930 results about "Magnetometer" patented technology

The invention provides a global magnetic disturbance compensation method in aviation magnetic survey. The method comprises the following steps: S1, performing high-altitude calibration flight through a motion platform, and acquiring total magnetic field data based on detection data of an optical pump magnetometer; s2, obtaining geomagnetic background gradient information and obtaining geomagnetic field data based on the geomagnetic background gradient information; s3, obtaining motion platform magnetic interference data according to the total magnetic field data and the geomagnetic field data; s4, motion platform attitude information, motion platform current information and fluxgate magnetometer detection data are acquired; s5, obtaining a motion platform magnetic interference coefficient according to the motion platform magnetic interference data, the motion platform attitude information, the motion platform current information and the fluxgate magnetometer detection data; and S6, according to the geomagnetic background gradient information and the motion platform magnetic interference coefficient, performing data compensation on the total magnetic field data in real time during actual aviation magnetic measurement.

The invention discloses a wind power generation tower pose monitoring method based on a GNSS / MEMS IMU / magnetometer combination, and the method comprises the steps: carrying out the estimation of a state vector containing the position, speed, attitude error, sensor zero offset and scale factor error through error state Kalman filtering based on the GNSS / MEMS IMU combination, and carrying out the correction and fusion of GNSS and IMU data through a lever arm effect; a complementary filtering algorithm is adopted, an error vector is constructed by combining measured values of an accelerometer and a magnetometer, a gyro angular velocity is corrected through a PI controller, an attitude quaternion is recurred, a course angle is calculated, and the course angle is used as an auxiliary observed quantity to update filtering. According to the invention, by adding course information provided by the MEMS IMU and the magnetometer, the position and the attitude are comprehensively estimated, and high-precision six-degree-of-freedom pose monitoring is realized.

According to the displacement modulation and optical assistance-based SERF atom magnetometer magnetic imaging method, an SERF atom magnetometer integrated with a magnetic flux guider is used as a magnetic sensor, and low-frequency magnetic field modulation is introduced to the magnetic sensor by controlling a to-be-tested sample to perform periodic infinitesimal displacement in the sensitive direction of the magnetic sensor; the modulation signal is demodulated by combining a phase-locked amplification technology, and a magnetic response signal subjected to phase-locked demodulation at each spatial position is extracted; constructing a magnetic response matrix through two-dimensional track scanning of micron-order step pitch; an image acquisition module and a reflection optical assembly are introduced for spatial registration so as to monitor the relative position in real time, and the visibility and controllability of the magnetic imaging process are guaranteed; the point-by-point detection of fT-level weak magnetic signals can be realized on the premise that an array structure is not needed; the low-frequency noise interference can be effectively inhibited, the stability and definition of direct-current and low-frequency magnetic field imaging are improved, and the method is suitable for high-resolution space imaging application of weak magnetic sources such as magnetic domain structures, nervous tissue slices and ancient rock samples.

The invention discloses a fusion filtering attitude estimation method based on EKF and Mahony, and the method comprises the steps: firstly obtaining the original data information of an IMU sensor at the current moment, carrying out the normalization of the attitude information of an accelerometer and a magnetometer, carrying out the error calculation, and compensating the error to the angular velocity of a gyroscope through a PI controller, the method comprises the following steps: performing Mahony filtering correction on an angular velocity and a corrected attitude quaternion to obtain an angular velocity subjected to Mahony filtering correction and a corrected attitude quaternion, constructing a state equation of an EKF by using the corrected attitude quaternion and a gyroscope zero offset value, and constructing an observation equation by using data of an accelerometer and a magnetometer so as to obtain an optimally estimated attitude quaternion and a gyroscope zero offset value; and finally, compensating the optimally estimated zero offset value of the gyroscope to the angular velocity correction process in the Mahony filtering process.

