Hybrid baseline based lightning location method and system

Abstract

This invention belongs to the field of lightning detection technology, specifically relating to a lightning location method and system based on hybrid baselines. It aims to solve the problem that existing technologies cannot integrate short-baseline and long-baseline lightning detection data, thus failing to achieve hybrid baseline lightning location. The invention includes: real-time acquisition, labeling, and compression of lightning electromagnetic pulse waveform data by long- and short-baseline electromagnetic pulse detection devices; real-time transmission of the compressed lightning electromagnetic pulse waveform data to a data processing center station; decompression and filtering of the lightning electromagnetic pulse waveforms at the data processing center station; and calculation of the accurate arrival time of the signal at each detection device at the data processing center station; and calculation of the lightning event location using a time-difference positioning algorithm at the data processing center station. This invention can significantly improve the detection range, efficiency, and positioning accuracy of existing lightning electromagnetic pulse detection systems, and is suitable for low-cost, large-area lightning event detection, especially for accurate real-time detection of thunderstorm activity in offshore areas.

Description

Technical Field

[0001] This invention belongs to the field of lightning detection technology, specifically relating to a lightning location method and system based on a hybrid baseline. Background Technology

[0002] A high-precision ground-based lightning detection system consists of at least four lightning electromagnetic pulse (EMP) detection devices and a data processing center. The detection devices transmit the detected EMP data to the data processing center via the internet, where the center calculates the location of the lightning EMP source. Based on the spatial distance between the detection devices, the system is divided into a short-baseline (100-300 km) positioning system and a long-baseline (>1000 km) lightning detection system.

[0003] Short baseline lightning detection systems operate in the very low frequency and low frequency bands, primarily detecting ground wave signals generated by lightning radiation. The detection range of a single station is 300–500 kilometers, and the average location error for lightning events within the network is less than 300 meters. A large number of detection devices are required to meet the real-time monitoring needs of lightning events in large areas.

[0004] Long baseline lightning detection systems operate in the very low frequency band and can simultaneously detect ground wave and sky wave signals generated by lightning radiation. The detection range of a single station is greater than 3,000 kilometers, and the average location error of lightning events within the network is 5-10 kilometers. Only a small number of detection devices are needed to meet the real-time monitoring of lightning events in a large area.

[0005] Currently, short-baseline and long-baseline lightning detection systems operate independently. Therefore, there is an urgent need in this field to develop new lightning detection technologies to integrate short-baseline and long-baseline lightning detection data and form a hybrid baseline very low frequency / low frequency lightning detection network, so as to achieve complementary advantages and comprehensively improve the quality of lightning detection data. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, namely, the inability to fuse short-baseline and long-baseline lightning detection data, thus hindering hybrid baseline lightning localization, this invention provides a hybrid baseline-based lightning localization method, comprising:

[0007] Step S10: Monitor the electromagnetic pulse signal of lightning radiation in real time using short-baseline lightning detection equipment and long-baseline lightning detection equipment;

[0008] Step S20: The detection device records the original waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold, and marks the trigger time of the original waveform data.

[0009] Step S30: The marked raw waveform data is encoded and compressed, and sent to the data processing center. After the data processing center decodes the data, it performs the fusion positioning calculation of short baseline lightning detection data and long baseline detection data.

[0010] Step S40: The data processing center outputs the location information of the hybrid baseline lightning event.

[0011] In some preferred embodiments, the original waveform data is obtained by:

[0012] The electromagnetic pulse signal sensed at the antenna end of the detection device is converted into a digital signal through an analog-to-digital conversion circuit;

[0013] The converted signals are formatted into a data file according to a set format to obtain the original waveform data.

[0014] In some preferred embodiments, the trigger time of the original waveform data is marked using the following method:

[0015] Obtain real-time high-precision time through satellite navigation and timing systems;

[0016] The trigger time is marked based on the real-time high-precision time.

[0017] In some preferred embodiments, the method for encoding and compressing the marked raw waveform data in step S30, and for the data processing center to decode the data, is as follows:

[0018] A = XD T

[0019] X′=AD

[0020] Where X = {x1, x2, ..., x} n} represents the original waveform data, n is the number of sampling points in the original waveform data, and D is a feature vector of dimension k. T Let be the transpose of eigenvector D, A be the encoded and compressed waveform data, and X′ be the similar data of the original waveform data X obtained after decoding the encoded and compressed waveform data A based on eigenvector D.

