tailieunhanh - Electronic Navigation Systems 3E Episode 12

Tham khảo tài liệu 'electronic navigation systems 3e episode 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | The ship s master compass 319 A gyrocompass fitted on board a ship is affected by dynamic errors. They are rolling error manoeuvring error speed and course error and latitude or damping error. All these errors are predictable and controllable. When starting from cold gyrocompasses require time to settle on the meridian. A settling time period of 75 min is typical. Stepper systems are transmission devices that relay the bearing on the master compass to remote repeaters. Magnetic repeating compasses are based on flux gate technology. A flux gate is an electrical device that interprets the compass bearing to produce control functions. Revision questions 1 Describe what you understand by the term gyroscopic inertia 2 What do you understand by the term precession when applied to a gyrocompass 3 Why is a free gyroscope of no use for navigation purposes 4 How is earth s gravity used to turn a controlled gyroscope into a north-seeking gyroscope 5 How is a north-seeking gyroscope made to settle on the meridian and indicate north 6 When first switched on a gyrocompass has a long settling period in some cases approaching 75 min. Why is this 7 Explain the terms gyro-tilt and gyro-drift. 8 How is a gyrocompass stabilized in azimuth 9 What is rolling error and how may its effects be minimized 10 Why do gyrocompass units incorporate some form of latitude correction adjustment 11 What effect does an alteration of a ship s course have on a gyrocompass 12 What are static errors in a gyrocompass system 13 When would you use the slew rate control on a gyrocompass unit 14 Why is temperature compensation critical in a gyrocompass 15 What is a compass follow-up system 16 What is a compass repeater system 17 A flux gate is the central element of magnetic repeating compasses. Explain its operation. 18 Flux gate elements are known as second harmonic units. Why is this 19 What are the advantages of using a dual axis magnetometer in preference to a flux gate 20 Why is a magnetic .