System and method for improving tuning precision and signal-to-noise ratios of proton precession type sensors

Abstract

The invention provides a system and method for improving the tuning precision and signal-to-noise ratios of proton precession type sensors. According to the system and method, a PCA algorithm, SVD algorithm and FFT algorithm combined method is adopted to realize the tuning of the proton precession type sensors, so that the defect that the existing tuning algorithms are low in tuning speed, low intuning precision under interference environments and easy to cause detuning phenomena is effectively overcome. The system and method are capable of improving the tuning precision of the proton precession type sensors while shortening the tuning time, realizing the selection for tuning capacitors in wide measurement ranges and improving the signal-to-noise ratios of the later measurement signals, and are applied in instruments, depending on the proton precession type sensors, such as proton precession type magnetometers, optical pump magnetometers and magnetic resonnance imaging proton precession FID signal imagers so as to effective the performance of the instrument.

Description

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

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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