Automatic calibration device and method for very low frequency-low frequency lightning locator

Abstract

The invention relates to the technical field of lightning position indicators, and discloses an automatic calibration device and method for a very low frequency-low frequency lightning position indicator. The device comprises a shielding cabin, an electric field radiation antenna, a magnetic field radiation antenna, a lightning signal simulation board and a test instrument. The interior of the shielding cabin is divided into two independent areas, the two radiating antennas are arranged in the shielding cabin, and a taking and placing window is arranged on the outer side of the shielding cabin. The electric field radiation antenna is of a parallel metal plate structure, and the magnetic field radiation antenna is of a Helmholtz coil structure; the lightning signal analog board is connected with the two radiation antennas through shielding cables, and the test instrument is respectively communicated with the lightning signal analog board and the lightning locator to be calibrated. An electric field antenna and a magnetic field antenna of a position indicator to be calibrated can be correspondingly placed in the two radiating antennas through the taking and placing windows. The device can realize the automatic calibration of the positioning instrument, guarantee the accuracy and reliability of calibration, improve the calibration efficiency, and adapt to the respective calibration requirements of the double antennas of the positioning instrument.

Description

Technical Field

[0001] This application relates to the field of lightning locator technology, specifically to an automated calibration device and method for a very low frequency to low frequency lightning locator. Background Technology

[0002] Very low frequency (VLF) to low frequency (LHF) refers to the electromagnetic wave band with a frequency range of approximately 300Hz to 300kHz. This band of electromagnetic waves has the characteristics of long propagation distance and strong penetration ability, making it the core operating frequency band for lightning locators to detect lightning discharge signals. It can effectively capture the electromagnetic pulse signals generated by lightning and achieve long-distance monitoring, adapting to the detection needs of lightning locators for different types of lightning signals. Existing calibration devices for lightning locators are mostly of general-purpose design, not adapted to the separate testing requirements of the electric and magnetic field antennas of VLF to LHF lightning locators. Furthermore, they are susceptible to external electromagnetic interference during calibration and lack an integrated automated calibration structure, resulting in insufficient calibration accuracy and cumbersome operation, making it difficult to meet the precise calibration requirements of this type of locator. Summary of the Invention

[0003] To solve or at least partially solve the above-mentioned technical problems, this application provides an automated calibration device and method for very low frequency to low frequency lightning location instruments.

[0004] In the first aspect, this application provides an automated calibration device for a very low frequency to low frequency lightning locator, including a shielded chamber, an electric field radiation antenna, a magnetic field radiation antenna, a lightning signal simulation board, and test instruments; The shielded cabin is divided into two independent areas, and the electric field radiation antenna and the magnetic field radiation antenna are respectively set in the two independent areas. The outside of the shielded cabin is provided with a window for taking out and putting in the lightning locator antenna. The electric field radiating antenna is a parallel metal plate structure, and the magnetic field radiating antenna is a Helmholtz coil structure. The lightning signal simulation board is connected to the electric field radiation antenna and the magnetic field radiation antenna respectively via shielded cables, and the testing instrument is communicatively connected to the lightning signal simulation board and the lightning locator to be calibrated respectively. The electric field antenna of the lightning locator to be calibrated can be placed inside the electric field radiating antenna through the pick-and-place window, and the magnetic field antenna of the lightning locator to be calibrated can be placed inside the magnetic field radiating antenna through the pick-and-place window.

[0005] Optionally, the magnetic field radiating antenna includes a pair of parallel coaxial circular coils, the pair of coils are interconnected and have the same current direction, the spacing between the pair of coils is the same as the coil radius, and a first stage is provided at the midpoint of the common axis of the pair of coils, the first stage being used to place the magnetic field antenna of the lightning locator to be calibrated.

[0006] Optionally, the electric field radiating antenna includes two parallel metal plates arranged opposite each other, and a second stage is provided between the two parallel metal plates. The second stage is used to place the electric field antenna of the lightning locator to be calibrated.

[0007] Secondly, this application also provides an automated calibration method for a very low frequency (VLF) to low frequency (LLF) lightning locator, applied to the apparatus described in any of the first aspects; the method includes the following steps: S1. Send a control command to the lightning signal simulation board, the control command being used to control the lightning signal simulation board to generate a test waveform signal; S2. Control the lightning signal simulation board to transmit the test waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively, control the electric field radiation antenna to convert the test waveform signal into a uniform electric field signal, and control the magnetic field radiation antenna to convert the test waveform signal into a uniform magnetic field signal. S3. Control the electric field antenna of the lightning locator to be calibrated to receive the uniform electric field signal and the magnetic field antenna to receive the uniform magnetic field signal. After processing the uniform electric field signal and the uniform magnetic field signal, transmit the processing result back to the test instrument. S4. Analyze the processing results to determine whether the performance indicators of the lightning locator to be calibrated meet the performance requirements, and generate a calibration report.

[0008] Optionally, in step S2, the test waveform signal includes a sine wave signal and a simulated lightning pulse waveform signal; The control command includes a waveform type selection command, which is used to control the lightning signal simulation board to switch and generate the corresponding test waveform signal. When the generated test waveform signal is a sinusoidal waveform signal, it is used to perform frequency response curve testing on the lightning locator; when the generated test waveform signal is a simulated lightning pulse waveform signal, it is used to perform time accuracy, amplitude accuracy, and characteristic quantity testing on the lightning locator.

[0009] Optionally, when the test waveform signal is a sinusoidal waveform signal, step S2 specifically includes: S21. Send the control command containing frequency band parameters to the lightning signal simulation board. The control command containing frequency band parameters is used to control the lightning signal simulation board to generate multiple sinusoidal waveform signals of different frequency bands according to the frequency band parameters. S22. Control the lightning signal simulation board to transmit the sinusoidal waveform signals of each frequency band to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into uniform electric field signals and uniform magnetic field signals of the corresponding frequency bands. S4 specifically includes: S41. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive uniform electric field signals and uniform magnetic field signals of each frequency band respectively, process them, and transmit the uniform electric field signals and uniform magnetic field signals of each frequency band back to the test instrument. S42. Organize the uniform electric field signal and uniform magnetic field signal data of each frequency band, determine the frequency point with the highest signal peak, and then search for the starting and ending frequency points on both sides where the peak value meets the preset conditions, and calculate the frequency response bandwidth of the lightning locator.

[0010] Optionally, when the test waveform signal is a simulated lightning pulse waveform signal, step S2 specifically includes: S23. Send the control command containing the amplitude reduction parameter to the lightning signal simulation board. The control command containing the amplitude reduction parameter is used to control the lightning signal simulation board to generate multiple sets of simulated lightning pulse waveform signals with successively decreasing amplitudes according to the amplitude reduction parameter. S24. Control the lightning signal simulation board to transmit each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into uniform electric field signals and uniform magnetic field signals of corresponding amplitudes. S4 specifically includes: S43. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process the detected uniform electric field signals and uniform magnetic field signals and transmit the processing results back to the test instrument, and stop the transmission when no signal can be detected. S44. Record the signal amplitude corresponding to the last received processing result, and determine the signal amplitude as the electric field sensitivity and magnetic field sensitivity of the lightning locator.

