The UK has an abundant offshore wind resource with offshore wind farming set to grow rapidly over the coming years. Optimisation of energy production is of the utmost importance and accurate estimates of wind speed distributions are critical for the planning process. Synthetic aperture radar (SAR) data can provide synoptic, wide area wind field estimates at resolutions of a few kilometres and has great potential for wind resource assessment. This thesis addresses the key challenges for the operational implementation of SAR in this context; namely the accuracy of SAR wind retrievals and the ability of SAR to characterise the mean wind speed and wind power density. We consider the main stages of SAR wind retrieval; the retrieval algorithm; sources of a priori information; the optimal configuration of the retrieval system; and the challenges for and accuracy of SAR wind resource estimation. This study was conducted for the eastern Irish Sea in the UK, a region undergoing significant offshore wind energy development. A new wind retrieval algorithm was developed that implements a maximum a posterior probability (MAP) method drawn from Bayesian statistics. MAP was demonstrated to be less sensitive to input errors than the standard direction-based wind speed algorithm (DWSA) and provides a simple retrieval quality check via the error reduction ratio. Retrieval accuracy is strongly influenced by the quality of a priori information. The accuracy of two operationally viable a priori sources, mesoscale numerical weather prediction (NWP) data and WISAR image directions, was evaluated by comparison against in-situ wind observations and WERA coastal data. Results show that NWP wind speeds produce good wind speed and direction estimates with standard deviations of ¬±2 ms-1 and ±16o respectively. WISAR directions were less accurate producing standard deviations ranging from ±20o to ±29o, but were preferable when strong differences between NWP timesteps were observed. The accuracy of SAR wind retrievals was evaluated by comparison against in-situ wind observations. The MAP algorithm was found to provide modest improvements in retrieval accuracy over DWSA. Highest quality retrievals achieved using the CMOD5 forward model, producing wind speeds with a RMSE of 1.83 ms-1. Regarding the ability of SAR to estimate offshore wind resources, dataset density was found to be a controlling parameter. With 103 scenes available mean wind speeds were well characterised by comparison against in-situ observations and Wind Atlas results, while wind power density showed considerable errors. The accuracy of wind speed maps was further improved by accounting for wind direction and fetch effects upon the SAR wind distribution. A key strength of the SAR wind fields is their ability to identify the effect of mesoscale structures upon the surface wind field with atmospheric gravity waves observed in 30% of the images. These structures are shown to introduce wind speed fluctuations of up to ±2 ms-1 at scales of 5 to 10 km and may have significant implications for wind power prediction. These findings show that SAR may provide an important source of wide area wind speed observations as a complement to existing wind resource estimation techniques. SAR may be of particular use in coastal areas where complex wind fields are observed.

Made available in DSpace on 2017-07-10T19:24:27Z (GMT). No. of bitstreams: 1 Andre Luiz Justi.pdf: 417849 bytes, checksum: 8c0574623c4c093e98515ba5e1e5e5c8 (MD5) Previous issue date: 2008-07-10 / The contribution of irrigation in the alimentary supply, is due to the fact of more and more to look for more efficient systems, monitoring the indexes of uniformity of distribution of the water. The application of fertilizers through irrigation water took very big pulse in the last times, mainly due to the emergence of pressurized systems, of the tunnels of plastic, of the increment of the located irrigation and of the researches proving that the application of liquid fertilizers becomes more appropriate to the plants, to the soil and, besides under the analysis of the involved economical aspects. Being necessary tests to verify the system this operating appropriately in field in order to avoid losses so much in productivity as maintenance of systems. It was aimed at with this work to evaluate an overhead irrigation for aspersion, so much in the application of water as in the fertilizer application, and to submit him/it to quality control techniques to evaluate the capacity of the process. The experiment was driven in the Experimental Nucleus of Engineering Agricultural, belonging the State University of the West of Paraná, located in the km 95 of the highway BR 467. They were appraised 25 irrigations and 25 fertigations, following the established methodology for NBR 7749 (ABNT, 1999). For the irrigation, they were obtained values of Coefficient of Uniformity of Christiansen (CUC) of 72,25 and 89,45% as values minimum and maximum, and a medium CUC of 79,72%, considered value below the minimum of 80% for irrigation for aspersion, and the system operated in wind conditions with speeds of up to 2,97 m.s-1. For fertigation, the values of found CUC were 70,91 and 81,04% as minimum and maximum, and a medium CUC of 77,14%, under maximum wind of 2,18 m.s-1.Aplicando the quality control tests, for the irrigation with water, it was obtained a correlation index between CUC and the speed of the wind of 83,6% and 68,4% for the irrigation and fertigation, respectively and a correlation among CUC and to the index of capacity of process (CP) of 63,3 and 20,9% for the irrigation and fertigation, respectively. / A contribuição da irrigação no suprimento alimentar, se deve ao fato de cada vez mais buscar-se sistemas mais eficientes, monitorando os índices de uniformidade de distribuição da água. A aplicação de fertilizantes via água de irrigação tomou impulso muito grande nos últimos tempos, principalmente devido ao aparecimento de sistemas pressurizados, dos túneis de plástico, do incremento da irrigação localizada e das pesquisas comprovando que a aplicação de adubos líquidos torna-se mais adequada às plantas, ao solo e, inclusive sob a análise dos aspectos econômicos envolvidos. Sendo necessários testes para verificar se o sistema esta operando adequadamente em campo a fim de evitar perdas tanto em produtividade quanto manutenção dos sistemas. Objetivou-se com este trabalho avaliar um sistema de irrigação por aspersão, tanto na aplicação de água como na aplicação de fertilizante, e submetê-lo a técnicas de controle de qualidade para avaliar a capacidade do processo. O experimento foi conduzido no Núcleo Experimental de Engenharia Agrícola, pertencente à Universidade Estadual do Oeste do Paraná, localizado no km 95 da rodovia BR 467. Foram avaliadas 25 irrigações e 25 fertirrigações, seguindo a metodologia estabelecida pela NBR 7749 (ABNT, 1999). Para a irrigação, foram obtidos valores de Coeficiente de Uniformidade de Christiansen (CUC) de 72,25 e 89,45% como valores mínimo e máximo, e um CUC médio de 79,72%, considerado valor abaixo do mínimo de 80% para irrigação por aspersão, sendo que o sistema operou em condições de vento com velocidades de até 2,97 m.s-1. Para fertirrigação, os valores de CUC encontrados foram 70,91 e 81,04% como mínimo e máximo, e um CUC médio de 77,14%, sob vento máximo de 2,18 m.s-1. Aplicando os testes de controle de qualidade, para a irrigação com água, foi obtido um índice de correlação entre o CUC e a velocidade do vento de 83,6% e 68,4% para a irrigação e fertirrigação, respectivamente e uma correlação entre o CUC e a o índice de capacidade do processo (CP) de 63,3 e 20,9% para a irrigação e fertirrigação, respectivamente.

