452 results about "Field strength" patented technology

The invention discloses an experimental calibration method based on multi-sensor signal fusion processing, particularly relates to the field of data analysis, and comprises the steps of a stepped confrontation disturbance protocol, data stream processing and real-time analysis, and multi-stage logic judgment and calibration execution. A stepped confrontation disturbance protocol is created for the first time, potential errors of the sensor are excited in real time and corrected in a closed loop mode under the condition that system operation is not interrupted, and a traditional shutdown calibration mode is thoroughly replaced; a multi-stage disturbance defense system is constructed, and composite interferences such as spectrum aliasing, overload distortion and signal-to-noise ratio attenuation caused by electromechanical thermal multi-physical field strong coupling are effectively suppressed; laser space calibration and dynamic rigidity modulation technologies are fused, and space drift errors caused by deformation of the mounting base and mechanical loosening are accurately diagnosed and compensated. Finally, long-term precision stability and data fusion reliability of the multi-source sensor under complex working conditions are achieved.

The invention discloses a power distribution network line fault positioning detection system, and relates to the technical field of power distribution network fault detection. The system comprises a mixed information acquisition layer, a fault feature extraction layer, an intelligent diagnosis layer and a fault positioning layer. The mixed signal acquisition layer comprises a high-frequency transient wave recording unit, a power frequency measurement unit, a wireless pulse sensor and a distributed optical fiber temperature measurement unit; the fault feature extraction layer comprises a time-frequency analysis module, a preprocessing module and a three-dimensional feature vector module; the intelligent diagnosis layer comprises a convolutional attention network, a space-time diagram neural network and a transfer learning module; the fault positioning layer comprises a particle swarm module and a fuzzy reasoning module. According to the invention, data information of the cable is acquired through the mixed information acquisition layer, a video analysis window function is dynamically matched with signal characteristics, a time domain graph scale, a frequency domain resonance component and a space field intensity gradient are constructed, fault diagnosis and positioning are carried out by using the intelligent diagnosis layer, and the fault positioning detection efficiency of the power distribution network is improved.

The invention discloses a response time conduction type testing device and method for a radio frequency channel protection device. The response time conduction type testing device comprises a transient field intensity generating device, an isolator, a directional coupler, a first attenuator, a second attenuator, a third attenuator, a first power meter, a second power meter, a high-speed oscilloscope, a vector network analyzer and a radio frequency channel protection device to be tested. According to the method, the response performance of the protection device under the influence of the transient strong field can be comprehensively, safely and accurately evaluated, the amplitude limiting function of the protection device can still be effectively exerted under the action of the transient strong field with an extremely narrow rising edge, and then subsequent devices, circuits and equipment are prevented from being damaged.

The invention relates to the technical field of connector detection, and discloses a reliability detection method based on a connector. The method comprises the following steps: acquiring real-time monitoring data of a multi-channel electrical sensor of a connector in a power-on state, wherein the real-time monitoring data covers a contact impedance fluctuation sequence, temperature rise gradient distribution and an electromagnetic leakage intensity spectrum; performing time-frequency domain fusion processing on the monitoring data, and extracting dynamic characteristic parameter sets such as impedance attenuation rate, heat conduction lag coefficient and field intensity distortion factor of each contact point; then, according to the parameter space distribution difference, a three-dimensional degradation model comprising a material performance attenuation layer, a contact surface deformation topology layer and an insulating medium loss layer is constructed; coupling mechanical stress and electric heating field intensity distribution based on the model, and generating life prediction indexes of each region; and finally, completing reliability grading according to the indexes, and outputting a detection report with key failure position marks. According to the method, comprehensive and accurate evaluation of the reliability of the connector is realized, and an effective technical path is provided for quality control of the connector.

