Ultra-short baseline lightning positioning method for multi-antenna single-station three-dimensional layout and related apparatus

Abstract

A ultra-short baseline lightning positioning method for a multi-antenna single-station three-dimensional layout, and a related apparatus. The method comprises: using a multi-antenna three-dimensional layout, and forming a set of equilateral pentagonal interferometer arrays without angle errors and multiple sets of equilateral triangle interferometer arrays having angular errors by means of combinations of different numbers of antennas; obtaining a time difference of a same pulse signal between VHF antennas by means of different antenna combinations, performing two-dimensional observation without system errors by using the equilateral pentagon interferometer arrays, and correcting two-dimensional observation results having systematic errors obtained by the equilateral triangle arrays; finally, using two-dimensional information obtained by the equilateral pentagon interferometer arrays as a reference, performing spatial intersection with corrected two-dimensional information obtained by multiple equilateral triangle interferometer arrays, to acquire three-dimensional information. The present method implements ultrahigh-resolution three-dimensional positioning during lightning discharge, and implements nanosecond time resolution and decimeter-level spatial resolution during lightning discharge.

Description

Ultra-short baseline lightning location method and related device with multi-antenna single-station three-dimensional layout

[0001] Cross-references to related publications

[0002] This disclosure claims priority to Chinese Patent Publication No. 2024102087018, filed with the Patent Office of China on February 26, 2024, entitled “Ultra-short baseline lightning location method and related device with multi-antenna single-station stereoscopic layout,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of lightning location, and in particular to an ultra-short baseline lightning location method and related devices with a multi-antenna single-station three-dimensional layout. Background Art

[0004] In the field of lightning detection technology, existing methods mainly include magnetic direction finding, time difference of arrival (TOA), and interferometry, each of which uses electromagnetic signals to locate lightning. Of these, TOA and interferometry have attracted much attention due to their unique detection methods. TOA relies on measuring the time difference between the arrival of electromagnetic signals at different receivers, while interferometry relies on the detection of broadband very high frequency signals. However, these traditional methods have certain limitations in practical applications. For example, while TOA can provide three-dimensional information, its temporal resolution and spatial accuracy are limited; while interferometry, while having high temporal resolution, can only provide two-dimensional information about lightning.

[0005] To obtain high-precision positioning information on lightning discharges and their development, three-dimensional lightning observations based on interferometer arrays have gradually become an important exploration and research direction in the field of lightning observation. Currently, a dual-station interferometer array observation scheme based on two interferometer arrays set up remotely has achieved three-dimensional observation of lightning discharge processes. However, when the two interferometer arrays are set up 10 km apart, interference from factors such as the local electromagnetic environment, electromagnetic signal attenuation, positioning result matching, and system errors greatly limits the high-precision three-dimensional lightning positioning capability of the dual-station interferometer array. There have also been attempts to use ultra-short baseline interferometer arrays with multiple antennas at a single station. However, actual observations have found that while this observation scheme can achieve three-dimensional positioning of some signals to a certain extent, due to electromagnetic signal interference and the baseline length being much smaller than the distance at which the lightning signal occurs, the errors in most three-dimensional positioning results spread radially, leading to problems such as dispersion of positioning results.

[0006] Public content

[0007] One of the objectives of the present disclosure is to provide an ultra-short baseline lightning location method and related apparatus using a multi-antenna, single-station, three-dimensional configuration. This method enables ultra-high-resolution, three-dimensional location of lightning discharges, with a temporal resolution of nanoseconds and a theoretical spatial error resolution of decimeters. The embodiments of the present disclosure can be implemented as follows:

[0008] In a first aspect, the present disclosure provides an ultra-short baseline lightning location method with a multi-antenna monostatic stereoscopic layout, wherein the multi-antenna monostatic stereoscopic layout includes an interferometer array composed of different numbers of very high frequency (VHF) antennas; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; the method includes: collecting a very high frequency radiation signal received by each of the VHF antennas, and determining the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal; based on the time difference of the same pulse signal between different VHF antennas, using the equilateral pentagonal interferometer array and the equilateral triangle interferometer array to locate the radiation source emitting the very high frequency radiation signal, respectively, to obtain a set of first azimuth angles and first elevation angles, as well as multiple sets of second azimuth angles. angle and a second elevation angle; wherein, the first azimuth angle and the first elevation angle have no systematic error, and the multiple two azimuth angles and the second elevation angle have systematic errors; multiple groups of the second azimuth angles and the second elevation angles are corrected to obtain multiple groups of target azimuth angles and target elevation angles; taking the direction of the first azimuth angle and the first elevation angle as the reference direction, a target position point is determined in the reference direction, so that the distance between the ray passing through the target position point in the reference direction and the center of the ray in the reference direction with the multiple groups of the target azimuth angles and the target elevation angles as the reference direction is minimized, and based on the target position point and the first azimuth angle and the second azimuth angle, the three-dimensional coordinates of the radiation source are determined; according to the three-dimensional coordinates and the time when the very high frequency radiation signal is transmitted to the central VHF antenna at the speed of light, the occurrence time of the very high frequency radiation signal is determined.

[0009] In a second aspect, the present disclosure provides an ultra-short baseline lightning locating device with a multi-antenna monostatic stereoscopic layout, wherein the multi-antenna monostatic stereoscopic layout includes an interferometer array composed of different numbers of VHF antenna combinations; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; and includes: an acquisition module configured to acquire the very high frequency radiation signal received by each of the VHF antennas; a preprocessing module configured to determine the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal; and a two-dimensional positioning module configured to perform interferometer positioning using the equilateral pentagonal interferometer array and the equilateral triangle interferometer array based on the time difference of the same pulse signal between different VHF antennas, thereby obtaining a set of first azimuth angles and first elevation angles of the radiation source emitting the very high frequency radiation signal and multiple sets of second azimuth angles. angle and a second elevation angle; wherein, the first azimuth angle and the first elevation angle have no systematic error, and the multiple two azimuth angles and the second elevation angle have systematic errors; a correction module is configured to correct multiple groups of the second azimuth angles and the second elevation angles to obtain multiple groups of target azimuth angles and target elevation angles; a three-dimensional positioning module is configured to use the direction of the first azimuth angle and the first elevation angle as a reference direction, determine a target position point in the reference direction, minimize the distance between the ray in the reference direction and the center of the ray with the multiple groups of the target azimuth angles and the target elevation angles as the reference direction, and determine the three-dimensional coordinates of the radiation source based on the target position point and the first azimuth angle and the second azimuth angle; the three-dimensional positioning module is further configured to determine the occurrence time of the very high frequency radiation signal according to the three-dimensional coordinates and the time when the very high frequency radiation signal is transmitted to the central VHF antenna at the speed of light.

[0010] In a third aspect, the present disclosure provides an ultra-short baseline lightning three-dimensional positioning system with a multi-antenna monopole stereoscopic layout, comprising: multiple very high frequency (VHF) antennas and a computer device; wherein the multi-antenna monopole stereoscopic layout includes an interferometer array composed of different numbers of the VHF antenna combinations; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; the multiple very high frequency (VHF) antennas are configured to receive very high frequency radiation signals and transmit them to the computer device, and the computer device is configured to execute the ultra-short baseline lightning positioning method with a multi-antenna monopole stereoscopic layout as described in any of the aforementioned embodiments.