[0011] Optionally, when the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S25. Send the control command containing the pulse count and peak time interval parameters to the lightning signal simulation board. The control command containing the pulse count and peak time interval parameters is used to control the lightning signal simulation board to generate multiple sets of identical simulated lightning pulse waveform signals according to the pulse count and peak time interval parameters. S26. Control the lightning signal simulation board to transmit each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into corresponding uniform electric field signals and uniform magnetic field signals. S4 further includes: S45. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process them, and transmit the peak time data of each set of uniform electric field signals and uniform magnetic field signals back to the test instrument. S46. Calculate the mean and standard deviation of the peak times from the received multiple sets of peak time data, and determine the waveform time accuracy of the lightning locator.

[0012] Optionally, when the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S27. Send the control command containing the preset standard amplitude parameter to the lightning signal simulation board. The control command containing the preset standard amplitude parameter is used to control the lightning signal simulation board to generate a simulated lightning pulse waveform signal with a fixed waveform according to the preset standard amplitude parameter. S28. Control the lightning signal simulation board to transmit the simulated lightning pulse waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert it into a uniform electric field signal and a uniform magnetic field signal with corresponding standard amplitude; S4 further includes: S47. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, and transmit the measured amplitude data back to the test instrument. S48. Calculate the difference and ratio between the measured amplitude data and the preset standard amplitude parameter to determine the amplitude accuracy of the lightning locator.

[0013] Optionally, when the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S29. Send the control command containing pulse polarity and pulse width parameters to the lightning signal simulation board. The control command containing pulse polarity and pulse width parameters is used to control the lightning signal simulation board to generate simulated lightning pulse waveform signals with different polarities and different pulse widths according to the pulse polarity and the pulse width parameters. S210. Control the lightning signal simulation board to transmit various types of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into corresponding uniform electric field signals and uniform magnetic field signals. S4 further includes: S49. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, extract the polarity and pulse width characteristic data of uniform electric field signals and uniform magnetic field signals, and transmit the polarity and pulse width characteristic data back to the test instrument. S410. The received polarity and pulse width feature data are compared with the pulse polarity and pulse width parameters preset in the control command to determine the accuracy of the feature quantity recognition of the lightning locator.

[0014] The apparatus and method provided in this application have the following beneficial effects: The automated calibration device and method of this application utilizes two independent areas within a shielded chamber to house the electric field radiating antenna and the magnetic field radiating antenna respectively. This effectively prevents signal interference between the two antennas during operation, while the shielded chamber isolates external electromagnetic interference, ensuring the stability of the calibration environment. The electric field radiating antenna employs a parallel metal plate structure, and the magnetic field radiating antenna uses a Helmholtz coil structure, capable of generating uniform electric and magnetic field signals respectively. This adapts to the testing requirements of the electric and magnetic field antennas of the lightning locator to be calibrated, ensuring accurate signal reception. The testing instrument communicates simultaneously with the lightning signal simulation board and the lightning locator to be calibrated, uniformly realizing the transmission of control commands, reception and analysis of signal processing results without the need for additional equipment, thus automating the calibration process. The placement of the first and second stages provides stable placement positions for the magnetic field and electric field antennas of the locator, respectively, preventing antenna displacement during testing from affecting the calibration results. Different types of test waveform signals can be used to conduct targeted performance tests such as frequency response curves, time accuracy, and amplitude accuracy. Through specific test steps, the key performance parameters of the locator can be fully obtained, making the calibration results more comprehensive and reliable, and meeting the needs of product acceptance and periodic calibration of the lightning locator. Attached Figure Description

[0015] Figure 1 A schematic diagram of an automated calibration device for a very low frequency to low frequency lightning locator provided in this application embodiment; Figure 2 This is a schematic diagram of a magnetic field radiating antenna structure provided in an embodiment of this application; Figure 3 A schematic diagram of an electric field radiating antenna structure provided in an embodiment of this application; Figure 4 This is a schematic diagram of an automated calibration method for a very low frequency (VLF) to low frequency (LLF) lightning locator provided in an embodiment of this application.

[0016] Reference numerals in the attached diagram: 1. Shielded chamber; 2. Electric field radiating antenna; 21. Parallel metal plate; 3. Magnetic field radiating antenna; 31. Coil; 4. Lightning signal simulation board; 5. Test instrument; 6. Lightning locator; 7. First stage; 8. Second stage. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0018] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0019] See Figures 1 to 4 This application provides an automated calibration device for a very low frequency to low frequency lightning locator, including a shielded chamber 1, an electric field radiation antenna 2, a magnetic field radiation antenna 3, a lightning signal simulation board 4, and a testing instrument 5; The shielded cabin 1 is divided into two independent areas. The electric field radiation antenna 2 and the magnetic field radiation antenna 3 are respectively set in the two independent areas. The outside of the shielded cabin 1 is provided with a window for taking out and putting in the lightning locator antenna. The electric field radiating antenna 2 has a parallel metal plate structure, and the magnetic field radiating antenna 3 has a Helmholtz coil structure. The lightning signal simulation board 4 is connected to the electric field radiation antenna 2 and the magnetic field radiation antenna 3 respectively via shielded cables. The test instrument 5 is connected to the lightning signal simulation board 4 and the lightning locator 6 to be calibrated respectively. The electric field antenna of the lightning locator 6 to be calibrated can be placed inside the electric field radiation antenna 2 through the pick-up and put-in window, and the magnetic field antenna of the lightning locator 6 to be calibrated can be placed inside the magnetic field radiation antenna 3 through the pick-up and put-in window.

[0020] The Very Low Frequency (VLF) to Low Frequency (LHF) Lightning Locator Automated Calibration Device is a specialized equipment for calibrating the performance of lightning locators. Its core consists of a shielded chamber 1, an electric field radiation antenna 2, a magnetic field radiation antenna 3, a lightning signal simulation board 4, and testing instruments 5. These components work together to achieve automated calibration of the lightning locator. The shielded chamber 1 serves as the protective and separating element for the entire device. Its interior is physically divided into two independent, non-interconnected areas. This design primarily prevents interference between the signals generated by the electric field radiation antenna 2 and the magnetic field radiation antenna 3 during operation, ensuring independent transmission and stable output of the two signals. Simultaneously, the shielded chamber 1 itself possesses electromagnetic shielding capabilities, blocking electromagnetic signals from the external environment from entering the chamber, providing a stable testing environment free from external interference during calibration. An antenna placement window for the lightning locator 6 is located on the outside of the shielded chamber 1. The window's position corresponds to the two independent areas within the chamber, facilitating the operator to accurately place the antenna of the lightning locator 6 to be calibrated into the corresponding test area. Furthermore, the window does not affect the shielding effect of the shielded chamber 1 when closed.

