At 1444 ZT on 28 July, in DR position LAT 40° 56.8' N, LONG 167° 12.4' E, you observe an amplitude of the Moon. The upper limb of the Moon is on the visible horizon and bears 299.3° psc. The variation is 1° E. What is the deviation?

Question

At 1444 ZT on 28 July, in DR position LAT 40&deg; 56.8' N, LONG 167&deg; 12.4' E, you observe an amplitude of the Moon. The upper limb of the Moon is on the visible horizon and bears 299.3&deg; psc. The variation is 1&deg; E. What is the deviation?

Accepted Answer

Option A: 3.1&deg;W. Determine the Moon's declination and LHA for the observation time. Calculate the true amplitude using the formula sin(Amp) = sin(Dec) / cos(Lat). Adjust for the Moon's semi-diameter and parallax. Comparing the true bearing to the compass bearing (299.3° psc) with 1°E variation results in 3.1°W deviation.

At 1444 ZT on 28 July, in DR position LAT 40&deg; 56.8' N, LONG 167&deg; 12.4' E, you observe an amplitude of the Moon. The upper limb of the Moon is on the visible horizon and bears 299.3&deg; psc. The variation is 1&deg; E. What is the deviation?

At 1444 ZT on 28 July, in DR position LAT 40° 56.8' N, LONG 167° 12.4' E, you observe an amplitude of the Moon. The upper limb of the Moon is on the visible horizon and bears 299.3° psc. The variation is 1° E. What is the deviation?