淺析“人為航向法”消除磁羅經自差

摘要  磁羅經是一種傳統(tǒng)的航海指向儀器，目前仍是船舶必備的航海儀器之一。安裝在鋼鐵船舶上的磁羅經除受地磁力作用外，還將受到船舶磁場的影響，致使羅經北偏離磁北方向一個夾角而產生自差。在鋼鐵船舶上，磁羅經自差一般可達到幾十度之多，當自差較大時，在有些航向上由于磁北力被嚴重削弱，將影響羅經指向的穩(wěn)定性；在船舶轉向的過程中，由于羅經北相對地磁北極的夾角變化較大會出現(xiàn)轉向時的遲鈍現(xiàn)象；若磁羅經自差沒有消除，將嚴重影響船舶的航行安全。鑒于船舶導航設備的日益完善以及磁羅經在船上所處的地位，能否在保證船舶航行安全的前提下，探討簡化校正磁羅經自差的方法，采用“人為航向法”消除磁羅經自差，對于中小型船舶來說是一種既簡捷又實用的有效方法。這不僅可以提高船舶的經濟效益，而且還可保證船舶航行安全。

關鍵詞  船舶  磁羅經  自差 

The Artificial Direction Method of Eliminating The Magnetic Compass Deviation

[Abstract]  The magnetic compass is one traditional navigation direction instrument, at present was still one of ships necessary nautical instruments. Installs besides receives earth magnetism action of force on the steel and iron ships' magnetic compass, will also receive the ships magnetic field the influence, a cause compass north deviation magnetic north direction included angle produces the autodyne. On the steel and iron ships, the magnetic compass autodyne may achieve several dozens degree many generally, when the autodyne is big, in some directions, because the magnetic north strength is weakened seriously, will affect the compass direction the stability; Changes in the ships in process, when the compass north relative earth magnetism North Pole's included angle change compares the congress appears changes the slow phenomenon; If the magnetic compass autodyne has not eliminated, serious influence ships' navigation security. In view of the fact that the ship navigation equipment's day-by-day consummation as well as the magnetic compass the status which locates on the ship, whether under the guarantee ships navigation security's premise, the discussion simplification adjustment magnetic compass  method, the use “the artificial direction law” to eliminate the magnetic compass autodyne, regarding the middle and small scale ships is one kind both simple and direct and the practical efficacious device. Not only this may raise ships' economic efficiency, moreover may also assure the ships navigation security.

[Key words]  Vessel;   Magnetic  compass ;   deviation 

目  錄

引 言 1
第1章 磁羅經自差及其校正 2
1.1 磁羅經自差的產生原因 2
1.1.1 磁羅經的指北原理 2
1.1.2 船體的磁性及其變化 2
1.1.3 船體磁性對磁羅經的影響 4
1.2　測校自差前的準備與檢查 5
1.3 磁羅經自差的消除方法 6
1.3.1　船半圓自差硬鐵力的準確消除 7
1.3.2 船軟鐵半圓自差力的準確消除 7
1.3.3　傾斜自差校正的不合理性 9
1.3.4　感應自差的變化 10
第2章 人為航向法 12
2.1 “人為航向法”的校正原理 12
2.2 “人為航向法”消除船用磁羅經自差的基本步驟 13
2.3 “人為航向法”消除船用磁羅經自差的幾個具體問題 15
第3章 “人為航向法”實例分析及校差的探討 18
3.1 實例分析 18
3.2 “人為航向法”校差的探討 21
結束語 23
致謝語 24
參考文獻 25