósito de esta investigación es maximizar el impacto de la asimilación de datos radar sobre el pronóstico de precipitación a muy corto plazo usando el modelo Weather Research and Forecasting (WRF), de tal manera que pueda ser implementado de modo operativo en los Servicios Meteorológicos Nacionales.
En una primera fase se utiliza un episodio de precipitación extrema que tuvo lugar en Cataluña (NE de España) para probar varias configuraciones de predicción inmediata, basadas en el modelo WRF con la asimilación de datos radar, y en una segunda fase, se profundizan los resultados a través de una serie de experimentos basados en diez eventos de precipitación extrema ocurridos en Cataluña en el periodo 2015 - 2017.
Las configuraciones consideradas se generan modificando: 1) el ciclo de inicialización del WRF, 2) los procedimientos de preprocesamiento de datos radar utilizados por el Centro Nacional de Investigación Atmosférica (NCAR) y por el Servicio Meteorológico de Cataluña (SMC), 3) datos convencionales y de radar asimilados dentro del sistema variacional tridimensional (3DVAR), y 4), otros parámetros tales como la escala de longitud de las observaciones, el número de bucles externos y la parametrización de la convección húmeda.
El efecto de los anteriores parámetros se evalúa mediante la habilidad de una serie de experimentos para simular la cantidad y localización de la precipitación usando técnicas estadísticas convencionales, índices categóricos y el Receiver Operating Characteristic (ROC). Sin embargo, en este estudio la construcción de las tablas de contingencia está condicionada al desplazamiento del patrón de precipitación y la cercanía entre los valores observados y pronosticados, sin considerar los umbrales de precipitación.
El método de control de calidad desarrollado por el SMC es confiable y en el caso particular del 12 de octubre de 2016, produjo mejores resultados que el método de NCAR. La predicción inmediata de precipitación logra mejores resultados cuando el modelo WRF es ejecutado con dos ciclos de asimilación, uno en frío y otro en caliente con un length scale de 0.75 y 0.50 respectivamente, asimilando en cada ciclo datos radar y datos convencionales en un mismo momento y con el error del background CV7. Los largos ciclos de inicialización, las actuales parametrizaciones usadas en el SMC y el uso de tres bucles externos no mejoran los resultados del pronóstico.The purpose of this research is to maximize the radar data assimilation impact on precipitation nowcasting using the Weather Research and Forecasting (WRF), in such a way that it can be implemented operationally in the National Meteorological Services. In a first phase is used an episode of extreme precipitation that took place in Catalonia (NE Spain) to test several nowcasting system configurations, which are based on the Weather Research and Forecasting (WRF) model with radar data assimilation, and in a second phase, the results are deepened through a series of experiments based on ten extreme precipitation events that occurred in Catalonia in the period 2015 - 2017. The configurations considered are generated by modifying the following elements: 1) the WRF initialization cycle, 2) the radar data preprocessing procedures used by the National Center for Atmospheric Research (NCAR) and by the Meteorological Service of Catalonia (SMC), 3) conventional and radar data assimilated within the three dimensional variational system (3DVAR), and 4), other parameters such as the observations length scale, number of outer loops and the cumulus parameterization. The effect of the previous parameters is evaluated through the skill of the different experiments to simulate both the amount and location of precipitation using conventional statistical techniques, categorical indices and the Receiver Operating Characteristic (ROC). However, in this study the construction of the contingency tables has been conditioned to the precipitation pattern displacement and the closeness between the observed and forecast values without considering precipitation thresholds. The quality control method developed by the SMC is trustworthy and in the particular case occurred on October 12, 2016, it produced better results than the NCAR method. The precipitation nowcasting achieves better results when the WRF model is executed with two assimilation cycles, one in cold and another in warm with a length scale of 0.75 and 0.50 respectively, assimilating in each of these cycles radar data and conventional data (METAR and SYNOP) at the same time and with the background error CV7. The long initialization cycles, the current parameterizations used in the SMC and the use of three external loops do not improve the forecast results.
10
Lai, Kim (Hsin-Jung). "A super fast scanning technique for phased array weather radar applications /." [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17007.pdf.
Повний текст джерела
11
Averyanova, Yulia, and Felix Yanovsky. "Polarimetric Method to Discriminate the Drops on Sizes within the Resolution Volume." Thesis, 2016 International Conference on Mathematical Methods in Electromagnetic Theory, 2016. http://er.nau.edu.ua/handle/NAU/30097.
Повний текст джерелаАнотація:
In this paper we consider possibilities of radar polarimetry to solve different meteorological tasks including identification of atmospheric pfenomena microstructure and hydrometeor orientation, hydrometeors size measurement, wind related phenomena estimation. The potentials and restrictions of radar polarimetry are discussed. The approach that allows to increase informativity of polarization measuremens by distinguishing hydrometeors with similar polarization properties inside the reflecting volume and estimating their differential impact onto polarization properties of reflected signal is presented. The overvew of the polarimetric system with multiple receiving antenna system for aproach realization is done. The results are important for different practical applications of radar meteorology including drop size distribution estimate, rainfall intensity estimate, wind speed measurement, turbulence and strong wind shear detection.
12
del, Moral Méndez Anna. "Radar-based nowcasting of severe thunderstorms: A better understanding of the dynamical influence of complex topography and the sea." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670869.
