Coordinate time sequence periodic term extraction method

Abstract

The invention relates to a coordinate time sequence periodic term extraction method, and belongs to the technical field of positioning navigation. The method comprises the steps of obtaining an original coordinate time sequence, and calculating a power spectrum of the original coordinate time sequence; carrying out R times of random rearrangement on the original coordinate time sequence, and calculating a power spectrum after each time of random rearrangement; determining the confidence level of each frequency point according to the original power spectrum density value of each frequency point after each rearrangement and the rearrangement power spectrum density value, wherein the higher the confidence level is, the lower the probability that the frequency point is noise is; the lower the confidence level is, the higher the probability that the frequency point is noise is; selecting frequency points of which the confidence level is greater than a confidence threshold value from the original power spectrum to obtain a denoised power spectrum; and extracting a periodic term in the de-noised power spectrum. According to the method, the confidence level of each frequency point is calculated through random rearrangement, the influence of noise on periodic term extraction is removed, and the scientificity and accuracy of periodic extraction are improved.

Description

technical field [0001] The invention relates to a method for extracting periodic items of coordinate time series, belonging to the technical field of positioning and navigation. Background technique [0002] The coordinate time series contains significant nonlinear changes (especially in the vertical direction), and studies have shown that the amplitude of nonlinear changes can reach 1-2 cm. However, the coordinate time series of the reference station is the key basic data for the establishment and maintenance of the earth reference frame. This nonlinear change will affect the accuracy and stability of the earth reference frame. Therefore, it is a further improvement to study the nonlinear change of the coordinate time series. An important means of reference frame accuracy and stability. [0003] The nonlinear changes in the coordinate time series mainly include: 1. The real nonlinear changes of the reference station coordinates caused by geophysical effects, such as enviro...

AI Technical Summary

Problems solved by technology

[0007] The purpose of this application is to provide a method for extracting periodic items of coordinate time series to solve the problem of low accuracy of extracting existing periodic items

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