[0011] The disclosed embodiments provide an ultra-short baseline lightning location method and related device with a multi-antenna single-station three-dimensional layout, which is used to achieve ultra-high-precision single-station three-dimensional positioning of lightning discharge events. A multi-antenna three-dimensional layout is adopted, and a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error are formed by combining different numbers of antennas. The radiation information of each VHF antenna is then collected and analyzed and processed to obtain the time difference of the same pulse signal between the different VHF antennas. Combining the various time differences, two-dimensional observation is performed using an equilateral pentagonal interferometer array and multiple equilateral triangle interferometer arrays. Based on the spatial relationship between the equilateral triangle interferometer array and the equilateral pentagonal interferometer array, the two-dimensional directional information obtained by the multiple equilateral triangle interferometer arrays is corrected. Finally, the two-dimensional information without systematic error obtained by the equilateral triangle interferometer array is used as a reference, and spatially intersected with the two-dimensional information obtained by the multiple equilateral triangle interferometer arrays to obtain three-dimensional information. The present disclosure can achieve ultra-high-resolution three-dimensional positioning of lightning discharge processes. The time resolution of locating lightning discharge events can reach the nanosecond level, and the theoretical resolution of spatial error is improved to the decimeter level. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0013] FIG1 is a schematic diagram of a single-station layout of multiple antennas provided by an embodiment of the present disclosure;

[0014] FIG2 is a schematic flowchart of an ultra-short baseline lightning location method based on a multi-antenna single-station stereoscopic layout provided by an embodiment of the present disclosure;

[0015] FIG3 is a schematic diagram showing a comparison between original data and upsampled data provided by an embodiment of the present disclosure;

[0016] FIG4 is a schematic diagram of a generalized cross-correlation waveform matching method combining a main window and a variable auxiliary window provided by an embodiment of the present disclosure;

[0017] FIG5 is a schematic diagram of VHF waveforms matched together by generalized cross-correlation technology according to an embodiment of the present disclosure;

[0018] FIG6a is a schematic diagram for determining source two-dimensional information;

[0019] FIG6 b is a schematic diagram of a positioning error evaluation method using a three-antenna array as an example;

[0020] FIG7a is a schematic diagram of a three-dimensional positioning principle provided by an embodiment of the present disclosure;

[0021] FIG7 b is a schematic diagram showing the uniform distribution of the target azimuth angles around the real azimuth angle of the radiation source Q obtained by five sets of three-antenna interferometer arrays centered on antenna G in an embodiment of the present disclosure;

[0022] FIG7 c is a schematic diagram showing the uniform distribution of the actual elevation angle of the target around the radiation source Q obtained by five sets of three-antenna interferometer arrays centered on antenna G in an embodiment of the present disclosure;

[0023] FIG8 is a functional module diagram of an ultra-short baseline lightning locating device 300 with a multi-antenna single-station three-dimensional layout provided by an embodiment of the present disclosure;

[0024] FIG9 is a structural block diagram of a computer device 400 provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of them. Generally, the components of the embodiments of the present disclosure described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but merely represents selected embodiments of the present disclosure. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort shall fall within the scope of protection of the present disclosure.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of the present disclosure, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the disclosed product is usually placed when in use. It is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present disclosure.

[0029] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0030] It should be noted that, in the absence of conflict, the features in the embodiments of the present disclosure may be combined with each other.

[0031] In the embodiment of the present disclosure, the very high frequency (VHF) radiation detection antenna commonly used in the lightning broadband interferometer (INTF) array is installed according to the layout scheme shown in Figure 1. Figure 1 is a schematic diagram of the multi-antenna single-stand three-dimensional layout provided by the embodiment of the present disclosure, which includes seven VHF antennas, namely antennas AG.

[0032] Antenna A is mounted directly above the central VHF antenna coordinate origin, O. Antennas B through F are arranged around O. The distance between any two adjacent antennas in antennas BF is L. The five antennas BF form a highly symmetrical equilateral pentagon. Each antenna BF is spaced L1 (denoted as the short baseline length) from antenna A. Therefore, antennas A and BF form an equilateral triangle with each other. Thus, antennas AF form a six-antenna, equilateral pentagonal interferometer array (denoted ABCDEF) with no angular error. Antenna G is located directly above antenna A. Its height from the coordinate origin, O, is such that antenna G forms an equilateral triangle with the other antennas in antennas BF. The equilateral triangle baseline length is L2. Thus, antennas BG form five equilateral triangle interferometer arrays, each containing three antennas (denoted GBD, GCE, GDF, GEB, and GFC). The zenith directions of the cosine planes of the five equilateral triangle interferometer arrays are evenly distributed around the coordinate origin, O, and the axis of antenna G.

[0033] To ensure signal matching accuracy and antenna installation feasibility, the short baseline length L1 is limited to approximately 10 meters (for example, L1 = 11.76 meters). This creates an ultra-short baseline observation system, significantly shorter than existing international 3D lightning location systems. Furthermore, in the example layout of Figure 1, the baseline length L2 of the equilateral triangle can be set to 19.02 meters.

[0034] Because the interferometer array positioning principle is employed, for convenience, the antenna array consisting of antennas AG will be referred to as the INTF array. The seven VHF antennas in this INTF array share identical performance specifications, utilizing broadband VHF (50-180 MHz) RF receiving antennas. The time series waveforms of each receiver are synchronously recorded at a sampling rate of 400 MHz / s and 14-bit sampling accuracy, with an initial time resolution of 2.5 ns, which can be improved based on the performance of future acquisition cards. This ensures that the ABCDEF arrays maintain a regular hexagonal structure while providing vertical observation margin for the entire antenna array.

[0035] In the embodiment of the present disclosure, antenna A is used as the central antenna. After being erected off the ground, the baseline length formed by it and any antenna is relatively small, which can significantly improve the accuracy of matching signals between different antennas. The installation position of antenna G, on the one hand, provides five sets of equilateral triangle interferometer arrays, which can also provide vertical observation margins for the antenna arrays. On the other hand, when antenna G is used as the central antenna of the five interferometer arrays GBD, GCE, GDF, GEB, and GFC, the zenith directions of the cosine planes of these five interferometer arrays are evenly distributed around the axis OG, and their respective system error distribution curves are arranged in equal angles according to the true incident direction of the radiation signal. The embodiment of the present disclosure can make full use of the error distribution characteristics inherent in these five sets of equilateral triangle interferometer arrays to eliminate the influence of system errors and obtain accurate three-dimensional positioning information.

[0036] In the disclosed embodiment, the fast electric field change meter (abbreviated as fast antenna, FA) also participated in the joint network observation with INTF. It is specifically used to measure the changes in the vertical electric field on the ground and has a decay constant of 100μs. The fast antenna has high sensitivity in the frequency range of 3kHz to more than 20MHz. This observation scheme greatly improves the precise matching between the VHF radiation signal generated during the lightning discharge process and the low-frequency electric field waveform, which is particularly important for analyzing the development details of microsecond discharge events. It should be noted that the fast electric field change meter is mainly used to identify the physical process of lightning discharge, and is not used for lightning location.

[0037] Based on the multi-antenna, monostatic, and stereoscopic layout shown in FIG1 , an embodiment of the present disclosure provides a method for three-dimensionally locating ultra-short baseline lightning. FIG2 is a schematic flow chart of the method for locating ultra-short baseline lightning based on the multi-antenna, monostatic, and stereoscopic layout provided by an embodiment of the present disclosure. The method is executed by a high-performance computer device and may include the following steps:

[0038] S201, collecting the very high frequency radiation signal received by each VHF antenna, and determining the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal;

[0039] S202. Based on the time difference of the same pulse signal between different VHF antennas, use an equilateral pentagonal interferometer array and an equilateral triangle interferometer array to perform positioning, thereby obtaining a set of first azimuth angles and first elevation angles and multiple sets of second azimuth angles and second elevation angles of a radiation source emitting the very high frequency radiation signal; wherein the first azimuth angle and the first elevation angle have no systematic error, and the multiple sets of second azimuth angles and second elevation angles have systematic errors;

[0040] S203, correcting the multiple sets of second azimuth angles and second elevation angles to obtain multiple sets of target azimuth angles and target elevation angles;

[0041] S204: Using the direction of the first azimuth angle and the first elevation angle as a reference direction, determine a target location point in the reference direction so that the center distance between a ray passing through the target location point in the reference direction and a ray passing through the plurality of sets of target azimuth angles and target elevation angles as reference directions is minimized, and determine the three-dimensional coordinates of the radiation source based on the target location point, the first azimuth angle, and the second azimuth angle.