Повний текст джерелаАнотація:
Natural disasters of hydro-meteorological origin are the biggest risk worldwide. In Catalonia (NE of the Iberian Peninsula), severe weather and flash floods occur each year, resulting in major damage to property, losses in agriculture, and also of human lives. To reduce its impact, we need to improve the early warning systems and storm short-term forecasting. There’s a need to gain in-depth knowledge of severe thunderstorm dynamics, since the current accused conditions of global warming can impact in factors triggering these storms. The main objective of the present thesis is to enhance the knowledge of severe storms dynamics and to improve their identification and monitoring in real time, in order to help prevent their surface effects on the citizens. The project addresses the unresolved problem of storm anomalous motion, as it becomes a great challenge to predict their evolution and impact in the next few hours.
For this purpose, the area of Catalonia has been chosen as the study region of this project, due to the proximity to the sea and complex topography, which are often key factors in varying the weather at a local scale. There is also the advantage of having good radar coverage, which will be the essential tool for characterizing storms.
We first propose a methodology that identifies potentially convective days from daily cumulative rainfall fields, selects them to search for storms, and determines if their motion is anomalous. We have found that the area with the highest convective activity between 2008-2015 in Catalonia was located in the eastern Pre-Pyrenees, due to the possible creation of a convergence line. It has also been identified that there are more convective structures with possible anomalous propagation in summer and spring, with the main patterns being related to splitting, merging, stationarity and elongated storms.
Once the study sample is defined, we have developed an algorithm to improve the identification and tracking of these thunderstorms, especially those with anomalous propagations. The keys of improvement have been based on proposing new techniques in the three main modules; 2D, 3D identification and tracking. In addition, it incorporates alerts before possible cell splitting or merging. These changes have shown that the algorithm is able to faithfully reproduce storm life cycle, correctly identify in advanced anomalous motion, and correctly distinguish storms in highly dense convective situations.
The algorithm has been verified first over 30 severe cases, proving that it can identify anomalous movements with a mean 30-min lead-time, being the splitting, the easiest one to do. It has also been demonstrated a good ability at not only identifying these movements but also separating cases with and without anomalous motion. On the other hand, the algorithm has demonstrated a good performance in cases of heavy rainfall on a Catalan flood-prone coastal area of touristic interest. It is identified that storms are usually organized in convergence lines, and that topography and the sea play a very important role, whether affecting the movement, the time of exposure, or the amount of precipitable water causing flash floods.
Finally, the dual-Doppler technique is applied in Catalonia for the first time. This allows getting complete information of the internal dynamics of a thunderstorm, without the need of running idealized models, and then, getting to know the local topographic influence on the evolution and organization. It is demonstrated that the complex local topography changes and/or amplifies the wind flow inside and near thunderstorms, modifying completely their life cycle and their possible interactions with their neighbor cells. It is also shown that this qualitative improvement into storm-scale dynamic knowledge can improve the nowcasting techniques and the early warning systems in the future.Els desastres naturals d’origen hidro-meteorològic constitueixen el major risc a nivell mundial. A Catalunya, cada any es succeeixen diferents episodis de temps advers i inundacions, provocant també danys importants en béns materials, pèrdues en l’agricultura, o pèrdua de vides humanes. Aquestes dades poden augmentar en les condicions cada cop més acusades d’escalfament global. Per reduir l’impacte d’aquest fenòmens és necessari millorar els sistemes d’alerta primerenca a molt curt termini, així com la monitorització dels sistemes meteorològics causants d’aquests fenòmens. En aquest context l’objectiu principal d’aquesta tesi doctoral es millorar el coneixement profund de la dinàmica de les tempestes severes, la seva identificació, predicció a molt curt termini, i monitoratge a temps real. Assolir aquest objectiu implica millorar la prevenció dels seus efectes en superfície. La tesis aborda una problemàtica encara no resolta sobre el moviment anòmal d’aquestes tempestes, que esdevé un gran repte a l’hora de pronosticar-ne la seva evolució en les properes hores, i per tant, el seu impacte. A més, es centra a Catalunya, degut a la seva proximitat al Mar Mediterrani i la complexa topografia, factors claus resultants en una meteorologia variada quasi a nivell de municipi, on hi ha l’avantatge de disposar d’una bona cobertura radar, eina essencial per la caracterització de les tempestes. Primer, es proposa una metodologia que permet identificar les situacions potencialment convectives a partir de camps de precipitació acumulada diària, seleccionant aquestes per cercar les tempestes i determinar si el seu moviment és anòmal (del Moral et al., 2017). Definida la mostra d’estudi, es desenvolupa un algoritme que permet millorar la identificació i seguiment d’aquestes tempestes, sobretot quan es tracta d’aquelles amb moviment anòmal (del Moral et al., 2018a). El funcionament de l’algorisme es verifica en dos règims de convecció diferent: casos severs d’interior (del Moral et al., 2018b), i pluges intenses a la costa (del Moral et al., 2020a). Finalment, s’introdueix per primer cop en un país sud-Europeu la tècnica dual-Doppler: obtenció de variables dinàmiques dins de les pròpies tempestes a partir d’observacions radar, per a l’estudi de les interaccions de més petita escala (del Moral et al., 2020b).