The invention provides a keyless entry system calibration method and apparatus, an electronic device and a medium. The method comprises the steps of determining a first region and a second region according to a to-be-calibrated function of a target antenna, a first field intensity threshold and a second field intensity threshold; the first field intensity threshold value is greater than the second field intensity threshold value; the second area comprises the first area; based on the position of the key in the expansion area, determining a first field intensity measurement value and a second field intensity measurement value corresponding to the position; the first field intensity measurement value is the field intensity measurement value of the key relative to the target antenna, and the second field intensity measurement value is the field intensity measurement value of the key relative to at least one other antenna on the vehicle; the expansion area is an area which is in the second area and is not in the first area; determining a judgment rule set according to the to-be-calibrated function; and determining a target field intensity threshold value corresponding to the to-be-calibrated function according to the judgment rule set, the first field intensity measurement value and the second field intensity measurement value.

The utility model discloses a crane equipment near-electricity alarm based on field intensity detection in the technical field of near-electricity alarms, which comprises a crane, a signal receiving component is mounted at one end of a crane body of the crane, an induction transmitting module is arranged at one end of a suspension arm of the crane, and the signal receiving component comprises a signal receiving module. The signal receiving module is in electric signal connection with the induction transmitting module, a supporting base is installed at the bottom of the signal receiving module, the safety protection design in the signal receiving module effectively reduces pollution and damage of the external environment to key parts of the equipment, long-term stable operation of the equipment is guaranteed, and the dust removing piece arranged in the protection part can effectively remove dust in the equipment. According to the near-electricity alarm designed in the scheme, impurities accumulated on the explosion-proof glass can be regularly cleaned through cooperation with the guide sliding groove, the clear display effect is ensured, sight blocking caused by dust accumulation is reduced, the safety and reliability in the operation process are improved, and potential safety hazards can be effectively reduced in an electric power construction site.

A system and method for measuring and mapping electromagnetic field strength using an unmanned aerial vehicle (UAV) equipped with a field strength indicator. The UAV records signal power levels while tracking its position via GPS, transmitting data in real-time to a ground station. The ground station software generates detailed maps and charts visualizing antenna signal propagation. Users can customize measurement parameters to achieve desired resolution and granularity. The system and method provide an efficient and automated method for assessing antenna performance across various azimuths and elevations.

The invention discloses a ship electromagnetic environment prediction method based on a deep forest model, and relates to the technical field of electromagnetic compatibility and antennae, and the method comprises the steps: converting the coordinates of each point of given data (simulation data) into a global rectangular coordinate relative to a main ship body, and obtaining an array rectangular coordinate of each point relative to an array plane; converting the array rectangular coordinates of the points relative to the array plane into relative array spherical coordinates of the points when the antenna attitudes are different; the original global rectangular coordinates, the relative array spherical coordinates, the azimuth angle and the pitch angle of each electromagnetic environment simulation point and the logarithmic transformation values of the field intensity values corresponding to the points are constructed into a feature combination of electromagnetic environment prediction; constructing a deep forest model, and training and obtaining optimal hyper-parameters of the model by using electromagnetic environment simulation data; performing coordinate conversion and feature combination on the coordinates of the spatial points to be predicted; obtaining a model prediction value; and obtaining a field intensity value under the original scale. By means of the method, prediction of the electromagnetic environment under a certain simulation working condition can be completed within a very short time.

The invention relates to a basin-type insulator noise reproduction method and system, computer equipment, a computer readable storage medium and a computer program product. The method is applied to a basin-type insulator noise reproduction system. The basin-type insulator noise reproduction system comprises a basin-type insulator, an M-element antenna array and a data acquisition system. The method comprises the following steps: acquiring target noise data of the basin-type insulator based on a data acquisition system; obtaining an expected radiation waveform and expected field intensity distribution of the M-element antenna array based on the basin-type insulator target noise; according to the expected radiation waveform and the expected field intensity distribution of the M-element antenna array, calling a phase regulation and control model to generate an excitation signal; and adopting the excitation signal to drive the M-element antenna array, and synthesizing a basin-type insulator to reproduce noise. By adopting the method, the noise reproduction of the basin-type insulator can be realized.

