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RNAV
Area navigation (RNAV, usually pronounced as ) is a method of instrument flight rules (IFR) navigation that allows aircraft to fly along a desired flight path, rather than being restricted to routes defined by ground-based navigation beacons. The acronym RNAV originally stood for "random navigation," reflecting the initial concept of flexible routing, though the term now refers to a precisely defined and controlled method. This flexibility enables more direct routes, potentially saving flight time and fuel, reducing congestion, and facilitating flights to airports lacking traditional navigation aids. RNAV achieves this by integrating information from various navigation sources, including ground-based beacons (station-referenced navigation signals), self-contained systems like inertial navigation, and satellite navigation (like GPS). In the United States, RNAV was developed in the 1960s, and the first such routes were published in the 1970s. In January 1983, the Federal Aviati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Performance Based Navigation
ICAO performance-based navigation (PBN) specifies that aircraft required navigation performance (RNP) and area navigation (RNAV) systems performance requirements be defined in terms of accuracy, integrity, availability, continuity, and functionality required for the proposed operations in the context of a particular airspace, when supported by the appropriate navigation infrastructure. Description Historically, aircraft navigation specifications have been specified directly in terms of sensors (navigation beacons and/or waypoints). A navigation specification that includes an additional requirement for on-board navigation performance monitoring and alerting is referred to as a required navigation performance (RNP) specification. One not having such requirements is referred to as an area navigation (RNAV) specification. Performance requirements are identified in navigation specifications, which also identify the choice of navigation sensors and equipment that may be used to meet th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Required Navigation Performance
Required navigation performance (RNP) is a type of performance-based navigation (PBN) that allows an aircraft to fly a specific path between two 3D-defined points in space. Navigation precision Area navigation, Area navigation (RNAV) and RNP systems are fundamentally similar. The key difference between them is the requirement for on-board performance monitoring and alerting. A navigation specification that includes a requirement for on-board navigation performance monitoring and alerting is referred to as an RNP specification. One not having such a requirement is referred to as an RNAV specification. Therefore, if ATC radar monitoring is not provided, safe navigation in respect to terrain shall be self-monitored by the pilot and RNP shall be used instead of RNAV. RNP also refers to the level of performance required for a specific procedure or a specific block of airspace. An RNP of 10 means that a navigation system must be able to calculate its position to within a circle with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VHF Omnidirectional Range
Very High Frequency Omnidirectional Range Station (VOR) is a type of short-range VHF radio navigation system for aircraft, enabling aircraft with a VOR receiver to determine the azimuth (also radial), referenced to magnetic north, between the aircraft to/from fixed VOR ground transmitter, radio beacons. VOR and the first DME(1950) system (referenced to 1950 since different from today's DME/N) to provide the slant range distance, were developed in the United States as part of a U.S. civil/military program for Aeronautical Navigation Aids in 1945. Deployment of VOR and DME(1950) began in 1949 by the U.S. CAA (Civil Aeronautics Administration). ICAO standardized VOR and DME(1950) in 1950 in ICAO Annex ed.1. Frequencies for the use of VOR are standardized in the very high frequency (VHF) band between 108.00 and 117.95 MHz Chapter 3, Table A. To improve azimuth accuracy of VOR even under difficult siting conditions, Doppler VOR (DVOR) was developed in the 1960s. VOR is accordi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waypoint
A waypoint is a point or place on a route or line of travel, a stopping point, an intermediate point, or point at which course is changed, the first use of the term tracing to 1880. In modern terms, it most often refers to coordinates which specify one's position on the globe at the end of each "leg" (stage) of a journey. Hence, the term connotes a reference point in physical space, most often associated with navigation. For example, in the case of sea navigation, a waypoint could mark the longitudinal and latitudinal coordinate or a GPS point in open water, a location near a known mapped shoal or other entity in a body of water, a point a fixed distance off of a geographical entity such as a lighthouse or harbour entrance, etc. In air navigation, waypoints most often consist of a series of abstract GPS points that create artificial airways—"highways in the sky"—created specifically for purposes of air navigation that have no clear connection to features of the real world. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Measuring Equipment
In aviation, distance measuring equipment (DME) is a radio navigation technology that measures the slant range (distance) between an aircraft and a ground station by timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz). Line-of-visibility between the aircraft and ground station is required. An interrogator (airborne) initiates an exchange by transmitting a pulse pair, on an assigned 'channel', to the transponder ground station. The channel assignment specifies the carrier frequency and the spacing between the pulses. After a known delay, the transponder replies by transmitting a pulse pair on a frequency that is offset from the interrogation frequency by 63 MHz and having specified separation.''Annex 10 to the Convention on International Civil Aviation, Volume I – Radio Navigation Aids''; International Civil Aviation Organization; International Standards and Recommended Practices. DME systems are used worldwide, usi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LNAV