13
Wolfe, Jonathan Paul. "Radar-estimated upslope snowfall rates in southeastern Wyoming." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1317345681&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Повний текст джерела
14
Vachon, Paris W. "Synthetic-aperture radar imaging of the ocean surface : theoretical considerations, and experiments with simulated and actual SAR imagery." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27556.
Повний текст джерелаАнотація:
Three key areas of controversy in synthetic-aperture radar (SAR) imaging of ocean surface waves are considered: first, the nature of Bragg scattering; second, the role, magnitude, and calculation of the scene coherence time; and third, the relevant ocean wave velocities for coherent Doppler modulations.
This work begins with a re-derivation and extension of existing SAR imaging theory for point and diffuse targets. Generic, relatively simple, closed-form expressions for the impulse response, the resolution, and the image bandwidth summarize this unified treatment. Theoretical differences between the imagery of point and diffuse targets are pointed out. Based upon these fundamental differences, a statistical testing procedure is formulated to address the question of scene target density.
Background ocean surface wave theory is outlined in preparation for discussions of SAR ocean imaging. Of central importance is the role of the phase velocity, which is the speed of translation of the mean pattern of reflectivity, and the orbital motion, which leads to coherent (phase) modulation, and hence to velocity bunching, acceleration defocus, and target decorrelation.
Based upon this theoretical background, one- and two-dimensional simulation models
are developed. The one-dimensional simulation addresses the effects of various parameters
upon the mean image contrast in a velocity bunching model and guides the development of the two-dimensional simulation. The two-dimensional simulation is unique because each target which constitutes the scene is explicitly considered. This leads to a degree of control and flexibility which is not available from actual SAR imagery.
Qualitative and quantitative comparisons are drawn between the simulated and actual SAR imagery to address the key areas of controversy. The assertion that Bragg scattering is a coherent process is defended, despite inability to conclusively verify this using SEASAT data. Comparisons between simulation and C-SAR imagery of waves propagating into ice verify the roles of the scene coherence time and the wave phase velocity.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
15
Lack, Steven A. "Quantifying the effect of wind-drift on radar-derived surface rainfall estimations /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1420931.
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16
Hume, A. L. "The measurement and study of fundamental processes in microwave scattering from melting ice particles." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.346435.
Повний текст джерела
17
Tan, Jun. "Analysis and application of differential propagation phase shift in polarization-diversity radar measurements of precipitation at centimeter wavelengths." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303477.
Повний текст джерела
18
Malvig, Steven C. "Analysis of a non-developing tropical circulation system during the Tropical Cyclone Structure (TCS08) field experiment." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Dec/09Dec%5FMalvig.pdf.
Повний текст джерелаАнотація:
Thesis (M.S. in Meteorology and Oceanography)--Naval Postgraduate School, December 2009.Thesis Advisor: Harr, Patrick. Second Reader: Elsberry, Russell. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Electra Doppler Radar (ELDORA), Tropical Cyclone Structure (TCS08), TCS08, tropical cyclone formation, Tropical Circulation System (TCS), TCS025. Includes bibliographical references (p. 75-76). Also available in print.
19
Streed, Daniel H. "High-frequency meteorological phenomena observed with the Naval Postgraduate School's UHF Doppler Wind Profiler." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA243762.
Повний текст джерелаАнотація:
Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Nuss, Wendell A. Second Reader: Wash, C. H. "December 1990." Description based on title screen as viewed on March 30, 2010. DTIC Descriptor(s): Marine Meteorology, Meteorological Radar, Wind, Specifications, Comparison, Doppler Radar, Accuracy, Theses, Meteorological Data, Time, Short Range(Time), Reliability, Profiles, Scale, Data Acquisition, California, Inversion, Statistical Analysis, Meteorological Phenomena, Radiosondes, Schools, Ultrahigh Frequency, High Frequency, Contracts. DTIC Identifier(s): Wind Profilers. Author(s) subject terms: Doppler Wind Profiler, Wind Profiler, Doppler Radar. Includes bibliographical references (p. 115-117). Also available in print.
20
Griggs, Desmond Bryan. "Computer control of an HF chirp radar." Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005240.
Повний текст джерелаАнотація:
This thesis describes the interfacing of an IBM compatible microcomputer to a BR Communications chirp sounder. The need for this is twofold: Firstly for control of the sounder including automatic scheduling of operations, and secondly for data capture. A signal processing card inside the computer performs a Fast Fourier Transform on the sampled data from two phase matched receivers. The transformed data is then transferred to the host computer for further processing, display and storage on hard disk or magnetic tape, all in real time. Critical timing functions are provided by another card in the microcomputer, the timing controller. Built by the author, the design and operation of this sub-system is discussed in detail. Additional circuitry is required to perform antenna and filter switching, and a possible design thereof is also presented by the author. The completed system, comprising the chirp sounder, the PC environment, and the signal switching circuitry, has a dual purpose. It can operate as either a meteor radar, using a fixed frequency (currently 27,99 MHz), or as an advanced chirp ionosonde allowing frequency sweeps from 1,6 to 30 MHz. In the latter case fixed frequency doppler soundings are also possible. Examples of data recorded in the various modes are given.
21
Rajopadhyaya, Deepak K. "Meteorological studies using a VHF radar /." Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phr1613.pdf.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1994.Copies of author's previously published articles inserted. Includes bibliographical references (p. 223-244).
