KUP 7: Ability to determine errors of the magnetic and gyro-compasses, using celestial and terrestrial means, and to allow for such errors

Learning objective:

The ability to determine errors in magnetic and gyro-compasses is essential for accurate navigation. The significance of determining errors in magnetic and gyro-compasses contains:

Accuracy of Course: Compass errors can lead to deviations from the intended course, which could result in significant navigational errors over long distances, potentially leading a vessel off course or even into danger zones.

Safety: Accurate heading information is vital for avoiding obstacles, ensuring safe passage through narrow channels, and preventing collisions. Even small errors in compass readings can compromise safety.

Efficient Navigation: Identifying and correcting compass errors allows for more efficient navigation, saving time and fuel by ensuring the vessel stays on the most direct and optimal course.

Redundancy: While modern vessels often use multiple navigation systems, compass accuracy is a key backup in case of electronic failures. Ensuring minimal errors maintains the reliability of these traditional systems.

The learning objective of this lesson is to determine errors of the magnetic and gyro-compasses, using celestial and terrestrial means.

Learning content:

1. The Azimuth method (azimuth of celestial body)

The Azimuth method is a way of determining gyro error by taking bearings of celestial bodies at known azimuths. The method involves taking bearings of celestial bodies at known azimuths and comparing them with the bearings obtained from the ship’s compass. The difference between the two bearings gives the gyro error. Below is the following procedure¹.

Details refer to the following document:

Recommendation:

Reference:

1. Navigation. Ding Yong. Publisher: People’s Communications Press.

2. Magnetic compass errors: variation & deviation. https://www.youtube.com/watch?v=fxveRt_1ThM