[0021] In some preferred embodiments, the feature vector D is calculated as follows:

[0022] Obtain a dataset X consisting of m raw waveform data points X. m Decentralize each original waveform data X to obtain decentralized data. Decentralized dataset

[0023]

[0024] Based on decentralized data and the corresponding transpose matrix Calculate matrix The eigenvalues ​​λ = {λ1, λ2,…,λ n} and the corresponding eigenvectors σ = {σ1, σ2, ..., σ} n}; where the elements of the eigenvalue vector σ and the eigenvalue λ correspond one-to-one;

[0025] Let the eigenvalues ​​λ = {λ1, λ2,…,λ n Arrange the eigenvalues ​​in descending order, and select the eigenvectors corresponding to the k largest eigenvalues ​​to form the eigenvector D.

[0026] In some preferred embodiments, the method for fusing and locating the short-baseline lightning detection data with the long-baseline detection data is as follows:

[0027] Step S31: Upsample the electromagnetic pulse waveform data decoded in the data center to make the sampling rate and data dimension of the short baseline detection data consistent with those of the long baseline detection data.

[0028] Step S32: Calculate the sequence correlation of the upsampled data and filter electromagnetic pulse waveform data with sequence correlation greater than a set threshold to form a waveform sequence of lightning events from the same source.

[0029] Step S33: Based on the waveform sequence of the same lightning event, calculate the arrival time of the electromagnetic pulse waveform data at each detection device using the time sliding window sequence arrival time extraction method;

[0030] Step S34: Based on the arrival time of the electromagnetic pulse waveform data at each detection device, solve for the location information of the lightning event.

[0031] In some preferred embodiments, the method for extracting arrival time using a time-sliding window sequence to calculate the arrival time of electromagnetic pulse waveform data at each detection device is as follows:

[0032] Step S331: Arrange the electromagnetic pulse waveform data according to the chronological order of the marked times to obtain a waveform sequence {S1, S2, ..., S...} of n electromagnetic pulse waveform data representing the same source lightning event. n The dimension l of each electromagnetic pulse waveform data is 1000;

[0033] Step S332: Select the electromagnetic pulse waveform data S1 with the earliest marked time as the reference, and use the time t corresponding to the pulse peak of the electromagnetic pulse waveform data S1 as the reference. S1 As a reference time, the electromagnetic pulse waveform data S1 is extended to S1′:

[0034] S1′={M,S1,M}

[0035] Where M is an array of all zeros with the same dimension as S1;

[0036] Step S333: Calculate the correlation coefficient c between S1′[a:l+a] and S2 sequentially. a [a:l+a] represents selecting a continuous data W of length l starting from the a-th element in S1′, where a∈[1,2l], resulting in a correlation queue C={c1,c2,…,c a};

[0037] Step S334: Calculate the relevant queue C = {c1, c2, ..., c a The index C corresponding to the maximum value of} imax And based on the index value C imax Calculate the arrival time t of electromagnetic pulse waveform data S2 S2 ;

[0038] Step S335: Traverse the waveform sequence {S1,S2,…,S} of the same-source lightning events using the methods corresponding to steps S332-S334. n For each data point, the time it takes for the electromagnetic pulse waveform data to reach each detection device is obtained.

[0039] In some preferred embodiments, step S34 includes:

[0040] Step S341: Assuming the lightning electromagnetic pulse signal propagates uniformly along the sphere, the time difference of arrival (TDOA) positioning method is used to calculate the two-dimensional position L(x,y) of the lightning event on the sphere and the resolved distance of the lightning event relative to the first detection device involved in the positioning. Where x is the spherical longitude and y is the spherical latitude;

[0041] Step S342: Using the position S1(x,y) of the first detection device participating in the positioning as a reference, calculate the actual geographical distance between points L(x,y) and S1(x,y).

[0042] Step S343, to resolve distance actual geographical distance and the height of lightning events H L Construct a triangular relationship to calculate the height H of the lightning event. L This allows us to obtain the location information of the lightning event.