The invention relates to the technical field of electromagnetic simulation, in particular to a W-band antenna pointing angle simulation analysis method, which comprises the following steps: acquiring the size of a W-band antenna and the form of a radiation unit, extracting main lobe curvature and feed matching characteristics, identifying a main lobe edge interference path, and adjusting a reflection phase to form a dynamic reflectivity boundary. Dividing tetrahedron and hexahedron grids to evaluate polarization consistency, optimizing a field intensity relationship between a main lobe and a side lobe, screening an angle interval, and obtaining a directional angle correction parameter. According to the invention, the specific size and form of the antenna are acquired, the curvature distribution of the main lobe coverage area and the matching relation with the feed structure are deeply analyzed, and the reflection intensity difference between the main lobe path and the side lobe path is monitored, so that the pointing precision and the coverage efficiency of the antenna are effectively improved; according to the antenna design, the performance is ensured, the specific area can be optimized, and the predictability and the stability of the antenna performance are remarkably improved.

The invention discloses a signal enhancement method and device in an industrial plant area, and relates to the field of wireless communication, and the method comprises the steps: firstly, obtaining complete channel state information, and guaranteeing that all decisions are based on real channel characteristics instead of theoretical assumptions; and secondly, if the complete channel state information does not meet the target QoS demand quantization parameter, maximizing a receiving signal to interference plus noise ratio and meeting the target QoS demand are taken as optimization targets, an optimization result is obtained based on channel field intensity distribution information of a preset digital twin model, and finally, the optimization result is controlled and executed to form closed-loop feedback. According to the method, optimization is carried out based on channel field intensity distribution information of a unit space in a digital twin model, and a complex problem needing to be solved by a high-dimensional iterative solution algorithm in related technologies is converted into table lookup and interpolation operation based on space coordinates, so that the calculation complexity is remarkably reduced, the time for obtaining an optimization result is greatly shortened, and the calculation efficiency is improved. Therefore, the time when the terminal is in a poor-quality signal state is greatly reduced.

The invention discloses a high-power stepless magnetic damping device and a power control method thereof.The high-power stepless magnetic damping device comprises a magnetic resistance magnetic core mechanism, the magnetic resistance magnetic core mechanism achieves control over high-power stepless magnetic damping according to the electromagnetic damping principle, regulation and control response is fast, continuity of constant-power output is guaranteed, and the high-power stepless magnetic damping device is suitable for large-power stepless magnetic damping. And a circle of Halbach magnet array formed by reinforcing magnets is arranged, so that the field intensity in the unit direction is enhanced, and the generation of high-power magnetic damping is realized. According to the power control method, a static Kalman data fusion updating model is introduced for power updating, speed and accuracy are balanced, a PWM signal is output through a PID controller to adjust the input current of a control coil, and therefore the size of a magnetic field is controlled, control over the size of magnetic damping is achieved, stepless regulation and control are achieved, and the control precision is improved. Therefore, stable output of constant power is ensured.

The invention belongs to the technical field of transformer substation engineering monitoring, and relates to a transformer substation engineering monitoring method based on intelligent perception, which dynamically generates a hoisting track envelope space containing a specified crane boom body and a hoisting object based on historical action inertia characteristics, current operation target constraints and real-time position feedback. Associating hoisting track envelope spaces of other cranes on a substation site, calibrating an envelope space intersection domain as a tangible collision risk domain, synchronously monitoring electromagnetic field intensity space distribution of an electric field source of the substation, and dynamically calculating a safety spacing margin threshold value between the tail end of a specified crane suspension arm and the nearest electric field source based on a field intensity gradient change rate and suspension arm pose parameters; and the nearest electric field source space coverage domain smaller than the margin threshold value is calibrated as an invisible collision risk domain, and when the specified crane enters the tangible collision risk domain or the invisible collision risk domain, a graded early warning signal is triggered, so that the application degree and precision of hoisting collision monitoring of the crane of the transformer substation are remarkably improved.

