Study On Detection And Compensation Of Magnetic Interference For OBE Based On Time-Series

Since the 1950 s,aeromagnetic anomaly detection with its unique characteristics and advantages has gradually played an increasingly important role in many fields,including geological exploration,humanitarian rescue,aviation navigation and so on.With the improvement of the measurement accuracy of magnetometer,aeromagnetic compensation becomes one of the critical factors to restrict its ability improvement.Many researchers have provided lots of methods to improve the compensation accuracy for different problems,among which the magnetic interference compensation of On-board Electronic is not within the effective compensation range of the "soft compensation" scheme based on the Tolles-Lawson model.the magnetic interference compensation of On-board Electronic has gradually entered the field of vision of researchers.However,most of the current methods are reference compensation which rely on the measurement of dynamic current.Aeromagnetic data is a typical time series.In view of this,according to the different duration and geometric characteristics of On-board Electronic magnetic interference,this paper divides it into instantaneous magnetic interference and sustained magnetic interference.On the basis of analyzing the time series related characteristics,this paper explores a non reference detection and compensation method.It mainly includes the following aspects:First of all,in view of the problem of instantaneous magnetic interference detection with very short duration,based on the analysis of the characteristics of the time series of aeromagnetic data,the classic time series prediction model is used to fit the aeromagnetic data.Referring to the basic idea of time series outlier detection and considering the integrity and accuracy of the instantaneous magnetic interference detection,a kind of instantaneous magnetic interference detection based on residual statistics is proposed.Experiments show that the algorithm can detect more accurate and complete instantaneous magnetic interference.Secondly,To solve the problem of continuous magnetic interference detection with uncertain duration and obvious angle features,on the basis of analyzing the continuous magnetic interference feature angle extraction,the piecewise linear representation of the aeromagnetic data sequence and the similarity measurement methods,Savitzky-Golay filtering method is introduced into the angle feature extraction of continuous magnetic interference and the segmented linear representation of aeromagnetic data,Considering the similarity measurement factors such as Angle characteristics,change trend and duration,a method of continuous magnetic interference detection based on characteristic angle is proposed.Experiments show that the algorithm has a good detection effect on continuous magnetic interference.Finally,different methods are used to compensate the magnetic interference detected by the two methods.In view of the instantaneous magnetic interference,it can achieve a very good compensation effect by using a simple compensation method because of its instantaneous characteristics.In view of the continuous magnetic interference,the data characteristics other than magnetic interference need to be destroyed as little as possible.The continuous magnetic interference is divided into two parts for compensation.Experiments show that the compensation method can effectively compensate the magnetic interference of airborne electrical equipment without reference.