[0043] In some preferred embodiments, the lightning event height H L The calculation method is as follows:

[0044]

[0045] Among them, analytical distance Let be the hypotenuse of the triangle in the constructed triangular relationship.

[0046] In another aspect, the present invention proposes a lightning positioning system based on a hybrid baseline, the system comprising:

[0047] The signal acquisition module is configured to monitor the electromagnetic pulse signal of lightning radiation in real time through short-baseline lightning detection equipment and long-baseline lightning detection equipment;

[0048] The signal marking module is configured to record the raw waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold by the detection device, and to mark the trigger time of the raw waveform data;

[0049] The positioning module is configured to encode and compress the marked raw waveform data and send it to the data processing center. The data processing center decodes the data and performs a fusion positioning calculation of the short baseline lightning detection data and the long baseline detection data.

[0050] The output module is configured to output the location information of hybrid baseline lightning events through the data processing center.

[0051] The beneficial effects of this invention are:

[0052] (1) The present invention is based on a hybrid baseline lightning location method. The lightning electromagnetic pulse waveform data recorded by the detection equipment can be integrated with lightning detection data of different baselines and different frequency bands to achieve hybrid baseline lightning location. This method complements each other's advantages, improves the detection efficiency and location accuracy of lightning events, expands the detection range, and especially enhances the detection efficiency and location accuracy of thunderstorm activities in the far sea area.

[0053] (2) The lightning location method based on hybrid baseline of the present invention uses a compression / decompression algorithm based on principal component analysis of the signal to realize real-time, efficient and high-speed transmission of electromagnetic pulse signals, and ensure the timeliness of data calculation.

[0054] (3) The lightning location method based on hybrid baseline of the present invention uses electromagnetic pulse waveform data collected by hybrid baseline lightning detection system to calculate the arrival time of time sliding window sequence, which ensures the accuracy and reliability of the calculation, reduces the influence of non-homogeneous pulse signals such as noise on the location calculation, and is also conducive to improving the positioning accuracy. Attached Figure Description

[0055] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0056] Figure 1This is a flowchart illustrating the lightning localization method based on hybrid baselines of the present invention.

[0057] Figure 2 This is long-baseline and short-baseline lightning electromagnetic pulse detection waveform data, which is an embodiment of the lightning location method based on hybrid baselines of the present invention.

[0058] Figure 3 This is a flowchart of lightning electromagnetic pulse compression-transmission-decompression of one embodiment of the lightning location method based on hybrid baseline of the present invention;

[0059] Figure 4 This is a comparison diagram of the original and decompressed waveforms of a lightning electromagnetic pulse in an embodiment of the lightning localization method based on hybrid baselines of the present invention.

[0060] Figure 5 This is a schematic diagram of a time-sliding window sequence arrival time extraction method according to an embodiment of the lightning localization method based on hybrid baselines of the present invention;

[0061] Figure 6 This is a schematic diagram illustrating the composition, signal acquisition, and data transmission of the lightning location system based on hybrid baselines according to the present invention;

[0062] Figure 7 This is a schematic diagram of a lightning event height calculation method according to an embodiment of the lightning location method based on hybrid baselines of the present invention;

[0063] Figure 8 This is a simulation result of the positioning accuracy of a short-baseline lightning electromagnetic pulse detection system, which is an embodiment of the lightning positioning method based on hybrid baselines of the present invention.

[0064] Figure 9 This is a simulation result of the positioning accuracy of a hybrid baseline lightning electromagnetic pulse detection system, which is an embodiment of the lightning positioning method based on hybrid baselines of the present invention. Detailed Implementation

[0065] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0066] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0067] The lightning localization method based on hybrid baselines of this invention needs to address the following issues:

[0068] (1) Fusion of lightning electromagnetic pulse detection data from different methods;

[0069] (2) Identify and filter electromagnetic pulse signals of the same origin from a large number of interference noise signals;

[0070] (3) Use fused data to detect the location of lightning events.

[0071] Based on solving the above problems, this invention integrates short-baseline very low frequency / low frequency lightning electromagnetic pulse detection waveform data and long-baseline very low frequency lightning electromagnetic pulse detection waveform data to form a hybrid baseline lightning detection, realizing the combination of long and short baseline detection, complementing each other's advantages, and comprehensively improving the detection efficiency, range and positioning accuracy of lightning events, which is especially suitable for conducting lightning detection in offshore areas.

