Download or read book Optimum Range for HF Communication written by Stanford University. Stanford Electronics Laboratories and published by . This book was released on 1966 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of HF communication indicates that for best signal-to-noise ratio there exists an optimum distance between transmitter and receiver, assuming a system which always operates on the frequency that maximizes the received signal-to-noise ratio. Computations were made assuming four different spherical ionospheres corresponding to summer and winter, noon and midnight, at a temperature latitude. A broadband vertically steerable antenna of fixed area was assumed at one end of the path; and 'isotrope' at the other. The calculations were performed with the aid of a digital computer, taking into account such effects as ray focusing and the variations of noise, absorption, and antenna gain with frequency. The results show that the signal-to-noise ratio increases with the range by amounts varying from 20 to 30 db, between roughly 500 and 3000 km. At longer ranges, the signal-to-noise ratio decreases due to the decrease in antenna gain for low angles.
Download or read book HF Communications written by Nicholas M Maslin and published by CRC Press. This book was released on 2017-06-30 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Communications using the high frequency spectrum (2-30 MHz) have experienced a considerable resurgence. In recent years, powerful microcomputers and VLSI technology have greatly enhanced the prospects of overcoming many of the unique problems that formerly afflicted the HF systems More...designer. The aim of this book, therefore, is to provide a fi
Download or read book Siting Criteria for HF Communication Centers written by William F. Utlaut and published by . This book was released on 1962 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: This note is intended to provide an engineering guide for the siting radio terminals for use in long-range HF communication systems. A brief summary of ionospheric effects upon HF radio signals is presented. Various factors required for an ideal site such as Fresnel zone size and smoothness, noise, antenna height, vertical radiation angle and electrical characteristics of the ground are discussed. Standards to guide compromises for practical cases of siting are considered. A partial bibliography which may be useful for those desiring a greater depth of understanding of the various subjects considered in provided.
Download or read book Technical Considerations in the Selection of Optimum Frequencies for High Frequency Sky wave Communication Services written by George W. Haydon and published by . This book was released on 1969 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selection of frequency complements for high frequency sky-wave communication circuits is examined with the assumption electronic computers are available to predict useful frequency ranges. Complete manual methods for calculating Maximum Usable Frequencies, Optimum Traffic Frequencies, system loss, received field strength, available signal-to-noise ratio, angles of arrival, circuit reliability, and Lowest Useful High Frequency are outlined and parallel computations by electronic computers are shown. The use of high frequency predictions in antenna selection or design, determination of required transmitter power, and estimation of broadcast coverage is discussed. Appendices contain basic data required in the calculations.
Download or read book Long Distance Propagation of HF Radio Waves written by Alexander V. Gurevich and published by Springer. This book was released on 1985-08 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of very long-distance and around-the-world propagation of HF radio waves becomes more urgent in connection with the problems of long distance ground-based radio communications, communications with space crafts and satellites, satellite-to-satellite communications, around-the-world radar scanning, around-the-world sounding of the ionosphere, etc. At pre sent, these investigations have acquired particular interest because transmit ters which make it possible to intentionally modify the ionospheric properties by powerful radio waves have become available. In the case of radio wave propagation over comparatively small distances (about 3000 - 5000 km, one - two hops), in a first approximation, the iono sphere can be considered homogeneous in the horizontal direction. The radio wave propagation theory in a horizontally-homogeneous, i. e. , spherically symmetric ionosphere was developed with sufficient completeness as early as in the 1920-1940's by Appleton, Ratcliffe, Beynon, Booker, Martyn, and others. This theory is presented in detail in the well-known monographs by Ginzburg (1967), Bremmer (1946), and Budden (1961). Based on this theory, detailed methods for the calculation of radio paths, determination of field amplitude, and interpretation of vertical and oblique ionograms have been developed. All these methods are well-known and widely used in practice, see monographs by Al'pert (1974), Shchukin (1940), and Davies (1969). An altogether different situation takes place in the case of very long-dis tance multihop and around-the-world propagation.
Download or read book HF Communications Systems and Technology written by John M. Goodman and published by Springer. This book was released on 1992-05-28 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Communications engineers, ionospheric scientists, engineers and scientists in DoD HF projects, and DoD managers will use this source to gain a working understanding of the basic theory involved in HF radiowave propagation and uses of HF technology today.
