3. is a circle whose center represents the South pole, whose rim is the Equator and whose radius is a meridian.
4. The most useful aid in visualizing any time and date problem and shows the relative positions of the meridians and hour circles involved in a particular problem. TIME DIAGRAM
5. M- upper branch of observer’s meridian m- lower branch of observer’s G- upper branch of Greenwich meridian g- lower branch of Greenwich meridian
6. The longitude of the observer indicates the position of Greenwich Meridian. If the longitude is east, Greenwich meridian is west of Local meridian and if longitude is west, Greenwich meridian is east of Local time meridian
7. Local Hour Angle (LHA)- is measured from the local meridian westward through 360
8. Greenwich Hour Angle (GHA) is measured from the Greenwich meridian westward through 360
9. Sidereal Hour Angle (SHA) is measured from the first Point of Aries westward through 360.
10. Meridian Angle (t) is measured from the local meridian eastward or westward through 180 and labeled E or W to indicate the direction of measurement.
11. Right ascension is measured from the Vertical Equinox(First of Aries) eastward through 24 hours.