694
THE HONG KONG GOVERNMENT GAZETTE, DECEMBER 24, 1930.
Given three sides of a spherical triangle to find any angle. (These two problems are preferably done by the use of the haversine formulae.)
A general understanding of the following:-
(9) The earth and its daily and annual movements. Meaning of equator and poles. The position of a place fixed by its latitude and longitude; meridians. Distances measured on the earth; nautical mile; departure. To show clearly, but without proof, the connection between departure, difference of longitude and middle latitude.
(h) The real movement of sun, moon and planets. The celestial sphere; celestial poles; celestial meridian above and below pole; zenith; celestial equator. Altitude and zenith distance of heavenly bodies; celestial horizon; prime vertical; circles of altitude.
(i) Apparent movements of heavenly bodies. Declina- tion. Rising and setting of heavenly bodies. Amplitude The position of a heavenly body on the celestial sphere both with and without reference to the observer, i.e., Declination with Right Ascension or Azimuth with altitude. Azimuth.
(1) Apparent movement of sun. Mean sun. Ecliptic. Length of day and night. First point of Aries. Right ascen- sion Right Ascension of mean sun.
(k) General ideas on time Hour angle. Greenwich and other standard times. Simultaneous hour angles of heavenly bodies in different places. Sidereal time. Relation of long- itude and time. Equation of time. Mean and apparent times at Greenwich and elsewhere.
(1) Hour angle of heavenly body + Right Ascension of heavenly body Hour Angle of Mean Sun + Right Ascension of Mean Sun
The meaning of E. and R. in the Nautical Almanac.
(m) Correction of sextant altitudes. True horizon and visual horizon; dip of the horizon. Effect of atmosphere, refraction. Semidiameter. Parallax.
(n) Geographical position of heavenly body.
The simple explanation of the "Circle of position" on the earth, based on the three following facts
Zenith Distance of heavenly body
distance of
geographical position from an observer. Latitude of geographical position = Declination of
heavenly body.
Longitude of geographical position
*********
Hour Angle of heavenly body West of the meridian of Green- wich.
How a position circle is placed on a chart in practice.
Position line. Intercept.
A simple description of how a position line is obtained from the observed altitude of a heavenly body by :--
(i) A Meridian Altitude.
(ii) An Ex-Meridian Altitude.
(iii) An Altitude of Polaris.
(iv) An Altitude with an assumed latitude (Longitude
by chronometer).
(v) An Altitude with an assumed Dead Reckoning
position (Marcq St. Hilaire).
ว
No comments yet.
Private notes are available after approval.