The invention discloses an SERF atom magnetometer double-axis magnetic field detection method and device based on pulsed magnetic field modulation, relates to the technical field of magnetic field precision measurement, and compresses the action time of a modulation magnetic field additionally applied in the same unit period on a hot atom ensemble by replacing conventional continuous sinusoidal magnetic field modulation with pulsed magnetic field modulation. The pulse magnetic field with the duty ratio of d can reduce the spin exchange relaxation rate to 2d times of that of a conventional method under the same modulation amplitude and frequency, due to the fact that the spin exchange relaxation rate is effectively restrained, the collected polarizability response signal is obviously improved, and the polarizability response signal can be obtained through the pulse magnetic field with the duty ratio of d and the pulse magnetic field with the duty ratio of d. Low-relaxation-rate sensitivity-enhanced double-axis magnetic field measurement under a pulse modulation scheme is realized, the double-axis measurement sensitivity of a miniaturized SERF atom magnetometer is further improved, and the method has great significance in supporting leap-type development of a future array type extremely-weak magnetic imaging system and medical application thereof.

The invention provides a cement-based material residual magnetism intensity detection device, a detection method and an evaluation method. The cement-based material residual magnetism intensity detection device comprises a magnetic shielding cylinder, a fluxgate magnetometer and a test tool, the magnetic shielding cylinder is used for shielding a magnetic field to ensure stable test environment magnetic field; the fluxgate magnetometer comprises a fluxgate probe and a fluxgate digital display meter, the fluxgate probe is used for measuring a vector value of space magnetic induction intensity at a position corresponding to the fluxgate probe, and the fluxgate digital display meter is used for displaying a residual magnetism intensity measured value measured by the fluxgate probe; the test tool is arranged in the magnetic shielding cylinder and is used for placing a sample to be tested and fixing a fluxgate probe; according to the invention, a fluxgate magnetometer and a magnetic shielding cylinder are adopted to detect the residual magnetism intensity of the cement-based material, a standardized detection process and a test method are provided for solid components, a liquid mixture and a molded test block, and quantitative characterization of the distribution rule of the residual magnetism intensity of the cement-based material is realized through fewer detection points.

The invention discloses a sensor calibration test system and a calibration test method for UUV intelligent perception, belongs to the technical field of underwater robots, and aims to solve the problems that the capability evaluation of the UUV intelligent perception system is difficult to realize, the credibility, the reliability and the accuracy are poor, and the UUV intelligent perception system cannot be fully matched with the actual application environment and cannot be optimized due to the existing underwater multi-mode comprehensive perception calibration mode. And the development and improvement of the intelligence of the UUV are directly influenced. The sensor calibration test system can simulate various motion modes of the underwater vehicle and the underwater target in navigation, so that a large number of calibration samples are formed, the three-dimensional imaging sonar, the underwater camera and the magnetometer can realize calibration of working parameters based on the underwater acousto-optic magnetic comprehensive beacon arranged on the underwater target, and the calibration precision is improved. After sensor calibration is completed, the system can be used for testing the calibration effect of the sensor, and the number of times and cost of sea test calibration are effectively reduced.

The invention relates to a method for activating a function of a motor vehicle by means of an activation device comprising at least four ultra-wide-band communication external antenna modules and an ultra-high-frequency communication module, from an item of “hands-free” portable access equipment (SD) carried by a user, comprising an accelerometer, a gyroscope and a magnetometer, the activation of the function being triggered by detection of the presence of the user in a predetermined zone around the vehicle, and depending on an authentication result, the method comprising the following steps:s) determining an initial position of the item of access equipment with respect to the vehicle,t) measuring the values from the gyroscope, from the magnetometer and from the accelerometer,u) obtaining a value of the probability of the intention to activate a vehicle function,v) comparing the probability value with at least one predetermined threshold,w) transmitting, at ultra-high frequency from said item of equipment to said vehicle, a request to place the external antenna modules in partial or full ultra-wide-band communication operation, depending on the result of said comparison,x) activating the vehicle function, depending on an estimate of the distance between said item of equipment and the vehicle made by said external antenna modules thus activated in the ultra-wide band.

