Waypoint
Encyclopedia
A waypoint is a reference point in physical space used for purposes of navigation
.
these coordinates can include longitude
and latitude
. Air navigation
also includes altitude
. Waypoints have only become widespread for navigational use by the layman since the development of advanced navigational systems, such as the Global Positioning System
(GPS) and certain other types of radio navigation. Waypoints located on the surface of the Earth are usually defined in two dimensions (e.g., longitude and latitude); those used in the Earth's atmosphere or in outer space are defined in at least three dimensions (four if time is one of the coordinates, as it might be for some waypoints outside the Earth).
Although the term waypoint has only come into common use in recent years, the equivalent of a waypoint in all but name has existed for as long as human beings have navigated. Waypoints have traditionally been associated with distinctive features of the real world, such as rock
formations, spring
s, oases
, mountain
s, buildings, roadways, waterways, railways, and so on. Today, these associations persist, but waypoints are more often associated with physical artifacts created specifically for navigation, such as radio beacons, buoy
s, satellite
s, control points
, etc.
In the modern world, waypoints are increasingly abstract, often having no obvious relationship to any distinctive features of the real world. These waypoints are used to help define invisible routing paths for navigation. For example, artificial airways
—“highways in the sky” created specifically for purposes of air navigation—often have no clear connection to features of the real world, and consist only of a series of abstract waypoints in the sky through which pilots navigate; these airways are designed to facilitate air traffic control and routing of traffic between heavily traveled locations, and do not reference natural terrain features. Abstract waypoints of this kind have been made practical by modern navigation technologies, such as land-based radio beacons and the satellite-based Global Positioning System
(GPS).
Abstract waypoints typically have only specified longitude
and latitude
or UTM coordinates plus the reference datum
, and often a name if they are marked on charts, and are located using a radio navigation
system such as a VOR
or GPS receiver. A waypoint can be a destination, a fix along a planned course
used to make a journey, or simply a point of reference useful for navigation.
(WAAS). Waypoints can also be marked on a computer mapping program and uploaded to the GPS receiver, marked on the receiver's own internal map, or entered manually on the device as a pair of coordinates.
If the GPS receiver has track-logging capabilities, one can also define waypoints after the fact from where one has been. For example, marine GPS receivers often have a "man overboard" function, which instantly creates a waypoint in the receiver for the boat's position when enabled and then begins displaying the distance and course back to that position.
In GPS navigation, a "route" is usually defined as a series of two or more waypoints. To follow such a route, the GPS user navigates to the nearest waypoint, then to the next one in turn until the destination is reached. Most receivers have the ability to compute a great circle route towards a waypoint, enabling them to find the shortest route even over long distances, although waypoints are often so closely spaced that this isn't a factor.
Many GPS receivers, both military and civilian, now offer integrated cartographic
database
s (also known as base maps), allowing users to locate a point on a map and define it as a waypoint. Some GPS systems intended for automobile navigation can generate a suggested driving route between two waypoints, based on the cartographic database. As one drives along the route, the system indicates the driver's current location and gives advance notice of upcoming turns. The best of these systems can take into account traffic restrictions such as one-way streets and intersections where left or right turns are prohibited when computing the suggested driving route.
Most GPS receivers allow the user to assign a name to each waypoint. Many models also let the user select a symbol or icon
to identify the waypoint on a graphical map display from a built-in library of icons. These include standard map symbols for marine navigation aids such as buoys, marina
s and anchorages, as well as such land-based symbols as churches, bridge
s, shopping centers, park
s, and tunnel
s.
GPS receivers used in air navigation have databases which contain named waypoints, radio navigation aids, airports and helo-ports. These references comprise the National Airspace System's method of allowing air traffic to select routes that yield efficient point to point navigation. Waypoints are often used in the termination phase of a flight to its destination airport. Some GPS receivers are integrated into autopilot or flight management system, to aid the pilot in control of an aircraft. Waypoints may be found on Aeronautical Charts known as IFR Enroute Charts, Terminal Arrival Procedures and Sectional Charts.
sports, of waypoints with a map that omits a coordinate system (see Control point (orienteering)
).
In aerial celestial navigation, waypoints are precomputed along an aircraft's great circle
route to divide the flight into rhumb lines and allow celestial fixes to be more rapidly taken using the pre-computed intercept method.
