Receiver autonomous integrity monitoringReceiver autonomous integrity monitoring (RAIM) is a technology developed to assess the integrity of global positioning system (GPS) signals in a GPS receiver system. It is of special importance in safety-critical GPS applications, such as in aviation or marine navigation. GPS does not include any internal information about the integrity of its signals. It is possible for a GPS satellite to broadcast slightly incorrect information that will cause navigation information to be incorrect, but there is no way for the receiver to determine this using the standard techniques.
Geodetic datumA geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame) is a global datum reference or reference frame for precisely representing the position of locations on Earth or other planetary bodies by means of geodetic coordinates. Datums are crucial to any technology or technique based on spatial location, including geodesy, navigation, surveying, geographic information systems, remote sensing, and cartography.
Meridian arcIn geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length. The purpose of measuring meridian arcs is to determine a figure of the Earth. One or more measurements of meridian arcs can be used to infer the shape of the reference ellipsoid that best approximates the geoid in the region of the measurements.
GarminGarmin Ltd. (shortened to Garmin, stylized as GARMIN, and formerly known as ProNav) is an American, Swiss-domiciled multinational technology company founded in 1989 by Gary Burrell and Min Kao in Lenexa, Kansas, United States, with headquarters in Olathe, Kansas. Since 2010, the company is legally incorporated in Schaffhausen, Switzerland. The company specializes in GPS technology for automotive, aviation, marine, outdoor, and sport activities.
Degree (angle)A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle in which one full rotation is 360 degrees. It is not an SI unit—the SI unit of angular measure is the radian—but it is mentioned in the SI brochure as an accepted unit. Because a full rotation equals 2pi radians, one degree is equivalent to pi/180 radians. The original motivation for choosing the degree as a unit of rotations and angles is unknown.
GradianIn trigonometry, the gradian, also known as the gon (from gōnía), grad, or grade, is a unit of measurement of an angle, defined as one hundredth of the right angle; in other words, there are 100 gradians in 90 degrees. It is equivalent to 1/400 of a turn, 9/10 of a degree, or pi/200 of a radian. Measuring angles in gradians is said to employ the centesimal system of angular measurement, initiated as part of metrication and decimalisation efforts.
Guided bombA guided bomb (also known as a smart bomb, guided bomb unit, or GBU) is a precision-guided munition designed to achieve a smaller circular error probable (CEP). The creation of precision-guided munitions resulted in the retroactive renaming of older bombs as unguided bombs or "dumb bombs". Missile guidance Guided bombs carry a guidance system which is usually monitored and controlled from an external device. A guided bomb of a given weight must carry fewer explosives to accommodate the guidance mechanisms.
Arc measurementArc measurement, sometimes degree measurement (Gradmessung), is the astrogeodetic technique of determining of the radius of Earth – more specifically, the local Earth radius of curvature of the figure of the Earth – by relating the latitude difference (sometimes also the longitude difference) and the geographic distance (arc length) surveyed between two locations on Earth's surface.
Axes conventionsIn ballistics and flight dynamics, axes conventions are standardized ways of establishing the location and orientation of coordinate axes for use as a frame of reference. Mobile objects are normally tracked from an external frame considered fixed. Other frames can be defined on those mobile objects to deal with relative positions for other objects. Finally, attitudes or orientations can be described by a relationship between the external frame and the one defined over the mobile object.
Non-directional beaconA non-directional beacon (NDB) or non-directional radio beacon is a radio beacon which does not include directional information. Radio beacons are radio transmitters at a known location, used as an aviation or marine navigational aid. NDB are in contrast to directional radio beacons and other navigational aids, such as low-frequency radio range, VHF omnidirectional range (VOR) and tactical air navigation system (TACAN). NDB signals follow the curvature of the Earth, so they can be received at much greater distances at lower altitudes, a major advantage over VOR.
