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VOACAP
VOACAP (Voice of America Coverage Analysis Program) is a radio propagation model that uses empirical data to predict the point-to-point path loss and coverage of a given transceiver if given as inputs: two antennas (configuration and position), solar weather, and time/date. Written in Fortran, it was originally designed for Voice of America. Some movies on the coverage during daytime can be found here. Simulating HF propagation conditions Currently versions based on the original source tree exist for Windows, Linux (voacapl) and OSX. The program core uses text files for I/O and a bunch of wrappers now exist. Besides commercial visualization tools, there are also Open Source implementations with GUI: * VOACAP online using ITS' IONCAP model, available at http://www.voacap.com/prediction.html * the PropagationPython Project. aka "Proppy" which is an evolution and alternate to VOACAP using the new ITURHFProp prediction model (formerly REC533) and always in development by James Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VOACAP HF Propagation Prediction
VOACAP (Voice of America Coverage Analysis Program) is a radio propagation model that uses empirical data to predict the point-to-point path loss and coverage of a given transceiver if given as inputs: two antennas (configuration and position), solar weather, and time/date. Written in Fortran, it was originally designed for Voice of America. Some movies on the coverage during daytime can be found here. Simulating HF propagation conditions Currently versions based on the original source tree exist for Windows, Linux (voacapl) and OSX. The program core uses text files for I/O and a bunch of wrappers now exist. Besides commercial visualization tools, there are also Open Source implementations with GUI: * VOACAP online using ITS' IONCAP model, available at http://www.voacap.com/prediction.html * the PropagationPython Project. aka "Proppy" which is an evolution and alternate to VOACAP using the new ITURHFProp prediction model (formerly REC533) and always in development by James Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VOACAP HF Propagation P2p
VOACAP (Voice of America Coverage Analysis Program) is a radio propagation model that uses empirical data to predict the point-to-point path loss and coverage of a given transceiver if given as inputs: two antennas (configuration and position), solar weather, and time/date. Written in Fortran, it was originally designed for Voice of America. Some movies on the coverage during daytime can be found here. Simulating HF propagation conditions Currently versions based on the original source tree exist for Windows, Linux (voacapl) and OSX. The program core uses text files for I/O and a bunch of wrappers now exist. Besides commercial visualization tools, there are also Open Source implementations with GUI: * VOACAP online using ITS' IONCAP model, available at http://www.voacap.com/prediction.html * the PropagationPython Project. aka "Proppy" which is an evolution and alternate to VOACAP using the new ITURHFProp prediction model (formerly REC533) and always in development by James Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Propagation Model
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems. Several different types of propagation are used in practical radio transmission systems. ''Line-of-sight propagation'' means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna. Line of sight transmission is used for medium-distance radio transmission, such as cell phones, cordless phones, walkie-tal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Propagation Model
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems. Several different types of propagation are used in practical radio transmission systems. ''Line-of-sight propagation'' means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna. Line of sight transmission is used for medium-distance radio transmission, such as cell phones, cordless phones, walkie-tal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Propagation
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems. Several different types of propagation are used in practical radio transmission systems. '' Line-of-sight propagation'' means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna. Line of sight transmission is used for medium-distance radio transmission, such as cell phones, cordless phones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Path Loss
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation. Path loss may be due to many effects, such as free-space loss, refraction, diffraction, reflection, aperture-medium coupling loss, and absorption. Path loss is also influenced by terrain contours, environment (urban or rural, vegetation and foliage), propagation medium (dry or moist air), the distance between the transmitter and the receiver, and the height and location of antennas. Causes Path loss normally includes ''propagation losses'' caused by the natural expansion of the radio wave front in free space (which usually takes the shape of an ever-increasing sphere), ''absorption losses'' (sometimes called penetration losses), when the signal passes thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Of America
Voice of America (VOA or VoA) is the State media, state-owned news network and International broadcasting, international radio broadcaster of the United States, United States of America. It is the largest and oldest U.S.-funded international broadcaster. VOA produces digital, TV, and radio content in 48 languages which it distributes to affiliate stations around the globe. It is primarily viewed by a non-American audience. VOA was established in 1942, and the VOA charter (Public Laws 94-350 and 103–415) was signed into law in 1976 by President Gerald Ford. VOA is headquartered in Washington, D.C., and overseen by the U.S. Agency for Global Media (USAGM), an independent agency of the U.S. government. Funds are appropriated annually under the budget for embassies and consulates. In 2016, VOA broadcast an estimated 1,800 hours of radio and TV programming each week to approximately 236.6 million people worldwide with about 1,050 employees and a taxpayer-funded annual budget of . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave
Shortwave radio is radio transmission using shortwave (SW) radio frequencies. There is no official definition of the band, but the range always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 to 10 metres); above the medium frequency band (MF), to the bottom of the VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are limited by the visual horizon, about 64 km (40 miles). Shortwave broadcasts of radio programs played an important role in the early days of radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Simulation Software
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electricity and magnetism, two distinct but closely intertwined phenomena. In essence, electric forces occur between any two charged particles, causing an attraction between particles with opposite charges and repulsion between particles with the same charge, while magnetism is an interaction that occurs exclusively between ''moving'' charged particles. These two effects combine to create electromagnetic fields in the vicinity of charge particles, which can exert influence on other particles via the Lorentz force. At high energy, the weak force and electromagnetic force are unified as a single electroweak force. The electromagnetic force is responsible for many o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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