[0042] S205 , determining the time when the very high frequency radiation signal occurs based on the three-dimensional coordinates and the time it takes for the very high frequency radiation signal to be transmitted to the central VHF antenna at the speed of light.

[0043] In the above steps S201 to S205, a multi-antenna three-dimensional installation layout is adopted, and a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error are formed by combining different numbers of antennas; then, very high frequency radiation information of each VHF antenna and fast electric field change measuring instrument is collected and analyzed and processed to obtain the time difference of the same pulse signal between different VHF antennas. Combined with each time difference, two-dimensional observation is performed using the equilateral pentagonal interferometer array and multiple equilateral triangle interferometer arrays. Then, based on the spatial relationship between the equilateral triangle interferometer array and the equilateral pentagonal interferometer array, the two-dimensional direction information obtained by the multiple equilateral triangle interferometer arrays is corrected. Finally, the two-dimensional information without systematic error obtained by the equilateral pentagonal interferometer array is used as a reference and spatially intersected with the two-dimensional information obtained by the multiple equilateral triangle interferometer arrays to obtain three-dimensional information. The present disclosure can achieve ultra-high-resolution three-dimensional positioning of lightning discharge processes, with the time resolution of locating lightning discharge events reaching the nanosecond level and the theoretical resolution of spatial error increased to the decimeter level.

[0044] The following is a detailed introduction to each of the above steps.

[0045] In the embodiment shown in FIG1 , in an optional implementation manner, step S201 may be implemented as follows:

[0046] Step a1: The VHF radiation signal received by each VHF antenna is collected by an acquisition card, and the VHF radiation signal is pre-processed.

[0047] In the embodiment of the present disclosure, a high-speed data acquisition card with a sampling frequency of 400 MHz may be used to acquire the VHF radiation signal of each VHF antenna.

[0048] As can be seen from the above, the fast electric field variation measuring instrument also participated in the joint network observation with the INTF. Like the INTF array antenna, the electric field variation signal of the fast electric field variation measuring instrument can also be synchronously recorded by another acquisition card at the same sampling rate and accuracy. Therefore, in the specific implementation process, the computer equipment can integrate two high-speed data acquisition cards with a sampling frequency of 400MHz and a total of 8 channels to respectively collect the VHF radiation signal of each VHF antenna and the electric field variation signal of a fast electric field instrument at high speed with 14-bit accuracy.

[0049] At the same time, high-precision GPS clock synchronization technology is required to ensure the time synchronization accuracy between the two acquisition cards. This method of using hardware triggering combined with software algorithms can further reduce time deviation. In addition, the huge amount of data generated by the 400MHz high-speed acquisition card places high demands on the data processing and storage systems. Therefore, high-performance computing platforms, large-capacity storage devices, and parallel processing technology can be used to increase data processing speed.

[0050] In actual implementation, since the combined baseline length of any antenna in the antenna array does not exceed 20m, in order to reduce the impact of data lines on signal acquisition, computer equipment can be equipped with an air-conditioned chassis and placed in the open space at the center of the multi-antenna array.

[0051] In the embodiment of the present disclosure, the preprocessing operation includes signal feature analysis, signal high-rate upsampling, and signal high-frequency truncation and noise reduction.

[0052] The signal feature analysis employed the DBM_EEMD method to analyze the VHF radiation signals generated by lightning. This method measured the key components of the ambient background noise and the lightning VHF radiation signals containing clutter noise. This provided the basis for subsequent signal matching to determine the time difference between the arrival of the same pulse signal at each VHF antenna. The DBM_EEMD algorithm, a further development of the ensemble empirical mode decomposition (EEMD) algorithm, optimizes signal features and enhances the algorithm's noise reduction performance by performing a double-sided bidirectional mirror (DBM) extension on the decomposed signal, particularly improving the accuracy of weak pulse signal extraction.

[0053] Before performing high-rate upsampling of the signal, considering that the INTF antenna operates in the VHF band, the 400M sampling rate acquisition card used only makes the ratio of the sampling rate to the cutoff frequency slightly higher than 2 (400 / 180). Even if an acquisition card with a higher sampling rate is used in the future, this ratio will be difficult to exceed 10 in a short period of time, resulting in the detected VHF radiation signal as shown in the original data in Figure 3. Figure 3 is a schematic diagram of the comparison of the original data and the upsampling data provided by the embodiment of the present disclosure, wherein the original data is presented as a broken line consisting of a scattered point every 2.5 nanoseconds. This broken line waveform is not differentiable and cannot be directly optimized and filtered using DBM_EEMD. In addition, due to the discreteness of the VHF radiation signal, the measurement values ​​within the narrow window are very limited, resulting in large errors when calculating the correlation coefficients of the window waveforms on different antennas using the cross-correlation method, making it difficult to achieve the expected signal matching effect. Although the time resolution of the waveform has reached 2.5 nanoseconds, this time resolution is still insufficient to achieve three-dimensional positioning with a spatial resolution of decimeters or even higher. To solve the above problems, the embodiments of the present disclosure provide a method for performing high-rate upsampling of the original VHF radiation signal using polyphase filter technology to achieve high-rate sampling of the original VHF radiation signal (for example, 100-500 times). This can greatly improve the time resolution of the signal and the improvement of the non-differentiability of the original signal, not only improving the accuracy of DBM_EEMD decomposition and reconstruction of the VHF radiation signal, but also enhancing the effect of cross-correlation analysis of different antenna signals.

[0054] After determining the main characteristics of the VHF radiation signal through signal feature analysis, the embodiment of the present disclosure uses a bandpass filter constructed based on DBM_EEMD to control the quality and reconstruct the VHF radiation signal to retain the high-frequency signal components of the VHF radiation signal, thereby effectively improving the accuracy of waveform matching and helping to more accurately capture the pulse peak time, which is crucial for obtaining the time difference of the same pulse signal between different antennas and thus achieving accurate positioning of the radiation source.

[0055] It is understandable that although some of the true signal components of the noisy VHF radiation signal are lost after being processed by the above-mentioned bandpass filter, this sacrifice of some signal components is extremely valuable for the accurate positioning of lightning discharge events. The reason is that only a very small amount of noise components remain in the signal, which greatly reduces the impact of noise. The signal components after bandpass filtering are relatively simple and the bandwidth is narrow, which effectively improves the accuracy of signal matching and helps to significantly enhance the richness and accuracy of pulse information extraction in the waveform.

[0056] Step a2: Perform signal matching on the VHF radiation signals received on all VHF antennas after preprocessing, determine the peak time when the same pulse signal reaches each VHF antenna, and determine the time difference based on the peak times corresponding to each two different VHF antennas.

[0057] Regarding step a2 above, the implementation method provided in the embodiment of the present disclosure includes the following steps:

[0058] Step a2-1: Use the generalized cross-correlation technique to match the very high frequency radiation signals on different VHF antennas. During the matching process, the signal to be matched on each VHF antenna consists of a main window and two auxiliary windows. For the signal to be matched on the center antenna, the values ​​of its two auxiliary windows are set to 0. For VHF antennas other than the center antenna, the size of the auxiliary window is determined by the length of the baseline formed with the center antenna.

[0059] In the disclosed embodiment, after completing the feature analysis and upsampling of the original VHF radiation signal in step a2, and performing quality control and reconstruction of the signal by constructing a bandpass filter using DBM_EEMD, the signals from different antennas can be matched using generalized cross-correlation technology, preparing for further pulse signal identification and matching. Therefore, the disclosed embodiment first provides a signal matching method based on a variable-scale window. For ease of understanding, please refer to Figure 4, which is a schematic diagram of the generalized cross-correlation waveform matching method provided in the disclosed embodiment, combining a main window and a variable auxiliary window.