The invention discloses a magnetic source positioning method based on a spin-exchange relaxation-free atom magnetometer, and aims to provide a high-precision brand-new solution for magnetic source positioning in a near-zero magnetic environment by performing physical modeling and least square estimation on space magnetic field distribution of a target magnetic source. The magnetometer is enabled to be simultaneously sensitive to a three-axis magnetic field, a light absorption detection method is utilized to ensure that complete three-axis magnetic field information is obtained, and the sensitivity of the three axes reaches fT / Hz1 / 2 (1fT = 10 <-15 > T) magnitude. In the positioning process, the target magnetic source is abstracted into a physical model of the magnetic dipole, and the space magnetic field information generated by the target magnetic source is obtained through the atom magnetometer, so that the long-term stability of the magnetic source positioning process and the high precision of the positioning result can be ensured in the zero magnetic environment; therefore, a high-precision magnetic positioning technical means with great potential is provided for various application scenes such as paleomagnetic sample testing and magnetic source positioning in medical research, and technical progress and application expansion in related fields are expected to be promoted.

An electronic interactive device includes an interaction surface for use with a user borne device. The interaction surface includes a contact detection surface for detecting a device contact event with the interaction surface; a plurality of magnetometers defining a reference coordinate system and a sensing volume proximate to the interaction surface, with each of the magnetometers having a rigid spatial relationship to the other magnetometers; and processing circuitry communicably coupled to at least the contact detection surface and the plurality of magnetometers. The plurality of magnetometers perform magnetic field measurements and provide measurement data to the processing circuitry. The processing circuitry determines at least one of position and / or magnet orientation relative to a longitudinal axis of the user borne device and a distance separating the magnet and / or magnet orientation relative to a longitudinal axis of the user borne device from the interaction surface when the contact event occurs.

The present invention relates to the technical field of dynamic measurement of drill tool attitude, and discloses a dynamic measurement method and system for attitude parameters of a rotary steering tool. The method includes: obtaining in real time the three-axis angular rate, the three-axis earth gravity field components, and the three-axis geomagnetic field components of the rotary steering tool; determining a prior estimate value of the attitude angle according to the three-axis angular rate; determining a posteriori observation values of the attitude angle according to the three-axis earth gravity field components and the three-axis geomagnetic field components; obtaining a posteriori optimal attitude angle estimation result by fusing the prior estimate value of the attitude angle and the posteriori observation values of the attitude angle through iterative extended Kalman filtering; and calculating the attitude parameters according to the posteriori optimal attitude angle estimation result. In this application, an iterative extended Kalman filter is used to adaptively fuse the dynamic observables measured by a three-axis gyroscope, a three-axis accelerometer, and a three-axis magnetometer, so as to eliminate the noise interference of external environments such as high rotational speed, strong vibration, and magnetic anomaly faced during the dynamic measurement process, thereby improving the control and measurement accuracy of the rotary steering tool.

The invention relates to the technical field of inertial navigation and sensor fusion, in particular to a multi-sensor fusion and adaptive filtering attitude estimation method, which comprises the following steps: S1, acquiring sensor data of a gyroscope, a magnetometer and an accelerometer, and respectively acquiring angular velocity, magnetic field direction and gravitational acceleration information; s2, angle information is obtained, and magnetometer and accelerometer sensor data are converted into attitude information; s3, carrying out weighting processing on the angle information and the attitude information through a fading memory weighting method and a limited memory weighting method; S4, carrying out filtering fusion on the weighted angle information and attitude information through an RAEKF filtering fusion algorithm; s5, an adaptive factor and a robust factor are introduced into the RAEKF filtering fusion algorithm; s6, outputting attitude angle estimation; according to the method, the theoretical contradiction that long-term drifting and stability cannot be achieved at the same time is fundamentally solved, stable precision is kept under abnormal data interference, and the robust performance is remarkably improved.

