Mallat algorithm-based marine gravity measurement error eliminating method

Abstract

Disclosed in the invention is a Mallat algorithm-based marine gravity measurement error eliminating method. The method comprises the following steps: obtaining latitude, course, and ship speed information outputted by an inertial navigation system as well as a gravity signal measured by a gravity meter in real time; calibrating an initial parameter of the gravity meter; selecting a wavelet function and calculating a scaling function phi (t) and a wavelet function psi (t); calculating coefficients of a high-pass filter and a low-pass filter; carrying out decomposition on the gravity signal by using a Mallat algorithm according to the selected filter coefficients and selecting a decomposition level number; according to a signal to noise ratio of an original signal, calculating a heuristic SURE threshold value and carrying out noise reduction on the gravity signal based on a soft threshold method; reconstructuring the gravity signal after noise reduction, calculating an Etvs correction value by utilizing the information outputted by the inertial navigation system and carrying out filtering processing on the Etvs correction value; and carrying out Etvs correction on the gravity signal after the reconstruction. According to the invention, a defect of insufficient real-time performance during the gravity measurement can be overcome; a main error during the gravity measurement can be eliminated; and the gravity signal precision is improved.

Description

technical field [0001] The invention belongs to the technical field of marine gravity measurement, in particular to a method for eliminating errors in marine gravity measurement based on Mallat algorithm. Background technique [0002] In the 1980s and 1990s, the United States and the former Soviet Union successively began to develop passive navigation assistance systems for strategic underwater vehicles. The initial auxiliary method is based on graphic matching, including matching with seabed topographic maps and magnetic field maps. However, due to the need to use sonar to measure seabed contours, the concealment of seabed topography matching is weak; at the same time, it is difficult to actually use it due to the complexity of magnetic field changes. In underwater vehicle navigation, gravity signals and gravity gradient data become the main passive information resources for underwater vehicle navigation. Gravity-assisted navigation has the advantages of high precision, st...

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Problems solved by technology

[0004] The purpose of the embodiments of the present invention is to provide a method for eliminating ocean gravity measurement errors based on the Mallat algorithm, which aims to solve the problem that traditional Fourier transform processes stationary signals. For non-stationary signals, various frequency components need to be distinguished, and Fourier transform cannot satisfy Issues with Signal Processing Requirements

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