On 23 August in DR position LAT 24°22.0'S, LONG 64°55.3'E, you take an ex-meridian observation of the Moon's upper limb at upper transit. The chronometer time of the sight is 02h 15m 04s, and the chronometer error is 01m 06s fast. The sextant altitude (hs) is 48°03.6'. The index error is 2.0' on the arc, and your height of eye is 60 feet (21.0 meters). What is the latitude at meridian transit?

Question

On 23 August in DR position LAT 24&deg;22.0'S, LONG 64&deg;55.3'E, you take an ex-meridian observation of the Moon's upper limb at upper transit. The chronometer time of the sight is 02h 15m 04s, and the chronometer error is 01m 06s fast. The sextant altitude (hs) is 48&deg;03.6'. The index error is 2.0' on the arc, and your height of eye is 60 feet (21.0 meters). What is the latitude at meridian transit?

Accepted Answer

Option A: 24&deg;20.5'S. For Moon observations, apply horizontal parallax and semidiameter corrections from the Nautical Almanac in addition to standard dip and index error corrections. Solve the ex-meridian sight reduction steps outlined in Bowditch to determine the exact latitude at upper transit as 24°20.5'S.