[0021] The electric field radiating antenna 2 adopts a parallel metal plate structure. This design is based on the fundamental principle of electric field generation. By creating an electric field between two parallel metal plates, a uniform and stable electric field signal can be generated. This signal matches the characteristics of the electric field signal generated during a lightning strike, thus meeting the testing requirements of the electric field antenna of the lightning locator 6 to be calibrated. The magnetic field radiating antenna 3 adopts a Helmholtz coil structure. A Helmholtz coil is composed of coils arranged in a specific pattern. The magnetic field it generates has the characteristics of good uniformity and high stability, which can simulate the magnetic field signal generated during a lightning strike. This matches the receiving requirements of the magnetic field antenna of the lightning locator 6 to be calibrated, ensuring the accuracy of the magnetic field signal test.

[0022] The lightning signal simulation board 4 is the core component for generating test signals. It is connected to the electric field radiation antenna 2 and the magnetic field radiation antenna 3 via shielded cables. The shielded cables reduce signal loss and external interference during transmission, ensuring complete transmission of the test signal from the simulation board to the antennas. The test instrument 5, as the control and testing core of the entire device, establishes a communication connection with the lightning signal simulation board 4, sending control commands to the board, including the type and parameters of the test signal, and controlling the board to generate the required test waveform signal. Furthermore, the test instrument 5 establishes a communication connection with the lightning locator 6 to be calibrated, receiving the processed signal data from the locator and analyzing and judging the data.

[0023] During the actual calibration process, the operator can place the electric field antenna of the lightning locator 6 to be calibrated into the electric field radiating antenna 2 and the magnetic field antenna into the magnetic field radiating antenna 3 through the loading and unloading window of the shielded chamber 1, and then ensure that the connections between the components are normal. The test instrument 5 sends control commands to the lightning signal simulation board 4. The simulation board generates test waveform signals according to the commands, which are transmitted to the electric field radiating antenna 2 and the magnetic field radiating antenna 3 via shielded cables, and are converted into uniform electric field signals and magnetic field signals, respectively. The electric field antenna and the magnetic field antenna of the lightning locator 6 to be calibrated receive the corresponding signals, and after internal processing, transmit the processing results to the test instrument 5. The test instrument 5 analyzes the processing results to determine whether the performance indicators of the locator meet the requirements, and finally completes the calibration process.

[0024] This device enables simultaneous calibration of the electric and magnetic field performance of lightning locators without the need for additional equipment, simplifying the calibration process and improving calibration efficiency. Simultaneously, the shielding effect of the shielded chamber 1 and the uniform signal generation capability of the two antennas ensure the accuracy and reliability of the calibration results, providing a stable and efficient calibration solution for product acceptance and periodic calibration of lightning locators.

[0025] To further improve the alignment between calibration results and actual working scenarios, the lightning signal simulation board 4 can be equipped with an interference signal generation unit. This unit works in conjunction with the standard test waveform generation module of the lightning signal simulation board 4 without altering the existing component connections. The interference signal generation unit can simulate common interference types in the natural environment, such as power frequency noise generated by power lines and composite pulse signals formed by the superposition of multiple lightning bolts. The testing instrument can send control commands containing the interference type and intensity to the lightning signal simulation board 4. After receiving the commands, the lightning signal simulation board 4 superimposes the interference signal and the standard test waveform signal according to a preset ratio, and then transmits them to the electric field radiation antenna 2 and the magnetic field radiation antenna 3, converting them into uniform electric field signals and uniform magnetic field signals containing interference characteristics. Through this design, the calibration process can reproduce the signal reception environment of the positioning instrument in actual operation, avoiding performance misjudgments caused by pure signal calibration, and making the calibration results more valuable for practical reference.

[0026] See Figure 2 In some embodiments, the magnetic field radiating antenna 3 includes a pair of parallel coaxial circular coils 31, the pair of coils 31 are interconnected and have the same current direction, the spacing between the pair of coils 31 is the same as the coil radius, and a first stage 7 is provided at the midpoint of the common axis of the pair of coils 31. The first stage 7 is used to place the magnetic field antenna of the lightning locator 6 to be calibrated.

[0027] The magnetic field radiating antenna 3 uses a pair of circular coils 31 as the core radiating unit. The centers of the coils 31 are on the same straight line, and the planes on which the coils 31 are located are kept parallel. This arrangement allows the magnetic fields generated by the two coils 31 to form an orderly superposition in space, avoiding magnetic field disorder.

[0028] The two coils 31 are interconnected by a wire, forming a complete current loop, and the current flows in the same direction in both coils 31. If the current directions are opposite, the magnetic fields generated by the two coils 31 will cancel each other out, failing to form an effective magnetic field that meets the testing requirements. However, when the current directions are consistent, the magnetic fields of the two coils 31 will superimpose and strengthen in the region along the common axis, laying the foundation for the subsequent generation of a uniform magnetic field. Simultaneously, the spacing between the coils 31 is the same as the radius of each coil. This structure allows the two coils 31 to form a uniform and stable magnetic field space in the region around the midpoint of the common axis, with minimal magnetic field fluctuations in this region.

[0029] A first stage 7 is positioned at the midpoint of the common axis of the two coils 31. This stage can be made of non-metallic insulating material to avoid interfering with the magnetic field distribution and ensure that the magnetic field signal can act on the antenna to be calibrated without obstruction. The surface of the first stage 7 is horizontal, and its height is flush with the axis of the coils 31. When the magnetic field antenna of the lightning locator 6 to be calibrated is placed on the first stage 7, the receiving center of the antenna is precisely located at the midpoint of the axis where the magnetic field is most uniform, ensuring that the received magnetic field signal strength is stable and its characteristics are standard.

[0030] In actual calibration, the test waveform signal generated by the lightning signal simulation board 4 is transmitted to the coil circuit of the magnetic field radiating antenna 3 via a shielded cable. Current flows through the two coils 31 in a fixed direction, forming a uniform magnetic field in the common axis region. The operator places the magnetic field antenna of the lightning locator 6 stably on the first stage 7 through the access window of the shielded chamber 1, ensuring that the antenna and coil 31 are coaxial. At this time, the uniform magnetic field signal received by the antenna accurately reflects the characteristics of the test waveform. The signal data, after being processed internally by the locator, is transmitted to the testing instrument 5, truly reflecting the actual magnetic field receiving performance of the locator. This structural design improves the accuracy and repeatability of the calibration test, effectively reducing calibration errors caused by uneven magnetic fields or antenna placement deviations.

