On 30 March in DR position LAT 20°26.2'N, LONG 131°17.9'E, you take an ex-meridian observation of the Moon's lower limb at upper transit. The chronometer time of the sight is 10h 36m 02s, and the chronometer error is 02m 06s slow. The sextant altitude (hs) is 48°21.4'. The index error is 2.0' on the arc, and your height of eye is 40 feet. What is the latitude at meridian transit?

Question

On 30 March in DR position LAT 20&deg;26.2'N, LONG 131&deg;17.9'E, you take an ex-meridian observation of the Moon's lower limb at upper transit. The chronometer time of the sight is 10h 36m 02s, and the chronometer error is 02m 06s slow. The sextant altitude (hs) is 48&deg;21.4'. The index error is 2.0' on the arc, and your height of eye is 40 feet. What is the latitude at meridian transit?

Accepted Answer

Option B: LAT 20&deg;31.9'N. Ex-meridian observations of the Moon require applying the Moon's parallax and semi-diameter corrections in addition to standard altitude corrections. By determining the time of local apparent noon and applying the reduction to the meridian, the latitude is calculated as 20°31.9'N, matching the observed celestial data.