22
Bassan, José Marcio [UNESP]. "Avaliação da chuva produzida pelo modelo eta de previsão do tempo para o Estado de São Paulo com uso de radar meteorológico para aplicações agrícolas." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/110966.
Повний текст джерелаАнотація:
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000800048.pdf: 3915803 bytes, checksum: caa7df2bd754d00c76832ff751fc7611 (MD5)Este trabalho tem por objetivo examinar o uso das previsões de precipitação fornecidas pelo modelo n umérico de previsão do tempo ETA , para a agricultura , especialmente no que se refere à irrigação . O modelo ETA utilizado neste trabalho foi configurado c om a parametrização d a convecção de Kain - Fritsch, resolução horizontal de 10km x 10 k m, e 38 níveis na vertical. As previsões de precipitação acumulada em 24h do modelo ETA foram confrontadas com os dados de precipitação do radar meteorológico do Instituto de Pesquisas Meteoro lógicas da Unesp/Bauru (IPMet) , os quais foram obtidos usando a relação Z - R Rosenfeld , que pareceu a mais apropriada para a região estudada , dentre as demais relações Z - R testadas, como a Z - R Marshall - Palmer. Além de escolher a Z - R Rosenfeld , a s estimativas da precipitação pelo radar usando a relação Z - R foram corrigidas usando uma equação de regressão linear , desenvolvida com os dados de precipitação medida em três estações meteo rológicas disponíveis . O uso dessa equação é sugerido na solução de problemas práticos , tais como o cálculo de precipitação mensal no monitoramento climático. Esse procedimento permitiu reduzir significativamente a tendência que a relação Z - R escolhida ten de a subestimar a precipitação. O resultado da verificação do ETA mostra que q uando se considera somente a ocorrência do fenômeno chuva, independente da sua quantidade, o índice de acerto do modelo é em torno de 60 % para os dois primeiros dias de previsão e ligeiramente menor para o terceiro dia. Entretanto, quando a previsão da quantidade de precipitação é confrontada com a do radar, a percentagem de acerto na maior parte da área verificada não alcança mais que 50% . Além da verificação do modelo ETA propriamente dito, o trabalho a presenta uma metodologia de pesquisa que poderá futuramente ser ...
This work aims to determine the potential use of rainfall forecasts provided by the numerical model of weather prediction ETA, especially regarding irrigation in agriculture. The ETA model was configured with Kain - Fritsch convection parameterization and run with 10km x 10km horizontal resolution, and 38 vertical levels. The ETA 24h accumulated rainfall was compared to radar data precipitation from the Institute of Meteorological Research of the São Paulo State University (IPMet/UNESP), which were obtained using the Z - R Rosenfeld relationship that proved to be more appropriate than others, such as Marshal - Palmer. The systematic error of the radar precipitation data was corrected by using a linea r regression approximation, which statistically adjust these data to gauge rainfall data from three weather stations available. Some applications of this equation to practical problems solution are suggested, such as the calculation of monthly precipitatio n for climate monitoring in the radar resolution. This procedure allowed reducing the chosen ZR tend to underestimate precipitation. The verification result shows that when one considers only the occurrence of the rain phenomenon, regardless its amount, t he percentage of the success of ETA is around 60% for the first two days of the forecast and slightly lower for the third day. However, when the rainfall amount of the model is confronted with the radar precipitation, the percentage of the success most of time does not reach 50%, suggesting the need for substantial model improvement before being considered a useful source for issues related to irrigation. Besides the verification of the ETA model, the work presents a methodology that could be used in the e valuation of other models, in order to verify their potential in agriculture ...
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Bassan, José Marcio 1966. "Avaliação da chuva produzida pelo modelo eta de previsão do tempo para o Estado de São Paulo com uso de radar meteorológico para aplicações agrícolas /." Botucatu :, 2014. http://hdl.handle.net/11449/110966.
Повний текст джерелаАнотація:
Orientador: João Eduardo Machado Perea MartinsBanca: Reinaldo Bomfim da Silveira
Banca: Shigetoshi Sugahara
Banca: João Carlos Cury Saad
Banca: Dinival Martins
Resumo: Este trabalho tem por objetivo examinar o uso das previsões de precipitação fornecidas pelo modelo n umérico de previsão do tempo ETA , para a agricultura , especialmente no que se refere à irrigação . O modelo ETA utilizado neste trabalho foi configurado c om a parametrização d a convecção de Kain - Fritsch, resolução horizontal de 10km x 10 k m, e 38 níveis na vertical. As previsões de precipitação acumulada em 24h do modelo ETA foram confrontadas com os dados de precipitação do radar meteorológico do Instituto de Pesquisas Meteoro lógicas da Unesp/Bauru (IPMet) , os quais foram obtidos usando a relação Z - R Rosenfeld , que pareceu a mais apropriada para a região estudada , dentre as demais relações Z - R testadas, como a Z - R Marshall - Palmer. Além de escolher a Z - R Rosenfeld , a s estimativas da precipitação pelo radar usando a relação Z - R foram corrigidas usando uma equação de regressão linear , desenvolvida com os dados de precipitação medida em três estações meteo rológicas disponíveis . O uso dessa equação é sugerido na solução de problemas práticos , tais como o cálculo de precipitação mensal no monitoramento climático. Esse procedimento permitiu reduzir significativamente a tendência que a relação Z - R escolhida ten de a subestimar a precipitação. O resultado da verificação do ETA mostra que q uando se considera somente a ocorrência do fenômeno chuva, independente da sua quantidade, o índice de acerto do modelo é em torno de 60 % para os dois primeiros dias de previsão e ligeiramente menor para o terceiro dia. Entretanto, quando a previsão da quantidade de precipitação é confrontada com a do radar, a percentagem de acerto na maior parte da área verificada não alcança mais que 50% . Além da verificação do modelo ETA propriamente dito, o trabalho a presenta uma metodologia de pesquisa que poderá futuramente ser ...
