時至今日，人們為了精確地得知導航之航向角，使用眾多種方法來應用在各個載具中，例如慣性模組之陀螺儀、GPS、磁力計等等。上述方法含有各自所遇到之問題，陀螺儀會產生發散現象，GPS只能使用在收訊良好之場域中，而磁力計則會有磁場干擾問題，綜合考量下本研究使用磁力計作為估測航向角之方法，因磁力計所受限制較其他兩者小，磁力計無發散問題，亦可使用在訊號不良之環境。本研究將探討磁力計影響量測範圍為何，先將量測數據正規化校正後，再利用最小平方近似方法(Recursive Least Square Method)建立校正矩陣，最後使用適應性卡爾曼濾波器(Adaptive Kalman Filter)來估測航向角，藉此分析此方法在磁場干擾物質不影響估測器最短距離為多少。此方法確保估測器在無法使用GPS的條件下，仍準確地估測航向角，只要附近無任何干擾磁場量測物質，像是潛水艇在水下無法使用GPS來校正航向角，故套用此方法即可在水下導航時能準確地得知，此時自身之航向角。

Nowadays, to accurately estimate the heading angle of navigation, people use many methods to apply it to various vehicles, such as the gyroscope of the inertial module, GPS, and magnetometer, etc. The above method has its problems. The gyroscope will divergence, GPS can only be used in areas with good reception, and the magnetometer will have the problem of magnetic field interference. Under comprehensive consideration, this study uses a magnetometer as a method to estimate the heading angle. Since the magnetometer has fewer limitations than the other two, the magnetometer has no divergence problems and can also be used in environments with poor signals. This study will explore the influence of the magnetometer on the measurement range. After the measurement data is normalized, the Recursive Least Square method is used to establish the calibrate matrix, and finally, the Adaptive Kalman Filter is used to estimate it. Analyze how long is the shortest distance of the method when the magnetic field interference material does not affect the estimation. This method ensures that as long as there is no nearby measuring material that interferes with the magnetic field, the estimator can accurately estimate the heading angle when GPS cannot be used. For example, the submarine cannot use GPS to calibrate the underwater heading angle, so the application of this method can accurately observe its heading angle when navigating underwater.

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