AskDefine | Define navigational

Dictionary Definition

navigational adj : of or relating to navigation; "navigational aids"

User Contributed Dictionary

English

Adjective

  1. Pertaining to navigation.

Extensive Definition

Navigation is the process of planning, reading, and controlling the movement of a craft or vehicle from one place to another. The word navigate is derived from the Latin roots navis meaning "ship" and agere meaning "to move" or "to direct." Latitude is usually expressed in degrees (marked with °) ranging from 0° at the Equator to 90° at the North and South poles. A line of position can refer to two different things: a line on a chart and a line between the observer and an object in real life. A bearing is a measure of the direction to an object.
Lines (or circles) of position can be derived from a variety of sources:
  • celestial observation (a short segment of the circle of equal altitude, but generally represented as a line),
  • terrestrial range (natural or man made) when two charted points are observed to be in line with each other,
  • compass bearing to a charted object,
  • radar range to a charted object,
  • on certain coastlines, a depth sounding from echo sounder or hand lead line.
There are some methods seldom used today such as "dipping a light" to calculate the geographic range from observer to lighthouse
Methods of navigation have changed through history. Each new method has enhanced the mariner’s ability to complete his voyage. It is also used to predict a future position by projecting course and speed from a known present position. More so than in other phases of navigation, proper preparation and attention to detail are important. A chronometer differs from a spring-driven watch principally in that it contains a variable lever device to maintain even pressure on the mainspring, and a special balance designed to compensate for temperature variations. A fix consisting of only radar information is called a radar fix.
Types of radar fixes include "range and bearing to a single object," "two or more bearings," This technique involves creating a line on the screen that is parallel to the ship's course, but offset to the left or right by some distance.
Another special technique, known as the Franklin Continuous Radar Plot Technique, involves drawing the path a radar object should follow on the radar display if the ship stays on its planned course. During the transit, the navigator can check that the ship is on track by checking that the pip lies on the drawn line. including the replacement of aging satellites, and research and development. Despite this fact, GPS is free for civilian use as a public good.

Navigation processes

Day's work in navigation

The Day's work in navigation is a minimal set of tasks consistent with prudent navigation. The definition will vary on military and civilian vessels, and from ship to ship, but takes a form resembling:
  1. Maintain continuous dead reckoning plot.
  2. Take two or more star observations at morning twilight for a celestial fix. (prudent to observe 6 stars)
  3. Morning sun observation. Can be taken on or near prime vertical for longitude, or at any time for a line of position.
  4. Determine compass error by azimuth observation of the sun.
  5. Computation of the interval to noon, watch time of local apparent noon, and constants for meridian or ex-meridian sights.
  6. Noontime meridian or ex-meridian observation of the sun for noon latitude line. Running fix or cross with Venus line for noon fix.
  7. Noontime determination the day's run and day's set and drift.
  8. At least one afternoon sun line, in case the stars are not visible at twilight.
  9. Determine compass error by azimuth observation of the sun.
  10. Take two or more star observations at evening twilight for a celestial fix. (prudent to observe 6 stars)

External links

navigational in Afrikaans: Navigasie
navigational in Arabic: ملاحة
navigational in Min Nan: Tō-hâng
navigational in Belarusian (Tarashkevitsa): Навігацыя
navigational in Bulgarian: Навигация
navigational in Catalan: Navegació marítima
navigational in Czech: Navigace
navigational in Danish: Navigation
navigational in German: Navigation
navigational in Modern Greek (1453-): Ναυσιπλοΐα
navigational in Spanish: Navegación marítima
navigational in Persian: ناوبری
navigational in French: Navigation
navigational in Galician: Navegación marítima
navigational in Indonesian: Navigasi
navigational in Italian: Navigazione
navigational in Hebrew: ניווט
navigational in Hindi: दिक्चालन
navigational in Lithuanian: Navigacija
navigational in Dutch: Navigatie
navigational in Japanese: 航海
navigational in Norwegian: Navigasjon
navigational in Norwegian Nynorsk: Navigasjon
navigational in Low German: Navigatschoon
navigational in Polish: Nawigacja
navigational in Portuguese: Navegação
navigational in Russian: Навигация
navigational in Simple English: Navigation
navigational in Slovenian: Navigacija
navigational in Turkish: Seyir
navigational in Finnish: Navigointi
navigational in Swedish: Navigation
navigational in Ukrainian: Навігація
navigational in Chinese: 导航

Synonyms, Antonyms and Related Words

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