[0072] The present invention provides a lightning localization method based on a hybrid baseline, the method comprising:

[0073] Step S10: Monitor the electromagnetic pulse signal of lightning radiation in real time using short-baseline lightning detection equipment and long-baseline lightning detection equipment;

[0074] Step S20: The detection device records the original waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold, and marks the trigger time of the original waveform data.

[0075] Step S30: The marked raw waveform data is encoded and compressed, and sent to the data processing center. After the data processing center decodes the data, it performs the fusion positioning calculation of short baseline lightning detection data and long baseline detection data.

[0076] Step S40: The data processing center outputs the location information of the hybrid baseline lightning event.

[0077] To more clearly illustrate the lightning localization method based on hybrid baselines of this invention, the following will be combined with... Figure 1 The steps in the embodiments of the present invention will be described in detail below.

[0078] The lightning localization method based on hybrid baselines in the first embodiment of the present invention includes steps S10-S50, each step of which is described in detail below:

[0079] Step S10: Monitor the electromagnetic pulse signal of lightning radiation in real time using short-baseline lightning detection equipment and long-baseline lightning detection equipment.

[0080] In one embodiment of the present invention, the baseline distance of the short-baseline lightning detection device is 100-150km, and an orthogonal magnetic loop antenna and a planar electric field antenna are used to receive magnetic field signals and electric field signals respectively, with an operating frequency band of 3-400kHz and a signal sampling rate of 1MSPS; the baseline distance of the long-baseline lightning detection device is about 1000km, and an electric field whip antenna is used to receive electric field signals, with an operating frequency band of 3-30kHz and a signal sampling rate of 500KSPS.

[0081] In step S20, the detection device records the original waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold, and marks the trigger time of the original waveform data.

[0082] The original waveform data is obtained as follows:

[0083] The electromagnetic pulse signal sensed at the antenna end of the detection device is converted into a digital signal through an analog-to-digital conversion circuit;

[0084] The converted signals are formatted into a data file according to a set format to obtain the original waveform data.

[0085] The detection equipment uses an analog-to-digital converter circuit to convert electromagnetic pulse analog signals into digital signals in real time and compare them with a set threshold. When the amplitude of the acquired signal exceeds the set threshold, a sampling is triggered. The detection equipment records the data before and after the trigger for a certain period of time.

[0086] In one embodiment of the present invention, during a single sampling process, the short-baseline lightning electromagnetic pulse detection device records 120 sampling points before triggering and 880 sampling points after triggering, constituting 1000 sampling points; the long-baseline lightning electromagnetic pulse detection device records 60 sampling points before triggering and 440 sampling points after triggering, constituting 500 sampling points. The electromagnetic pulse waveform data recorded by the long-baseline and short-baseline lightning electromagnetic pulse detection devices are as follows: Figure 2 As shown. Although the number of sampling points of the long-baseline lightning electromagnetic pulse detection equipment is half that of the short-baseline equipment, the sampling rate of the long-baseline lightning electromagnetic pulse detection equipment is half that of the short-baseline equipment, so the sampling time of the two equipment is the same, which is one millisecond.

[0087] The trigger time of the original waveform data is marked as follows:

[0088] Obtain real-time high-precision time through satellite navigation and timing systems;

[0089] The trigger time is marked based on the real-time high-precision time.

[0090] In one embodiment of the present invention, in an outdoor open environment, the satellite navigation time service system provides an accurate second pulse signal, and the clock synchronization error is better than 100 nanoseconds. The detection device uses the second pulse signal as the reference clock signal. In each reference clock cycle, the local 10 MHz high-frequency clock is used for counting, so as to obtain the triggering time of the lightning electromagnetic pulse signal with an accuracy better than 100 nanoseconds.

[0091] Step S30: Encoding and compressing the original waveform data with marks, and sending it to the data processing center. After the data processing center decodes the data, it performs fusion positioning calculation on the short-baseline lightning detection data and the long-baseline detection data.