In air navigation, waypoints are sometimes defined as intersections between two VOR radials, or in terms of specific distances and headings towards or away from a radio beacon. For visual air navigation (see the article on visual flight rules
), waypoints may be directly associated with distinctive features on the ground that are easily identifiable from aircraft, such as stadiums, power plants, racetracks, etc. Temporary waypoints are sometimes defined as traffic requires, e.g., air-traffic controllers may instruct a pilot to reference a terrain feature at “your ten o'clock position, two miles.”
, area navigation
(RNAV)—a method of navigation that permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self contained aids, or a combination of these—relies heavily upon waypoints. RNAV is increasingly used as the primary method of navigation for aircraft.
In the RNAV context, a waypoint is a predetermined geographical position that is defined in terms of latitude/longitude coordinates (altitude is ignored). Waypoints may be a simple named point in space or may be associated with existing navigational aids, intersections, or fixes. A waypoint is most often used to indicate a change in direction, speed, or altitude along the desired path.
Aviation RNAV procedures make use of both fly-over and fly-by waypoints. A fly-over waypoint is a waypoint that must be crossed vertically by an aircraft. A fly-by waypoint is a waypoint that marks the intersection
of two straight paths, with the transition from one path to another being made by the aircraft using a precisely calculated turn that “flies by” but does not vertically cross the waypoint.
Waypoints used in aviation are given five-letter names. These names are meant to be pronounceable or have a mnemonic
value, so that they may easily be conveyed by voice.
(SMS
) is referred to as Gps2sms. Some vehicles and vessels are equipped with hardware that is able to automatically send an SMS
text message when a particular event happens, such as theft or anchor drift. The receiving party can ring an alert sound or store the waypoint in a computer system or draw a map indicating the location. Recreational use of GPS2SMS is used by travellers who want to show their digital breadcrumbs on a map. See also automatic identification system
.
Navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
.
Concept
Waypoints are sets of coordinates that identify a point in physical space. Coordinates used can vary depending on the application. For terrestrial navigationNavigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
these coordinates can include longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
and latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
. Air navigation
Air navigation
The basic principles of air navigation are identical to general navigation, which includes the process of planning, recording, and controlling the movement of a craft from one place to another....
also includes altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
. Waypoints have only become widespread for navigational use by the layman since the development of advanced navigational systems, such as the Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
(GPS) and certain other types of radio navigation. Waypoints located on the surface of the Earth are usually defined in two dimensions (e.g., longitude and latitude); those used in the Earth's atmosphere or in outer space are defined in at least three dimensions (four if time is one of the coordinates, as it might be for some waypoints outside the Earth).
Although the term waypoint has only come into common use in recent years, the equivalent of a waypoint in all but name has existed for as long as human beings have navigated. Waypoints have traditionally been associated with distinctive features of the real world, such as rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
formations, spring
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
s, oases
Oasis
In geography, an oasis or cienega is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source...
, mountain
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
s, buildings, roadways, waterways, railways, and so on. Today, these associations persist, but waypoints are more often associated with physical artifacts created specifically for navigation, such as radio beacons, buoy
Buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...
s, satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s, control points
Control point (orienteering)
A control point is a marked waypoint used in orienteering and related sports such as rogaining and adventure racing. It is located in the competition area; marked both on an orienteering map and in the terrain; and described on a control description sheet...
, etc.
In the modern world, waypoints are increasingly abstract, often having no obvious relationship to any distinctive features of the real world. These waypoints are used to help define invisible routing paths for navigation. For example, artificial airways
Airway (aviation)
In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
—“highways in the sky” created specifically for purposes of air navigation—often have no clear connection to features of the real world, and consist only of a series of abstract waypoints in the sky through which pilots navigate; these airways are designed to facilitate air traffic control and routing of traffic between heavily traveled locations, and do not reference natural terrain features. Abstract waypoints of this kind have been made practical by modern navigation technologies, such as land-based radio beacons and the satellite-based Global Positioning System
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
(GPS).
Abstract waypoints typically have only specified longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
and latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
or UTM coordinates plus the reference datum
Datum
A geodetic datum is a reference from which measurements are made. In surveying and geodesy, a datum is a set of reference points on the Earth's surface against which position measurements are made, and an associated model of the shape of the earth to define a geographic coordinate system...
, and often a name if they are marked on charts, and are located using a radio navigation
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
system such as a VOR
VHF omnidirectional range
VOR, short for VHF omnidirectional radio range, is a type of radio navigation system for aircraft. A VOR ground station broadcasts a VHF radio composite signal including the station's identifier, voice , and navigation signal. The identifier is typically a two- or three-letter string in Morse code...
or GPS receiver. A waypoint can be a destination, a fix along a planned course
Course (navigation)
In navigation, a vehicle's course is the angle that the intended path of the vehicle makes with a fixed reference object . Typically course is measured in degrees from 0° clockwise to 360° in compass convention . Course is customarily expressed in three digits, using preliminary zeros if needed,...
used to make a journey, or simply a point of reference useful for navigation.
