Radiowave Propagation Over Ground Software


Book Description

The purpose of the package is to answer the question 'What is the radio field strength at a certain point?' when power is radiated from a transmit ting source. Because of the complexity of the question in general, it can only be answered at present in certain idealized situations. Nevertheless it is valuable to have quantitative data available for these situations. The package is divided into two parts. In the first of these, propagation in free space and over a flat earth are dealt with. In the second, propagation over a spherical earth is considered. In the free-space situation the power density of the signal in a given direction will fall as the inverse square of the distance from the source. For propagation from a transmitting source at an arbitrary height above a perfecdy conducting flat earth, the field strength at large distances can be 3 dB higher than in free space. With a finite conduc tivity earth, the field strength will be lower than this because of the power dissipation in the earth.







Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




Radio Wave Propagation and Parabolic Equation Modeling


Book Description

An important contribution to the literature that introduces powerful new methods for modeling and simulating radio wave propagation A thorough understanding of electromagnetic wave propagation is fundamental to the development of sophisticated communication and detection technologies. The powerful numerical methods described in this book represent a major step forward in our ability to accurately model electromagnetic wave propagation in order to establish and maintain reliable communication links, to detect targets in radar systems, and to maintain robust mobile phone and broadcasting networks. The first new book on guided wave propagation modeling and simulation to appear in nearly two decades, Radio Wave Propagation and Parabolic Equation Modeling addresses the fundamentals of electromagnetic wave propagation generally, with a specific focus on radio wave propagation through various media. The authors explore an array of new applications, and detail various virtual electromagnetic tools for solving several frequent electromagnetic propagation problems. All of the methods described are presented within the context of real-world scenarios typifying the differing effects of various environments on radio-wave propagation. This valuable text: Addresses groundwave and surface wave propagation Explains radar applications in terms of parabolic equation modeling and simulation approaches Introduces several simple and sophisticated MATLAB scripts Teaches applications that work with a wide range of electromagnetic, acoustic and optical wave propagation modeling Presents the material in a quick-reference format ideal for busy researchers and engineers Radio Wave Propagation and Parabolic Equation Modeling is a critical resource forelectrical, electronics, communication, and computer engineers working on industrial and military applications that rely on the directed propagation of radio waves. It is also a useful reference for advanced engineering students and academic researchers.




Journal of Research


Book Description







Radio Propagation and Adaptive Antennas for Wireless Communication Links


Book Description

Antennas and Propogation for Wireless Communication covers the basics of wireless communication system design with emphasis on antennas and propagation. It contains information on antenna fundamentals and the latest developments in smart antennas, as well as the radiation effects of hand-held devices. Antennas and Propogation for Wireless Communication provides a complete discussion of all the topics important to the design of wireless communication systems. Written by acknowledged authorities in their respective fields, the book deals with practical applications and presents real world examples. A solutions manual for college adopters accompanies the text. Ideal for engineers working in communication, antennas, and propagation for telecomm, military, and aerospace applications, as well as students of electrical engineering, this book covers all topics needed for a complete system design.




Attenuation of High-frequency Ground Waves Over an Inhomogeneous Earth


Book Description

The primary objective of this study was to obtain theoretical estimates of the effect of inhomogeneities in the earth's surface upon ground-wave propagation along a particular set of land-sea paths.The results were obtained by numerically solving the integral equation [equation],where f* is the attenuation function for the inhomogeneous case, f is the Sommerfeld function, and g is obtained essentially from the spherical Green's function by a steepest-descent type integration. Sharp phase and amplitude changes in the attenuation function occur when crossing an "island" or inhomogeneity in the paths. The greater the difference in conductivity and dielectric constant between the island and the rest of the path, the greater are these changes. Also noted is the "recovery'' or "focusing" effect found in the amplitude and phase. The effect of moving the transmitting antenna across a coastline was also studied and the results were quite similar to the above. Computations were performed for three paths at frequencies of 10, 15, 20, and 25 MHz. The results are displayed in tabular and graphical form. This report is a revised and updated version of an earlier study (Rosich, 1968) which is now out of print.




NBS Technical Note


Book Description




OT/ITS Research Report


Book Description