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Distance Measuring Equipment (DME) is a transponder-based radio navigation technology that measures distance by timing the propagation delay of VHF or UHF radio signals. Download high resolution version (900x600, 378 KB) D-VOR station File links The following pages link to this file: VHF omnidirectional range User:Yaoleilei ...
Download high resolution version (900x600, 378 KB) D-VOR station File links The following pages link to this file: VHF omnidirectional range User:Yaoleilei ...
Image File history File links Metadata Size of this preview: 234 × 600 pixelsFull resolution (624 × 1600 pixel, file size: 515 KB, MIME type: image/jpeg) Distance Measuring Equipment from SGT airport I, the copyright holder of this work, hereby release it into the public domain. ...
Image File history File links Metadata Size of this preview: 234 × 600 pixelsFull resolution (624 × 1600 pixel, file size: 515 KB, MIME type: image/jpeg) Distance Measuring Equipment from SGT airport I, the copyright holder of this work, hereby release it into the public domain. ...
Very high frequency (VHF) is the radio frequency range from 30 MHz (wavelength 10 m) to 300 MHz (wavelength 1 m). ...
This article is about the radio frequency. ...
It was invented by Edward George "Taffy" Bowen whilst employed as Chief of the Division of Radiophysics of the Commonwealth Scientific and Industrial Research Organisation CSIRO in Australia. Another Australian world-first, engineered version of the system was deployed by Amalgamated Wireless Australasia Limited in the early 1950s operating in the 200 MHz VHF band. This Australian domestic version was referred by the Federal Department of Civil Aviation as DME(D) (or DME Domestic), and the later international version adopted by ICAO as DME(I). Edward George Taffy Bowen, CBE, FRS (14 January 1911 – 12 August 1991) was a British physicist who made a major contribution to the development of radar and so helped win both the Battle of Britain and the Battle of the Atlantic. ...
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is the national government body for scientific research in Australia. ...
This article or section does not adequately cite its references or sources. ...
The 1950s decade refers to the years 1950 to 1959 inclusive. ...
Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. ...
The International Civil Aviation Organization (ICAO), an agency of the United Nations, develops the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth. ...
DME is similar to Secondary Radar, except in reverse. The system was a post-war development of the IFF (Identification Friend or Foe) systems of World War II. To maintain compatibility, DME is functionally identical to the distance measuring component of TACAN. A Secondary Surveillance Radar (SSR) is a radar device installed in air traffic control facilities to allow the precise identification of aircraft. ...
In telecommunications, identification, friend or foe (IFF) is a crypto identification system designed for command and control. ...
Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki TÅjÅ Casualties Military dead: 17,000,000 Civilian dead: 33,000...
VORTAC TGO (TANGO) Germany TACAN is a contraction of Tactical Air Navigation, which is a navigation system employed by the military of the United States. ...
Operation Aircraft use DME to determine their distance from a land-based transponder by sending and receiving pulse pairs - two pulses of fixed duration and separation. The ground stations are typically colocated with VORs. A typical DME ground transponder system for enroute or terminal navigation will have a 1 kW peak pulse output on the assigned UHF channel. D-VOR (Doppler VOR) ground station, co-located with DME. VOR, short for VHF Omni-directional Radio Range, is a type of radio navigation system for aircraft. ...
A low power DME can also be colocated with an ILS localizer where it provides an accurate distance function, similar to that otherwise provided by ILS Marker Beacons. The Localizer station at Hanover/Langenhagen International Airport in Hanover, Germany. ...
Hardware The DME system is composed of a UHF transmitter/receiver (interrogator) in the aircraft and a UHF receiver/transmitter (transponder) on the ground. An Ontario Highway 407 toll transponder In telecommunication, the term transponder (short-for Transmitter-responder and sometimes abbreviated to XPDR, XPNDR or TPDR) has the following meanings: An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator). ...