A sensor element is for testing a planar data carrier with a spin resonance feature. The sensor element includes a magnetic core having an air gap into which the planar data carrier can be inserted for testing purposes, a polarization device for generating a static magnetic flux in the air gap, and a resonator device for exciting the spin resonance feature of the data carrier to be tested in the air gap. The resonator device has at least two stripline resonators positioned at different positions in the air gap. The polarization device generates an in-homogeneous magnetic flux in the air gap so that the static magnetic flux has a first field strength at the position of a first stripline resonator and a second, different field strength at the position of a second stripline resonator.

The invention provides a lightning protection device current leakage detection method and system, and the method comprises the steps: firstly determining equivalent uniform field response signals corresponding to a rotating electromagnetic field at different rotating moments, and dividing the surface of a lightning protection device into a plurality of current detection blocks; the field intensity coupling relation between the surface of the lightning protection device and the detection probe in the detection probe array is determined according to the equivalent uniform field response signal corresponding to the rotation moment; determining a current density inversion field of the surface of the lightning protection device at the rotation moment by combining the frequency domain characteristics of the equivalent uniform field response signal corresponding to the rotation moment through a field intensity coupling relationship; and generating a current density topological graph of the leakage current of the lightning protection device based on all the density inversion fields, and positioning the leakage current position of the lightning protection device according to a current density abnormal region in the current density topological graph. By adopting the scheme of the invention, the influence of the complex geometric structure of the lightning protection device on the space positioning of the surface leakage current can be reduced.

The invention provides a regional electromagnetic intelligent evaluation method and system based on spectral entropy weighting, and the method comprises the following steps: collecting electromagnetic spectrum data and the motion state of a patrol vehicle, and constructing a virtual aperture data matrix through the motion information; space covariance analysis and subspace projection are carried out on the matrix, multipath scattering interference is separated and eliminated, and a pure field intensity sequence is obtained through reconstruction. By calculating the normalized spectrum entropy of the Doppler power spectrum of the pure field intensity sequence, an inverse proportion weight coefficient representing the signal confidence is generated; and weighting the weight to a pure field intensity sequence, and mapping the pure field intensity sequence to a geographic space. And dynamically adjusting the density of the evaluation grid according to the field intensity gradient, and finally carrying out weighted centroid calculation based on inverse proportion weight to obtain a regional electromagnetic environment evaluation result. According to the method, the technical problem that a regional evaluation result is not accurate due to the fact that multipath components cannot be separated and single-point data quality cannot be evaluated in traditional mobile patrol is solved.

The invention discloses a multi-channel frequency modulation signal real-time monitoring system which comprises at least one monitoring node and a remote cloud platform. The monitoring nodes simultaneously receive multiple paths of frequency modulation signals through the multi-channel radio frequency receiving unit, the signal processing unit demodulates and detects multiple quality parameters such as field intensity, signal-to-noise ratio, frequency offset and multipath interference, the main control unit generates alarm information, and finally the alarm information is uploaded to the cloud platform through the communication unit integrated with 4G / 5G and Wi-Fi. And the cloud platform is responsible for storing and analyzing data and pushing alarms and information display to the authorized user terminal. According to the invention, a multi-core DSP parallel processing architecture, dual-path power supply and battery redundancy power supply and multi-parameter association intelligent alarm logic are adopted, cloud networking management is realized, and the problems of few monitoring channels, low efficiency, insufficient intelligent degree and difficult remote operation and maintenance in the prior art are solved. Therefore, efficient, reliable and intelligent remote monitoring of multi-channel FM signals is realized.

The absorber is formed by periodically arranging a plurality of absorption structure units, each absorption structure unit comprises a SiO2 substrate, a Ti metal layer and two Si3N4 regular hexagonal prisms which are coaxially arranged from bottom to top, and the embedded body which is coaxially arranged in the Si3N4 regular hexagonal prism at the bottom layer; the embedded body comprises an MgF2 regular hexagonal prism on the outer layer, a Cr metal circular ring on the middle layer and a TiO2 regular hexagonal prism on the inner layer. When the MgF2 regular hexagonal prism is internally tangent to the Si3N4 regular hexagonal prism at the bottom layer, the Cr metal circular ring is internally tangent to the MgF2 regular hexagonal prism, the TiO2 regular hexagonal prism is internally tangent to the Cr metal circular ring, and the top point of the bottom surface of the Si3N4 regular hexagonal prism at the top layer coincides with the midpoint of the edge of the top surface of the Si3N4 regular hexagonal prism at the bottom layer, it is ensured that an electromagnetic field / sound field is uniformly coupled between structural units, energy leakage or too high local field intensity is avoided, and the electromagnetic field / sound field is effectively improved. The coverage range of absorbed waves is 800-2800nm, and is not influenced by incident energy polarization, so that the application range is wide; structural unit layout facilitates accurate alignment, manufacturing difficulty and cost are reduced, and mass production, popularization and application are easy.

