Research On BDS Cycle Slip Detection And Repair Methods

With the more and more applications of navigation and positioning technology in life and military,the demand for positioning accuracy has become increasingly important.The establishment of BDS is of great significance to the development of our country,both in military and civil.How to improve the accuracy of the positioning,the detection of the cycle is a key factor.When dealing with BDS data,the existence of cycle slips will cause a deviation in the observed values,which will distort the observed values,so that the ambiguity resolution can not be accurately solved.Therefore,cycle slip detection is one of the problems that BDS carrier phase high precision location must solve.This paper studies the method of circumferential jump detection and repair in the phase positioning of the Beidou carrier,and focus on the small cycle slip detection and repair.The main study process and production are as follows:(1)The method of differential morphological filtering is used to denoise the signal of the cycle jump,then construct the eigenvector matrix,and decompose the matrix by singular value decomposition,and decompose the detection signal to get several component signals,and extract the singular value entropy of the eigenvector matrix.The magnitude of the singular value entropy reflects the cycle slip state.The size of the singular value entropy is a reflection of the state of the cycle slip,and the signal characteristics and the difference between signals are obtained by entropy analysis.The cycle slip information is obtained to determine the size of the cycle slip and the frequency of it.(2)Dynamic threshold detection structure of cycle slip,through an ionospheric residuals obtained by calculation and two times difference in composition test new adjacent epoch,based on polynomial fitting test of the quantity of the tes t sequence to detect cycle slip;At the same time,through the polynomial fitting forecast the next epoch ionospheric residual forecast value,compared to the judgment of the epoch and the true value is jump;Then move the sequence to a sequence of fixed length as the moving window to estimate the next epoch,until all the epoch detection so far.(3)The Hankel matrix is constructed by the detection signal and the multiresolution singular value decomposition is used to obtain a set of component signals with different resolution.Then,the sensitivity factors of component signals are analyzed and evaluated,and components containing cycle slips are selected to form sensitive feature vectors,and the obtained component signals are extracted and analyzed by kurtosis criterion.Finally,the kurtosis criterion is used to select the component of the kurtosis value to reconstruct the signal,so as to filter the noise interference and highlight the characteristics of the signal cycle slip.Then the location of the singularities in the signal is accurately detected by the modulus maxima spectrum,and the accurate detection of the small cycle is realized.After detecting the location of the cycle slip,the least-squares support vector machine prediction model is built on the basis of the selected sensitive eigenvectors,and the cycle slip repair is carried out.This paper studies the cycle slip detection and repair method in Beidou carrier phase positioning,which provides a theoretical reference for the cycle slip detec tion and repair in Beidou high-precision positioning.Based on the theory of phase measurement and pseudo range measurement data combination,the detection and repair of BDS single frequency cycle is focused on.Put forward several kinds of cycle slip detection method,and the sensitive component extraction and adaptive dynamic threshold structure,solves the problem of low detection accuracy of cycle slips,and rely on a priori value for the threshold to determine whether the problem of low reliability of cycle slip.And on the basis of small circumference jump detection,cycle jump repair is completed by constructing a cycle jump repair model.