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Glide Path
In aviation, instrument landing system glide path, commonly referred to as a glide path (G/P) or glide slope (G/S), is "a system of vertical guidance embodied in the instrument landing system which indicates the vertical deviation of the aircraft from its optimum path of descent". Principle of operation A glide slope station uses a phased antenna array sited on a tower which is offset approximately 250 to 650' to one side of the runway centerline and approximately 750 to 1250' beyond the approach end of the runway, adjacent to the runway touchdown zone. The GS transmits in the 328 to 336 MHz ultra high frequency (UHF) portion of the electromagnetic spectrum. Similar to the localizer, the GS signal is amplitude modulated with 90 and 150 Hz audio tones and transmitted on a carrier signal. The centre of the glide slope signal is arranged to define a glide path of approximately 3° above horizontal (ground level). Carrier frequency pairings Localizer (LOC) and glide s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difference In The Depth Of Modulation
The difference in the depth of modulation (DDM) is used by instrument landing systems in conjunction with the associated airborne receiving equipment to define a position in airspace. DDM is usually expressed in percentage but may also be expressed in microamperes. The two individual audio modulation frequencies and their associated sidebands are 90 and 150 Hz. The DDM for a localizer at the outer extremity of the course sector is 15.5% or an electric current equivalent of 150 microamperes full scale deflection. Method A modulation depth comparison navigational aid (MDCNA), also known as an Instrument landing System, uses the concept of space modulation to provide guidance to aircraft when on final approach. A carrier and sideband (CSB), and sideband only (SBO) signal, transmitted from localizer and glide path antennas produce a space-modulated signal resulting from the vectorial addition of two or more audio signals that vary according to position of the receiving aircra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navigational Aids
A navigational aid (NAVAID), also known as aid to navigation (ATON), is any sort of signal, markers or guidance equipment which aids the traveler in navigation, usually nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons. Definition According to the glossary of terms in the United States Coast Guard Light list, an ''aid to navigation'' (ATON) is any device external to a vessel or aircraft specifically intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation. Lateral marks Lateral marks indicate the edge of the channel. The standards are defined by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). Approaching harbour port a vessel leaves port hand marks to port (left) and starboard hand marks to starboard (right). Port hand marks are cylindrical, starboard marks are conical. If the mark is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Air Traffic Control
History is the systematic study of the past, focusing primarily on the human past. As an academic discipline, it analyses and interprets evidence to construct narratives about what happened and explain why it happened. Some theorists categorize history as a social science, while others see it as part of the humanities or consider it a hybrid discipline. Similar debates surround the purpose of history—for example, whether its main aim is theoretical, to uncover the truth, or practical, to learn lessons from the past. In a more general sense, the term ''history'' refers not to an academic field but to the past itself, times in the past, or to individual texts about the past. Historical research relies on primary and secondary sources to reconstruct past events and validate interpretations. Source criticism is used to evaluate these sources, assessing their authenticity, content, and reliability. Historians strive to integrate the perspectives of several sources to develop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Landing Systems
An aircraft ( aircraft) is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, rotorcraft (including helicopters), airships (including blimps), gliders, paramotors, and hot air balloons. Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air." The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called ''aeronautics.'' Crewed aircraft are flown by an onboard pilot, whereas unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeronautical Navigation Systems
Aeronautics is the science or art involved with the study, design, and manufacturing of air flight-capable machines, and the techniques of operating aircraft and rockets within the atmosphere. While the term originally referred solely to ''operating'' the aircraft, it has since been expanded to include technology, business, and other aspects related to aircraft. The term "aviation" is sometimes used interchangeably with aeronautics, although "aeronautics" includes lighter-than-air craft such as airships, and includes ballistic vehicles while "aviation" technically does not. A significant part of aeronautical science is a branch of dynamics called aerodynamics, which deals with the motion of air and the way that it interacts with objects in motion, such as an aircraft. History Early ideas Attempts to fly without any real aeronautical understanding have been made from the earliest times, typically by constructing wings and jumping from a tower with crippling or lethal res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Glide Slope Indicator
Visual Glide Slope Indicator or Visual Glideslope Indicator (VGSI) is a ground device that uses lights to assist a pilot in landing an airplane at an airport. The lights define a vertical approach path during the final approach to a runway and can help the pilot determine if the airplane is too high or too low for an optimum landing. There are several different types of VGSIs: ; :; Visual Approach Slope Indicator (VASI) :; Precision Approach Path Indicator (PAPI) :; Pulsating Visual Approach Slope Indicator (PVASI) :; Three-color Visual Approach Slope Indicator (T-VASI) :; Helicopter Approach Path Indicator (HAPI) In the United States, the Federal Aviation Administration The Federal Aviation Administration (FAA) is a Federal government of the United States, U.S. federal government agency within the United States Department of Transportation, U.S. Department of Transportation that regulates civil aviation in t ... includes VGSI information in its Chart Supplement (former ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocommunication Service
Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves. They can be received by other antennas connected to a radio receiver; this is the fundamental principle of radio communication. In addition to communication, radio is used for radar, radio navigation, remote control, remote sensing, and other applications. In radio communication, used in radio and television broadcasting, cell phones, two-way radios, wireless networking, and satellite communication, among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal (impressing an information signal on the radio wave by varying some aspect of the wave) in the transmitter. In radar, used to locate and track objects like air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Station
Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in '' satellite radio'' the radio waves are broadcast by a satellite in Earth orbit. To receive the content the listener must have a broadcast radio receiver (''radio''). Stations are often affiliated with a radio network that provides content in a common radio format, either in broadcast syndication or simulcast, or both. The encoding of a radio broadcast depends on whether it uses an analog or digital signal. Analog radio broadcasts use one of two types of radio wave modulation: amplitude modulation for AM radio, or frequency modulation for FM radio. Newer, digital radio stations transmit in several different digital audio standards, such as DAB (Digital Audio Broadcasting), HD radio, or DRM ( Digital Ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Final Approach
In aeronautics, the final approach (also called the final leg and final approach leg) is the last leg in an aircraft's approach to landing, when the aircraft is lined up with the runway and descending for landing.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 213 and 241. Aviation Supplies & Academics, 1997. In aviation radio terminology, it is often shortened to "final". The last section of the final approach is sometimes referred to as short final. In a standard airport landing pattern, which is usually used under visual meteorological conditions (VMC), aircraft turns from base leg to final within one-half to two miles of the airport. For instrument approaches, as well as approaches into a controlled airfield under visual flight rules (VFR), often a "straight-in" final approach is used, where all the other legs are dispensed within. Straight-in approaches are discouraged at non-towered airports in the United States. Approach slope An approach slope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phased Array
In antenna (radio), antenna theory, a phased array usually means an electronically scanned array, a computer-controlled Antenna array, array of antennas which creates a radio beam, beam of radio waves that can be electronically steered to point in different directions without moving the antennas. In a phased array, the power from the transmitter is fed to the radiating elements through devices called ''phase shifters'', controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow beamwidth, phased arrays are mainly practical at the high frequency end of the radio spectrum, in the ultrahigh frequency, UHF and microwave bands, in which the operating wavelengths are conveniently small. Phased arrays were originally invented for use in military radar systems, to detect fast moving pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
