Celestial Air NavigationU.S. Government Printing Office, 1941 - 226 σελίδες |
Συχνά εμφανιζόμενοι όροι και φράσεις
adjustment Ageton Air Almanac AIR CORPS aircraft airplane apparent approximate assumed position astronomical triangle azimuth bubble error bubble horizon CELESTIAL AIR NAVIGATION celestial body celestial navigation celestial sphere chart collimation computed altitude correction counter dead reckoning declination determined difference DR position earth Enter equator figure flight geographical position Greenwich civil Greenwich meridian hack watch heavenly body hour angle hour circle indicated instrument intercept interpolation intersect knob line of position located longitude master watch mean sun measured method minutes minutes of arc moon observed altitude observer's meridian obtained octant paragraph parallax planets plotted Polaris position circle position line precomputed procedure refraction right ascension rotation rude star finder scale screw selected sextant sidereal sights Sirius solution Star Altitude Curves subtraction synchronizer tabulated tion true sun vernal equinox vertical whole degree zenith distance zero zone نه نه نه
Δημοφιλή αποσπάσματα
Σελίδα 31 - Greenwich civil time. The zones lying in east longitude from the zero zone are numbered in sequence from 1 to 12, and are called minus zones, because, in each of them, the zone number must be subtracted from the standard time in order to obtain the Greenwich civil tune. The zones lying in west longitude from the zero zone...
Σελίδα 17 - In order to obtain accurate measurements each degree is divided into 60 equal parts called minutes and each minute is divided into 60 equal parts called seconds.
Σελίδα 10 - ... it may also be regarded as the arc of the equinoctial intercepted between those circles. It is measured toward the west as a positive direction through...
Σελίδα 9 - The Zenith Distance of any point is its angular distance from the zenith, measured upon the vertical circle passing through the point; the zenith distance of any point which is above the horizon of an observer must therefore equal 90° minus the altitude.
Σελίδα 113 - Flo 33 that when a ray of light undergoes two reflections in the same plane the angle between its first and its last direction is equal to twice the inclination of the reflecting surfaces.
Σελίδα 30 - Greenwich civil time is zero. And each of the zones in turn is designated by a number representing the number of hours by which the standard time of the zone differs from Greenwich civil time. The zones lying in east longitude from the zero zone...
Σελίδα 9 - The equinoctial or celestial equator is the great circle of the celestial sphere formed by extending the plane of the earth's equator until it intersects the celestial sphere. The celestial equator intersects the horizon at its east and west point.
Σελίδα 126 - The function of this element is to elongate the image of the sun or moon to a band of light about 3° long, and the image of a star, to a line of light of the same length. This renders the observations more accurate in certain cases, by enabling the observer to bisect the bubble with the line formed by the astigmatizer, rather than bringing the true image of a star, or of the sun, to the same horizontal level as the bubble, by placing the two objects side by side.
Σελίδα 10 - ... circle passing through the point; it must therefore equal 90° minus the declination, if measured from the pole of the same name as the declination, or 90° plus the declination, if measured from the pole of opposite name.
Σελίδα 9 - Hour Circles, Declination Circles, or Celestial Meridians are great circles of the celestial sphere passing through, the poles; they are therefore secondary to the equinoctial, and may be formed by extending the planes of the respective terrestrial meridians until they intersect the celestial sphere.