Abstract: This work aims to determine the potential use of rainfall forecasts provided by the numerical model of weather prediction ETA, especially regarding irrigation in agriculture. The ETA model was configured with Kain - Fritsch convection parameterization and run with 10km x 10km horizontal resolution, and 38 vertical levels. The ETA 24h accumulated rainfall was compared to radar data precipitation from the Institute of Meteorological Research of the São Paulo State University (IPMet/UNESP), which were obtained using the Z - R Rosenfeld relationship that proved to be more appropriate than others, such as Marshal - Palmer. The systematic error of the radar precipitation data was corrected by using a linea r regression approximation, which statistically adjust these data to gauge rainfall data from three weather stations available. Some applications of this equation to practical problems solution are suggested, such as the calculation of monthly precipitatio n for climate monitoring in the radar resolution. This procedure allowed reducing the chosen ZR tend to underestimate precipitation. The verification result shows that when one considers only the occurrence of the rain phenomenon, regardless its amount, t he percentage of the success of ETA is around 60% for the first two days of the forecast and slightly lower for the third day. However, when the rainfall amount of the model is confronted with the radar precipitation, the percentage of the success most of time does not reach 50%, suggesting the need for substantial model improvement before being considered a useful source for issues related to irrigation. Besides the verification of the ETA model, the work presents a methodology that could be used in the e valuation of other models, in order to verify their potential in agriculture ...
Doutor
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Weygandt, Stephen Scott. "The retreival of initial forecast fields from single Doppler observations of a supercell thunderstorm /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1998.
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Grey, David B. "Analysis of the internal structure of storm systems using a dual polarized radar." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-04122010-083711/.
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Zhang, Limin. "Intelligent algorithms applied to weather radar based flood forecasting system." Thesis, University of Salford, 1999. http://usir.salford.ac.uk/42998/.
Повний текст джерелаАнотація:
The UK weather radar network and telemetry system for the raingauges and river level gauges provided the solid physical base which produce the large amount of data in real time and a large variety of operational flood forecasting models were supplied from SW Region of the Environment Agency. Data processing, the selection of a suitable model, model calibration and parameters updating have played a more and more important role in real time forecasting and this thesis focuses on many of the key issues involved in the emerging area. Within this context, surface fitting, interpolation and cluster analysis were used for adjustment of the weather radar data and comparison between the raingauge data and radar data. As the core of the forecasting system the rainfall runoff model and river routing model were investigated in a wide-ranging manner, the key model utilised is the Transfer Function model. Potential misinterpretation of the TF model was explained by distinguishing between the "Black Box" model and the "White Box" model. The physically based Genetic Cascade Transfer Function (GCTF) model was introduced and shown to be consistent with the Gamma function and Muskingum model which were based upon the three common assumptions: linear, time-invariant and Single Input Single Output (SISO) system. The calculation formula for the moment parameters and the geometry coefficients (t-peak time, volume parameter) create the initial model and a genetic algorithm provides the basic tool to global search for the parameters. An expert system plus the genetic algorithm are combined to provide a real time updating capability. A dentritic model composed of the SISO rainfall runoff model at several tributaries and the Multi-Input Single Output (MISO) routing model in the mainstream were developed and applied to the Bristol Avon catchment. As a Weather Radar Information Processor, WRIP(II) was extended and implemented on a SPARC 10 workstation and communions at Environment Agency South West Region (Exeter) with a graphical user interface based on X/Motif.
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Schumacher, Courtney. "Tropical precipitation in relation to the large-scale circulation /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10041.
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Xiao, Jingwei. "Meteor radar studies of the mesopause region and nonlinear atmospheric waves." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/25771.
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Holdsworth, David A. "Signal analysis with applications to atmospheric radars /." Title page, abstract and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phh728.pdf.
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Yoho, Peter K. "Satellite scatterometers : calibration using a ground station and statistical measurement theory /." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd306.pdf.
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Towers, Sandra Y. "Vertical reflectivity profiles and the correction of operational radar rainfall data." Thesis, University of Salford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360409.
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Sanabia, Elizabeth R. "The re-intensification of Typhoon Sinlaku (2008)." Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/dissert/2010/Jun/10Jun%5FSanabia%5FPhD.pdf.
Повний текст джерелаАнотація:
Dissertation (Ph.D. in Meteorology)--Naval Postgraduate School, June 2010.Dissertation supervisor: Harr, Patrick A. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Tropical Cyclones, TCS-08, T-PARC, Extratropical Transition, Airborne Dual Doppler Radar, ELDORA, Axisymmetrization, Mesoscale Vortices, Mesoscale Convective System. Includes bibliographical references (p. 207-212). Also available in print.
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Greenwood, Andrew D. "Azimuth modulation of the radar backscatter at near-normal incidence /." Diss., CLICK HERE for online access, 1995. http://contentdm.lib.byu.edu/ETD/image/etd5.pdf.