[0031] See Figure 3 In some embodiments, the electric field radiating antenna 2 includes two parallel metal plates 21 arranged opposite each other, and a second stage 8 is provided between the two parallel metal plates 21. The second stage 8 is used to place the electric field antenna of the lightning locator 6 to be calibrated.

[0032] The core purpose of designing the electric field radiating antenna 2 is to generate a uniform electric field signal that meets the test standards through this structural design, ensuring that the electric field antenna of the lightning locator 6 to be calibrated can obtain stable and accurate test input, thereby improving the reliability of electric field performance calibration. The electric field radiating antenna 2 uses two parallel metal plates 21 as its core working components. After an electrical signal is applied, the electric field distribution formed between the parallel metal plates 21 is uniform, and the electric field strength is stable and controllable. It can highly simulate the electric field characteristics formed in a certain area when lightning occurs, and perfectly match the signal reception requirements of the electric field antenna of the lightning locator 6 to be calibrated.

[0033] The two parallel metal plates 21 are made of metal materials with excellent conductivity and high stability, such as copper or aluminum alloy. These materials can respond quickly to changes in electrical signals, reduce signal loss, and ensure the fidelity of the electric field signal. The size of the parallel metal plates 21 is determined according to the size of the antenna to be calibrated, ensuring that the antenna is placed within a uniform electric field region between the plates. The two plates are kept parallel, and the spacing between the plates avoids both too small a spacing, which would make antenna placement difficult, and too large a spacing, which would reduce the uniformity of the electric field. The resulting electric field region can cover the entire receiving range of the antenna.

[0034] A second stage 8 is positioned at the center between the two parallel metal plates 21. This stage can be made of a non-metallic material with excellent insulation properties, such as polytetrafluoroethylene (PTFE) or epoxy resin. Such materials do not interfere with the distribution of the electric field between the plates due to their own conductivity, ensuring that the electric field signal can act completely and uniformly on the antenna to be calibrated. The surface of the second stage 8 is machined to be horizontal, and its height is flush with the central axis of the two parallel metal plates 21. When the electric field antenna of the lightning locator 6 to be calibrated is placed on the stage, the signal receiving center of the antenna is precisely located in the core region where the electric field between the plates is most uniform, avoiding deviations in the received signal due to antenna positional offset.

[0035] In actual electric field calibration, the test waveform signal generated by the lightning signal simulation board 4 is transmitted through shielded cables to the two parallel metal plates 21 of the electric field radiating antenna 2, forming a stable and uniform electric field between the parallel metal plates 21. The operator places the electric field antenna of the lightning locator 6 to be calibrated stably on the second stage 8 through the loading / unloading window of the shielded cabin 1. After confirming that the antenna is parallel to the parallel metal plates 21 and not in contact, the calibration process can be started. At this time, the uniform electric field signal received by the antenna accurately reflects the parameter characteristics of the test waveform. The data, after being processed internally by the locator and transmitted to the testing instrument 5, truly reflects the quality of the locator's electric field receiving performance. This structural design effectively reduces the fluctuation of the electric field signal and test errors, making the electric field performance calibration results more reliable and repeatable.

[0036] To accommodate potential directional deviations during actual installation of the lightning locator, a stepping rotation mechanism can be added to the bottom of the first stage 7 and / or the second stage 8. This mechanism establishes a communication connection with the test instrument 5, without altering the relative position of the stage and the antenna or the original structural compatibility. During calibration, the test instrument 5 can send rotation commands to drive the stepping rotation mechanism, causing the locator's electric and magnetic field antennas, placed on the stage, to rotate gradually at preset angles, completing signal reception and data acquisition at different directional angles. This design allows for comprehensive testing of the locator's antenna signal reception performance in different orientations, generating directional characteristic data, avoiding on-site usage deviations caused by single-direction calibration, making the calibration results more closely match actual installation requirements, and improving the comprehensiveness and reference value of the calibration.

[0037] Furthermore, to cover the signal response test across the entire detection range of the lightning locator, linear guide rail mechanisms can be installed in two independent areas of the shielded chamber 1. The electric field radiation antenna 2 and the magnetic field radiation antenna 3 are fixed to the guide rails, and the guide rails are linked with the testing instrument 5. During calibration, the testing instrument 5 can send distance adjustment commands to drive the antennas to move smoothly along the guide rails, changing the relative distance with the locator antenna and simulating signal propagation scenarios from near to far distances. Simultaneously, the lightning signal simulation board 4 fine-tunes the signal amplitude to reproduce the signal attenuation characteristics at real distances, avoiding a disconnect between single fixed-distance calibration and actual detection scenarios, and making the calibration results more comprehensive.

[0038] To verify the lightning locator's ability to capture sudden lightning signals, a transient pulse generation module can be added to the lightning signal simulation board 4. This module can generate simulated lightning pulse signals with ultra-short rise times, closely mimicking the sudden characteristics of natural lightning. During the calibration process, the test instrument 5 controls this module to suddenly output a transient pulse signal, while simultaneously recording the time difference between the locator receiving the signal and outputting the processing result in real time. By comparing this time difference with a preset response speed threshold, the locator's transient response performance can be determined, filling the gap in testing dynamic response capabilities using static signals.

[0039] To simulate the complex scenario of multiple lightning strikes occurring simultaneously, one or two sets of auxiliary radiating antennas (with the same structure as the main antenna in the same area) can be added to the same independent area of ​​the shielded cabin 1. The auxiliary antennas are symmetrically distributed with the main antenna and connected to the lightning signal simulation board 4 through a signal splitter to achieve independent signal control. During the calibration process, the test instrument 5 controls the main antenna and auxiliary antenna to output simulated lightning signals with different characteristics. After receiving the mixed signal, the positioning device extracts the independent characteristics of each signal and transmits them back to the test instrument 5. The instrument compares the extracted characteristics with the output signal characteristics of each antenna to determine the multi-target resolution capability of the positioning device, making the calibration more closely resemble the actual situation in complex weather.

[0040] To test the stability of the lightning locator in complex electromagnetic environments, a cross-frequency interference generation module can be added to the lightning signal simulation board 4. This module can generate common cross-frequency interference signals such as power frequency and radio frequency. During calibration, the lightning signal simulation board 4 superimposes the cross-frequency interference signal and the standard lightning signal according to a preset ratio, and then transmits them to the electric field radiation antenna 2 and the magnetic field radiation antenna 3. The lightning locator 6 to be calibrated receives the mixed signal and extracts the characteristics of the standard lightning signal. The testing instrument 5 compares the deviation between the extracted results and the standard characteristics to determine the locator's anti-multi-frequency interference capability and improve the adaptability of the calibration results to complex electromagnetic environments.