[0060] As shown in Figure 4, the disclosed embodiment divides the VHF radiation signal of 48 sampling points into three parts: the main window (Main Mindow) is located in the middle and is 16 sampling points long, with an auxiliary window of the same length on each side. In conjunction with the multi-antenna single-station example layout shown in Figure 1, in the specific implementation process, antenna A (chA) is used as the central antenna, the main window intercepts 16 sampling points, and the auxiliary window is set to 0. For antennas B to G (chX, X = B...G), although the main window intercepts the real signal in the same time period as chA, their auxiliary windows are extended to the real signal of N sampling points, where the length of the auxiliary window is calculated based on the optical path difference between the baseline formed by the current antenna and the central antenna.

[0061] For example, assuming the short baseline length L1 in Figure 1 is 11.76 meters, when the VHF radiation signal generated by lightning is received by the INTF antenna, the resulting time difference will not exceed the 39 nanoseconds required for light to travel 11.76 meters. At a 400 MHz sampling rate (with a time resolution of 2.5 nanoseconds), this corresponds to a deviation of approximately 16 sampling points (applicable to antennas BCDEF). For antenna G, assuming the distance between A and G is 10 meters, 14 sampling points is the upper limit of its auxiliary window. Although this difference is only two sampling points compared to other antennas, for the 400 MHz sampling rate VHF signal in the ultra-short baseline layout shown in Figure 1, even a single sampling point mismatch can seriously affect positioning. Therefore, the auxiliary window length is set to 16 or 14 sampling points. To maintain similar weighting between the main and auxiliary windows, the main window length is also set to 16 sampling points.

[0062] This combination of a main window and a variable auxiliary window has multiple advantages. First, it avoids the possible reuse of pulse signals in positioning, because on the time axis of chA, when traversing the signal with 16 sampling points (40 nanoseconds), the signals on other antennas (the main window and the two auxiliary windows) will be matched with the main window signal form of chA through the generalized cross-correlation method, thereby avoiding repeated positioning information. Secondly, this combination method actually breaks through the minimum window width limit of the window matching algorithm based on the INTF antenna baseline length. In particular, when there is only a main window but no auxiliary window on chA, the accuracy of window matching by generalized cross-correlation is significantly improved, providing higher accuracy for matching and information extraction of pulse signals on a smaller time scale.

[0063] Step a2-2: Use a microscale window with a preset width to traverse the matching results. When the number of pulse peaks in the microscale window is consistent with the number of VHF antennas, it is determined that the pulses on all VHF antennas are detected.

[0064] In order to match pulse signals and extract information on a smaller time scale, the embodiment of the present disclosure also provides a pulse extraction under a microscale window, that is, after signal matching based on a variable-scale window, a microscale window with a width of only preset nanoseconds (wherein the specific value of the preset nanoseconds can be determined according to the signal characteristics, such as 5 nanoseconds) is used to traverse the window. The goal is to find a specific combination of 7 pulse peaks in the microwindow, so as to accurately extract the time of the matching pulse peak.

[0065] Continuing with FIG4 , when the signals of antennas B to G (chX, X=B…G) are offset by Δt relative to the signal of antenna chA, AXAfter that, window matching is achieved, and the result is shown in FIG5 , which is a schematic diagram of VHF waveforms matched together by generalized cross-correlation technology provided by an embodiment of the present disclosure. In the previous interferometer positioning technology and the long baseline three-dimensional lightning location system LMA, this time difference Δt AX This technique is used to obtain the direction or location of a radiation source. However, in window-based positioning techniques, the correlation between time series within the windows on two antennas is primarily affected by one or several strong pulse signals. Due to interference from other signals within the window, the inter-antenna delay calculated using the generalized cross-correlation method often deviates from the peak moment of the strongest pulse within the window.

[0066] Continuing with Figure 5, in a specific implementation, the peak times of all pulses with peak values ​​greater than a set threshold can be identified within the main window of chA at the central station. For example, the peak time of the strongest pulse on chA in Figure 5 is Tp. A microscale window with a width of 5 nanoseconds is then constructed, centered at Tp, covering chA and chX (X = B…G). Whether a pulse peak appears within the window on chX (X = B…G) is detected. If pulses are detected on all seven antennas within the 5 nanosecond microscale window, the next step is performed.

[0067] Step a2-3: Perform similarity judgment on the waveforms of the pulses detected on all VHF antennas. When the correlation coefficient of the pulses on every two VHF antennas is greater than a preset threshold, extract the peak moments of the pulses on all VHF antennas, and determine the time difference based on the peak moments corresponding to two different VHF antennas.

[0068] In the embodiment of the present disclosure, it is necessary to first perform a similarity judgment on all the pulse waveforms that are preliminarily matched in the above steps. Specifically, with the peak moments of each successfully paired pulse (TpA, TpB, ..., TpG) as the center, intercept waveforms with a width of 10 nanoseconds and calculate the correlation coefficients between them. Only when the correlation coefficients between these pulse waveforms are greater than 0.8, are these pulse signals considered to originate from the same "lightning" event. The peak moments of the pulses that are confirmed to be successfully paired are TpA, TpB, ..., TpG, respectively, and then the time difference between the arrival of the same pulse information at two different antennas can be determined based on these peak moments. For example, taking chA and chB as an example, the time difference between the arrival of the same pulse signal at antennas A and B is Δt AB =T pA -T pB The antenna array consisting of n antennas will produce Group time difference τ ij , where τ ij It is the time difference between the same radiation source reaching the i-th and j-th antennas, n is the number of antennas, and m=2.

[0069] Continuing with the embodiment shown in FIG2 , in step S202 , the arrival time of the 7-station matching pulse can be used to perform group interferometer positioning. In conjunction with FIG1 , a six-antenna regular pentagonal interferometer array (ABCDEF) can be used to obtain the angular error-free two-dimensional direction (Az_0, El_0) of the pulse signal, and then five sets of equilateral triangle interferometer arrays (GBD, GCE, GDF, GEB, GFC) with angular error, each containing three antennas, can be used to obtain the angular error two-dimensional direction (Az_0, El_0) of the pulse signal. i ,El i ; i=1,2…5).

[0070] For ease of understanding, we first introduce the basic general solution method for interferometer positioning.

[0071] In an array with at least three antennas deployed, the number of baseline combinations is n(n-1) / 2n, as shown in Figure 6a. Figure 6a is a geometric diagram for determining the two-dimensional position of a source, with the baseline direction and the source with a time delay τ shown in Figure 6a. The arrival time difference τ between the two antennas is d In the cosine projection, a straight line perpendicular to the baseline is defined, and its mathematical expression is shown in equation (1):

[0072] Among them, cos(α) and cos(β) are the cosines of the azimuth angles of the baseline formed by the i-th and j-th antennas, which are unknown parameters; θ ij is the angle between the baseline formed by the i-th and j-th antennas and the north direction, d ij is the baseline length formed by the i-th and j-th antennas, τ ij is the time difference between the arrival of the same radiation source at the i-th and j-th antennas. As long as the time delay is accurate, equation (1) can be solved.

[0073] In the specific implementation process, the nonlinear least squares method can be used to solve Equation (1), which is widely used in three-dimensional lightning location systems. In the interferometer array detection system, the antenna array of n antennas can form n(n-1) / 2 equations of the form (1). There are two unknown parameters cos(α) and cos(β) in Equation (1), so when there are three antennas forming three baselines, Equation (1) is a supersolvable. The result obtained by the nonlinear least squares method is the projection of the radiation source on the cosine plane, which satisfies Equation (2):

[0074] Where Δt rms Indicates the error level of pulse peak time extraction. The estimated time error of INTF at a sampling frequency of 400 MHz does not exceed 2.5 nanoseconds (1 sampling point). It represents the arrival time difference of the same radiation source on the i-th and j-th antennas obtained by nonlinear least squares iteration. represents the observed arrival time difference of the same radiation source on the i-th and j-th antennas. The nonlinear least squares method is used to solve a set of cos(α) and cos(β) to minimize the value of equation (2), as shown in Figure 6b. Figure 6b is a schematic diagram of the positioning error evaluation method using a three-antenna array as an example. This error is a calculation error caused by a slight time error, which is different from the system error involved in the embodiment of the present disclosure. This is because the basic principle of interferometer positioning is based on the assumption that the radiation signal is transmitted as a plane wave, while the actual situation is that the radiation signal is transmitted as a spherical wave. The plane wave assumption will lead to system errors. The distribution characteristics of the system error are related to the number of antennas and antenna layout. The stronger the symmetry of the antenna layout, the smaller the system error. The system error of the equilateral triangle (three antennas) interferometer is periodically distributed. When the number of antennas increases to more than 5 and the antenna layout forms a highly symmetrical structure with central symmetry and axis symmetry, the system error is completely eliminated.

