System and method for improving signal to noise ratio of proton magnetic precession signal

Abstract

The present invention provides a system and method for improving the signal to noise ratio of a proton magnetic precession signal. The present invention adopts a combination of a PCA algorithm, an SVDalgorithm and an FFT algorithm to realize tuning of a proton precession sensor, thereby effectively overcoming the disadvantages of an existing tuning algorithm, such as slow tuning speed, low tuningprecision under an interference environment, and easy detuning occurrence; and while the tuning time is reduced, the tuning precision of the proton-precession type sensor is improved. The selection of the tuning capacitance can be realized in a wide measurement range, and the signal-to-noise ratio of a subsequent measurement signal is improved. With the application in instruments which rely on aproton-precession type sensor, such as proton-precession type magnetometers, optical pump magnetometers, and nuclear magnetic resonance proton-precession FID signal imagers, the performance of the instruments are improved.

Description

technical field [0001] The invention relates to the technical field of weak magnetic field measurement, in particular to a system and a method for improving the signal-to-noise ratio of proton magnetic precession signals. 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 obtain...

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-tuning the sensor brings great inconvenience to users; 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. In an environment with high interference, it is easy to have a large error in spectrum analysis and cause "misalignment", which makes the instrument unable to work normally.

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