[0092] According to statistics, there are more than 100 lightning events occurring globally per second on average, radiating a large amount of electromagnetic pulse signals. These signals can propagate tens of thousands of kilometers in the ground-ionosphere waveguide. Therefore, the lightning electromagnetic pulse detection device will collect a large number of pulse signals, and these signals need to be transmitted and aggregated to the data processing center station in real time through the network for unified analysis and processing.

[0093] In one embodiment of the present invention, the original waveform collected by the detection device is compressed, and the compressed data is transmitted to the data processing center station. The data processing center station decompresses the data to achieve fast data transmission. The data compression and transmission process is as Figure 3 shown.

[0094] The electromagnetic pulse waveform compression method is based on signal principal component analysis, and performs lossy compression on the original signal to achieve fast and efficient transmission of a large number of electromagnetic pulse signals, without affecting subsequent data processing and positioning calculation. The use of signal principal component analysis in the calculation process involves data compression (encoding) and data decompression (decoding) of the signal. The method is as follows:

[0095] Assume that the original electromagnetic pulse waveform X has n sampling points {x1, x2, …, x n}, and there is a feature vector D with a dimension of k, k < n, satisfying the relationship in Equation (1):

[0096] X′ ∼ XD T D(1)

[0097] where X′ is the data similar to X, and D T is the transpose matrix of the feature vector D.

[0098] The detection device encodes the original electromagnetic pulse waveform X to obtain the encoded waveform A, as shown in Equation (2):

[0099] A = XD T (2)

[0100] where the dimension of A is k.

[0101] The data processing center decodes the encoded waveform A to obtain data X′ similar to X, as shown in equation (3):

[0102] X′=AD (3)

[0103] Where X′ has a dimension of n.

[0104] Based on the above relationship, the same feature vector D is stored in the lightning electromagnetic pulse detection equipment and the data processing center. Since the dimension of the encoded waveform A is smaller than the dimension of the original electromagnetic pulse waveform, the compression of the original electromagnetic pulse waveform is achieved.

[0105] The eigenvector D is calculated as follows:

[0106] Step A1: Obtain a dataset X consisting of m original waveform data X. m Decentralize each original waveform data X to obtain decentralized data. Decentralized dataset

[0107] While ensuring sufficient computer memory, m should be as large as possible to guarantee data diversity.

[0108] Step A2, based on decentralized data and the corresponding transpose matrix Calculate matrix The eigenvalues ​​λ = {λ1, λ2,…,λ n} and the corresponding eigenvectors σ = {σ1, σ2, ..., σ} n The elements of the eigenvector σ and the eigenvalue λ are in one-to-one correspondence.

[0109] The original electromagnetic pulse waveform X is decentered, that is, each bit feature is subtracted from its respective average value X. mean To obtain decentralized data

[0110] Step A3, assign the eigenvalues ​​λ = {λ1, λ2, ..., λ} n Arrange them in descending order, select the k largest eigenvalues ​​and their corresponding eigenvectors to form the eigenvector D, as shown in equation (4):

[0111]

[0112] in, The eigenvector corresponding to the largest eigenvalue, and so on. This is the eigenvector corresponding to the kth largest eigenvalue.

[0113] In one embodiment of the present invention, since the dimensions of long-baseline electromagnetic pulse detection data and short-baseline detection data are inconsistent, the historical data of the two detection systems are statistically analyzed according to steps A1 to A3 to obtain the feature vector D of the long-baseline electromagnetic pulse detection data. l and the feature vector D of short baseline electromagnetic pulse detection data s .

[0114] In one embodiment of the present invention, combining the dimensions of the original electromagnetic pulse data, the feature vector D... l The dimension is (40×500), and the feature vector D s The dimension is (90×1000).

[0115] The system receives detection data from various stations of the short-baseline and long-baseline lightning detection systems in real time. In this embodiment, to ensure real-time data transmission, the User Datagram Protocol (UDP) is used to transmit the data, with the data processing center acting as the server and the detection equipment as the client.

[0116] Using the method described in equation (3), the electromagnetic pulse waveform data is decompressed. Figure 4 The original data and the decompressed electromagnetic pulse waveform data are displayed respectively. The decompressed data is highly similar to the original data, thus achieving effective restoration of the original data.