[0041] See Figure 4 This application also provides an automated calibration method for a very low frequency (VLF) to low frequency (LF) lightning locator, applicable to any of the devices described in the above embodiments; the method includes the following steps: S1. Send control commands to the lightning signal simulation board. The control commands are used to control the lightning signal simulation board to generate test waveform signals. S2. Control the lightning signal simulation board to transmit the test waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively. Control the electric field radiation antenna to convert the test waveform signal into a uniform electric field signal, and control the magnetic field radiation antenna to convert the test waveform signal into a uniform magnetic field signal. S3. Control the electric field antenna of the lightning locator to be calibrated to receive the uniform electric field signal and the magnetic field antenna to receive the uniform magnetic field signal. After processing the uniform electric field signal and the uniform magnetic field signal, transmit the processing result back to the test instrument. S4. Analyze the processing results, determine whether the performance indicators of the lightning locator to be calibrated meet the performance requirements, and generate a calibration report.

[0042] Specifically, before starting the calibration work, basic preparations must be completed: the electric field antenna of the lightning locator to be calibrated is placed inside the electric field radiation antenna through the pick-up and drop window of the shielded cabin, and the magnetic field antenna is placed inside the magnetic field radiation antenna. Ensure that the antenna is placed stably and is compatible with the antenna structure. At the same time, check the communication connection between the test instrument and the lightning signal simulation board and the lightning locator to be calibrated to ensure that the signal transmission channel is unobstructed and fault-free, and avoid calibration interruption or data distortion due to connection problems.

[0043] After preparation, the formal calibration process begins: First, the testing instrument sends control commands to the lightning signal simulation board. These commands include the basic requirements for generating test waveform signals, ensuring the simulation board can generate signals that meet calibration requirements. These waveform signals must simulate the electromagnetic signal characteristics generated during lightning strikes, providing a realistic test input for the lightning locator. Next, upon receiving the control commands, the simulation board generates the corresponding test waveform signals as required. These signals are then transmitted via shielded cables to the electric field radiation antenna and the magnetic field radiation antenna, respectively. The shielded cables effectively reduce external interference and signal loss during transmission, ensuring signal integrity. The electric field radiation antenna receives the signal and converts it into a uniform electric field signal, while the magnetic field radiation antenna converts it into a uniform magnetic field signal. These two uniform signals ensure stable and standardized signal reception by the locator antenna, preventing test result deviations due to signal unevenness.

[0044] Next, the electric field antenna of the lightning locator to be calibrated specifically receives the uniform electric field signal generated by the electric field radiation antenna, and the magnetic field antenna specifically receives the uniform magnetic field signal generated by the magnetic field radiation antenna. The locator internally processes the two types of signals, extracts key characteristic parameters, and then transmits these processed results back to the testing instrument through the communication channel. Finally, the testing instrument performs a systematic analysis of the received processing results, compares the extracted characteristic parameters with the preset performance requirements, and determines whether the lightning locator to be calibrated meets the standards in core performance indicators such as electric field receiving sensitivity and magnetic field receiving accuracy. If it meets the requirements, the calibration is deemed qualified; if not, the unmet performance items are identified, and a complete calibration report containing calibration results and performance parameter analysis is generated, providing a basis for the quality assessment or subsequent adjustments of the locator.

[0045] The entire process, from command sending, signal generation, transmission and conversion, to signal reception, processing and feedback, and then to result analysis and report generation, forms a complete calibration process. No additional manual operation is required. This simplifies the cumbersome steps of the traditional calibration process and ensures the comparability and reliability of calibration results for different batches and models of lightning positioners through standardized signal processing and analysis. It is suitable for product acceptance after mass production and daily periodic calibration work.

[0046] In some implementations, in S2, the test waveform signal includes a sine wave signal and a simulated lightning pulse waveform signal; The control commands include waveform type selection commands, which are used to control the lightning signal simulation board to switch and generate the corresponding test waveform signals. When the generated test waveform signal is a sine wave signal, it is used to perform frequency response curve testing on the lightning locator; when the generated test waveform signal is a simulated lightning pulse waveform signal, it is used to perform time accuracy, amplitude accuracy, and characteristic quantity testing on the lightning locator.

[0047] In step S2 of the calibration process, the test waveform signal is not of a single type, but includes two categories: sinusoidal waveform signals and simulated lightning pulse waveform signals. These two types of signals are matched to different performance test scenarios of the positioning instrument. The control commands sent by the test instrument to the lightning signal simulation board include an additional waveform type selection command. This command indicates the type of waveform to be generated. After receiving the command, the lightning signal simulation board generates the corresponding test waveform signal through rapid switching of its internal circuitry, achieving automatic switching of waveform types without the need for manual adjustment of hardware parameters.

[0048] When the waveform type selection command is specified as a sine wave signal, the sine wave generated by the lightning signal simulation board has the characteristics of stable frequency and uniform amplitude. This type of signal is consistent with the characteristics of very low frequency to low frequency electric and magnetic field signals received by the locator when it is working. It is specifically used to test the frequency response curve of the lightning locator. By inputting sine waves of different frequencies, the signal receiving capability of the locator in different frequency bands can be detected.

[0049] When the command is specified as a simulated lightning pulse waveform signal, the generated signal simulates the pulse characteristics produced during a natural lightning strike, including the rising edge, falling edge, and peak characteristics, closely matching the real lightning signal. This type of signal is primarily used to test the time accuracy, amplitude accuracy, and characteristic quantity of lightning locators. Time accuracy focuses on the locator's accuracy in identifying the timing of the pulse signal occurrence; amplitude accuracy assesses its measurement error of signal strength; and characteristic quantity testing focuses on its ability to extract key features such as pulse polarity and pulse width.

[0050] In actual calibration, the waveform type can be flexibly selected according to the test requirements. For example, the frequency response curve test can be completed first using a sine wave signal, and then the test can be conducted using a simulated lightning pulse waveform signal. Multiple calibration targets can be completed without changing the test equipment. This design allows a single calibration method to cover the core performance indicators of the positioning instrument, which simplifies the operation process and ensures the matching degree between the test signal and the real working scenario. This makes the calibration results closer to the actual working performance of the positioning instrument and enhances the reference value of the calibration data.

[0051] In some implementations, when the test waveform signal is a sinusoidal waveform signal, S2 specifically includes: S21. Send a control command containing frequency band parameters to the lightning signal simulation board. The control command containing frequency band parameters is used to control the lightning signal simulation board to generate multiple sinusoidal waveform signals of different frequency bands according to the frequency band parameters. S22. The control lightning signal simulation board transmits the sinusoidal waveform signals of each frequency band to the electric field radiation antenna and the magnetic field radiation antenna respectively, and converts them into uniform electric field signals and uniform magnetic field signals of the corresponding frequency bands. S4 specifically includes: S41. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive uniform electric field signals and uniform magnetic field signals of each frequency band respectively, process them, and transmit the uniform electric field signals and uniform magnetic field signals of each frequency band back to the test instrument. S42. Organize the uniform electric field signal and uniform magnetic field signal data of each frequency band, determine the frequency point with the highest signal peak, and then find the starting and ending frequency points on both sides where the peak value meets the preset conditions, and calculate the frequency response bandwidth of the lightning locator.

