# Relative bearing

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Relative bearing

In nautical navigation the relative bearing of an object is the angle formed by the heading of the vessel and a straight line drawn from the observation station on the vessel to the object.

The relative bearing is measured with a pelorus or other optical and electronic aids to navigation such as a periscope, sonar system, and radar systems. Since World War II, relative bearings of such diverse point sources have been and are calibrated carefully to one another. The United States Navy operates a special range off Puerto Rico and another on the west coast to perform such systems integration. Relative bearings then serve as the baseline data for converting relative directional data into true bearings (N-S-E-W, relative to the Earth's true geography). By contrast, Compass bearings have an varying error factor at differing locations about the globe, and are less reliable than the compensated or true bearings.

The measurement of relative bearings of fixed landmarks and other navigation aids is useful for the navigator because this information can be used on the nautical chart together with simple geometrical techniques to aid in determining the position of the vessel and/or its speed, course, etc.

The measurement of relative bearings of other vessels and objects in movement is useful to the navigator in avoiding the danger of collision.

* Example: The navigator on a ship observes a lighthouse when its relative bearing is 45º and again when it is 90º. he now knows that the distance from the ship to the lighthouse is equal to the distance trvelled by the vessel between both observations.

* Absolute bearing
* Bearing

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### Look at other dictionaries:

• relative bearing — The direction expressed as a horizontal angle measured clockwise from the fore and aft axis of the aircraft or vehicle. To obtain the true bearing from the relative bearing, the aircraft heading must be added to the latter …   Aviation dictionary

• Relative bearing — Mit Funkseitenpeilung (engl. relative bearing, RB) wird der Winkel zwischen der Flugzeuglängsachse und der Funkstandlinie, d.h. der Linie Flugzeug Bodensender, gemessen im Uhrzeigersinn, bezeichnet. Die Angabe des RB allein reicht noch nicht aus …   Deutsch Wikipedia

• relative bearing — santykinis pelengas statusas T sritis Gynyba apibrėžtis Kryptis, išreikšta horizontaliuoju kampu, paprastai matuojamu pagal laikrodžio rodyklę nuo orlaivio, laivo ar automobilio išilginės ašies priekinio taško iki kurio nors objekto ar kūno.… …   NATO terminų aiškinamasis žodynas

• relative bearing — noun : a bearing relative to the heading of a ship or airplane * * * Navig. the bearing of an object, relative to the heading of a vessel or aircraft …   Useful english dictionary

• relative bearing — Navig. the bearing of an object, relative to the heading of a vessel or aircraft. * * * …   Universalium

• relative bearing — The direction expressed as a horizontal angle normally measured clockwise from the forward point of the longitudinal axis of a vehicle, aircraft, or ship to an object or body. See also bearing; grid bearing …   Military dictionary

• Relative Bearing Indicator — Der Relative bearing indicator ist eine Art der Anzeige eines Radiokompass (ADF) in der Luftfahrt, bei dem die relative Richtung zum Funkfeuer (hauptsächlich Non Directional Beacon) angezeigt wird. D.h. es kann abgelesen werden, in welchem Winkel …   Deutsch Wikipedia

• Relative bearing indicator — Der Relative bearing indicator ist eine Art der Anzeige eines Radiokompass (ADF) in der Luftfahrt, bei dem die relative Richtung zum Funkfeuer (hauptsächlich Non Directional Beacon) angezeigt wird. D.h. es kann abgelesen werden, in welchem Winkel …   Deutsch Wikipedia

• Relative bearing indicator — A Relative bearing indicator shows the bearing of some source relative to a vehicle carrying a detector. It is most commonly used in conjunction with an ADF (automatic direction finder) in an aircraft navigating with the aid of an NDB (non… …   Wikipedia

• relative-bearing indicator — An indicator in which the compass card is fixed with 000° at the top of the display, and the pointer indicates bearing to the beacon relative to the aircraft heading. This can be a radio bearing or an omnibearing …   Aviation dictionary