Использование моментов Чебышева в задачах подавления высокочастотных помех в полях гравитационных аномалий

The work is devoted to the problem of improving the quality of anomalous gravitational fields by reducing the level of their high-frequency noise. A brief review of existing approaches and methods for suppressing high-frequency noise in the fields of gravitational anomalies is given. A method for filtering fields of gravitational anomalies based on the transformation performed in the Chebyshev moment domain is proposed. The paper presents empirically established values of coefficients, which can be useful for an unknown level of noise. Using the simulated map of gravity anomalies, it was demonstrated that the proposed denoising filter is comparable in speed and superior in quality of the result to the bilateral filter, wavelet–filter, non–local means filters as well as the Wiener filter, which is well proven in the preliminary processing of gravitational fields.Работа посвящена вопросу повышения качества аномальных гравитационных полей путем снижения уровня содержащихся в них высокочастотных помех. Приведен краткий обзор существующих подходов и методов подавления высокочастотных помех в полях гравитационных аномалий. Предложен метод фильтрации полей гравитационных аномалий, основанный на преобразовании, выполняемом в области моментов Чебышева. Приведены эмпирически установленные значения коэффициентов предложенного фильтра, использование которых оказывается целесообразным при неизвестном уровне помех. На примере смоделированной карты аномалий гравитационного поля продемонстрировано, что предложенный фильтр подавления помех сопоставим по скорости и превосходит по качеству результата такие фильтры, как билатеральный фильтр, вейвлет-фильтр, фильтры нелокального усреднения, а также хорошо зарекомендовавший себя в практике предварительной обработки гравитационных полей фильтр Винера

Recent Advances in Signal Processing

The signal processing task is a very critical issue in the majority of new technological inventions and challenges in a variety of applications in both science and engineering fields. Classical signal processing techniques have largely worked with mathematical models that are linear, local, stationary, and Gaussian. They have always favored closed-form tractability over real-world accuracy. These constraints were imposed by the lack of powerful computing tools. During the last few decades, signal processing theories, developments, and applications have matured rapidly and now include tools from many areas of mathematics, computer science, physics, and engineering. This book is targeted primarily toward both students and researchers who want to be exposed to a wide variety of signal processing techniques and algorithms. It includes 27 chapters that can be categorized into five different areas depending on the application at hand. These five categories are ordered to address image processing, speech processing, communication systems, time-series analysis, and educational packages respectively. The book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion