Accuracy Assessment Method of Electromagnetic Compass Based on Shortest Interval Estimation
Aiming at the practical problem that the existing marine compass and other navigation equipments require multiple long flight time samples and the actual test time is difficult to organize,an accuracy evaluation method based on t-distribution and χ2 distribution shortest interval estimation is proposed.By improving the selection of the quantiles of the χ2 distribution,the shortest variance interval with n degrees of freedom and 1-α confidence is obtained,and the shortest RMS confidence interval is obtained through the confidence intervals of mean and variance to assess the overall error.The method can realize the evaluation performance of the RMS accuracy of the navigation system parameters according to different numbers of navigation test samples.The results of the example analysis show that the evaluation method achieves the evaluation of the accuracy performance of marine electromagnetic compasses based on different samples,which is more accurate and reasonable than the results of the existing evaluation methods.It can also appropriately lower the requirements for voyages when the confidence level is met.