In aviation, lateral navigation (LNAV, usually pronounced ''el-nav'') is azimuth navigation, without vertical navigation (VNAV). Area navigation (RNAV) approach plates include LNAV as a non-precision instrument approach (NPA). When combined with VNAV, the resulting instrument approach, LNAV/VNAV, is referred to as an Approach with Vertical Guidance (APV). Instrument approaches An LNAV approach is flown to a Minimum Descent Altitude, MDA, while an LNAV/VNAV approach is flown to a Decision Altitude, DA. If WAAS becomes unavailable, a GPS or WAAS equipped aircraft can revert to the LNAV MDA using GPS only. Autopilots LNAV is also the name of an autopilot lateral ( roll) mode on several aircraft. In Boeing aircraft, when in LNAV mode, the autopilot will follow the lateral flight path programmed in to the Flight Management Computer. See also *Index of aviation articles * LPV *Navigation Navigation is a field of study that focuses on the process of monitoring and controlling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Of View
The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to electromagnetic radiation. It is further relevant in ''angle of view, photography''. Humans and animals In the context of human and primate vision, the term "field of view" is typically only used in the sense of a restriction to what is visible by external apparatus, like when wearing spectacles or virtual reality goggles. Note that eye movements are allowed in the definition but do not change the field of view when understood this way. If the analogy of the eye's retina working as a sensor is drawn upon, the corresponding concept in human (and much of animal vision) is the visual field. It is defined as "the number of degrees of visual angle during stable fixation of the eyes".Strasburger, Hans; Pöppel, Ernst (2002). Visual Field. In G. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (navigation)
In navigation, bearing or azimuth is the horizontal angle between the direction of an object and north or another object. The angle value can be specified in various angular units, such as degrees, mils, or grad. More specifically: * Absolute bearing refers to the clockwise angle between the magnetic north (''magnetic bearing'') or true north (''true bearing'') and an object. For example, an object to due east would have an absolute bearing of 90 degrees. Thus, it is the same as azimuth.U.S. Army, ''Advanced Map and Aerial Photograph Reading'', Headquarters, War Department, Washington, D.C. (17 September 1941), pp. 24-2/ref> * #Relative, Relative bearing refers to the angle between the craft's forward direction ( heading) and the location of another object. For example, an object relative bearing of 0 degrees would be immediately in front; an object relative bearing 180 degrees would be behind. Bearings can be measured in mils, points, or degrees. Thus, it is the same as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Speed
Ground speed is the horizontal component of the velocity of an aircraft relative to the Earth’s surface, also referred to as "speed over the ground". It is vital for accurate navigation that the pilot has an estimate of the ground speed that will be achieved during each leg of a flight. Theoretically, an aircraft diving vertically and unaffected by wind would have a ground speed of zero. Information displayed to passengers through the entertainment system of airline aircraft usually gives the aircraft ground speed rather than airspeed. Ground speed can be determined by the vector sum of the aircraft's true airspeed and the current wind speed and direction; a headwind subtracts from the ground speed, while a tailwind adds to it. Winds at other angles to the heading will have components of either headwind or tailwind as well as a crosswind component. An airspeed indicator indicates the aircraft's speed relative to the air mass it is flying through. The air mass may be moving ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Management System
A flight management system (FMS) is a fundamental component of a modern airliner's avionics. An FMS is a specialized computer system that automates a wide variety of in-flight tasks, reducing the workload on the flight crew to the point that modern civilian aircraft no longer carry flight engineers or navigators. A primary function is in-flight management of the flight plan. Using various sensors (such as GPS and INS often backed up by radio navigation) to determine the aircraft's position, the FMS can guide the aircraft along the flight plan. From the cockpit, the FMS is normally controlled through a Control Display Unit (CDU) which incorporates a small screen and keyboard or touchscreen. The FMS sends the flight plan for display to the Electronic Flight Instrument System (EFIS), Navigation Display (ND), or Multifunction Display (MFD). The FMS can be summarised as being a dual system consisting of the Flight Management Computer (FMC), CDU and a cross talk bus. The modern F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean
A mean is a quantity representing the "center" of a collection of numbers and is intermediate to the extreme values of the set of numbers. There are several kinds of means (or "measures of central tendency") in mathematics, especially in statistics. Each attempts to summarize or typify a given group of data, illustrating the magnitude and sign of the data set. Which of these measures is most illuminating depends on what is being measured, and on context and purpose. The ''arithmetic mean'', also known as "arithmetic average", is the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the numbers are from observing a sample of a larger group, the arithmetic mean is termed the '' sample mean'' (\bar) to distinguish it from the group mean (or expected value) of the underlying distribution, denoted \mu or \mu_x. Outside probability and statistics, a wide rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