An unidentified aerial phenomena field disturbance detector includes an accelerometer configured to measure a gravitational field surrounding the unidentified aerial phenomena field disturbance detector; a magnetometer configured to measure a magnetic field surrounding the unidentified aerial phenomena field disturbance detector; a microwave frequency detector configured to measure a specific band of microwave frequencies surrounding the unidentified aerial phenomena field disturbance detector; a controller; and an optical indicator configured to optically communicate information to a user of the unidentified aerial phenomena field disturbance detector. The controller determines a change in the gravitational field surrounding the unidentified aerial phenomena field disturbance detector when generates gravitational field values are outside a predetermined range of non-event field values. The controller controls the optical indicator to optically communicate the determined change in the gravitational field surrounding the unidentified aerial phenomena field disturbance detector.

The invention discloses an aeromagnetic compensation method and system for a large unmanned aerial vehicle, and relates to the technical field of aeromagnetic exploration compensation, and the method comprises the steps: obtaining a compensation matrix through an inertial navigation system, a GPS and a three-axis fluxgate magnetometer of the large unmanned aerial vehicle based on a T-L model; and based on the compensation matrix, performing aeromagnetic compensation on the large unmanned aerial vehicle by increasing the maneuvering motion range of the large unmanned aerial vehicle and utilizing a compensation optimization algorithm. The large multi-load unmanned aerial vehicle is effectively compensated, and the actual use value of the large unmanned aerial vehicle is improved.

The invention relates to the technical field of quantum sensing, and discloses a quantum magnetometer device based on diamond NV color center photoelectric detection magnetic resonance. Wherein the optical path module performs optical excitation and imaging positioning on a diamond sample through a laser and an objective lens. The circuit module integrates a microwave source, a lock-in amplifier, a low-noise current amplifier and a programmable power supply, applies a microwave field and bias voltage to a microwave antenna and an interdigital electrode on the surface of a sample respectively, and collects sample dependency photocurrent signals. And the operation module realizes automatic control and data processing of the system. According to the device, NV color center spin state information is converted into a photocurrent signal through a photoelectric detection magnetic resonance mechanism, an amplitude or frequency modulated signal is demodulated by using a lock-in amplification technology, information of a detection magnetic field is obtained through a high signal-to-noise ratio photoelectric detection magnetic resonance spectrum, and the sensitivity of the magnetic field is evaluated. Magnetic resonance signals are detected in an all-electricity mode, a complex optical system of traditional fluorescence detection is simplified, and the device has the advantages of being compact in structure, easy to integrate, high in measurement sensitivity and the like.

The invention discloses a quantum magnetometer device based on a diamond nitrogen-vacancy color center. The quantum magnetometer device comprises a laser emission unit used for generating a 532nm laser beam based on a laser trigger signal; the beam shaping unit is used for focusing the laser beam to the diamond sample; the diamond sample comprises an NV color center array with specific depth on the surface or in the diamond sample, and electrons in NV color centers are excited based on laser beams to transition and generate fluorescence; the fluorescence collection unit is used for separating exciting light from 650-800nm fluorescence signals and converting the fluorescence signals into multi-channel electric signals; the microwave radiation unit is distributed around a diamond sample space and emits three independently regulated microwave frequencies at the same time; and the control and processing unit is used for receiving and processing the multi-channel electric signals in real time and analyzing magnetic field parameters based on the optical detection magnetic resonance spectral line. Synchronous measurement of a three-dimensional magnetic field is realized, and the limitation of single-axis measurement of a traditional NV magnetometer is broken through.

The invention relates to the technical field of quantum precision measurement, and provides a quantum magnetometer which comprises a solid-state spinning color center probe, a microwave module, a laser module, a photoelectric detection module, a lock-in amplification module, a PID module and a data processing module. According to the scheme, an ODMR sweep frequency spectrum line does not need to be drawn when the magnetic field is measured every time, tracking of the changing magnetic resonance frequency can be rapidly achieved through comparison of the target data and the demodulation result, the time for obtaining the new magnetic resonance frequency is greatly shortened, and the magnetic measurement efficiency of the quantum magnetometer is improved.

