A
waypoint is a reference point in physical space used for purposes of
navigationNavigation is the process of reading, 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. The word navigate is derived from the Latin "navigare", meaning "to sail"...
.
Concept
Waypoints are sets of coordinates that identify a point in physical space. For the purposes of
terrestrial navigationNavigation is the process of reading, 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. The word navigate is derived from the Latin "navigare", meaning "to sail"...
, these coordinates usually include
longitudeLongitude , identified by the Greek letter lambda , is the geographic coordinate most commonly used in cartography and global navigation for east-west measurement...
and
latitudeLatitude, usually denoted by the Greek letter phi gives the location of a place on Earth north or south of the equator. Lines of Latitude are the imaginary horizontal lines shown running east-to-west on maps that run either north or south of the equator...
, and sometimes
altitudeAltitude 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...
(particularly for air navigation). Waypoints have only become widespread for navigational use by the layman since the development of advanced navigational systems, such as the
Global Positioning SystemThe Global Positioning System is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.GPS is made up of three parts: between 24...
(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
rockIn geology, rock 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,
springA spring is any natural occurrence where water flows on to the surface of the earth from below the surface, and is thus where the aquifer surface meets the ground surface.- Formation :...
s,
oasesIn geography, an oasis or cienega is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source...
,
mountainA mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The adjective montane is used to describe mountainous areas and things associated with them...
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,
buoyA 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,
satelliteIn the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s,
control pointsA 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
airwaysIn 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 SystemThe Global Positioning System is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.GPS is made up of three parts: between 24...
(GPS).
Abstract waypoints typically have only specified
longitudeLongitude , identified by the Greek letter lambda , is the geographic coordinate most commonly used in cartography and global navigation for east-west measurement...
and
latitudeLatitude, usually denoted by the Greek letter phi gives the location of a place on Earth north or south of the equator. Lines of Latitude are the imaginary horizontal lines shown running east-to-west on maps that run either north or south of the equator...
or UTM coordinates plus the reference
datumA 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 navigationRadio navigation or radionavigation is the application of radio frequencies to determining 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
VORVOR, short for VHF Omni-directional 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 in morse code , and data that allows the airborne receiving equipment to derive a magnetic bearing from...
or GPS receiver. A waypoint can be a destination, a fix along a planned
courseIn navigation, a course is the intended path of a vehicle over the surface of the Earth. The course is the intended path of a vehicle of a line drawn on a chart representing the intended path. It is expressed as the angle measured from an object clockwise from 0° through 360° to the line. The...
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 SystemThe 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
cartographicCartography is the study and practice of making geographical 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 cartography are to:*Set the map's...
databaseA database is an integrated collection of logically related records or files consolidated into a common pool that provides data for one or more multiple uses....
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
iconOn computer displays, a computer icon is a small pictogram. Icons have been used to supplement the normal alphanumerics of the computer...
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,
marinaA marina is a sheltered harbor where boats and yachts are kept in the water and where services geared to the needs of recreational boating are found....
s and anchorages, as well as such land-based symbols as churches,
bridgeA bridge is a structure built to span a valley, road, body of water, or other physical obstacle, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge and the nature of the terrain where the bridge is constructed.-History:The first...
s, shopping centers,
parkA park is a protected area, in its natural or semi-natural state or planted, and set aside for human recreation and enjoyment. It may consist of, rocks, soil, water, flora and fauna and grass areas....
s, and
tunnelA tunnel is an underground passageway. The definition of what constitutes a tunnel is not universally agreed upon. However, in general tunnels are at least twice as long as they are wide. In addition, they should be completely enclosed on all sides, save for the openings at each end...
s.
GPS receivers used in air or marine navigation may contain large databases of standard, named waypoints that can be used to coordinate navigation with other aircraft or ships in the area. Some receivers are integrated into
autopilotAn autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. Most people understand an autopilot to refer specifically to aircraft, but self-steering gear for ships, boats, space craft and missiles are sometimes also called by this...
s or
flight management systemA flight management system is a fundamental part of a modern aircraft in that it controls the navigation. The flight management system is the avionics that holds the flight plan, and allows the pilot to modify as required in flight. The FMS uses various sensors to determine the aircraft's position...
s that will pilot an aircraft or ship along a planned route without human intervention. The routing information for the flight plans used in modern aviation often consists of a list of the waypoints that the flight will follow. Most waypoints used by aviation GPS receivers correlate with waypoints established on
chartAn aeronautical chart is a map designed to assist in navigation of aircraft, much as nautical charts do for watercraft, or a roadmap for drivers...
s and other navigational documentation.
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 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. Participants are given a map, usually a specially prepared orienteering map, which they use to find control points...
sports, of waypoints with a map that omits a coordinate system (see
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 circleA great circle of a sphere is a circle that runs along the surface of that sphere so as to cut it into two equal halves, as distinct from a small circle. The great circle therefore has both the same circumference and the same center as the sphere...
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 VFR), 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 is the activity involving man-made air-borne flying devices , including the people, organizations, and regulatory bodies involved with them.- History :...
,
area navigationArea Navigation is a method of air navigation that allows an aircraft to choose any course within a network of navigation beacons, rather than navigating directly to and from the beacons...
(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 and SMS
Establishing waypoints in real-time and transmitting them via GSM cellular telephone networks using the
Short Message Service- Companies and organizations :* Sabooj Maroon Swapna , a fan club of Mohun Bagan AC in Kolkata, India* Southdown Motor Services, a former UK bus company* Youth Party of Slovenia, a Slovenian political party...
(
SMS- Companies and organizations :* Sabooj Maroon Swapna , a fan club of Mohun Bagan AC in Kolkata, India* Southdown Motor Services, a former UK bus company* Youth Party of Slovenia, a Slovenian political party...
) is referred to as Gps2sms. Some vehicles and vessels are equipped with hardware that is able to automatically send an
SMS- Companies and organizations :* Sabooj Maroon Swapna , a fan club of Mohun Bagan AC in Kolkata, India* Southdown Motor Services, a former UK bus company* Youth Party of Slovenia, a Slovenian political party...
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 systemThe Automatic Identification System is a short range coastal tracking system used on ships and by Vessel Traffic Services for identifying and locating vessels by electronically exchanging data with other nearby ships and VTS stations. Information such as unique identification, position, course,...
.
See also
- 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 ....
- Autopilot
An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. Most people understand an autopilot to refer specifically to aircraft, but self-steering gear for ships, boats, space craft and missiles are sometimes also called by this...
- 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 use; not least as a sub-set of the published hCalendar and hCard microformat specifications.Use of Geo allows parsing...
- Geotagging
Geotagging is the process of adding geographical identification metadata to various media such as photographs, video, websites, or RSS feeds and is a form of geospatial metadata...
- Global Positioning System
The Global Positioning System is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.GPS is made up of three parts: between 24...
- GPS Phone
- GSM localization
- GPX
GPX, or GPS eXchange Format is an XML schema designed for describing GPS data between software applications.It can be used to describe waypoints, tracks, and routes. The format is open and can be used without the need to pay license fees. Its tags store location, elevation, and time and can in this...
(XML 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 Rules
Instrument flight rules are regulations and procedures for flying aircraft by referring only to the aircraft instrument panel for navigation. Even if nothing can be seen outside the cockpit windows, an IFR-rated pilot can fly while looking only at the instrument panel...
- Landmark
This 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...
- Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
- Orienteering
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. Participants are given a map, usually a specially prepared orienteering map, which they use to find control points...
- Point of interest
A 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 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...