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Cervera, Manuel A. "Meteor observations with a narrow beam VHF radar /." Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phc419.pdf.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1996.Copies of author's previously published articles are inserted between p. 272-283 and are not numbered as part of main text. Includes bibliographical references (p. 283-293).
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Sandifer, John B. "Meteorological measurements with a MWR-05XP phased array radar." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Mar%5FSandifer.pdf.
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Billings, Don, Mei Wei, Joseph Leung, Michio Aoyagi, Fred Shigemoto, and Rob Honeyman. "REAL-TIME INTEGRATION OF RADAR INFORMATION, AND GROUND AND RADIOSONDE METEOROLOGY WITH FLIGHT RESEARCH DATA." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607368.
Повний текст джерелаАнотація:
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, CaliforniaAlthough PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.
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Metzger, Eric L. "The relationship between total cloud lightning behavior and radar derived thunderstorm structure." Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Mar/10Mar%5FMetzger.pdf.
Повний текст джерелаАнотація:
Thesis (M.S. in Meteorology)--Naval Postgraduate School, March 2010.Thesis Advisor: Nuss, Wendell. Second Reader: Pfeiffer, Karl. "March 2010." Author(s) subject terms: Total cloud lightning, thunderstorm structure, hail, severe wind(s), tornadoes, lightning jumps, lightning detection, Lightning behavior, radar derived thunderstorm structure. Includes bibliographical references (p. 83-85). Also available in print.
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Gray, Warren R. "The vertical profile of reflectivity and errors in radar estimates of rainfall." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304253.
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Antonio, Carlos Alberto de Agostinho [UNESP]. "Geoestatística aplicada à acumulação da precipitação pluviométrica com radar meteorológico." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/90631.
Повний текст джерелаАнотація:
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antonio_caa_me_botfca.pdf: 2765325 bytes, checksum: 280098279ffdbea961a48e5dc795f5a5 (MD5)As medidas diárias de chuva acumulada são informações de suma importância para a agricultura como, por exemplo, na aplicação de insumos, na estimativa da irrigação ou em cálculos de balanços hídricos. As informações atualmente disponíveis sobre chuvas diárias são, no geral, provenientes de pluviômetros convencionais de operação manual. A eficiência de pluviômetros em mensurar a precipitação em uma área está diretamente relacionada à distância entre os equipamentos. A maior rede de pluviômetros em operação no Estado de São Paulo, que está sob responsabilidade do DAEE (Departamento de Águas e Energia Elétrica), disponibiliza os totais diários com vários meses de defasagem, impossibilitando a utilização imediata dessas informações. A utilização de radares meteorológicos para a quantificação de chuva está associada à eficiência de equações de conversão do sinal eletrônico do radar (Z) em chuva (R), denominada relação ZR. Utilizando dados pluviométricos diários, entre 1995 e 1999, de sete estações dispostas numa área de 1.500 km2, e comparando com dados de radar no mesmo período, foi possível estabelecer uma relação ZR probabilística visando à acumulação diária da precipitação, representativa a área delimitada. A aplicação da relação ZR ajustada à área delimitada resultou em acumulações diárias mais próximas dos resultados observados pelos dados dos pluviômetros, quando comparadas aos resultados da relação ZR atualmente em uso, nos radares da UNESP. Nas acumulações de chuva, obtidas por radar, foram aplicadas interpolações geoestatísticas, resultando na melhoria da distribuição espacial dessas acumulações. Objetivando a complementação espacial e temporal das informações de chuva acumulada atualmente disponíveis, este estudo demonstra uma metodologia apropriada para determinação...
The daily measures of accumulated rain are very important information for agriculture, for example, in the fertilezer applications, the estimate of the irrigation or calculation of water balance. Currently, the information available of daily rain is, generally, provenient form conventional rain gauges manually operated. The efficiency of rain gauges in measuring the precipitation in an area is directly related to the distance between equipment. The biggest rain gauges net operating in the State of São Paulo in under responsibility of DAEE (Department of Water and Electric Energy) which provides daily information with several months of delay, impeding the information to be used immediately. The use of meteorological radars for the quantification of rain is associated to the efficiency of conversion equations of the radar electronic sign (Z) in rain (R), known as relationship ZR. Using daily rain data between 1995 and 1999, from seven stations located in an area of 1,500 km2 and comparing whit data from the radar in the same period, it was possible do establish a ZR probabilistic relation aiming at the daily amount of precipitation, which represents the delimited area. The application of the ZR relationship adjusted to the delimited area resulted in daily accumulation closer to the results observed by the rain gauges data when compared to the results of the ZR relationship currently in use in radar operated by UNESP. In the accumulation of rain, taken by the radar, geostatistic interpolations were applied, and the results were a better spatial distribution of these accumulations. Objectifying the space and temporal complementation of currently available the accumulated rain information, this research demonstrates an appropriate methodology to determinate regional ZR relationship, based on data from rain gauges, and the application of geoestaistic interpolation... (Complete abstract click electronic access below)
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Mead, Reginald Marshall. "A system for automating identification of biological echoes in NEXRAD level II radar data." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/mead/MeadR1209.pdf.