[0052] In step S2 of the calibration process, the control command sent by the test instrument to the lightning signal simulation board includes specific frequency band parameters. These parameters cover the operating frequency range of the lightning locator, ensuring that the test comprehensively covers the actual usage scenarios of the locator. Upon receiving the command, the lightning signal simulation board generates multiple sinusoidal waveform signals of different frequency bands based on the frequency band parameters. These signals are sequentially connected without omissions or overlaps, ensuring the integrity of the test. Subsequently, the lightning signal simulation board transmits these sinusoidal waveform signals of different frequency bands to the electric field radiation antenna and the magnetic field radiation antenna, respectively, via shielded cables. Upon receiving the signals, both antennas synchronously convert them into uniform electric field and uniform magnetic field signals of the corresponding frequency bands. Furthermore, the frequency characteristics of these signals are consistent with the input sinusoidal waveform signal, ensuring the stability and standardization of the test signal.

[0053] Upon entering S4, the electric and magnetic field antennas of the lightning locator to be calibrated receive uniform electric and magnetic field signals for each frequency band, respectively. The locator internally processes the signals for different frequency bands independently, extracting key data such as intensity and phase, and then transmits this processed signal data back to the testing instrument. Upon receiving the data, the testing instrument first systematically organizes the signal data for all frequency bands, selecting the frequency point with the highest signal peak value. This frequency point is the optimal response frequency for the locator. Subsequently, using this optimal frequency point as a benchmark, it progressively searches for the starting and ending frequencies that meet the preset performance requirements in both adjacent frequency bands. Finally, by calculating the frequency range between the starting and ending frequencies, the frequency response bandwidth of the lightning locator is determined.

[0054] The entire process requires no manual intervention in frequency band switching and data calculation; it is completed automatically by the equipment. This ensures the continuity and accuracy of testing across all frequency bands while avoiding errors introduced by manual operation. Comprehensive testing covering the positioning device's operating frequency bands clearly reflects the device's signal reception performance at different frequencies, providing accurate frequency response data to support the determination of whether the positioning device meets actual operational requirements.

[0055] In some implementations, when the test waveform signal is a simulated lightning pulse waveform signal, S2 specifically includes: S23. Send a control command containing amplitude reduction parameters to the lightning signal simulation board. The control command containing amplitude reduction parameters is used to control the lightning signal simulation board to generate multiple sets of simulated lightning pulse waveform signals with successively decreasing amplitudes according to the amplitude reduction parameters. S24. The control lightning signal simulation board transmits each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and converts them into uniform electric field signals and uniform magnetic field signals of corresponding amplitudes. S4 specifically includes: S43. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process the detected uniform electric field signals and uniform magnetic field signals and transmit the processing results back to the test instrument, and stop the transmission when no signal can be detected. S44. Record the signal amplitude corresponding to the last received processing result, and determine the signal amplitude as the electric field sensitivity and magnetic field sensitivity of the lightning locator.

[0056] After the process starts, the control command sent by the test instrument in S2 carries an amplitude reduction parameter. This parameter is set according to the theoretical sensitivity range of the positioning instrument, and the generated signal amplitude gradient covers the complete range from strong to weak. After receiving the command, the lightning signal simulation board generates multiple sets of simulated lightning pulse waveform signals according to the sequentially decreasing amplitude. Except for the amplitude, the core characteristics such as pulse polarity and pulse width of each set of simulated lightning pulse waveform signals are consistent to avoid interference from other parameters with the sensitivity test results. Subsequently, these simulated lightning pulse waveform signals are transmitted to the electric field radiation antenna and the magnetic field radiation antenna through shielded cables, and are converted into uniform electric field signals and uniform magnetic field signals of corresponding amplitudes. The signal strength decreases synchronously with the input waveform.

[0057] In step S4, the electric and magnetic field antennas of the lightning locator to be calibrated synchronously receive the corresponding sets of uniform electric and magnetic field signals. When the signal amplitude is high, the locator can stably detect and process the signals, transmitting the processing results, including signal strength and characteristics, back to the testing instrument. As the signal amplitude continues to decrease, when the signal weakens below the locator's recognition threshold, the locator cannot effectively detect it and will stop transmitting data. The testing instrument records the status of the received data in real time. When it detects a data transmission interruption, it traces back and records the signal amplitude corresponding to the last received processing result—this amplitude is the lowest signal strength that the locator can recognize, and is used as its electric field sensitivity and magnetic field sensitivity, respectively.

[0058] The entire process simulates the attenuation process of lightning signals from near to far in nature. There is no need for manual judgment of signal strength. The equipment automatically completes the gradient test and data recording, which avoids the subjective error of manual operation and ensures that the sensitivity test results are close to the actual working scenario of the locator, providing a basis for evaluating the weak signal capture capability of the locator.

[0059] In some implementations, when the test waveform signal is a simulated lightning pulse waveform signal, S2 further includes: S25. Send a control command containing pulse count and peak time interval parameters to the lightning signal simulation board. The control command containing pulse count and peak time interval parameters is used to control the lightning signal simulation board to generate multiple sets of the same simulated lightning pulse waveform signals according to the pulse count and peak time interval parameters. S26. The control lightning signal simulation board transmits each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and converts them into corresponding uniform electric field signals and uniform magnetic field signals. S4 also includes: S45. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process them, and transmit the peak time data of each set of uniform electric field signals and uniform magnetic field signals back to the test instrument. S46. Calculate the mean and standard deviation of the peak times from the received multiple sets of peak time data to determine the waveform time accuracy of the lightning locator.

[0060] In step S2 of the calibration process, the control commands sent by the test instrument to the lightning signal simulation board include, in addition to the waveform type, specific parameters such as the number of pulses and the peak time interval. The pulse count setting must meet the requirements of statistical analysis to ensure data representativeness; the peak time interval simulates the signal timing characteristics that may occur in natural lightning, matching the actual working scenario of the locator. Based on these parameters, the lightning signal simulation board generates multiple sets of identical simulated lightning pulse waveform signals. The peak occurrence time interval of each set of simulated lightning pulse waveform signals is fixed, eliminating interference from differences in the signal itself on the time test. Subsequently, these simulated lightning pulse waveform signals are transmitted via shielded cables to the electric field radiation antenna and the magnetic field radiation antenna, where they are converted into corresponding uniform electric field signals and uniform magnetic field signals, with consistent timing characteristics across all sets of signals.