The invention discloses a non-contact wire ice edge corona wind and leakage current measuring device and method, and relates to the field of corona wind and leakage current measurement. An icicle is fixed at the geometric center of the wire; the measuring assembly is used for detecting corona wind and leakage current generated by the wire; the automatic lifting platform is used for controlling the vertical distance between the measuring assembly and the icicle; the invention provides the non-contact comprehensive measuring device for the first time, the corona wind speed and the leakage current can be synchronously measured, the discharge phenomenon can be observed in real time, the technical blank is filled, and the measuring device is high in practicability and high in practicability. Through the transparent acrylic shell, the tip discharge phenomenon of the icicle can be directly observed, real-time recording of the discharge form in the experiment process is facilitated, the shell fixes a wire at the geometric center, it is ensured that the icicle is vertically downward, uneven field intensity distribution is avoided, and a stable electric field environment is provided for measurement.

The invention relates to the technical field of power system communication, in particular to a transformer substation wireless network coverage area optimization method based on artificial intelligence, which comprises a data acquisition module, a feature fusion and extraction module, an intelligent decision model module, a closed loop optimization execution module and a dynamic adaptive module, and all the modules work cooperatively through external communication interfaces. According to the application, signal quality is directly reflected through wireless signal sensing data (RSSI / SNR / channel occupancy rate), spatial topological data (three-dimensional point cloud model) accurately locates the position relationship between the AP and the equipment, electromagnetic interference data (spectrum characteristic / field intensity distribution) quantifies the attenuation influence of the high-voltage equipment on the signal, and service demand data (time delay sensitivity level) distinguishes the priority of key services, so that the service quality of the high-voltage equipment is improved. Meteorological data (temperature and humidity) is used for correcting propagation loss in rainy and foggy weather, and coverage bottlenecks (such as interference main lobe direction and signal shielding in equipment dense areas) can be more comprehensively identified through multi-source data fusion.

The invention relates to the technical field of magnetic material detection, in particular to a magnetizing body performance detection method and system and a medium, and the method comprises the steps: constructing a directional coupling magnetic circuit, enabling a magnetic sensor to synchronously sweep along the length direction of a magnetizing chain, applying external excitation, collecting signals in real time, and detecting the performance of a magnetizing body through the convergence effect of the directional coupling magnetic circuit on leakage magnetic flux. In the scanning process, a leakage magnetic flux space distribution spectrum on the surface of a magnetizing chain is collected, signal feature analysis is conducted on the leakage magnetic flux space distribution spectrum, a local field intensity distortion area is recognized, a defect fingerprint feature vector is generated, the defect fingerprint feature vector is compared with a preset eligibility criterion threshold value, and the eligibility of the magnetizing chain is judged. Therefore, the performance of each magnet in the magnetizing chain is judged and analyzed, the detection sensitivity of early defects and recessive magnet performance degradation is effectively improved, and the signal-to-noise ratio of an unqualified magnet identification signal is improved.