[0075] 6b, which shows the intersection of the pulse arrival time differences of the two baselines on the projection plane, and the determined azimuth coordinates (cos(α), cos(β)). According to the two-dimensional coordinates S on the cosine projection plane p (cos(α), cos(β)), the two-dimensional spatial coordinates of the pulse radiation source can be calculated, as shown in formula (3):

[0076] According to the above basic general solution method, the embodiment of the present disclosure first uses a six-antenna (ABCDEF) interferometer array, with antenna A as the reference, to obtain the first azimuth and first elevation angle (Az_0, El_0) of the radiation source. Among them, when the interferometer array antenna is greater than or equal to 5 sets and the antenna layout is symmetrically distributed, the systematic error of the two-dimensional positioning result is completely eliminated, so there is no systematic error in the first azimuth and the first elevation angle. Then, a three-antenna interferometer array (GBD, GCE, GDF, GEB, GFC) is used, with antenna G as the reference, to obtain the second azimuth and second elevation angle of the radiation source, which are recorded as (Az_0, El_0). ′i ′ ,El i ′ ; i = 1, 2, ... 5). When the interferometer array antennas are fewer than five, the two-dimensional positioning results contain periodic systematic errors. The periodic distribution characteristics of these systematic errors are related to the antenna layout. Therefore, there are systematic errors in the second azimuth and the second azimuth.

[0077] After obtaining the first azimuth and elevation angles (Az_0, E1_0) without systematic errors and multiple sets of second azimuth and elevation angles with systematic errors, the correction method for step S203 may include, but is not limited to: establishing azimuth and elevation correction formulas based on known parameters. For example, a correction function is established by taking into account factors such as system deviation and environmental influences, and the second azimuth and elevation angles are substituted into the function for correction calculation to obtain target values. Alternatively, the systematic errors between the azimuth and elevation angles and the true values ​​may be obtained by collecting multiple sets of second azimuth and elevation angles under known parameters, comparing and statistically analyzing them. Subsequently, the second azimuth and elevation angles are corrected based on this set of calibration parameters. Therefore, in the embodiment of the present disclosure, combined with the observation layout shown in FIG1 , since the cosine plane of the positioning result of the three-antenna interferometer array (GBD, GCE, GDF, GEB, GFC) is parallel to the plane formed by the three antennas and has an intersection angle with the cosine plane formed by the antenna BCDEF, the cosine plane formed by GBD, GCE, GDF, GEB, and GFC can be rotated to be parallel to the cosine plane formed by ABCDEF (i.e., the BCDEF plane) through the polar coordinates of the plane formed by the three antennas and the cosine plane formed by the five antennas BCDEF, and the corrected target azimuth and target elevation (Az′) are obtained. i , El′ i ; i=1,2…5).

[0078] Based on the corrected target azimuth and target elevation (Az′ i , El′ i ; i=1, 2...5), the radiation source can be three-dimensionally positioned. Continuing with the embodiment shown in 2, in an optional embodiment, for step S204, the embodiment of the present disclosure provides the following implementation:

[0079] Step b1: Determine a first ray expression to be solved with the coordinate origin as the starting point and the first azimuth angle and the first elevation angle as the direction vectors; determine a second ray expression to be solved with antenna G as the starting point and the center azimuth angle and the center elevation angle of all target azimuth angles and target elevation angles as the direction vectors; both the first ray expression to be solved and the second ray expression to be solved contain parameters to be solved;

[0080] Step b2: constructing a distance function between the first ray expression to be solved and the second ray expression to be solved, and performing nonlinear optimization on the distance function to determine the target parameters that minimize the function value of the distance function;

[0081] Step b3: Solve the first ray expression to be solved according to the target parameters to obtain the three-dimensional coordinates of the radiation source.

[0082] For easier understanding of the above implementation, please refer to FIG7a, which is a schematic diagram of the three-dimensional positioning principle provided by the embodiment of the present disclosure. Among them, the first azimuth and the second azimuth (Az_0, El_0) obtained by the interferometer array composed of ABCEDF have a systematic error of 0, and theoretically they should point to the true direction of the radiation source Q. The target azimuth and target elevation (Az′) obtained by the corrected three-antenna interferometer array (GBD, GCE, GDF, GEB, GFC) are i ,El′ i ; i = 1, 2…5) have systematic errors and are arranged periodically according to the interferometer array baseline layout, which makes it impossible for the two-dimensional positioning results of these five sets of three-antenna interferometer arrays (GBD, GCE, GDF, GEB, GFC) for the same radiation source Q to intersect at Q.

[0083] For example, continuing with Figure 7a, assume that the central azimuth and central elevation angles of the five rays drawn from antenna point G point to Q, which can be expressed by formula (4):

[0084] where N is the number of antennas in the three-antenna interferometer array. Ideally, (Az_0, El_0) and (Az′, El′) should intersect at Q. However, due to the random positioning error caused by the 2.5ns time resolution at a 400M sampling rate, Q and Q do not overlap, meaning that (Az_0, El_0) and (Az′, El′) cannot intersect.

[0085] However, the embodiment of the present disclosure, based on the layout scheme shown in FIG1 , can make the target azimuth and target elevation (Az′) obtained by the five sets of three-antenna interferometer arrays (GBD, GCE, GDF, GEB, GFC) i , El′ i ; i = 1, 2…5) are stably distributed around the true position of the radiation source Q, as shown in Figures 7b and 7c. Figure 7b is a schematic diagram showing the uniform distribution of the true azimuth angles of the target azimuth angles around the radiation source Q obtained by the five sets of three-antenna interferometer arrays centered on antenna G in the embodiment of the present disclosure. Figure 7c is a schematic diagram showing the uniform distribution of the true elevation angles of the target elevation angles around the radiation source Q obtained by the five sets of three-antenna interferometer arrays centered on antenna G in the embodiment of the present disclosure. Therefore, the two-dimensional direction (Az_0, El_0) obtained by the six-antenna interferometer array ABCEDF can be used as the reference direction, that is, the direction OQ in Figure 7a is the reference direction. When the ray L2 (Az′, El′) is closest to the ray L1 (Az_0, El_0), the coordinates of the point on L1 are the three-dimensional coordinates (x, y, z) of the radiation source Q that need to be solved. Therefore, for the above steps b1 to b3, it can be understood as follows:

[0086] With the coordinate origin O as the starting point, the first azimuth and the first elevation (Az_0, El_0) are the direction vectors (denoted as ) and the parameter to be solved (denoted as t), construct the first ray expression L1 to be solved, expressed as Where A is the coordinate of the origin O.

[0087] Taking antenna G as the starting point, the central azimuth and central elevation of all target azimuths and target elevations (denoted as ) is the direction vector, and the parameter s related to the parameter t to be solved, the second ray expression L2 to be solved is constructed, which is expressed as Here, s is a function of t.

[0088] Then, the distance function can be expressed as This is a common nonlinear optimization problem that can be solved using existing solutions, which will not be described here. By finding the optimal parameter t that minimizes the distance function, the coordinates of the corresponding point on L1 can be calculated, that is, The real three-dimensional coordinates (x, y, z) of the radiation source Q can be obtained.

