Great-circle navigation

Great-circle navigation

Great-circle navigation is the practice of navigating a vessel (such as a ship or aircraft) along a track that follows a great circle. A great circle track is the shortest distance between two points on the surface of the earth.

Methods

In order to construct a great circle track, the navigator of a ship may employ several methods.

Gnomonic chart

A straight line drawn on this chart would represent a great circle track. When this is transferred to a Mercator chart, it becomes a curve. The positions are transferred at a convenient interval of longitude and this is plotted on the Mercator chart with the appropriate latitude.

Spherical trigonometry

Mathematically, it is possible to determine the distance of a great circle track between two known positions. Other features of the great circle track may also be calculated.

Computer software

Software is available that allows a navigator to input a departure and arrival position to create a list of waypoints which follow a great circle track. Normally, such programs will also calculate the total distance, the distance between successive waypoints, and the courses to be followed between successive waypoints.

See also

* Great circle
* Great circle distance
* Rhumb line

Resources

* [http://mathworld.wolfram.com/GreatCircle.html Great Circle – from MathWorld] Great Circle description, figures, and equations. Mathworld, Wolfram Research, Inc. c1999
* [http://gc.kls2.com/ Great Circle Mapper] Interactive tool for plotting great circle routes.
* [http://williams.best.vwh.net/gccalc.htm Great Circle Calculator] deriving (initial) course and distance between two points.
* [http://www.acscdg.com/ Great Circle Distance] Graphical tool for drawing great circles over maps. Also shows distance and azimuth in a table.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Great-circle distance — The great circle distance is the shortest distance between any two points on the surface of a sphere measured along a path on the surface of the sphere (as opposed to going through the sphere s interior). Because spherical geometry is rather… …   Wikipedia

  • great circle route — ▪ navigation       the shortest course between two points on the surface of a sphere. It lies in a plane that intersects the sphere s centre and was known by mathematicians before the time of Columbus. Until the 19th century ships generally… …   Universalium

  • great-circle sailing — noun : the navigation or conducting of a ship on a great circle track or on a course determined in relation to a great circle track compare sailing * * * /grayt serr keuhl/, Navig. sailing between two points more or less according to an arc of a… …   Useful english dictionary

  • navigation — I (New American Roget s College Thesaurus) Travel on water Nouns 1. navigation; celestial navigation, dead reckoning; circumnavigation; pilotage, steerage; seamanship; navigability. 2. (active boating) boating, yachting, yacht racing, sailing,… …   English dictionary for students

  • navigation — navigational, adj. /nav i gay sheuhn/, n. 1. the act or process of navigating. 2. the art or science of plotting, ascertaining, or directing the course of a ship, aircraft, or guided missile. [1520 30; < L navigation (s. of navigatio) a voyage.… …   Universalium

  • Navigation — This article is about determination of position and direction on or above the surface of the earth. For other uses, see Navigation (disambiguation). Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia. Navigation is the… …   Wikipedia

  • Great Lakes — This article is about the Great Lakes of North America. For the region, see Great Lakes region (North America). For other uses of this term, see Great Lakes (disambiguation). A rare cloudless satellite view of the entire Great Lakes region, April …   Wikipedia

  • History of navigation — In the pre modern history of human migration and discovery of new lands by navigating the oceans, a few peoples have excelled as sea faring explorers. Prominent examples are the Phoenicians, the ancient Greeks, the Persians, the Arabians, the… …   Wikipedia

  • Bearing (navigation) — This article is about the navigational term. For other uses, see Bearing. A standard Brunton Geo compass, used commonly by geologists and surveyors to obtain a bearing in the field. In marine navigation, a bearing is the direction one object is… …   Wikipedia

  • Radar navigation — Marine radar systems can provide very useful navigation information in a variety of situations. When the vessel is within radar range of land or special radar aids to navigation, the navigator can take distances and angular bearings to charted… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”