8 results on '"radar image"'
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2. Повышение информативности радиолокационных изображений в системах дистанционного зондирования Земли на основе методов фрактальной обработки
- Author
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Тренихин, В. А., Коберниченко, В. Г., Trenikhin, V. A., Kobernichenko, V. G., Тренихин, В. А., Коберниченко, В. Г., Trenikhin, V. A., and Kobernichenko, V. G.
- Abstract
Анализируется фрактальная размерность, которая количественно оценивает сложность и хаотический характер радиолокационного изображения природных текстур. Показано, что построение поля фрактальной размерности с последующей многопороговой обработкой позволяет выделить различные классы слабоконтрастных объектов. Проведено сравнение эффективности кластеризации методами ISODATA и K-ближайших соседей яркостного поля и поля фрактальной размерности на основе экспериментальной обработки фрагментов космических радио-локационных изображений., We analyze fractal dimension, which quantifies the complexity and chaotic nature of the radar image of natural textures. We establish that regardless of the method used for calculating the fractal dimension, the General appearance of the histograms is preserved, and the boundaries of the regions are characterized by the same values of fractal dimension, which makes it possible to identify the types of textures. We demonstrate that the construction of the field of fractal dimension of the radar image and the subsequent multi-threshold processing allow distinguishing different classes of natural textures (water surface, shallows, oil spills, land, etc.). The efficiency of clustering by ISODATA and K-nearest neighbors of the brightness field and the fractal dimension field is compared on the basis of experimental processing of fragments of space radar images.
- Published
- 2019
3. Применение разностной обработки сигналов поляриметрического РСА для выделения слабоконтрастных распределенных объектов
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Ницак, Д. А., Nitsak, D. A., Ницак, Д. А., and Nitsak, D. A.
- Abstract
Определены границы обнаружения слабоконтрастных объектов поляриметрическим радиолокатором с синтезированием апертуры антенны (РСА) для случая двумерной входной статистики. Получено простое правило приближенной оценки вероятности обнаружения флуктуирующей цели на фоне флуктуирующей пассивной помехи. Сравнение границ обнаружения показывает преимущество разностной обработки при обнаружении малоразмерных и распределенных объектов в системах мониторинга земной поверхности., A low in contrast polarimetric synthetic aperture radar (SAR) objects detection limits are specified for bivariate statistics. The simple rule of the probability approximate estimation of the fluctuating target on passive clutter is obtained. The detection limits comparison demonstrates the advantages of the subtract processing for the detection of the radar resolution comparable and distributed objects detection in the earth surface monitoring systems. The paper reveals that the subtract processing is more effective when a passive masking clutter has better masking properties in accordance to detectable signal.
- Published
- 2019
4. Моделирование процесса обработки сигналов в космических РСА высокого разрешения : магистерская диссертация
- Author
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Коберниченко, В. Г., Kobernichenko, V. G., УрФУ. Институт радиоэлектроники и информационных технологий-РТФ, Кафедра теоретических основ радиотехники, Курганский, А. А., Kurganski, A. A., Коберниченко, В. Г., Kobernichenko, V. G., УрФУ. Институт радиоэлектроники и информационных технологий-РТФ, Кафедра теоретических основ радиотехники, Курганский, А. А., and Kurganski, A. A.
- Abstract
В работе актуализируется цель создания учебного программного приложения, позволяющего моделировать процесс формирования и обработки сигналов в космических РСА высокого разрешения. В ходе работы разработано программное приложение, которое позволяет создать облучаемую сцену земной поверхности и сформировать в зависимости от сцены отраженный сигнал с пользовательскими характеристиками РСА, провести его обработку с целью получения радиоголограмм и радиолокационных изображений. Результатом разработки стало учебное программное приложение, которое позволит магистрам направления «Радиотехника» понять принцип формирования и обработки сигналов в космических РСА высокого разрешения и провести ряд исследований, направленных на изучения особенностей формирования радиолокационных изображений., Problem of development of educational software application that allows to simulate the process of forming and signal processing in space high-resolution SAR is disclosed. In result software application that allows to create an irradiated scene of earth's surface and to form depending on the scene reflected signal with custom features SAR in order to obtain RF holograms and radar images was developed. The achievement is the educational software application that allows magisters of speciality «Radiotechnics» to understand the principle of formation and signal processing in high-resolution SAR and to perform a series of test aimed at studying the characteristics of radar image .
- Published
- 2015
5. Использование анизотропных фильтров в обработке радиолокационных изображений
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Мартьянова, А. В., Martyanova, A. V., Мартьянова, А. В., and Martyanova, A. V.
- Abstract
В данной статье предлагаются алгоритмы выделения границ, основанных на ортогональных преобразованиях двумерных сигналов. В качестве операторов преобразования используются анизотропные фильтры, определяющие границы в четырех направлениях. С помощью статистических характеристик полученных изображений определена эффективность анизотропных фильтров в решении задачи обработки радиолокационных изображений., In given article algorithms of contours extraction are proposed, that based on two-dimensional discrete orthogonal transformations. Anisotropic filters is used as operator of transformation. They define contours in four directions. The modeling experiment results allow to determine the advantages and disadvantages of the filters in digital image processing.
