Modern navigation methods

Posted by ramel nortega

Modern navigation methods
Illustration	Description	Application
	Dead reckoning or DR, in which one advances a prior position using the ship's course and speed. The new position is called a DR position. It is generally accepted that only course and speed determine the DR position. Correcting the DR position for leeway, current effects, and steering error result in an estimated position or EP. An inertial navigator develops an extremely accurate EP.[7]	Used at all times.
	Pilotage involves navigating in restricted waters with frequent determination of position relative to geographic and hydrographic features.[7]	When within sight of land.
	Celestial navigation involves reducing celestial measurements to lines of position using tables, spherical trigonometry, and almanacs.	Used primarily as a backup to satellite and other electronic systems in the open ocean.[7]
Electronic navigation covers any method of position fixing using electronic means, including:
	Radio navigation uses radio waves to determine position by either radio direction finding systems or hyperbolic systems, such as Decca, Omega and LORAN-C.	Losing ground to GPS.
	Radar navigation uses radar to determine the distance from or bearing of objects whose position is known. This process is separate from radar’s use as a collision avoidance system.[7]	Primarily when within radar range of land.
	Satellite navigation uses artificial earth satellite systems, such as GPS, to determine position.[7]	Used in all situations.