[0089] Optionally, after determining the three-dimensional coordinates of the radiation source, the time when the radiation source undergoes a lightning event (i.e., emits a very high frequency radiation signal) can also be determined. Therefore, for step S205, the implementation method can be: using the calculated Q (x, y, z) coordinates, and then using the time it takes for the VHF radiation signal to be transmitted from the radiation source Q to the antenna A at the speed of light, calculate the occurrence time t0 of the radiation source, and finally complete the spatiotemporal positioning of the radiation event, expressed as Q (t0, x, y, z).

[0090] From the above embodiments, it can be seen that the ultra-short baseline lightning location method based on a multi-antenna single-station stereoscopic layout provided by the embodiments of the present disclosure has the following advantages:

[0091] First, the embodiment of the present disclosure adopts an ultra-wideband (50-180MHz) and highly sensitive radiation signal receiving antenna, and uses two high-speed data acquisition cards with a sampling frequency of 400M and a sampling accuracy of 14bit. The time resolution of the detected lightning discharge events is very high, reaching the nanosecond level. Combined with signal processing and matching technology, it is possible to obtain ultra-fine three-dimensional channels and development characteristics of the lightning discharge process with nanosecond resolution.

[0092] Secondly, the ultra-short baseline single-station multi-antenna three-dimensional layout scheme proposed in the embodiment of the present disclosure fully utilizes the system error characteristics of interferometer arrays with different numbers of antennas, that is, the system error of the six-antenna regular polygon interferometer array is 0, and the system error of the three-antenna equilateral triangle interferometer array is periodically distributed. The multi-antenna combined interference positioning intersection technology proposed in the present disclosure can accurately obtain the three-dimensional spatial position and time of the lightning VHF radiation signal.

[0093] Furthermore, the disclosed embodiments utilize ultra-high-rate upsampling technology to process the original observed signal. The upsampled signal is then optimized and bandpass filtered using DBM-EEMD technology, resulting in a cross-correlation matching technique that combines a main window with a resizable auxiliary window. This process not only improves the temporal resolution of VHF radiation signals but also significantly enhances the accuracy of waveform cross-correlation matching.

[0094] Finally, compared to the centroid method commonly used in traditional lightning location technology, the disclosed embodiments provide a novel pulse matching technique based on signal matching within a variable-scale window and pulse extraction within a microscale window. This technique can accurately match and locate every pulse event in a lightning VHF radiation signal, significantly improving the ability to identify and locate lightning discharge events. By utilizing various combinations of different numbers of antennas, two-dimensional positioning information is acquired from six interferometer arrays, and coordinate corrections are performed. Finally, a multi-interferometer array intersection technique is used to achieve precise three-dimensional positioning of lightning radiation signals. This yields richer and more accurate lightning discharge information than traditional two-dimensional interferometer array positioning methods and long-baseline lightning location systems.

[0095] Based on the same concept as FIG2 , an embodiment of the present disclosure further provides an ultra-short baseline lightning locating device 300 with a multi-antenna, monostatic, three-dimensional layout. FIG8 is a functional module diagram of the ultra-short baseline lightning locating device 300 with a multi-antenna, monostatic, three-dimensional layout provided by an embodiment of the present disclosure, including: an acquisition module 310 , a preprocessing module 320 , a two-dimensional positioning module 330 , a correction module 340 , and a three-dimensional positioning module 350 .

[0096] The acquisition module 310 is configured to acquire the very high frequency radiation signal received by each VHF antenna, and the pre-processing module 320 is configured to determine the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal;

[0097] The two-dimensional positioning module 330 is configured to perform interferometer positioning using an equilateral pentagonal interferometer array and an equilateral triangle interferometer array based on a time difference of a same pulse signal between different VHF antennas, respectively, to obtain a set of first azimuth angles and first elevation angles and multiple sets of second azimuth angles and second elevation angles of a radiation source emitting a very high frequency radiation signal; wherein the first azimuth angle and the first elevation angle have no systematic error, and the multiple sets of second azimuth angles and second elevation angles have systematic errors;

[0098] A correction module 340 is configured to correct the multiple sets of second azimuth angles and second elevation angles to obtain multiple sets of target azimuth angles and target elevation angles;

[0099] The three-dimensional positioning module 350 is configured to determine a target location point in the reference direction, using the direction of the first azimuth angle and the first elevation angle as a reference direction, minimize the distance between the ray in the reference direction and the center of the ray in the reference direction using multiple sets of target azimuth angles and target elevation angles as reference directions, and determine the three-dimensional coordinates of the radiation source based on the target location point, the first azimuth angle, and the second azimuth angle;

[0100] The three-dimensional positioning module 350 is configured to determine the occurrence time of the VHF radiation signal based on the three-dimensional coordinates and the time it takes for the VHF radiation signal to be transmitted to the central VHF antenna at the speed of light.

[0101] It can be understood that the acquisition module 310, preprocessing module 320, two-dimensional positioning module 330, correction module 340 and three-dimensional positioning module 350 provided in the embodiment of the present disclosure can collaboratively execute the various steps in Figure 2 to achieve corresponding technical effects.

[0102] In an optional embodiment, there are seven VHF antennas, including antenna A to antenna G; antenna A is the central VHF antenna, located directly above the coordinate origin; antennas B to antenna F are arranged around the coordinate origin and are equidistant from the coordinate origin; antennas B to antenna F form a highly symmetrical equilateral pentagon, and antennas A to antenna F form a set of equilateral pentagonal interferometer arrays; antennas A and antennas B to antenna F form an equilateral triangle with two adjacent antennas forming an equilateral triangle; antenna G is located directly above antenna A, and the height of antenna G from the coordinate origin is such that antenna G and the antennas spaced apart from antennas B to antenna F form five sets of equilateral triangle interferometer arrays.

[0103] In an optional embodiment, the three-dimensional positioning module 350 is specifically configured to: determine a target position point in the reference direction with the direction of the first azimuth angle and the first elevation angle as the reference direction, so that the center distance between the ray passing through the target position point in the reference direction and the ray in the reference direction with multiple groups of target azimuth angles and target elevation angles is minimized, and determine the three-dimensional coordinates of the radiation source based on the target position point, the first azimuth angle and the second azimuth angle, including: determining a first ray expression to be solved with the coordinate origin as the starting point and the first azimuth angle and the first elevation angle as the direction vector, and determining a second ray expression to be solved with the antenna G as the starting point and the center azimuth angle and the center elevation angle of all target azimuth angles and target elevation angles as the direction vector; both the first ray expression to be solved and the second ray expression to be solved contain parameters to be solved; construct a distance function between the first ray expression to be solved and the second ray expression to be solved, and perform nonlinear optimization on the distance function to determine the target parameters when the function value of the distance function is minimized; solve the first ray expression to be solved according to the target parameters to obtain the three-dimensional coordinates of the radiation source.

[0104] In an optional embodiment, the correction module 340 is specifically configured to rotate each set of second azimuth angles and second elevation angles through polar coordinates between a cosine plane formed by five sets of equilateral triangle interferometer arrays and a cosine plane formed by an equilateral pentagonal interferometer array, and use each set of corrected second azimuth angles and second elevation angles as the target azimuth angle and target elevation angle.

[0105] In an optional embodiment, the acquisition module 310 is specifically configured to acquire the very high frequency radiation signal received by each VHF antenna through an acquisition card, and the preprocessing module 320 is specifically configured to preprocess the acquired very high frequency radiation signal; perform signal matching on the very high frequency radiation signals received on all VHF antennas after preprocessing, determine the peak moment when the same pulse signal arrives at each VHF antenna, and determine the time difference based on the peak moments corresponding to each two different VHF antennas.