[0061] Upon entering S4, the electric and magnetic field antennas of the lightning locator to be calibrated receive each group of signals. The internal processing module accurately captures the peak occurrence time of each group of signals, extracts the peak time data, and transmits it back to the testing instrument. After collecting the peak time data for all groups, the testing instrument first calculates the mean of these data, which reflects the average level of the locator's time recognition. Then, by calculating the standard deviation, it analyzes the degree of deviation of each group of data from the mean; the smaller the standard deviation, the more stable the locator's time recognition. Finally, by combining the mean and standard deviation, the waveform time accuracy of the lightning locator is comprehensively determined.

[0062] The entire process replaces single tests with multiple sets of repeated tests, reduces random errors through data statistics, and automates signal generation, data acquisition, and analysis throughout the entire process. This avoids deviations caused by manual timing, making the time accuracy test results more reliable and providing a scientific basis for evaluating the ability of the locator to judge the time of lightning occurrence.

[0063] In some implementations, when the test waveform signal is a simulated lightning pulse waveform signal, S2 further includes: S27. Send a control command containing preset standard amplitude parameters to the lightning signal simulation board. The control command containing preset standard amplitude parameters is used to control the lightning signal simulation board to generate a simulated lightning pulse waveform signal with a fixed waveform according to the preset standard amplitude parameters. S28. Control the lightning signal simulation board to transmit the simulated lightning pulse waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert it into a uniform electric field signal and a uniform magnetic field signal with corresponding standard amplitude. S4 also includes: S47. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, and transmit the measured amplitude data back to the test instrument. S48. Calculate the difference and ratio between the measured amplitude data and the preset standard amplitude parameters to determine the amplitude accuracy of the lightning locator.

[0064] In step S2 of the calibration process, the control command sent by the test instrument to the lightning signal simulation board includes a clearly defined preset standard amplitude parameter. This parameter is set according to the design specifications of the lightning locator or industry testing standards, and has a unified reference benchmark. After receiving the control command, the lightning signal simulation board generates a simulated lightning pulse waveform signal with a fixed waveform according to this parameter—the pulse characteristics of the waveform remain stable, and only the amplitude matches the preset standard, avoiding fluctuations in other parameters from affecting the amplitude test results. Subsequently, this signal is transmitted to the electric field radiation antenna and the magnetic field radiation antenna via shielded cables, and converted into a uniform electric field signal and a uniform magnetic field signal with the corresponding standard amplitude.

[0065] In step S4, after the electric and magnetic field antennas of the lightning locator to be calibrated receive the signal, the internal measurement module detects and processes the signal amplitude, transmitting the measured amplitude data to the testing instrument in real time. Upon receiving the data, the testing instrument first calculates the difference between the measured amplitude data and the preset standard amplitude parameter to determine the absolute error; then it calculates the ratio of the two to determine the relative error. Through comprehensive analysis of the absolute and relative errors, the measurement deviation of the locator in terms of signal strength can be clearly determined, ultimately confirming its amplitude accuracy.

[0066] The entire process is based on a standard amplitude value, eliminating the need for manual intervention in amplitude judgment. It automates signal generation, data acquisition, and error calculation, avoiding errors from manual readings and making the amplitude accuracy test results more authoritative through the unified reference of standard parameters, thus providing a basis for evaluating the signal strength measurement capabilities of the positioning instrument.

[0067] In some implementations, when the test waveform signal is a simulated lightning pulse waveform signal, S2 further includes: S29. Send a control command containing pulse polarity and pulse width parameters to the lightning signal simulation board. The control command containing pulse polarity and pulse width parameters is used to control the lightning signal simulation board to generate simulated lightning pulse waveform signals with different polarities and different pulse widths according to the pulse polarity and pulse width parameters. S210, the control lightning signal simulation board transmits various types of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and converts them into corresponding uniform electric field signals and uniform magnetic field signals. S4 also includes: S49. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, extract the polarity and pulse width characteristic data of uniform electric field signals and uniform magnetic field signals, and transmit the polarity and pulse width characteristic data back to the test instrument. S410. Compare the received polarity and pulse width characteristic data with the preset pulse polarity and pulse width parameters in the control command to determine the accuracy of the lightning locator's characteristic quantity recognition.

[0068] In step S2 of the calibration process, the control commands sent by the test instrument to the lightning signal simulation board include specific pulse polarity and pulse width parameters. These parameters cover the common positive and negative polarities and different pulse width ranges in natural lightning, matching the signal characteristics that the locator may encounter in actual operation. Based on the commands, the lightning signal simulation board generates various types of simulated lightning pulse waveform signals. Each group of signals differs only in polarity (e.g., positive pulse, negative pulse) and pulse width; other core characteristics remain consistent, ensuring that the test focuses solely on the ability to identify characteristic quantities and eliminating interference from irrelevant parameters. Subsequently, these signals are transmitted via shielded cables to the electric field radiation antenna and the magnetic field radiation antenna, where they are converted into corresponding uniform electric field signals and uniform magnetic field signals, with the polarity and pulse width characteristics of the signals fully preserved.

[0069] In S4, after the electric and magnetic field antennas of the lightning locator to be calibrated receive signals, the internal feature extraction module captures the polarity and pulse width information of the signals and transmits these feature data back to the testing instrument. The testing instrument compares the received measured feature data with the preset pulse polarity and pulse width parameters in the control command one by one: if the two are completely consistent or the deviation is within the allowable range, the locator is judged to have accurately identified the feature quantity; if there is a significant deviation, the identification is clearly problematic.

[0070] The entire process simulates diverse lightning signal characteristics, automating feature extraction, data transmission, and comparison judgment. This avoids subjective errors from manual analysis, making the test results closer to the actual working scenario of the positioning device, and providing a direct and reliable basis for evaluating its feature recognition capabilities.

[0071] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application.

Claims

1. An automated calibration device for a very low frequency (VLF) to low frequency lightning location instrument, characterized in that, Includes a shielded cabin (1), an electric field radiation antenna (2), a magnetic field radiation antenna (3), a lightning signal simulation board (4), and test instruments (5); The shielding chamber (1) is divided into two independent areas. The electric field radiation antenna (2) and the magnetic field radiation antenna (3) are respectively set in the two independent areas. The shielding chamber (1) is provided with a lightning locator antenna pick-up and drop window on the outside. The electric field radiating antenna (2) is a parallel metal plate structure, and the magnetic field radiating antenna (3) is a Helmholtz coil structure; The lightning signal simulation board (4) is connected to the electric field radiation antenna (2) and the magnetic field radiation antenna (3) respectively via shielded cables, and the test instrument (5) is connected to the lightning signal simulation board (4) and the lightning locator (6) to be calibrated respectively. The electric field antenna of the lightning locator (6) to be calibrated can be placed inside the electric field radiation antenna (2) through the pick-up and put-out window, and the magnetic field antenna of the lightning locator (6) to be calibrated can be placed inside the magnetic field radiation antenna (3) through the pick-up and put-out window.