Made available in DSpace on 2017-05-12T14:47:45Z (GMT). No. of bitstreams: 1 Andre Luiz Justi.pdf: 417849 bytes, checksum: 8c0574623c4c093e98515ba5e1e5e5c8 (MD5) Previous issue date: 2008-07-10 / The contribution of irrigation in the alimentary supply, is due to the fact of more and more to look for more efficient systems, monitoring the indexes of uniformity of distribution of the water. The application of fertilizers through irrigation water took very big pulse in the last times, mainly due to the emergence of pressurized systems, of the tunnels of plastic, of the increment of the located irrigation and of the researches proving that the application of liquid fertilizers becomes more appropriate to the plants, to the soil and, besides under the analysis of the involved economical aspects. Being necessary tests to verify the system this operating appropriately in field in order to avoid losses so much in productivity as maintenance of systems. It was aimed at with this work to evaluate an overhead irrigation for aspersion, so much in the application of water as in the fertilizer application, and to submit him/it to quality control techniques to evaluate the capacity of the process. The experiment was driven in the Experimental Nucleus of Engineering Agricultural, belonging the State University of the West of Paraná, located in the km 95 of the highway BR 467. They were appraised 25 irrigations and 25 fertigations, following the established methodology for NBR 7749 (ABNT, 1999). For the irrigation, they were obtained values of Coefficient of Uniformity of Christiansen (CUC) of 72,25 and 89,45% as values minimum and maximum, and a medium CUC of 79,72%, considered value below the minimum of 80% for irrigation for aspersion, and the system operated in wind conditions with speeds of up to 2,97 m.s-1. For fertigation, the values of found CUC were 70,91 and 81,04% as minimum and maximum, and a medium CUC of 77,14%, under maximum wind of 2,18 m.s-1.Aplicando the quality control tests, for the irrigation with water, it was obtained a correlation index between CUC and the speed of the wind of 83,6% and 68,4% for the irrigation and fertigation, respectively and a correlation among CUC and to the index of capacity of process (CP) of 63,3 and 20,9% for the irrigation and fertigation, respectively. / A contribuição da irrigação no suprimento alimentar, se deve ao fato de cada vez mais buscar-se sistemas mais eficientes, monitorando os índices de uniformidade de distribuição da água. A aplicação de fertilizantes via água de irrigação tomou impulso muito grande nos últimos tempos, principalmente devido ao aparecimento de sistemas pressurizados, dos túneis de plástico, do incremento da irrigação localizada e das pesquisas comprovando que a aplicação de adubos líquidos torna-se mais adequada às plantas, ao solo e, inclusive sob a análise dos aspectos econômicos envolvidos. Sendo necessários testes para verificar se o sistema esta operando adequadamente em campo a fim de evitar perdas tanto em produtividade quanto manutenção dos sistemas. Objetivou-se com este trabalho avaliar um sistema de irrigação por aspersão, tanto na aplicação de água como na aplicação de fertilizante, e submetê-lo a técnicas de controle de qualidade para avaliar a capacidade do processo. O experimento foi conduzido no Núcleo Experimental de Engenharia Agrícola, pertencente à Universidade Estadual do Oeste do Paraná, localizado no km 95 da rodovia BR 467. Foram avaliadas 25 irrigações e 25 fertirrigações, seguindo a metodologia estabelecida pela NBR 7749 (ABNT, 1999). Para a irrigação, foram obtidos valores de Coeficiente de Uniformidade de Christiansen (CUC) de 72,25 e 89,45% como valores mínimo e máximo, e um CUC médio de 79,72%, considerado valor abaixo do mínimo de 80% para irrigação por aspersão, sendo que o sistema operou em condições de vento com velocidades de até 2,97 m.s-1. Para fertirrigação, os valores de CUC encontrados foram 70,91 e 81,04% como mínimo e máximo, e um CUC médio de 77,14%, sob vento máximo de 2,18 m.s-1. Aplicando os testes de controle de qualidade, para a irrigação com água, foi obtido um índice de correlação entre o CUC e a velocidade do vento de 83,6% e 68,4% para a irrigação e fertirrigação, respectivamente e uma correlação entre o CUC e a o índice de capacidade do processo (CP) de 63,3 e 20,9% para a irrigação e fertirrigação, respectivamente.