The invention discloses a self-adaptive recognition method and system based on a four-bar linkage single station machine motion trail, and belongs to the technical field of motion trail recognition. The method comprises the following steps: acquiring a multi-source synchronous data stream, detecting a peak interference frequency, adjusting an adaptive notch filter in real time, obtaining a pure geomagnetic field signal, calculating the equivalent length of a connecting rod by using angle and force data, and establishing a kinematics equation to solve track coordinates; establishing a magnetic field space gradient tensor model through a magnetometer array, fitting a nonlinear mapping relation between an angle and a gradient tensor, and generating a metal magnetic interference compensation model; judging a motion mode and dynamically adjusting filter parameters; constructing a fast and slow dual-time scale filter to fuse multi-source information, and introducing a fading factor to prevent divergence; a future angle is predicted by using a long-short-term memory neural network to serve as a virtual observed quantity to enhance the fault-tolerant capability; and optimizing the reconstruction trajectory through multiple physical constraints. According to the method, the track identification precision, the anti-interference capability and the system robustness are remarkably improved.

A method for making axial magnetic field measurements in a downhole tool includes evaluating axial magnetic field measurements to determine a magnetic interference offset and removing the magnetic interference offset to obtain compensated axial magnetic field measurements.

The invention discloses a diamond low-frequency current measurement method with nonlinear response to magnetic field intensity, which is characterized in that two coils are wound on a magnetic flux collector with a communicated structure, a high-frequency (800Hz) high-voltage (7V) driving current is injected into one of the coils, a magnetic field generated by the coil is amplified through the magnetic flux collector and guided to an area where an NV color center magnetometer is located, and the NV color center magnetometer is located; and the signal is driven to enter a nonlinear response interval in the demodulated ODMR spectrum. A weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal is injected into the other coil, amplitude modulation is performed on the weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal by using the same frequency as the driving current, and the weak (1-50mV) to-be-measured low-frequency (0.1-10Hz) current signal is amplified by the magnetic flux collector and guided to the NV The microwave frequency is locked at the maximum slope point of the ODMR frequency spectrum through CW-ODMR phase-locked amplification, so that the relationship between the change of the red fluorescence signal intensity and the size of the external magnetic field is obtained, and the signal intensity of the low-frequency current magnetic field to be measured is measured according to the relationship.

The embodiment of the invention discloses a leveling robot positioning and navigation method based on multi-sensor fusion, and the method comprises the steps: obtaining IMU data through error calibration, and the error calibration comprises gyroscope error calibration, accelerometer error calibration and magnetometer error calibration; based on the IMU data, a strapdown inertial navigation system is adopted for calculation, and navigation parameters are obtained; estimating and correcting the error of the strapdown inertial navigation system by using UWB data through a combined filter; the fault of the IMU and the fault data of the IMU can be corrected in time, and the error of the strapdown inertial navigation system is estimated and corrected by using the UWB data through the filter, so that the strapdown inertial navigation system keeps high-precision navigation capability.

The invention provides a geomagnetic compensation and bias magnetic field generation system and method for cold atom interference. The system comprises a triaxial magnetometer, a triaxial Helmholtz coil, a voltage-controlled current source and an FPGA regulation and control module. The three-axis magnetometer is used for collecting space magnetic field data at a plurality of monitoring positions in the space where the three-axis Helmholtz coil is located in real time; the FPGA regulation and control module is used for calculating control voltage data required by the voltage-controlled current source according to a target magnetic field and any space magnetic field data collected by the three-axis magnetometer in each sampling period, controlling coil current transmitted to the three-axis Helmholtz coil, and outputting the coil current to the three-axis Helmholtz coil. And loop iteration is carried out until the three-axis Helmholtz coil generates a target magnetic field at a plurality of monitoring positions, wherein the target magnetic field is a near-zero magnetic field in the X / Y direction, and the magnetic field intensity in the Z direction is constant and is a non-zero value. The device can respond to the change of the environmental magnetic field in real time, and provides a stable and accurate magnetic field environment for the cold atom interference test on the basis of compensating the influence brought by the geomagnetic field.

