A Cascading Correction Method Based on ica-ra for Borehole Strain Data by Frequency Division

Abstract

The invention relates to the field of borehole strain, specifically relates to an ICA-RA-based (independent component analysis-regression analysis-based) band cascaded correction method for borehole strain data and aims at removing strain change caused by external environmental interferences. The band cascaded correction method provided by the invention comprises the following steps: firstly performing four-layer wavelet decomposition on borehole strain data, air temperature data, air pressure data, precipitation data and calculated theoretical solid tide data of the same observation station;in five decomposed bands, performing correlation analysis between multiple factors and strain band by band; and finding an influence factor having maximum correction with the borehole strain data in each band by utilizing an ICA-RA cascaded correction method. An ICA method is introduced for calculating strain change caused by water level change and eliminating the strain change; and for data whichis not air temperature, air pressure and solid tide and the like, an RA method is utilized for calculating influence produced by main factors in a corresponding band and correcting the influence. Byvirtue of the band cascaded correction method provided by the invention, each band of the borehole strain data can be effectively analyzed, and the band cascaded correction method has an important correction action on a real strain situation.

Description

technical field

[0001] The invention relates to the field of borehole strain, in particular to a cascading correction method for borehole strain data based on ICA-RA, which aims to remove strain changes caused by external environmental disturbances. Background technique

[0002] During the national "Tenth Five-Year Plan" period, China's first four-component borehole strain gauge observation points developed rapidly, and the number of observation stations nationwide increased to more than 50. Among several mainstream geodetic observation methods (seismometry, GPS and borehole strain observation), the borehole strain gauge fills the measurement blind area of ​​seismometry and GPS, and has the highest observation accuracy in the period of several months to several hours. However, after decades of observation practice, it is found that there are many factors that affect the changes in borehole strain observations, which increases the difficulty of extracting effective undergroun...

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