observation twilight

observation twilight
That part of the twilight period during which the horizon may be observed as a sharply defined line and the navigational stars may be seen. The light diffused during this period. For computation purposes, this twilight begins or ends when the middle of the sun is at a point about 10° below the horizon. See civil twilight and nautical twilight.

Aviation dictionary. 2014.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Cold Fusion (The Twilight Zone) — Cold Fusion The Twilight Zone (2nd revival) episode Episode no. Season 1 Episode 36 Directed by Eli Richbourg Written by A …   Wikipedia

  • Timeline of meteorology — The timeline of meteorology contains events of scientific and technological advancements in the area of atmospheric sciences. The most notable advancements in observational meteorology, weather forecasting, climatology, atmospheric chemistry, and …   Wikipedia

  • literature — /lit euhr euh cheuhr, choor , li treuh /, n. 1. writings in which expression and form, in connection with ideas of permanent and universal interest, are characteristic or essential features, as poetry, novels, history, biography, and essays. 2.… …   Universalium

  • Geography in medieval Islam — Islamic geography includes the advancement of geography, cartography and earth sciences under various Islamic civilizations. During the medieval ages, Islamic geography was driven by a number of factors: the Islamic Golden Age, parallel… …   Wikipedia

  • Elevator — For other uses, see Elevator (disambiguation). A set of lifts in the lower level of a London Underground station. The arrows indicate each elevator s position and direction of travel …   Wikipedia

  • Ibn al-Haytham — Infobox Muslim scholars | notability = Muslim scientist| era = Islamic Golden Age| color = #cef2e0 | | image caption = Ibn al Haytham drawing taken from a 1982 Iraqi 10 dinar note. | | name = Unicode|Abū ‘Alī al Ḥasan ibn al Ḥasan ibn al Haytham… …   Wikipedia

  • Meteorology — For other uses of the root word meteor , see Meteor (disambiguation). For the work by Aristotle, see Meteorology (Aristotle). Not to be confused with Metrology. Part of the Nature series on Weather   …   Wikipedia

  • 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

  • Mercury (planet) — Mercury  ☿ …   Wikipedia

  • .hack//Roots — hack//Roots ドットハック ルーツ (Dotto Hakku Rūtsu) Genre Adventure, Fantasy, Science fiction …   Wikipedia

Share the article and excerpts

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