At 1547 ZT on 22 May, in DR position LAT 45° 12.8'N, LONG 028° 15.4'W, the Moon's upper limb is observed on the visible horizon, bearing 120.0°psc. Variation is 2°W. What is the deviation?

Question

At 1547 ZT on 22 May, in DR position LAT 45&deg; 12.8'N, LONG 028&deg; 15.4'W, the Moon's upper limb is observed on the visible horizon, bearing 120.0&deg;psc. Variation is 2&deg;W. What is the deviation?

Accepted Answer

Option B: 2.6&deg;E. Amplitude observation of the Moon's upper limb on the visible horizon requires correcting for semi-diameter and refraction. The computed true bearing combined with 2°W variation yields a magnetic bearing that contrasts with the 120.0°psc to establish 2.6°E deviation.

At 1547 ZT on 22 May, in DR position LAT 45&deg; 12.8'N, LONG 028&deg; 15.4'W, the Moon's upper limb is observed on the visible horizon, bearing 120.0&deg;psc. Variation is 2&deg;W. What is the deviation?

At 1547 ZT on 22 May, in DR position LAT 45° 12.8'N, LONG 028° 15.4'W, the Moon's upper limb is observed on the visible horizon, bearing 120.0°psc. Variation is 2°W. What is the deviation?