Method and system for improving tuning precision and signal-to-noise ratio of proton precession sensor

Abstract

The invention relates to a method and a system for improving tuning precision and signal-to-noise ratio of a proton precession sensor. The method comprises the steps of outputting a first FID signal by an excitation sensor; waiting by a preset time period after excitation, acquiring the first FID signal and generating discrete data; constructing a spatial matrix according to the discrete data, performing singular value decomposition on the spatial matrix according to an SVD algorithm for eliminating noises and obtaining reconstructed data; processing the reconstructed data according to an FFT algorithm, and acquiring a first frequency value which corresponds with a maximal peak voltage in a first FID signal frequency spectrum; introducing the capacitance and the first frequency value of the sensor into an LC resonance formula for solving a first capacitance, and switching the capacitance of a tuning capacitor which is parallelly connected with the sensor from zero to the first capacitance. The method in which the SVD algorithm and the FFT algorithm are combined realizes tuning of the proton precession sensor and effectively overcomes defects such as low tuning speed, low tuning precision in an interference environment and easy imbalance phenomenon in an existing tuning algorithm.

Description

technical field [0001] The invention relates to the technical field of proton precession sensors, in particular to a method and system for improving the tuning accuracy and signal-to-noise ratio of proton precession sensors. Background technique [0002] The proton precession type magnetometer is a magnetic field measuring instrument used to measure slowly changing weak magnetic fields or constant weak magnetic fields, and its sensor, the proton precession type sensor, is an inductive element. The measurement principle is to use certain excitation conditions to make the protons in the solution where the inductor is in an activated state. After the excitation conditions are removed, the protons will perform Larmor precession around a stable external magnetic field, that is, the earth's magnetic field, and generate FID (Free Induction Decay) signals. Its precession frequency is proportional to the external magnetic field; therefore, the external magnetic field value can be obt...

AI Technical Summary

Problems solved by technology

[0004] The existing proton precession magnetometers still have the following problems in the design of the sensor tuning algorithm: 1) The tuning speed is generally slow, and it takes about a few seconds. Re-tune the sensor, causing great inconvenience to the user

2) Since the untuned FID signal output by the proton precession magnetometer is extremely weak, it is easily interfered by noise signals, and the signal-to-noise ratio is low. Out of adjustment", resulting in the instrument not working properly

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