Download or read book Long Term Predictions of Maximum Usable Frequencies and of Optimum Working Frequencies for High Frequency Radio Communication written by Council for Scientific and Industrial Research (Australia). Radio Research Board. Australian Radio Propagation Committee and published by . This book was released on 1947 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Applications of Neural Networks written by Dominic Palmer-Brown and published by Springer Science & Business Media. This book was released on 2009-08-19 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: A cursory glance at the table of contents of EANN 2009 reveals the am- ing range of neural network and related applications. A random but revealing sample includes: reducing urban concentration, entropy topography in epil- tic electroencephalography, phytoplanktonic species recognition, revealing the structure of childhood abdominal pain data, robot control, discriminating angry and happy facial expressions, ?ood forecasting, and assessing credit worthiness. The diverse nature of applications demonstrates the vitality of neural comp- ing and related soft computing approaches, and their relevance to many key contemporary technological challenges. It also illustrates the value of EANN in bringing together a broad spectrum of delegates from across the world to learn from each other’s related methods. Variations and extensions of many methods are well represented in the proceedings, ranging from support vector machines, fuzzy reasoning, and Bayesian methods to snap-drift and spiking neurons. This year EANN accepted approximately 40% of submitted papers for fu- length presentation at the conference. All members of the Program Committee were asked to participate in the reviewing process. The standard of submissions was high, according to the reviewers, who did an excellent job. The Program and Organizing Committees thank them. Approximately 20% of submitted - pers will be chosen, the best according to the reviews, to be extended and - viewedagainfor inclusionin a specialissueofthe journalNeural Computing and Applications. We hope that these proceedings will help to stimulate further research and development of new applications and modes of neural computing.
Download or read book Aircraft Systems written by Chris Binns and published by John Wiley & Sons. This book was released on 2018-10-12 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative guide to the various systems related to navigation, control, and other instrumentation used in a typical aircraft Aircraft Systems offers an examination of the most recent developments in aviation as it relates to instruments, radio navigation, and communication. Written by a noted authority in the field, the text includes in-depth descriptions of traditional systems, reviews the latest developments, as well as gives information on the technologies that are likely to emerge in the future. The author presents material on essential topics including instruments, radio propagation, communication, radio navigation, inertial navigation, and puts special emphasis on systems based on MEMS. This vital resource also provides chapters on solid state gyroscopes, magnetic compass, propagation modes of radio waves, and format of GPS signals. Aircraft Systems is an accessible text that includes an investigation of primary and secondary radar, the structure of global navigation satellite systems, and more. This important text: Contains a description of the historical development of the latest technological developments in aircraft instruments, communications and navigation Gives several “interesting diversion” topics throughout the chapters that link the topics discussed to other developments in aerospace Provides examples of instruments and navigation systems in actual use in cockpit photographs obtained during the authors work as a flight instructor Includes numerous worked examples of relevant calculations throughout the text and a set of problems at the end of each chapter Written for upper undergraduates in aerospace engineering and pilots in training, Aircraft Systems offers an essential guide to both the traditional and most current developments in aviation as it relates to instruments, radio navigation, and communication.
Download or read book Estimating the Performance of Telecommunication Systems Using the Ionospheric Transmission Channel written by and published by . This book was released on 1983 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Considerations Leading to an Optimum Allocation of Radio Frequencies in the Band 25 to 60 Mc written by Kenneth Alva Norton and published by . This book was released on 1959 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Transportation and Related Agencies Appropriations for Fiscal Year 1994 Department of Health and Human Services pt 3 Submitted questions and statements written by United States. Congress. Senate. Committee on Appropriations. Subcommittee on Transportation and Related Agencies and published by . This book was released on 1993 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Applications of Neural Networks written by Lazaros S. Iliadis and published by Springer Science & Business Media. This book was released on 2011-09-08 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two-volume set IFIP AICT 363 and 364 constitutes the refereed proceedings of the 12th International Conference on Engineering Applications of Neural Networks, EANN 2011, and the 7th IFIP WG 12.5 International Conference, AIAI 2011, held jointly in Corfu, Greece, in September 2011. The 52 revised full papers and 28 revised short papers presented together with 31 workshop papers were carefully reviewed and selected from 150 submissions. The first volume includes the papers that were accepted for presentation at the EANN 2011 conference. They are organized in topical sections on computer vision and robotics, self organizing maps, classification/pattern recognition, financial and management applications of AI, fuzzy systems, support vector machines, learning and novel algorithms, reinforcement and radial basis function ANN, machine learning, evolutionary genetic algorithms optimization, Web applications of ANN, spiking ANN, feature extraction minimization, medical applications of AI, environmental and earth applications of AI, multi layer ANN, and bioinformatics. The volume also contains the accepted papers from the Workshop on Applications of Soft Computing to Telecommunication (ASCOTE 2011), the Workshop on Computational Intelligence Applications in Bioinformatics (CIAB 2011), and the Second Workshop on Informatics and Intelligent Systems Applications for Quality of Life Information Services (ISQLIS 2011).
Download or read book Naval Communications written by United States. Bureau of Naval Personnel and published by . This book was released on 1964 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Boat Communications written by John C. Payne and published by Sheridan House, Inc.. This book was released on 2006 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: John C. Payne is a professional marine electrical engineer with 23 years merchant marine and off-shore oil experience.