Повний текст джерелаАнотація:
Since its inception in the mid twentieth century, radar ornithology has provided scientists with new tools for studying the behavior of birds, especially with regards to migration. A number of studies have shown that birds can be detected using a wide variety of radar devices. Generally, these studies have focused on small portable radars that typically have a finer resolution than large weather surveillance radars. Recently, however, a number of researchers have presented qualitative evidence suggesting that birds, or at least migration events, can be identified using large broad scale radars such as the WSR-88D used in the NEXRAD weather surveillance system. This is potentially a boon for ornithologists because NEXRAD data covers a large portion of the country, is constantly being produced, is freely available, and is archived back into the early 1990s. A major obstacle is that identifying birds in NEXRAD data currently requires having a trained technician manually inspect a graphically rendered radar sweep. The immense amount of available data makes manual classification of radar echoes infeasible over any practical span of space or time. In this thesis, a system is presented for automating this process using machine learning techniques. This approach begins with classified training data that has been interpreted by experts or collected from direct observations. The data is preprocessed to ensure quality and to emphasize relevant features. A classifier is then trained using this data and cross validation is used to measure performance. The experiments in this thesis compare neural network, naïve Bayes, and k-nearest neighbor classifiers. Empirical evidence is provided showing that this system can achieve classification accuracies in the 80th to 90th percentile.
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Ghate, Virendra Prakash. "Turbulence and Mass-Transports in Stratocumulus Clouds." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/265.
Повний текст джерелаАнотація:
Boundary layer (BL) stratocumulus clouds are an important factor in the earth's radiation budget due to their high albedo and low cloud top heights. Continental BL stratocumulus clouds are closely coupled to the diurnal cycle and the turbulence in the BL affecting the surface energy and moisture budgets. In this study the turbulence and mass-transport structures in continental BL stratocumulus clouds are studied using data from the Atmospheric Radiation Measurements (ARM)'s Southern Great Plains (SGP) observing facility located at Lamont, Oklahoma. High temporal (4 sec) and spatial (45 m) resolution observations from a vertically pointing 35 GHz cloud Doppler radar were used to obtain the in-cloud vertical velocity probability density function (pdf) in the absence of precipitation size hydrometeors. A total of 70 hours of radar data were analyzed to report halfhourly statistics of vertical velocity variance, skewness, updraft fraction, downdraft and velocity binned mass-flux at five cloud depth normalized levels. The variance showed a general decrease with increase in height in the cloud layer while the skewness is weakly positive in the cloud layer and negative near cloud top. The updraft fraction decreases with height with the decrease mainly occurring in the upper half of the cloud layer. The downdraft fraction increases with decrease in height with the increase being almost linear. The velocity of eddies responsible for maximum mass-transport decreases from of 0.4 ms-1 near cloud base to 0.2 ms-1 near cloud top. The half-hour periods were then classified based on the surface buoyancy flux as stable or unstable and it was found that the variance near cloud top is higher during the stable periods as compared to the unstable periods. Classification was also made based on the cloud depth to BL depth ratio (CBR) being greater or less than 0.3. The variance profile was similar for the classification while the skewness was almost zero during periods with CBR less 0.3 and positive during periods with CBR greater than 0.3. A 14 hour period of stratocumulus cloud on March 25, 2005 was analyzed to study the diurnal changes in the turbulence structure and mass transports. The variance near cloud base during the day time when the BL turbulence is primarily due to surface buoyancy production was higher than during the nighttime when the BL turbulence is driven by radiative cooling near the cloud top. Output from a one dimensional radiative transfer model was analyzed to study the vertical structure of the radiative fluxes. A radiative velocity scale analogous to the surface convective velocity scale is proposed to assess the relative importance of radiative cooling near cloud top in generating turbulence compared with the surface buoyancy production. An attempt was also made to calculate the hourly liquid water flux by combining the high temporal resolution (20 sec) liquid water content estimates from the radar reflectivity and a microwave radiometer with the radar observed vertical velocity. The liquid water flux was found to peak at a level below the cloud top and show a divergence with height that was similar to that from model simulations.
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Adhikari, Loknath. "Cloudy condition assessment within an AIRS pixel by combining MODIS and ARM ground-based lidar and radar measurements." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1456295781&sid=7&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Barrowes, Benjamin E. "YSCAT backscatter distributions /." Diss., CLICK HERE for online access, 1999. http://contentdm.lib.byu.edu/ETD/image/etd2.pdf.
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Patoux, Jérôme. "Frontal wave development over the Southern Ocean /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10067.
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Halterman, R. Ryan. "Observation and tracking of tropical cyclones using resolution enhanced scatterometry /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1667.pdf.
Повний текст джерела
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Hajjam, Sohrab. "Real-time flood forecasting model intercomparison and parameter updating rain gauge and weather radar data." Thesis, University of Salford, 1997. http://usir.salford.ac.uk/43019/.