The invention provides a frequency converter electromagnetic interference spectrum real-time monitoring and tracing method and device, and relates to the technical field of frequency converters, and the method comprises the steps: building a mapping relation between frequency converter operation state parameters and magnetic leakage point electromagnetic interference data; taking the operation state parameters of the frequency converter as excitation sources to be injected into an electromagnetic simulation space, and generating predicted interference spectrum and electromagnetic field distribution information in real time; according to the mapping relation, matching and comparing the predicted interference spectrum and electromagnetic field distribution information with the electromagnetic interference data, and comparing with a preset interference fingerprint database; and positioning field intensity space coordinates by combining the space magnetic field distribution of the electromagnetic interference data according to the interference spectrum characteristics, and generating an interference spectrum traceability result based on the interference spectrum characteristics, the field intensity space coordinates and predicted interference spectrum and electromagnetic field distribution information. According to the invention, the technical problem of low electromagnetic interference identification precision of the frequency converter in the prior art can be solved, and the technical effect of improving the electromagnetic interference identification precision is achieved.

The invention relates to the technical field of electromagnetic compatibility, and discloses a wireless radio frequency electromagnetic field immunity test method, which comprises the following steps of S1, generating a continuous wave radio frequency signal in a frequency band of 80MHz-6GHz through a programmable radio frequency signal generation device; s2, constructing an orthogonal polarization electromagnetic field in the radiation test area; s3, three-dimensional space field intensity distribution is monitored in real time based on the 16-channel digital probe array, and a space field intensity distribution cloud picture is generated; s4, synchronously monitoring performance parameters of the tested equipment through an optical coupler isolation acquisition channel; s5, using a slope type field intensity incremental method to increase the field intensity at a step length less than or equal to 1V / m; and S6, establishing a field intensity-performance incidence matrix, generating a three-dimensional electromagnetic vulnerability distribution map, and outputting an immunity grade index. A multi-system interference scene in a real complex electromagnetic environment can be simulated through a programmable radio frequency signal generating device and a time division multiplexing mechanism in combination with carrier frequency hopping and modulation depth gradual change.

The invention relates to the technical field of wireless positioning, and discloses a wireless personnel positioning method and system through a positioning tag card. The method comprises the following steps: acquiring an original measurement value of a multi-band signal in a positioning tag card, and extracting an interfered band combination based on the original measurement value; carrying out fluctuation modeling on the frequency band combination by adopting field intensity detection, generating a fluctuation feature vector, carrying out weather type classification based on the fluctuation feature vector, and determining a rainy day attenuation calculation mode; adjusting the signal intensity according to a rainy day attenuation calculation mode, obtaining adjusted signal intensity data, calculating a distance estimation value, and generating a distance parameter set; and performing triangulation positioning according to the distance parameter set, generating a real-time position coordinate, matching the real-time position coordinate with historical trajectory data, adjusting a compensation coefficient of the compensation model, and generating an optimized positioning result by using the adjusted compensation model. According to the invention, the continuity and accuracy of wireless positioning are improved.

The invention relates to the technical field of antenna testing, in particular to a large-field-intensity testing system and method based on a high-gain antenna. The test system comprises a radiation source generation device and a test assembly, and the radiation source generation device comprises a signal source used for generating an electric signal of a specific frequency; the power amplifier is used for amplifying the electric signal to a required level; the high-gain radiation antenna is used for converting the amplified electric signals into electromagnetic waves, controlling the energy of the electromagnetic waves to be focused in a specific direction and improving the electric field intensity in the specific direction; the test assembly comprises a receiving antenna which is used for capturing electromagnetic waves radiated by a high-gain radiation antenna at a preset position and converting the electromagnetic waves into electric signals to be tested; and the analysis device is used for analyzing the to-be-measured electric signal to measure the electric field intensity of the preset position. By adopting the scheme provided by the invention, the test cost can be effectively reduced and the operability and applicability of the test can be improved on the premise of ensuring the test precision.

The present invention discloses an experimental calibration method based on multi-sensor signal fusion processing, which specifically relates to the field of data analysis, including a step-by-step anti-disturbance protocol, data stream processing and real-time analysis, and multi-level logical judgment and calibration execution. The present invention pioneered a step-by-step anti-disturbance protocol, which stimulates and corrects the potential errors of sensors in real time without interrupting system operation, completely replacing the traditional shutdown calibration mode; constructs a multi-level disturbance defense system to effectively suppress complex interference such as spectrum aliasing, overload distortion, and signal-to-noise ratio attenuation caused by strong coupling of electromechanical and thermal multi-physical fields; integrates laser spatial calibration and dynamic stiffness modulation technology to accurately diagnose and compensate for spatial drift errors caused by deformation of the mounting base and mechanical loosening. Ultimately, the long-term accuracy stability and data fusion reliability of multi-source sensors under complex working conditions are achieved.