Waypoints and GPS
GPS systems are increasingly used to create and use waypoints in navigation of all kinds. A typical GPS receiver can locate a waypoint with an accuracy of three meters or better when used with land-based assisting technologies such as the Wide Area Augmentation SystemWide Area Augmentation System
The Wide Area Augmentation System is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System , with the goal of improving its accuracy, integrity, and availability...
(WAAS). Waypoints can also be marked on a computer mapping program and uploaded to the GPS receiver, marked on the receiver's own internal map, or entered manually on the device as a pair of coordinates.
If the GPS receiver has track-logging capabilities, one can also define waypoints after the fact from where one has been. For example, marine GPS receivers often have a "man overboard" function, which instantly creates a waypoint in the receiver for the boat's position when enabled and then begins displaying the distance and course back to that position.
In GPS navigation, a "route" is usually defined as a series of two or more waypoints. To follow such a route, the GPS user navigates to the nearest waypoint, then to the next one in turn until the destination is reached. Most receivers have the ability to compute a great circle route towards a waypoint, enabling them to find the shortest route even over long distances, although waypoints are often so closely spaced that this isn't a factor.
Many GPS receivers, both military and civilian, now offer integrated cartographic
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...
database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
s (also known as base maps), allowing users to locate a point on a map and define it as a waypoint. Some GPS systems intended for automobile navigation can generate a suggested driving route between two waypoints, based on the cartographic database. As one drives along the route, the system indicates the driver's current location and gives advance notice of upcoming turns. The best of these systems can take into account traffic restrictions such as one-way streets and intersections where left or right turns are prohibited when computing the suggested driving route.
Most GPS receivers allow the user to assign a name to each waypoint. Many models also let the user select a symbol or icon
Icon (computing)
A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an...
to identify the waypoint on a graphical map display from a built-in library of icons. These include standard map symbols for marine navigation aids such as buoys, marina
Marina
A marina is a dock or basin with moorings and supplies for yachts and small boats.A marina differs from a port in that a marina does not handle large passenger ships or cargo from freighters....
s and anchorages, as well as such land-based symbols as churches, bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
s, shopping centers, park
Park
A park is a protected area, in its natural or semi-natural state, or planted, and set aside for human recreation and enjoyment, or for the protection of wildlife or natural habitats. It may consist of rocks, soil, water, flora and fauna and grass areas. Many parks are legally protected by...
s, and tunnel
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
s.
GPS receivers used in air navigation have databases which contain named waypoints, radio navigation aids, airports and helo-ports. These references comprise the National Airspace System's method of allowing air traffic to select routes that yield efficient point to point navigation. Waypoints are often used in the termination phase of a flight to its destination airport. Some GPS receivers are integrated into autopilot or flight management system, to aid the pilot in control of an aircraft. Waypoints may be found on Aeronautical Charts known as IFR Enroute Charts, Terminal Arrival Procedures and Sectional Charts.
Waypoints without GPS
Although the concept of waypoints has been greatly popularized among non-specialists by the development of the GPS, waypoints can be used with other navigational aids. A notable example is the worldwide use, in orienteeringOrienteering
Orienteering is a family of sports that requires navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain, and normally moving at speed. Participants are given a topographical map, usually a specially prepared orienteering map, which they...
sports, of waypoints with a map that omits a coordinate system (see Control point (orienteering)
Control point (orienteering)
A control point is a marked waypoint used in orienteering and related sports such as rogaining and adventure racing. It is located in the competition area; marked both on an orienteering map and in the terrain; and described on a control description sheet...
).
In aerial celestial navigation, waypoints are precomputed along an aircraft's great circle
Great circle
A great circle, also known as a Riemannian circle, of a sphere is the intersection of the sphere and a plane which passes through the center point of the sphere, as opposed to a general circle of a sphere where the plane is not required to pass through the center...
route to divide the flight into rhumb lines and allow celestial fixes to be more rapidly taken using the pre-computed intercept method.
In air navigation, waypoints are sometimes defined as intersections between two VOR radials, or in terms of specific distances and headings towards or away from a radio beacon. For visual air navigation (see the article on visual flight rules
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
), waypoints may be directly associated with distinctive features on the ground that are easily identifiable from aircraft, such as stadiums, power plants, racetracks, etc. Temporary waypoints are sometimes defined as traffic requires, e.g., air-traffic controllers may instruct a pilot to reference a terrain feature at “your ten o'clock position, two miles.”