- Published
- 2015
6. Multi-temporal land-cover classification of agricultural areas in two European regions with high resolution spotlight TerraSAR-X data
- Author
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Bargiel, Damian, Herrmann, Sylvia, Bargiel, Damian, and Herrmann, Sylvia
- Abstract
Functioning ecosystems offer multiple services for human well-being (e.g., food, freshwater, fiber). Agriculture provides several of these services but also can cause negative impacts. Thus, it is essential to derive up-to-date information about agricultural land use and its change. This paper describes the multi-temporal classification of agricultural land use based on high resolution spotlight TerraSAR-X images. A stack of l4 dual-polarized radar images taken during the vegetation season have been used for two different study areas (North of Germany and Southeast Poland). They represent extremely diverse regions with regard to their population density, agricultural management, as well as geological and geomorphological conditions. Thereby, the transferability of the classification method for different regions is tested. The Maximum Likelihood classification is based on a high amount of ground truth samples. Classification accuracies differ in both regions. Overall accuracy for all classes for the German area is 61.78% and 39.25% for the Polish region. Accuracies improved notably for both regions (about 90%) when single vegetation classes were merged into groups of classes. Such regular land use classifications, applicable for different European agricultural sites, can serve as basis for monitoring systems for agricultural land use and its related ecosystems. © 2011 by the authors.
- Published
- 2011
7. Multi-temporal land-cover classification of agricultural areas in two European regions with high resolution spotlight TerraSAR-X data
- Author
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Bargiel, Damian, Herrmann, Sylvia, Bargiel, Damian, and Herrmann, Sylvia
- Abstract
Functioning ecosystems offer multiple services for human well-being (e.g., food, freshwater, fiber). Agriculture provides several of these services but also can cause negative impacts. Thus, it is essential to derive up-to-date information about agricultural land use and its change. This paper describes the multi-temporal classification of agricultural land use based on high resolution spotlight TerraSAR-X images. A stack of l4 dual-polarized radar images taken during the vegetation season have been used for two different study areas (North of Germany and Southeast Poland). They represent extremely diverse regions with regard to their population density, agricultural management, as well as geological and geomorphological conditions. Thereby, the transferability of the classification method for different regions is tested. The Maximum Likelihood classification is based on a high amount of ground truth samples. Classification accuracies differ in both regions. Overall accuracy for all classes for the German area is 61.78% and 39.25% for the Polish region. Accuracies improved notably for both regions (about 90%) when single vegetation classes were merged into groups of classes. Such regular land use classifications, applicable for different European agricultural sites, can serve as basis for monitoring systems for agricultural land use and its related ecosystems. © 2011 by the authors.
- Published
- 2011
8. Flood-threat zoning map of the urban area of Chocó (Quibdó). A study based on interpreting radar, satellite and aerial photograph images
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Maturana Córdoba, Zamir and Maturana Córdoba, Zamir
- Abstract
A zoning map of areas which flood due to the Atrato River and its tributaries (the Cabí, Caraño and Yesca) overflowing in the urban area of Chocó (Quibdó) was drawn up to be used by aid authorities and Quibdó city as a planning and control tool. This research relied on CIAF (Centro Interamericano de Fotointerpretación) support and assessment. This entity is a subsidiary institution of the Instituto Geográfico Agustín Codazzi which provided their installations and the required geographical material. This research was initially based on interpreting radar (INTERA), satellite ((ANDSAT) and aerial photographic images; this was verified by field verification of the interpreted data. Other variables such as climatic, geological, temperature, topographic conditions, historic and hydrological series and facts regarding the region were studied as additional information required for drawing conclusions. Aerial photographs provided the most reliable images due to their scales, quantity and quality and the date of when they were taken. Radar images (INTERA) were also important when visually analysing a sector’s topography as they were produced by an active microwave sensor (totally eliminating climatic obstacles). On the contrary, satellite images did not have great relevance due to the amount of clouds hampering any kind of analysis. Complementing these results, a calibration curve for analysing this section’s maximum flow values was based on historical series data regarding the Atrato River’s flows and maximum levels recorded at the Quibdó hydrographical station and the river-bed’s cross-section. Implications that the river would overflow or has overflowed were statistically estimated on these results, thereby setting the limits (supported by cartographic data) for the corresponding areas at risk of flooding. A map marking areas at risk of flooding in the urban zone of Quibdó was then designed and a document prepared concluding that neighborhoods on land lying at 25-27 meters, Se elaboró del casco urbano del municipio de Quibdó (Chocó) un mapa de zonificación de áreas inundables causadas por las crecientes del río Atrato y sus afluentes (Cabí, caño El Caraño y Quebrada La Yesca), con el objetivo de que sea utilizado por las autoridades de socorro y del municipio de Quibdó como un instrumento de planeación y control. En esta investigación se contó con el apoyo y asesoría del Centro Interamericano de Fotointerpretación, CIAF, adscrito al Instituto Geográfico Agustín Codazzi, quien proporcionó sus instalaciones y el material geográfico empleado. Inicialmente el trabajo se basó en la visualización de zonas inundables a través de interpretación de imágenes de radar (Intera), de satélite (Landsat) y fotografías aéreas, todo esto apoyado por la comprobación en terreno de los datos interpretados. Como información adicional necesaria para el planteamiento de conclusiones en un trabajo como este, se requirió estudiar otras variables como fueron las condiciones climáticas, geológicas, de temperatura, topográficas, series y ocurrencias históricas hidrológicas e hidrográficas en la región. Las imágenes que brindaron mayor confianza por muchas razones, entre las que sobresalieron las escalas, la cantidad y calidad de las mismas y la fecha de toma, fueron las fotografías aéreas. Las de radar (Intera) por ser producidas por un sensor activo de rango de las microondas por su esencia de eliminación completa de obstáculos climáticos, fueron también importantes a la hora de analizar visualmente la topografía del sector. Al contrario, las imágenes del satélite (Landsat) tuvieron un papel secundario producto del gran porcentaje de nubes que dificultaban cualquier tipo de análisis. Como complemento a los resultados obtenidos, se elaboró con datos multianuales de series históricas de caudales y niveles máximos del rio Atrato registrados en la estación hidrográfica Quibdó y con el área de la sección transversal de su cauce en el sitio de ubicación de la estación
- Published
- 2007
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