[0117] The method for fusing short-baseline lightning detection data and long-baseline detection data to calculate the location is as follows:

[0118] Step S31 involves upsampling the electromagnetic pulse waveform data decoded in the data center to ensure that the sampling rate and data dimension of the short baseline detection data are consistent with those of the long baseline detection data. This process achieves the initial fusion of the short baseline and long baseline detection data.

[0119] Step S32: Calculate the sequence correlation of the upsampled data and filter electromagnetic pulse waveform data with sequence correlation greater than a set threshold to form a waveform sequence of lightning events from the same source.

[0120] Reduce the impact of noise signals on lightning event localization and enhance the correlation between short-baseline and long-baseline detection data.

[0121] It should be noted that in this embodiment, the electromagnetic pulse time difference positioning algorithm requires data from at least four detection devices. Therefore, if the selected waveform data of the same lightning event are less than four, the subsequent steps cannot be performed, and it is necessary to return to the real-time data detection step.

[0122] In this embodiment, the electromagnetic pulse data upsampling uses a linear interpolation method with equal signal spacing to improve the sampling rate of the detected data. Since the operating frequency band of the short-baseline lightning detection system is higher than that of the long-baseline lightning detection system, the sampling rate of the short-baseline lightning detection device is twice that of the long-baseline lightning detection device. Therefore, it is only necessary to upsample the long-baseline lightning detection data to achieve the same sampling rate of 1 MSPS for both the short-baseline and long-baseline lightning detection devices.

[0123] Step S33: Based on the waveform sequence of the same-source lightning event, the arrival time of the electromagnetic pulse waveform data at each detection device is calculated using the time sliding window sequence arrival time extraction method, such as... Figure 5 As shown, it includes:

[0124] Step S331: Arrange the electromagnetic pulse waveform data according to the chronological order of the marked times to obtain a waveform sequence {S1, S2, ..., S...} of n electromagnetic pulse waveform data representing the same source lightning event. n The dimension l of each electromagnetic pulse waveform data is 1000;

[0125] Step S332: Select the electromagnetic pulse waveform data S1 with the earliest marked time as the reference, and use the time t corresponding to the pulse peak of the electromagnetic pulse waveform data S1 as the reference. S1 As a reference time, the electromagnetic pulse waveform data S1 is extended to S1′, as shown in equation (5):

[0126] S1′={M,S1,M} (5)

[0127] Where M is an array of all zeros with the same dimension as S1, that is, the data dimension of S1′ is 3l.

[0128] Step S333: Calculate the correlation coefficient c between S1′[a:l+a] and S2 sequentially. a [a:l+a] represents selecting a continuous data W of length l starting from the a-th element in S1′, where a∈[1,2l], resulting in a correlation queue C={c1,c2,…,c a}

[0129] Correlation coefficient c a The calculation method is shown in equation (6):

[0130]

[0131] Among them, W i This represents the i-th value of the continuous data W. S represents the mean of continuous data W. 2,i This represents the i-th value of the electromagnetic pulse waveform data S2. This represents the mean value of the electromagnetic pulse waveform data S2.

[0132] Step S334: Calculate the relevant queue C = {c1, c2, ..., c a The index C corresponding to the maximum value of} imax And based on the index value C imax Calculate the arrival time t of electromagnetic pulse waveform data S2 S2 As shown in equation (7):

[0133]

[0134] Among them, f s The sampling rate of the signal.

[0135] Step S335: Traverse the waveform sequence {S1,S2,…,S} of the same-source lightning events using the methods corresponding to steps S332-S334. n For each data point, the time it takes for the electromagnetic pulse waveform data to reach each detection device is obtained.

[0136] like Figure 6 The diagram illustrates one configuration of a hybrid baseline lightning electromagnetic pulse (EMP) detection system, comprising four short-baseline EMP detectors and one long-baseline EMP detector. The data collected by these detectors is transmitted via network to a central data processing station. It is important to emphasize that the configuration of a hybrid baseline lightning EMP detection system includes, but is not limited to, the following configurations. Figure 6 The system composition shown in this invention demonstrates that the lightning location method is applicable to hybrid baseline lightning electromagnetic pulse detection systems with arbitrary baseline lengths and arbitrary types and quantities of detection equipment.