The invention relates to the technical field of wireless communication, and discloses an adaptive LDPC code coding method, system and device based on evaporation waveguide field intensity distribution, and a medium, and the method comprises the steps: obtaining the evaporation waveguide field intensity distribution in real time, and generating a field intensity distribution diagram; calculating a channel state parameter, and dynamically selecting a low-density parity check code rate according to the channel state parameter information; dynamic low-density parity check coding is adopted, and a sparse structure is adjusted through a check matrix, so that real-time switching of multi-code-rate low-density parity check codes is carried out; and a receiving end carries out decoding by adopting an NW-RBP decoding algorithm, defines a node updating rule, and dynamically schedules a node updating sequence through a residual error. According to the method, the bit error rate under a complex channel is reduced, and meanwhile, the reliable transmission efficiency of system data is improved.

A frequency source automatic test system disclosed by the present invention comprises a frequency spectrograph test main body, the lower part of the rear surface of the frequency spectrograph test main body is provided with a sealing frame, the rear side of the sealing frame is provided with a second magnet, a sealing cover and an annular sealing groove, and the second magnet is located at the inner side of the annular sealing groove. A waterproof sealing ring and a first magnet are arranged on one side of the sealing cover, the first magnet corresponds to the second magnet, the first magnet is located on the inner side of the waterproof sealing ring, and the waterproof sealing ring is matched with the annular sealing groove. The frequency source automatic test system can measure various characteristic parameters of radio frequency signals, including frequency, frequency selection power, bandwidth, adjacent channel power, modulation waveform, field intensity and the like. Therefore, the frequency spectrograph has higher flexibility and accuracy when processing complex signals; and the center frequency of the signal can be accurately measured, which is very important for the design and debugging of a wireless communication system.

The invention relates to the technical field of field intensity prediction, in particular to a medium-wave broadcast-based field intensity prediction method and system, and the method comprises the following steps: obtaining the environment space information of an emission source for medium-wave broadcast, and constructing an environment model of the emission source based on the environment space information; rasterizing the target area of the emission source based on the prediction model to form a plurality of grid receiving points; predictive control information is configured for the emission source based on the predictive model, and the predictive control information comprises a vernier and a selection frame chain corresponding to the vernier; driving the verniers to sequentially move in the target area along the propagation direction; the field intensity value of the vernier at each position is predicted based on the selection frame chain of the vernier, the grid points meeting the preset field intensity condition are connected to form the field intensity range contour, the field intensity range and the field intensity values of the grid points in the field intensity range are output to serve as the final prediction result, and the accuracy of field intensity prediction can be effectively improved.

The application discloses a near electric field alarm safety helmet and an alarm method for omnidirectional field intensity vector monitoring, and relates to the field of electric power safety protection. The safety helmet comprises an omnidirectional field intensity sensing array, a vector field signal processing module and an alarm module which are assembled on a safety helmet body. The omnidirectional field intensity sensing array comprises at least five electric field sensors which are arranged on the top of the safety helmet body and around the brim of the safety helmet body. The vector field signal processing module is used for acquiring electric field intensity components collected by the electric field sensors, and performing vector synthesis on the electric field intensity components to determine the spatial electric field intensity and the field source direction. The spatial electric field intensity is compared with preset safety threshold values and critical threshold values respectively to determine the alarm level of the position where the safety helmet is located. The alarm module is used for outputting corresponding alarm prompts according to the alarm level. The spatial electric field intensity and the field source direction are determined by synthesizing electric field intensity components in different directions, thereby solving the problem that the electric field detection result of the existing safety helmet is inaccurate.