The invention provides a calibration device of a bias magnetic field and a measurement device and method of an absolute magnetic field, and the calibration device comprises a magnetometer which is used for implementing ODMR measurement and outputting magnetic field vector data; the rotating table is used for placing at least a probe part in the magnetometer, and after placing, the xyz coordinate axis of the diamond is aligned with the x'y'z 'rotating coordinate axis of the rotating table one by one; the control module is used for controlling the rotary table to rotate by 180 degrees around the x axis, the y axis and the z axis from the initial position; and the data processing module is used for calculating to obtain a bias magnetic field vector # imgabs5 # according to the magnetic field vector # imgabs0 # of the initial position output by the magnetometer, the magnetic field vectors # imgabs1 #, # imgabs2 # and # imgabs3 # after the initial position respectively rotates around the x axis, the y axis and the z axis by 180 degrees, and a formula # imgabs4 #, wherein the magnetic field vectors # imgabs0 #, the magnetic field vectors # imgabs1 #, # imgabs2 # and # imgabs3 # are obtained by rotating around the x axis, the y axis and the z axis by 180 degrees from the initial position by 180 degrees. The method can achieve the calibration of the bias magnetic field, is high in precision based on the precision measurement technology of the diamond NV color center, and can improve the measurement precision when being applied to the calculation of an absolute magnetic field.

The invention discloses an imaging type optical system for a high-intensity magnetic field Fourier infrared spectrum device, which comprises a solenoid superconducting magnet tubular sample cavity for the high-intensity magnetic field Fourier infrared spectrum device, and a non-magnetic damping sleeve arranged in the solenoid superconducting magnet tubular sample cavity, a non-magnetic mirror surface gold-plated optical waveguide is arranged at the upper part in the non-magnetic damping sleeve, a Faraday optical module is arranged at the lower part in the non-magnetic damping sleeve, and an adjustable sample bearing table and a low-temperature thermometer and magnetometer assembly are arranged below the non-magnetic mirror surface gold-plated optical waveguide; the non-magnetic mirror surface gold-plated optical waveguide comprises a light-in waveguide and a light-out waveguide, and the Faraday optical module integrates a switchable reflection module and a transmission module which are respectively adapted to different strong magnetic field Fourier infrared spectrum measurement requirements. The optical efficiency of the high-intensity magnetic field Fourier infrared spectrum device is improved, the problems of high optical loss and scattering interference of a traditional device are solved, and the signal-to-noise ratio is increased.

The invention discloses a positioning and attitude determination method and device integrating Beidou navigation and inertial navigation, and relates to the technical field of attitude measurement, the method comprises the following steps: correcting a gyroscope error by using an accelerometer error and a magnetometer error based on proportional integral operation to obtain a gyroscope output after error correction; using the gyroscope output after error correction to update the quaternion of the moving object, using the quaternion to calculate the attitude, and obtaining the attitude angle of the moving object under the carrier coordinate system calculated through inertial navigation; moving object positioning and attitude determination calculation is carried out by using the time difference of the satellite carrier phase double differences between the double BDS receivers and the different groups of satellites, and the attitude angle of the moving object under a carrier coordinate system calculated through Beidou satellite navigation is obtained; and performing Kalman filtering fusion on the attitude angle calculated by inertial navigation and the attitude angle calculated by Beidou satellite navigation to obtain a final attitude angle. The method can adapt to a dynamic environment, and the attitude measurement precision is improved.

