Hour angle - Wikipedia
网页The angle may be measured in degrees or in time, with 24 h = 360° exactly. In celestial navigation, the convention is to measure in degrees westward from the prime meridian (Greenwich hour angle, GHA), from the local meridian (local hour angle, LHA) or from the first point of Aries (sidereal hour angle, SHA).
Local Hour Angle and Greenwich Hour Angle - Astro …
网页The hour angle between the Greenwich Meridian and the meridian of a celestial body is known as the Greenwich Hour Angle. The Local Hour Angle between an observer’s position and the geographical position of a celestial body can be found by combining the observer’s longitude with the GHA as shown in the following diagram.
格林威治时角 - 百度百科
网页格林威治时角（GHA）是格林威治天子午线沿天赤道向西到天体时圆所夹的角距，范围为0°~360° [1]。. 格林威治时角是天文导航中的一个重要术语，用于表示天体的经度信息。. 中文名. 格林威治时角. 外文名. Greenwich Hour Angle. 范 围. 0°- 360°. 起始点.
Greenwich Hour Angle – AstroNavigation - Vanderbilt University
网页Greenwich Hour Angle, abbreviated GHA, is the angular measure of the celestial body from the Greenwich Meridian (also known as the Prime Meridian) along the celestial equator. Tabulated GHA is found in the daily pages of The Nautical Almanac.
時角 - 维基百科，自由的百科全书
网页春分点的本地时角 又被定义为本地的 恒星时 （ ），则上式同样可以表述成：. 其中, GST 為 格林威治恆星時 (Greenwich sidereal time), 即格林威治所測的的本地恆星時, 為觀測者所在的 經度 (由 本初子午線 (prime meridian) 起算，以東為正). [3] 負時角（−180° < < 0°）表示 ...
Greenwich hour angle - Oxford Reference
网页4 天之前 · Quick Reference. The hour angle of a celestial object as seen by an observer on the Greenwich meridian. GHA is a global standard. The hour angle for any other observer is simply GHA + λ, where λ is the observer's geographical longitude east. A star's Greenwich hour angle can be found by subtracting the star's right ascension from the ...
Sidereal Time - United States Navy
网页Sidereal time is the hour angle of the equinox. If the mean equinox is used, the result is mean sidereal time; if the true equinox is used, the result is apparent sidereal time. The hour angle...
Astronomical Times - Harvard University
网页The Greenwich sidereal day begins when the vernal equinox is on the Greenwich Meridian. Greenwich Mean Sidereal Time (GMST) is the hour angle of the average position of the vernal equinox, neglecting short term motions of the equinox due to nutation.
The Demystified Astro Navigation Course Unit 2
网页2015年10月29日 · Greenwich Hour Angle (GHA). The hour angle between the Greenwich Meridian and the meridian of a celestial body is known as the Greenwich Hour Angle. The Local Hour Angle between an observer’s position and the geographical position of a celestial body can be found by combining the observer’s longitude with the GHA.
Sidereal Time - University of Houston–Clear Lake
网页We define the Greenwich Hour Angle of X as the Hour Angle of X relative to the celestial meridian at Greenwich. Then we can define Greenwich Sidereal Time (GST) as the Greenwich Hour Angle of the vernal equinox. This gives the important relation LST = GST - longitude west. Recall that the Local Hour Angle (LHA) of a star = Local Sidereal Time ...