2. The apparatus according to claim 1, characterized in that, The magnetic field radiating antenna (3) includes a pair of parallel coaxial circular coils (31), the pair of coils (31) are connected to each other and the current direction is the same, the spacing between the pair of coils (31) is the same as the coil radius, and a first stage (7) is provided at the midpoint of the common axis of the pair of coils (31), the first stage (7) is used to place the magnetic field antenna of the lightning locator (6) to be calibrated.

3. The apparatus according to claim 1, characterized in that, The electric field radiating antenna (2) includes two parallel metal plates (21) arranged opposite to each other, and a second stage (8) is provided between the two parallel metal plates (21). The second stage (8) is used to place the electric field antenna of the lightning locator (6) to be calibrated.

4. An automated calibration method for a very low frequency (VLF) to low frequency (LLF) lightning locator, characterized in that, Applied to the apparatus as described in any one of claims 1-3; the method comprises the following steps: S1. Send a control command to the lightning signal simulation board, the control command being used to control the lightning signal simulation board to generate a test waveform signal; S2. Control the lightning signal simulation board to transmit the test waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively, control the electric field radiation antenna to convert the test waveform signal into a uniform electric field signal, and control the magnetic field radiation antenna to convert the test waveform signal into a uniform magnetic field signal. S3. Control the electric field antenna of the lightning locator to be calibrated to receive the uniform electric field signal and the magnetic field antenna to receive the uniform magnetic field signal. After processing the uniform electric field signal and the uniform magnetic field signal, transmit the processing result back to the test instrument. S4. Analyze the processing results to determine whether the performance indicators of the lightning locator to be calibrated meet the performance requirements, and generate a calibration report.

5. The method according to claim 4, characterized in that, In step S2, the test waveform signal includes a sine wave signal and a simulated lightning pulse waveform signal; The control command includes a waveform type selection command, which is used to control the lightning signal simulation board to switch and generate the corresponding test waveform signal. When the generated test waveform signal is a sinusoidal waveform signal, it is used to perform frequency response curve testing on the lightning locator; when the generated test waveform signal is a simulated lightning pulse waveform signal, it is used to perform time accuracy, amplitude accuracy, and characteristic quantity testing on the lightning locator.

6. The method according to claim 5, characterized in that, When the test waveform signal is a sinusoidal waveform signal, S2 specifically includes: S21. Send the control command containing frequency band parameters to the lightning signal simulation board. The control command containing frequency band parameters is used to control the lightning signal simulation board to generate multiple sinusoidal waveform signals of different frequency bands according to the frequency band parameters. S22. Control the lightning signal simulation board to transmit the sinusoidal waveform signals of each frequency band to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into uniform electric field signals and uniform magnetic field signals of the corresponding frequency bands. S4 specifically includes: S41. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive uniform electric field signals and uniform magnetic field signals of each frequency band respectively, process them, and transmit the uniform electric field signals and uniform magnetic field signals of each frequency band back to the test instrument. S42. Organize the uniform electric field signal and uniform magnetic field signal data of each frequency band, determine the frequency point with the highest signal peak, and then search for the starting and ending frequency points on both sides where the peak value meets the preset conditions, and calculate the frequency response bandwidth of the lightning locator.

7. The method according to claim 5, characterized in that, When the test waveform signal is a simulated lightning pulse waveform signal, S2 specifically includes: S23. Send the control command containing the amplitude reduction parameter to the lightning signal simulation board. The control command containing the amplitude reduction parameter is used to control the lightning signal simulation board to generate multiple sets of simulated lightning pulse waveform signals with successively decreasing amplitudes according to the amplitude reduction parameter. S24. Control the lightning signal simulation board to transmit each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into uniform electric field signals and uniform magnetic field signals of corresponding amplitudes. S4 specifically includes: S43. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process the detected uniform electric field signals and uniform magnetic field signals and transmit the processing results back to the test instrument, and stop the transmission when no signal can be detected. S44. Record the signal amplitude corresponding to the last received processing result, and determine the signal amplitude as the electric field sensitivity and magnetic field sensitivity of the lightning locator.

8. The method according to claim 5, characterized in that, When the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S25. Send the control command containing the pulse count and peak time interval parameters to the lightning signal simulation board. The control command containing the pulse count and peak time interval parameters is used to control the lightning signal simulation board to generate multiple sets of identical simulated lightning pulse waveform signals according to the pulse count and peak time interval parameters. S26. Control the lightning signal simulation board to transmit each group of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into corresponding uniform electric field signals and uniform magnetic field signals. S4 further includes: S45. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive each set of uniform electric field signals and uniform magnetic field signals respectively, process them, and transmit the peak time data of each set of uniform electric field signals and uniform magnetic field signals back to the test instrument. S46. Calculate the mean and standard deviation of the peak times from the received multiple sets of peak time data, and determine the waveform time accuracy of the lightning locator.

9. The method according to claim 5, characterized in that, When the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S27. Send the control command containing the preset standard amplitude parameter to the lightning signal simulation board. The control command containing the preset standard amplitude parameter is used to control the lightning signal simulation board to generate a simulated lightning pulse waveform signal with a fixed waveform according to the preset standard amplitude parameter. S28. Control the lightning signal simulation board to transmit the simulated lightning pulse waveform signal to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert it into a uniform electric field signal and a uniform magnetic field signal with corresponding standard amplitude; S4 further includes: S47. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, and transmit the measured amplitude data back to the test instrument. S48. Calculate the difference and ratio between the measured amplitude data and the preset standard amplitude parameter to determine the amplitude accuracy of the lightning locator.

10. The method according to claim 5, characterized in that, When the test waveform signal is a simulated lightning pulse waveform signal, step S2 further includes: S29. Send the control command containing pulse polarity and pulse width parameters to the lightning signal simulation board. The control command containing pulse polarity and pulse width parameters is used to control the lightning signal simulation board to generate simulated lightning pulse waveform signals with different polarities and different pulse widths according to the pulse polarity and the pulse width parameters. S210. Control the lightning signal simulation board to transmit various types of simulated lightning pulse waveform signals to the electric field radiation antenna and the magnetic field radiation antenna respectively, and convert them into corresponding uniform electric field signals and uniform magnetic field signals. S4 further includes: S49. Control the electric field antenna and magnetic field antenna of the lightning locator to be calibrated to receive and process uniform electric field signals and uniform magnetic field signals, extract the polarity and pulse width characteristic data of uniform electric field signals and uniform magnetic field signals, and transmit the polarity and pulse width characteristic data back to the test instrument. S410. The received polarity and pulse width feature data are compared with the pulse polarity and pulse width parameters preset in the control command to determine the accuracy of the feature quantity recognition of the lightning locator.

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