Waypoints and aviation
In aviationAviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...
, area navigation
Area navigation
Area Navigation is a method of Instrument Flight Rules navigation that allows an aircraft to choose any course within a network of navigation beacons, rather than navigating directly to and from the beacons. This can conserve flight distance, reduce congestion, and allow flights into airports...
(RNAV)—a method of navigation that permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self contained aids, or a combination of these—relies heavily upon waypoints. RNAV is increasingly used as the primary method of navigation for aircraft.
In the RNAV context, a waypoint is a predetermined geographical position that is defined in terms of latitude/longitude coordinates (altitude is ignored). Waypoints may be a simple named point in space or may be associated with existing navigational aids, intersections, or fixes. A waypoint is most often used to indicate a change in direction, speed, or altitude along the desired path.
Aviation RNAV procedures make use of both fly-over and fly-by waypoints. A fly-over waypoint is a waypoint that must be crossed vertically by an aircraft. A fly-by waypoint is a waypoint that marks the intersection
Intersection (aviation)
In aviation, an intersection is a virtual navigational fix that helps aircraft to maintain their flight plan. It is usually defined as the intersection of two VOR radials. They are usually identified as major airway intersections where aircraft, operating under instrument flight rules, often...
of two straight paths, with the transition from one path to another being made by the aircraft using a precisely calculated turn that “flies by” but does not vertically cross the waypoint.
Waypoints used in aviation are given five-letter names. These names are meant to be pronounceable or have a mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
value, so that they may easily be conveyed by voice.
Waypoints and SMS
Establishing waypoints in real-time and transmitting them via GSM cellular telephone networks using the Short Message ServiceSMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
(SMS
SMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
) is referred to as Gps2sms. Some vehicles and vessels are equipped with hardware that is able to automatically send an SMS
SMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
text message when a particular event happens, such as theft or anchor drift. The receiving party can ring an alert sound or store the waypoint in a computer system or draw a map indicating the location. Recreational use of GPS2SMS is used by travellers who want to show their digital breadcrumbs on a map. See also automatic identification system
Automatic Identification System
The Automatic Identification System is an automatic tracking system used on ships and by Vessel traffic services for identifying and locating vessels by electronically exchanging data with other nearby ships and AIS Base stations...
.
See also
- Airway (aviation)Airway (aviation)In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....
- AutopilotAutopilotAn autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...
- Geo (microformat)Geo (microformat)Geo is a microformat used for marking up WGS84 geographical coordinates in HTML. Although termed a "draft" specification, this is a formality, and the format is stable and in widespread use; not least as a sub-set of the published hCalendar and hCard microformat specifications, neither of which is...
- GeotaggingGeoTaggingGeotagging is the process of adding geographical identification metadata to various media such as a geotagged photograph or video, websites, SMS messages, QR Codes or RSS feeds and is a form of geospatial metadata...
- Global Positioning SystemGlobal Positioning SystemThe Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
- GPS Phone
- GSM localization
- GPX GPS eXchange Format (XML schemaXML schemaAn XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself...
for interchange of waypoints) - Instrument Flight RulesInstrument flight rulesInstrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....
- LandmarkLandmarkThis is a list of landmarks around the world.Landmarks may be split into two categories - natural phenomena and man-made features, like buildings, bridges, statues, public squares and so forth...
- MapMapA map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
- OrienteeringOrienteeringOrienteering is a family of sports that requires navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain, and normally moving at speed. Participants are given a topographical map, usually a specially prepared orienteering map, which they...
- Point of interestPoint of interestA point of interest, or POI, is a specific point location that someone may find useful or interesting. An example is a point on the Earth representing the location of the Space Needle, or a point on Mars representing the location of the mountain, Olympus Mons.The term is widely used in...
- Visual Flight RulesVisual flight rulesVisual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
External links
- Route MGR Free online GPS Waypoint Editor
- List of flight information including (currently, at 8 April 2010) 1,951 waypoints (the WYP lines) (latitude (east) first), for example, the waypoint listed as "WYP 21.780001 39.866665 ISLAM" is at or near MeccaMeccaMecca is a city in the Hijaz and the capital of Makkah province in Saudi Arabia. The city is located inland from Jeddah in a narrow valley at a height of above sea level...
. - 'UK Name Code Designators for Significant Points' 2011-03-10 from NATS Aeronautical Information Service, accessed 2011-05-08