Повний текст джерелаАнотація:
This thesis describes the development of real-time flood forecasting models at selected catchments in the three countries, using rain gauge and radar derived rainfall estimates and time-series analysis. An extended inter-comparison of real-time flood forecasting models has been carried out and an attempt has been made to rank the flood forecasting models. It was found that an increase in model complexity does not necessarily lead to an increase in forecast accuracy. An extensive analysis of group calibrated transfer function (TF) models on the basis of antecedent conditions of the catchment and storm characteristics has revealed that the use of group model resulted in a significant improvement in the quality of the forecast. A simple model to calculate the average pulse response has also been developed. The development of a hybrid genetic algorithm (HGA), applied to a physically realisable transfer function model is described. The techniques of interview selection and fitness scaling as well as random bit mutation and multiple crossover have been included, and both binary and real number encoding technique have been assessed. The HGA has been successfully applied for the identification and simulation of the dynamic TF model. Four software packages have been developed and extensive development and testing has proved the viability of the approach. Extensive research has been conducted to find the most important adjustment factor of the dynamic TF model. The impact of volume, shape and time adjustment factors on forecast quality has been evaluated. It has been concluded that the volume adjustment factor is the most important factor of the three. Furthermore, several attempts have been made to relate the adjustment factors to different elements. The interaction of adjustment factors has also been investigated. An autoregressive model has been used to develop a new updating technique for the dynamic TF model by the updating of the B parameters through the prediction of future volume adjustment factors over the forecast lead-time. An autoregressive error prediction model has also been combined with a static TF model. Testing has shown that the performance of both new TF models is superior to conventional procedures.
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Robinson, Sean D. "Utility of tactical environmental processor (TEP) as a Doppler at-sea weather radar." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FRobinson.pdf.
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Antonio, Carlos Alberto de Agostinho 1960. "Geoestatística aplicada à acumulação da precipitação pluviométrica com radar meteorológico /." Botucatu : [s.n.], 2007. http://hdl.handle.net/11449/90631.
Повний текст джерелаАнотація:
Orientador: Célia Regina Lopes ZimbackBanca: Carlos Alberto Oliveira de Matos
Banca: Paulo Cesar Sentelhas
Resumo: As medidas diárias de chuva acumulada são informações de suma importância para a agricultura como, por exemplo, na aplicação de insumos, na estimativa da irrigação ou em cálculos de balanços hídricos. As informações atualmente disponíveis sobre chuvas diárias são, no geral, provenientes de pluviômetros convencionais de operação manual. A eficiência de pluviômetros em mensurar a precipitação em uma área está diretamente relacionada à distância entre os equipamentos. A maior rede de pluviômetros em operação no Estado de São Paulo, que está sob responsabilidade do DAEE (Departamento de Águas e Energia Elétrica), disponibiliza os totais diários com vários meses de defasagem, impossibilitando a utilização imediata dessas informações. A utilização de radares meteorológicos para a quantificação de chuva está associada à eficiência de equações de conversão do sinal eletrônico do radar (Z) em chuva (R), denominada relação ZR. Utilizando dados pluviométricos diários, entre 1995 e 1999, de sete estações dispostas numa área de 1.500 km2, e comparando com dados de radar no mesmo período, foi possível estabelecer uma relação ZR probabilística visando à acumulação diária da precipitação, representativa a área delimitada. A aplicação da relação ZR ajustada à área delimitada resultou em acumulações diárias mais próximas dos resultados observados pelos dados dos pluviômetros, quando comparadas aos resultados da relação ZR atualmente em uso, nos radares da UNESP. Nas acumulações de chuva, obtidas por radar, foram aplicadas interpolações geoestatísticas, resultando na melhoria da distribuição espacial dessas acumulações. Objetivando a complementação espacial e temporal das informações de chuva acumulada atualmente disponíveis, este estudo demonstra uma metodologia apropriada para determinação... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The daily measures of accumulated rain are very important information for agriculture, for example, in the fertilezer applications, the estimate of the irrigation or calculation of water balance. Currently, the information available of daily rain is, generally, provenient form conventional rain gauges manually operated. The efficiency of rain gauges in measuring the precipitation in an area is directly related to the distance between equipment. The biggest rain gauges net operating in the State of São Paulo in under responsibility of DAEE (Department of Water and Electric Energy) which provides daily information with several months of delay, impeding the information to be used immediately. The use of meteorological radars for the quantification of rain is associated to the efficiency of conversion equations of the radar electronic sign (Z) in rain (R), known as relationship ZR. Using daily rain data between 1995 and 1999, from seven stations located in an area of 1,500 km2 and comparing whit data from the radar in the same period, it was possible do establish a ZR probabilistic relation aiming at the daily amount of precipitation, which represents the delimited area. The application of the ZR relationship adjusted to the delimited area resulted in daily accumulation closer to the results observed by the rain gauges data when compared to the results of the ZR relationship currently in use in radar operated by UNESP. In the accumulation of rain, taken by the radar, geostatistic interpolations were applied, and the results were a better spatial distribution of these accumulations. Objectifying the space and temporal complementation of currently available the accumulated rain information, this research demonstrates an appropriate methodology to determinate regional ZR relationship, based on data from rain gauges, and the application of geoestaistic interpolation... (Complete abstract click electronic access below)
Mestre
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Russell, Frances Marion. "Semi-permanent zones of radar radial shear within the planetary boundary layer : observations and effects on high intensity precipitation in the wider Auckland region, New Zealand : a thesis submitted to the Victoria University of Wellington in partial fulfilment of the requirements for the degree of Master of Science in Geophysics /." ResearchArchive@Victoria e-Thesis, 2009. http://hdl.handle.net/10063/1215.
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Foster, James A. "A Comparison of Mobile Radar-Inferred Rain-Drop Size Estimates between Tornadic and Non-Tornadic Supercell Hook Echoes." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou157832340334202.
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