At 1524 ZT on 14 June, in DR position LAT 30°51'N, LONG 30° 02'W, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 103.9°pgc. The variation is 10°W. What is the gyro error?

Question

At 1524 ZT on 14 June, in DR position LAT 30&deg;51'N, LONG 30&deg; 02'W, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 103.9&deg;pgc. The variation is 10&deg;W. What is the gyro error?

Accepted Answer

Option D: 2.0&deg;E. Calculate the Moon's declination for the observation time. Determine the true amplitude using sin(Amp) = sin(Dec) / cos(Lat). Convert the true amplitude to a true bearing. Since the variation is 10°W, apply this to the gyro bearing to find the gyro error. The difference between true and gyro bearings is 2.0°E.

At 1524 ZT on 14 June, in DR position LAT 30&deg;51'N, LONG 30&deg; 02'W, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 103.9&deg;pgc. The variation is 10&deg;W. What is the gyro error?

At 1524 ZT on 14 June, in DR position LAT 30°51'N, LONG 30° 02'W, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 103.9°pgc. The variation is 10°W. What is the gyro error?