EMD filtering method and system for time-varying gravity field

A technology of gravity field and gravity field model, applied in the field of satellite data filtering, can solve problems such as unsatisfactory filtering effect, noise removal capability, and signal-to-noise ratio needs to be improved, and achieves high signal-to-noise ratio value, strong noise removal capability, Accurate results
CN112800831AInactive Publication Date: 2021-05-14CHANGAN UNIV +2
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
CHANGAN UNIV
Publication Date
2021-05-14
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses an EMD filtering method and system for a time-varying gravity field. The EMD filtering method for the time-varying gravity field comprises the following steps: acquiring equivalent water height data; the equivalent water height data is obtained by calculating the time-varying gravity field model data; respectively performing empirical mode decomposition on the equivalent water height data according to latitude zones to obtain a limited number of intrinsic mode function parts and a residual part; calculating a cross correlation coefficient between the equivalent water height data and each intrinsic mode function part; determining an intrinsic mode function part corresponding to a first local minimum point in all cross correlation coefficients as an aliasing mode part; and performing reconstruction based on the intrinsic mode function part and the residual part after the aliasing mode part to obtain denoised equivalent water height data. According to the invention, the noise removal capability can be enhanced, and the signal-to-noise ratio of the filtered signal is improved.
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Description

technical field

[0001] The invention relates to the field of satellite data filtering, in particular to an EMD filtering method and system for a time-varying gravity field. Background technique

[0002] Due to the influence of instrument measurement errors and satellite orbit errors of low- and low-tracking gravity measurement satellite loads, there are obvious north-south band noises in the results of surface mass changes retrieved from Level-2 time-varying gravity field model data, so it is necessary to The time-varying gravity field model data is filtered to eliminate the influence of band noise.

[0003] At present, there are two main methods for removing band noise from time-varying gravity field model data. One is Gaussian filtering, which removes noise by reducing the weight of high-order sub-coefficients in spherical harmonic coefficients. This method suppresses the true geophysical signal while removing the noise, resulting in a decrease in the spatial resolution o...

Claims

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