[0106] In an optional embodiment, the preprocessing module 320 is specifically configured to analyze the very high frequency radiation signal to obtain the background noise signal and the main components of the noisy very high frequency radiation signal; use a multi-phase filter to perform high-rate upsampling on the original signal to improve the time accuracy of the signal and change the non-differentiable characteristics of the original signal; construct a bandpass filter to filter the very high frequency radiation signal to retain the high-frequency signal component.

[0107] In an optional embodiment, the preprocessing module 320 is specifically configured to use generalized cross-correlation technology to match the very high frequency radiation signals on different VHF antennas; wherein, during the matching process, the signal to be matched on each VHF antenna consists of a main window and two auxiliary windows; for the signal to be matched of the central antenna, the values ​​of its two auxiliary windows are set to 0; for other VHF antennas except the central antenna, the scale of the auxiliary window is determined by the length of the baseline formed with the central antenna; a microscale window with a preset width is used to traverse the matching results, and when the number of pulse peaks in the microscale window is consistent with the number of VHF antennas, it is determined that the pulses on all VHF antennas are detected; the waveforms of the pulses detected on all VHF antennas are judged for similarity, and when the correlation coefficient of the pulses on each two VHF antennas is greater than a preset threshold, the peak moments of the pulses on all VHF antennas are extracted, and the time difference is determined based on the peak moments corresponding to the two different VHF antennas.

[0108] It should be noted that the division of modules in the above embodiments of the present application is illustrative and is only a logical functional division. In actual implementation, there may be other division methods. In addition, the functional units in the various embodiments of the present application may be integrated into a processing unit, or may exist separately physically, or two or more units may be integrated into a single unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units.

[0109] Based on the schematic diagram of a multi-antenna monopole stereoscopic layout shown in FIG1 and the concept shown in FIG2 , an embodiment of the present disclosure further provides an ultra-short baseline lightning three-dimensional positioning system with a multi-antenna monopole stereoscopic layout, comprising: a computer device with multiple very high frequency (VHF) antennas; wherein the multi-antenna monopole stereoscopic layout includes an interferometer array composed of different numbers of VHF antenna combinations; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; the multiple very high frequency (VHF) antennas are configured to receive very high frequency radiation signals and transmit them to the computer device, and the computer device is configured to execute the ultra-short baseline lightning positioning method with a multi-antenna monopole stereoscopic layout provided by the embodiment of the present disclosure.

[0110] Based on the embodiment shown in FIG2 , the embodiment of the present application further provides a computer device 400 , which is configured to execute the ultra-short baseline lightning location method with a multi-antenna monostatic stereoscopic layout provided by the embodiment of the present disclosure.

[0111] Please refer to Figure 9, which is a block diagram of a computer device 400 according to an embodiment of the present disclosure. Computer device 400 includes a memory 401, a processor 402, a communication interface 403, and a bus 404. Memory 401, processor 402, and communication interface 403 are electrically connected to each other, directly or indirectly, to enable data transmission or interaction. For example, these components may be electrically connected to each other via one or more communication buses or signal lines.

[0112] Optionally, bus 404 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, control buses, etc. For ease of illustration, FIG9 shows only one thick line, but this does not mean that there is only one bus or only one type of bus.

[0113] In the embodiment of the present application, the processor 402 can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in the processor. The software module can be located in the memory 401, and the processor 402 reads the program instructions in the memory 401 and completes the steps of the above method in combination with its hardware.

[0114] In the embodiment of the present application, the memory 401 may be a non-volatile memory, such as a hard disk (HDD) or a solid-state drive (SSD), or a volatile memory (Volatile Memory), such as RAM. The memory may also be any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application may also be a circuit or any other device that can implement a storage function, configured to store instructions and / or data.

[0115] The memory 401 can be configured to store software programs and modules, such as the instructions / modules of the ultra-short baseline lightning location device 300 with a multi-antenna, single-stand, three-dimensional layout provided in the embodiments of the present disclosure. These instructions / modules can be stored in the memory 401 in the form of software or firmware or in the operating system (OS) of the computer device 400. The processor 402 executes the software programs and modules stored in the memory 401 to perform various functional applications and data processing. The communication interface 403 can be configured to communicate signaling or data with other node devices.

[0116] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0117] It is understood that the structure shown in Figure 9 is merely illustrative, and the computer device 400 may also include more or fewer components than shown in Figure 9, or have a configuration different from that shown in Figure 9. Each component shown in Figure 9 may be implemented using hardware, software, or a combination thereof.

[0118] The computer device 400 can be any electronic product that can interact with a user, such as a personal computer, a tablet computer, a smart phone, a personal digital assistant (PDA), a game console, an interactive network television (IPTV), a smart wearable device, etc.

[0119] The computer device 400 may also include network devices and / or user devices. The network devices include, but are not limited to, a single network server, a server group consisting of multiple network servers, or a cloud based on cloud computing consisting of a large number of hosts or network servers.

[0120] The network where the computer device 400 is located includes but is not limited to the Internet, a wide area network, a metropolitan area network, a local area network, a virtual private network (VPN), etc.

[0121] Based on the above embodiments, the present application further provides a storage medium, in which a computer-readable storage medium stores a computer program. When the computer program is executed by a computer, the computer executes the ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout provided in the above embodiments.

[0122] Based on the above embodiments, the embodiments of the present application further provide a computer program. When the computer program is run on a computer, the computer executes the ultra-short baseline lightning location method with a multi-antenna monostatic stereoscopic layout provided in the above embodiments.

[0123] Based on the above embodiments, the present application also provides a chip, which is configured to read a computer program stored in a memory and to execute the ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout provided in the above embodiments.

[0124] The present application also provides a computer program product in an embodiment, including instructions, which, when executed on a computer, enable the computer to execute the ultra-short baseline lightning location method with a body multi-antenna single-station body layout provided in the above embodiments.

[0125] The present application embodiment is described with reference to the flow chart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present application.It should be understood that each flow process and / or box in the flow chart and / or block diagram and the flow process and / or box in the flow chart and / or block diagram can be realized by instructions.These instructions can be provided to the processor of general-purpose computer, special-purpose computer, embedded processing machine or other programmable data processing equipment to produce a machine, so that the instruction executed by the processor of computer or other programmable data processing equipment produces the device configured to realize the function specified in one flow chart flow chart or multiple flow charts and / or one block or multiple blocks of block diagram.

[0126] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0127] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0128] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims. Industrial Applicability

[0129] By adopting the above scheme, ultra-high-resolution three-dimensional positioning of the lightning discharge process can be achieved. The time resolution of locating lightning discharge events can reach the nanosecond level, and the theoretical resolution of spatial error is increased to the decimeter level.

Claims

1. An ultra-short baseline lightning location method with a multi-antenna single-station three-dimensional layout, characterized in that: The multi-antenna single-body configuration includes an interferometer array composed of different numbers of very high frequency (VHF) antennas; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; the method includes: collecting the very high frequency radiation signal received by each of the VHF antennas, and determining the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal; Based on the time difference of the same pulse signal between different VHF antennas, positioning is performed using an equilateral pentagonal interferometer array and an equilateral triangle interferometer array, respectively, to obtain a set of first azimuth angles and first elevation angles and multiple sets of second azimuth angles and second elevation angles of a radiation source emitting the very high frequency radiation signal; wherein the first azimuth angles and the first elevation angles have no systematic error, and the multiple sets of second azimuth angles and the second elevation angles have systematic errors; Correcting the plurality of sets of the second azimuth angles and the second elevation angles to obtain a plurality of sets of target azimuth angles and target elevation angles; Taking the direction of the first azimuth angle and the first elevation angle as a reference direction, determining a target location point in the reference direction so that the center distance between a ray passing through the target location point in the reference direction and a ray in the reference direction with multiple sets of the target azimuth angles and target elevation angles as reference directions is minimized, and determining the three-dimensional coordinates of the radiation source based on the target location point, the first azimuth angle, and the second azimuth angle; The generation time of the very high frequency radiation signal is determined according to the three-dimensional coordinates and the time when the very high frequency radiation signal is transmitted to the central VHF antenna at the speed of light.