A system for measuring magnetic fields from a subject's organ comprises a plurality of unshielded magnetometers in a three-dimensional arrangement and an electromagnetic source. The system is configured to simultaneously collect, via each magnetometer of the plurality of magnetometers, (i) a biomagnetic field from at least a portion of the subject's organ, (ii) an electromagnetic signal from the electromagnetic source, and (iii) a background magnetic field. The system is configured to synchronize a plurality of magnetic signals collected by the plurality of magnetometers according to the electromagnetic signal from the electromagnetic source. The system is configured to output a signal indicative of the collected biomagnetic field and the background magnetic field in accordance with the synchronizing. The system is configured to operate without magnetic shielding.

The invention relates to the technical field of inclination measurement coordinate correction, in particular to a multi-sensor fusion inclination measurement coordinate correction method. According to the inclination measurement coordinate correction method based on multi-sensor fusion, the forced constraint in the direction of the centering rod is eliminated fundamentally, so that a measurer can place the centering rod at will, tedious alignment operation is not needed, the operation difficulty is remarkably reduced, and the measurement efficiency and precision are improved; therefore, the correction method has better convenience and wider adaptability. Measurement data of the magnetometer and the gyroscope are calculated in a fusion mode through a Kalman filtering algorithm in the processing unit, the short-term high precision of the gyroscope and the long-term stability of the magnetometer are fully utilized, noise and instantaneous interference are effectively restrained, the high-precision true north azimuth angle is directly output, the limitation of a simple average method is avoided, and the real north azimuth angle is obtained. According to the correction method, the overall measurement precision and the system robustness are remarkably improved, so that the correction precision of the coordinates of the target point location is greatly improved.

The invention discloses an underground pipeline internal integrated positioning method based on multi-sensor cooperation, and belongs to the technical field of navigation positioning. The method comprises the following steps: correcting a yaw angle based on a magnetometer, performing attitude compensation on a Z axis through the magnetometer, and effectively eliminating an integral error caused by performing attitude calculation only depending on a gyroscope; on the basis of displacement estimation of multi-redundancy odometers, four wheels at the bottom of the robot are each provided with a motor encoder, the four odometers can complement one another, and position estimation of the IMU is effectively corrected through more reliable data; based on data fusion of bidirectional unscented Kalman filtering, non-linear errors are avoided through unscented Kalman filtering, and a smooth trajectory with higher precision can be obtained in cooperation with bidirectional filtering. According to the invention, the underground pipeline track positioning precision in a satellite signal rejection environment can be effectively improved.

The present disclosure relates to methods, systems, and apparatus, including computer programs encoded on computer storage media, for denoising magnetic measurements. An example method includes obtaining, using a plurality of magnetometers of a magnetically unshielded device, noisy magnetic measurement data of a magnetic field at least partially caused by an organ of a subject; obtaining, using one or more inertial measurement units (IMUs) of the magnetically unshielded device, a motional measurement of the plurality of magnetometers; determining cleaned magnetic field data based at least in part on the noisy magnetic measurement data and the motional measurement data; and taking an action based at least in part on the cleaned magnetic field data.

The invention relates to the field of quantum measurement, and provides a CPT magnetometer magnetic measurement signal-to-noise ratio improving method and device based on a differential EIT-EIA signal. The CPT magnetometer solves the problem that a traditional CPT magnetometer is low in magnetic measurement signal-to-noise ratio due to the influence of environment temperature noise, laser stability and atomic gas chamber buffer gas. According to the main scheme, the CPT magnetometer comprises a laser generation module, a reference correction module, a differential detection module, a non-magnetic heating module and a signal processing module. The laser generation module generates reference / measurement double beams through the laser and the polarization regulation and control assembly; the reference correction module performs polarization conversion and optical path regulation and control on the reference light; the differential detection module divides the measurement light into two paths by adopting polarization beam splitting, the first path is subjected to polarization state conversion through an interference light path after frequency modulation, the second path is converted into circularly polarized light after optical fiber transmission, the two paths of light are coupled and then enter an atomic gas chamber for interaction, and differential detection is realized through a polarization beam splitting detector; and the non-magnetic heating module accurately controls the temperature of the air chamber by using a non-contact photo-thermal conversion technology.