Radio frequency propagation

space probe launched by NASA to study the outer Solar System, furthest spacecraft from Earth

NASA probe that visited Pluto and Kuiper belt object 486958 Arrokoth

space probe launched by NASA to study the outer Solar System, second furthest spacecraft from Earth after Voyager 1

frequency change of a wave for observer relative to its source

thumb|upright=2|Relationship of the atmosphere and ionosphere The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. Travel through this layer also affects GPS signals, deflecting their paths and delayi

The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 101/20 (approximately ).

deviation from the normal change of an atmospheric property with altitude

radio transmitter to identify a location for navigation aid

physical quantity

branch of space physics concerned with conditions in the Solar System

mechanical wave that propagates along the interface between differing media

scattering of an electromagnetic plane wave by a homogeneous sphere, producing an infinite series of spherical multipole partial waves

radio signal transmission method invented by Hedy Lamarr

right|thumb|250px|Radio waves (black) Reflection (physics)|reflecting off the [[ionosphere (red) during skywave propagation. Line altitude in this image is significantly exaggerated and not to scale.]]

designation for a band of microwave frequencies from approximately 8 to 12 GHz

behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere

main design element of Cassegrain reflecting telescope

thumb|A schematic showing the relationship between dBu (the [[voltage source) and dBm (the power dissipated as heat by the 600 Ω resistor)]] dBm or dBmW (decibel-milliwatts) is a unit of power level expressed using a logarithmic decibel (dB) scale respective to one milliwatt (mW). It is commonly used by radio, microwave and fiber-optical communication technicians & engineers to measure the power of system transmissions on a log scale, which can express both very large and very small values in a short form. dBW is a similar unit measured relative to one watt (1000 mW) rather than a milliwa

region of space involved in radio propagation between a transmitting and receiving antenna

radio communication technique

method of communicating with microwave radio signals over considerable distances

layer of the Earth's ionosphere

antenna which radiates or receives greater power in specific directions

Enhanced ionization of the ionosphere

characteristic of electromagnetic radiation or acoustic wave propagation which means waves which travel in a direct path from the source to the receiver

propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths

Antenna

type of radio propagation

Radio propagation mode

unwanted signals, echoes, or images on the face of the display screen, which interfere with the observation of desired signals

radio wave propagating along the Earth's surface

Type of radio propagation

layer in ionosphere

highest radio frequency that can be used for skywave radio transmission

the time over which a propagating wave (especially a laser or maser beam) may be considered coherent

accounting of signal gains and losses in communications

the signal-to-noise ratio of a modulated signal

transition of source to receiver in telecommunications

area where radio transmissions can not be received

halt to communication abilities or utilization

submarine communications techniques

anomalous radio echo

redundancy method to improve communications reliability

thumb|A typical directional antenna radiation pattern in [[polar coordinate system representation, showing sidelobes. The radial distance from the center represents signal strength.]] thumb|250px|A typical antenna radiation pattern in cartesian coordinate system representation showing sidelobes

class of large multielement directional wire radio transmitting antennas

pertinent to space weather conditions

research project observing electrical activity in the ionosphere and magnetosphere

military communication system

German physicist (1913–2018)