EXERCISE 30 — LATITUDE BY MERIDIAN ALTITUDE SUN (Numerical Solution)

1. On21^st Jan 2008 AM, in DR 24˚ 36.0’ S 110˚ 20.0’ W,the sextant altitude of the Suns’sLL was 85˚ 03.5’. If IE was 1.6’ off the arc and HE was 10m, find the latitude and state the direction of the PL (LOP).

2. On 1^st Sept 2008, in DR equator 50˚ 27.0’ E, the sextant meridian altitude of the sun’s UL was 82˚ 10.4’. If IE was 2.4’ on the arc and HE was 17m, required the latitude and the PL (LOP).

3. ON 1^st May 2008, in DR longitude 179˚ 58.0’ E, the observed altitude of the sun’s LL on the meridian was 64˚ 35.9’ South of the observer. If HE was 15m, find the latitude and the PL.

4. ON 14^th Sept 2008, in DR longitude 116˚ 27.0’ W, the sextant meridian altitude of the sun’s UL North of the observer was 70˚ 29.8’. If IE was 3.2’ off the arc and HE was 12m, find the latitude and state the direction of the PL (LOP).

5. ON 1^st Dec 2008, in DR 06˚ 35.0’ N 064˚ 18.0’ W, owing to a hazy horizon to the South, a back angle observation of the sun’s LL on the meridian was made and the sextant altitude was found to be 118˚ 11.8’. If HE was 14m, and IE was 2.4’ on the arc, required the latitude and the direction of the PL.

Points to pounder prior to solving problems of this chapter.

• True Altitude is named same as Azimuth
• MZD is named opposite to T Alt.
• If MZD and Dec are of same name so add and retain same name and If of opposite names then subtract the smaller one from the larger one and retain the name of the larger one.
• Whether ‘d’ correction is to be added or subtracted is known by inspecting the Dec for the required hour and the next hour. If Dec is increasing, d correction is to be added and vice-versa.
• In order to know the naming of T Alt and MZD, one should draw a diagram and easily know and understand the naming system. Drawing the diagram in exams may leave a positive impression, that the candidate has understood the fundamentals correctly irrespective of clerical errors.