2. The ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout according to claim 1 is characterized in that: There are seven VHF antennas, including antenna A to antenna G; antenna A is the central VHF antenna, located directly above the coordinate origin; antennas B to antenna F are arranged around the coordinate origin and are equidistant from the coordinate origin; antennas B to antenna F form a highly symmetrical equilateral pentagon, and antennas A to antenna F form a set of equilateral pentagonal interferometer arrays; antennas A and antennas B to antenna F, each adjacent to each other, form an equilateral triangle; antenna G is located directly above antenna A, and the height of antenna G from the coordinate origin is such that antenna G and the antennas spaced apart from antennas B to antenna F form five sets of equilateral triangle interferometer arrays.

3. The ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout according to claim 2 is characterized in that: Taking the direction of the first azimuth angle and the first elevation angle as a reference direction, determining a target position point in the reference direction so that the center distance between a ray passing through the target position point in the reference direction and a ray in the reference direction with multiple sets of the target azimuth angles and target elevation angles as reference directions is minimized, and determining the three-dimensional coordinates of the radiation source based on the target position point, the first azimuth angle, and the second azimuth angle, including: A first ray expression to be solved is determined with the coordinate origin as a starting point and the first azimuth angle and the first elevation angle as direction vectors; a second ray expression to be solved is determined with the antenna G as a starting point and the central azimuth angle and central elevation angle of all the target azimuth angles and the target elevation angles as direction vectors; both the first ray expression to be solved and the second ray expression to be solved include parameters to be solved; Constructing a distance function between the first ray expression to be solved and the second ray expression to be solved, and performing nonlinear optimization on the distance function to determine a target parameter that minimizes a function value of the distance function; The first ray expression to be solved is solved according to the target parameters to obtain the three-dimensional coordinates of the radiation source.

4. The ultra-short baseline lightning location method with a multi-antenna single-station three-dimensional layout according to claim 2 or 3, characterized in that: Correcting the multiple sets of the second azimuth angles and the second elevation angles to obtain multiple sets of target azimuth angles and target elevation angles includes: Each group of the second azimuth angle and the second elevation angle is rotated by using the polar coordinates between the cosine plane formed by the five sets of equilateral triangle interferometer arrays and the cosine plane formed by the equilateral pentagonal interferometer array, and each group of the second azimuth angle and the second elevation angle after correction is used as the target azimuth angle and target elevation angle.

5. The ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout according to any one of claims 1 to 4, characterized in that: Collecting the very high frequency radiation signal received by each of the VHF antennas, and determining the time difference of the same pulse signal between different VHF antennas based on the very high frequency radiation signal, including: The VHF radiation signal received by each of the VHF antennas is collected by an acquisition card, and the VHF radiation signal is pre-processed; Signal matching is performed on the very high frequency radiation signals received on all the VHF antennas after preprocessing to determine the peak moment when the same pulse signal reaches each VHF antenna, and the time difference is determined according to the peak moments corresponding to each two different VHF antennas.

6. The ultra-short baseline lightning location method with a multi-antenna single-station stereoscopic layout according to claim 5 is characterized in that: Preprocessing the very high frequency radiation signal includes: Analyzing the very high frequency radiation signal to obtain a background noise signal and main components of the noisy very high frequency radiation signal; Use a polyphase filter to perform high-rate upsampling on the original signal to improve the time accuracy of the signal and change the non-differentiable characteristics of the original signal; A bandpass filter is constructed to filter the very high frequency radiation signal to retain the high frequency signal component.

7. The ultra-short baseline lightning location method with a multi-antenna single-station three-dimensional layout according to claim 5 or 6, characterized in that: Performing signal matching on the very high frequency radiation signals received by all the VHF antennas after preprocessing, determining the peak moment when the same pulse signal arrives at each VHF antenna, and determining the time difference according to the peak moments corresponding to each two different VHF antennas, including: The VHF radiation signals on different VHF antennas are matched using a generalized cross-correlation technique; wherein, during the matching process, the signal to be matched on each VHF antenna consists of a main window and two auxiliary windows; for the signal to be matched on the center antenna, the values ​​of its two auxiliary windows are set to 0; for VHF antennas other than the center antenna, the size of the auxiliary windows is determined by the length of the baseline formed with the center antenna; Using a microscale window with a preset width to traverse the matching results, when the number of pulse peaks in the microscale window is consistent with the number of the VHF antennas, it is determined that the pulses on all the VHF antennas are detected; A similarity judgment is performed on the waveforms of the pulses detected on all the VHF antennas. When the correlation coefficient of the pulses on every two VHF antennas is greater than a preset threshold, the peak moments of the pulses on all the VHF antennas are extracted, and the time difference is determined based on the peak moments corresponding to two different VHF antennas.

8. An ultra-short baseline lightning locating device with a multi-antenna single-station three-dimensional layout, characterized in that: The multi-antenna single-body stereoscopic layout includes an interferometer array composed of different numbers of VHF antenna combinations; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; including: an acquisition module configured to acquire a very high frequency radiation signal received by each of the VHF antennas; and a pre-processing module configured to determine a time difference of a same pulse signal between different VHF antennas based on the very high frequency radiation signal; a two-dimensional positioning module configured to perform interferometer positioning using an equilateral pentagonal interferometer array and an equilateral triangle interferometer array, respectively, based on a time difference of a same pulse signal between different VHF antennas, to obtain a set of first azimuth angles and first elevation angles and a plurality of sets of second azimuth angles and second elevation angles of a radiation source emitting the very high frequency radiation signal; wherein the first azimuth angles and the first elevation angles have no systematic error, and the plurality of second azimuth angles and the second elevation angles have systematic errors; A correction module configured to correct the multiple sets of the second azimuth angles and the second elevation angles to obtain multiple sets of target azimuth angles and target elevation angles; a three-dimensional positioning module configured to use the direction of the first azimuth angle and the first elevation angle as a reference direction, determine a target position point in the reference direction, minimize the distance between a ray in the reference direction and a center of rays in the reference directions using multiple sets of the target azimuth angles and target elevation angles as reference directions, and determine the three-dimensional coordinates of the radiation source based on the target position point and the first azimuth angle and the second azimuth angle; The three-dimensional positioning module is further configured to determine the occurrence time of the very high frequency radiation signal based on the three-dimensional coordinates and the time when the very high frequency radiation signal is transmitted to the central VHF antenna at the speed of light.

9. The ultra-short baseline lightning locating device with a multi-antenna single-station three-dimensional layout according to claim 8, characterized in that: There are seven VHF antennas, including antenna A to antenna G; antenna A is the central VHF antenna, located directly above the coordinate origin; antennas B to antenna F are arranged around the coordinate origin and are equidistant from the coordinate origin; antennas B to antenna F form a highly symmetrical equilateral pentagon, and antennas A to antenna F form a set of equilateral pentagonal interferometer arrays; antennas A and antennas B to antenna F form an equilateral triangle with two adjacent antennas forming an equilateral triangle; antenna G is located directly above antenna A, and the height of antenna G from the coordinate origin is such that antenna G and the antennas spaced apart from antennas B to antenna F form five sets of equilateral triangle interferometer arrays.

10. An ultra-short baseline lightning three-dimensional positioning system with a multi-antenna single-station three-dimensional layout, characterized by: include: Multiple very high frequency (VHF) antennas and a computer device; wherein the multi-antenna monopole stereoscopic layout includes an interferometer array composed of different numbers of the VHF antennas; the interferometer array includes a set of equilateral pentagonal interferometer arrays without angular error and multiple sets of equilateral triangle interferometer arrays with angular error; the multiple very high frequency (VHF) antennas are configured to receive very high frequency radiation signals and transmit them to the computer device, and the computer device is configured to execute the ultra-short baseline lightning location method of the multi-antenna monopole stereoscopic layout according to any one of claims 1 to 7.

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