Timing The aircraft interrogates the ground transponder with a series of pulse-pairs (interrogations), The ground station replies with an identical sequence of reply pulse-pairs with a precise time delay (typically 50 microseconds). The DME receiver in the aircraft searches for pulse-pairs (X-mode= 12 microsecond spacing) with the correct time interval between them. The correct time between pulse pairs is determined by each individual aircraft's particular interrogation pattern. The aircraft interrogator locks on to the DME ground station once it understands that the particular pulse sequence is the interrogation sequence it sent out originally. Once the receiver is locked on, it has a narrower window in which to look for the echoes and can retain lock.
Distance calculation A radio pulse takes around 12.36 microseconds to travel one nautical mile to and from, this is also referred to as a radar-mile. The time difference between interrogation and reply minus the 50 microsecond ground transponder delay is measured by the interrogator's timing circuitry and translated into a distance measurement in nautical miles which is then displayed in the cockpit.
Specification A typical DME transponder can provide concurrent distance information to about 100 aircraft.[1] Above this limit the transponder avoids overload by limiting the gain of the receiver. Replies to weaker more distant interrogations are ignored to lower the transponder load.
Radio frequency and modulation data DME frequencies are paired to VHF omnidirectional range (VOR) frequencies. A DME interrogator is designed to automatically tune to the corresponding frequency when the associated VOR is selected. An airplane’s DME interrogator uses frequencies from 1025 to 1150 MHz. DME transponders transmit on a channel in the 962 to 1150 MHz range and receive on a corresponding channel between 962 to 1213 MHz. The band is divided into 126 channels for interrogation and 126 channels for transponder replies. The interrogation and reply frequencies always differ by 63 MHz. The spacing of all channels is 1 MHz with a signal spectrum width of 100 kHz. Channel, in communications (sometimes called communications channel), refers to the medium used to convey information from a sender (or transmitter) to a receiver. ...
Technical references to X and Y channels relate only to the spacing of the individual pulses in the DME pulse pair, 12 microsecond spacing for X channels and 36 microsecond spacing for Y channels.
DME facilities identify themselves with a 1350 Hz morse code three letter identity. If collocated with a VOR or ILS it will have the same identity code as the parent facility. Additionally, the DME will identify itself between those of the parent facility. DME identity is 1350 Hz to differentiate itself from the 1020 Hz tone of the VOR or the ILS localizer. 1922 Chart of the Morse Code Letters and Numerals Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message. ...
Accuracy Accuracy of DME is 185 m (±0.1 nm).[1] One important thing to understand is that DME provides the physical distance from the aircraft to the DME transponder. This distance is often referred to as 'slant range' and depends trigonometrically upon both the altitude above the transponder and the ground distance from it. A nautical mile or sea mile is a unit of length. ...
For example, an aircraft directly above the DME station at 6000 feet altitude would still show one mile on the DME readout. The aircraft technically is a mile away, just a mile straight up. Slant range error is most pronounced at high altitudes when close to the DME station.
Future It is likely that DME installations will be phased out when space-based navigational systems such as GPS and Galileo become widely used for aviation.[2] However, the system is still widely used and new beacons are being built and installed still today (June 2007). GPS redirects here. ...
The Galileo positioning system, referred to simply as Galileo, is a planned Global Navigation Satellite System, to be built by the European Satellite Navigation Industries for the European Union (EU) and European Space Agency (ESA) as an alternative to the United States operated Global Positioning System (GPS) and the Russian...
See also It has been suggested that Air traffic control#Instrument Flight Rules (IFR) be merged into this article or section. ...
D-VOR (Doppler VOR) ground station, co-located with DME. VOR, short for VHF Omni-directional Radio Range, is a type of radio navigation system for aircraft. ...
VORTAC TGO (TANGO) Germany. ...
Radio Tower of NKR Leimen-Ochsenbach, Germany A Non-Directional Beacon (NDB) is a radio broadcast station in a known location, used as an aviation or marine navigational aid. ...
The Localizer station at Hanover/Langenhagen International Airport in Hanover, Germany. ...
GPS redirects here. ...
References is the 331st day of the year (332nd in leap years) in the Gregorian calendar. ...
Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ...
is the 214th day of the year (215th in leap years) in the Gregorian calendar. ...
Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...
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