[0137] Lightning location involves both two-dimensional (longitude and latitude) and three-dimensional (longitude, latitude, and altitude) locations. When a detected lightning event occurs inside a hybrid baseline lightning detection system, the altitude information can be calculated due to the small positioning error, thus obtaining the three-dimensional location of the lightning. When a detected lightning event occurs outside the hybrid baseline lightning detection system, the positioning error is larger, and only the two-dimensional location of the lightning is calculated.

[0138] Step S34: Based on the arrival time of the electromagnetic pulse waveform data at each detection device, calculate the location information of the lightning event, such as... Figure 7 As shown, it includes:

[0139] Step S341: Assuming the lightning electromagnetic pulse signal propagates uniformly along the sphere, the time difference of arrival (TDOA) positioning method is used to calculate the two-dimensional position L(x,y) of the lightning event on the sphere and the resolved distance of the lightning event relative to the first detection device involved in the positioning. Where x is the spherical longitude and y is the spherical latitude;

[0140] Step S342: Using the position S1(x,y) of the first detection device participating in the positioning as a reference, calculate the actual geographical distance between points L(x,y) and S1(x,y).

[0141] Step S343, to resolve distance actual geographical distance and the height of lightning events H L Construct a triangular relationship to calculate the height H of the lightning event. L This allows us to obtain the location information of the lightning event.

[0142] Lightning event height H L The calculation method is as shown in equation (8):

[0143]

[0144] Among them, analytical distance Let be the hypotenuse of the triangle in the constructed triangular relationship.

[0145] Step S40: The data processing center outputs the location information of the hybrid baseline lightning event.

[0146] Figure 8 The simulation results show that the positioning accuracy is achieved by using a short-baseline lightning electromagnetic pulse detection system alone. The areas with high positioning accuracy are concentrated within the network formed by the detection equipment. As the detection range expands, the positioning error increases rapidly.

[0147] According to the method of this invention, a long-baseline detection device is added to a short-baseline lightning electromagnetic pulse detection system to form a hybrid baseline lightning electromagnetic pulse detection system. The positioning accuracy of this hybrid baseline lightning detection system is simulated, and the simulation results are shown below. Figure 9 The addition of a long baseline detection device significantly improves the detection accuracy outside the short baseline detection system network. On the other hand, it also shows that the present invention effectively expands the detection range.

[0148] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such order. They can be executed simultaneously (in parallel) or in reverse order. These simple variations are all within the protection scope of this invention.

[0149] The second embodiment of the lightning location system based on hybrid baseline of the present invention includes:

[0150] The signal acquisition module is configured to monitor the electromagnetic pulse signal of lightning radiation in real time through short-baseline lightning detection equipment and long-baseline lightning detection equipment;

[0151] The signal marking module is configured to record the raw waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold by the detection device, and to mark the trigger time of the raw waveform data;

[0152] The positioning module is configured to encode and compress the marked raw waveform data and send it to the data processing center. The data processing center decodes the data and performs a fusion positioning calculation of the short baseline lightning detection data and the long baseline detection data.

[0153] The output module is configured to output the location information of hybrid baseline lightning events through the data processing center.

[0154] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the system described above can be found in the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0155] It should be noted that the lightning positioning system based on hybrid baselines provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be merged into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the various modules or steps and are not considered as an improper limitation of the present invention.

[0156] An electronic device according to a third embodiment of the present invention includes:

[0157] At least one processor;

[0158] and a memory communicatively connected to at least one of the processors;

[0159] The memory stores instructions that can be executed by the processor to implement the above-described hybrid baseline-based lightning positioning method.

[0160] A computer-readable storage medium according to a fourth embodiment of the present invention stores computer instructions for execution by the computer to implement the above-described hybrid baseline-based lightning location method.

[0161] The hybrid baseline very low frequency / low frequency lightning detection device of the fifth embodiment of the present invention includes:

[0162] Short-baseline very low frequency / low frequency lightning electromagnetic pulse signal detection equipment is used for real-time reception, processing, compression, and transmission of lightning electromagnetic pulse ground wave signals;

[0163] Long-baseline very low frequency lightning electromagnetic pulse signal detection equipment is used for real-time reception, processing, compression, and transmission of lightning electromagnetic pulse ground wave and sky wave signals;

[0164] The electromagnetic pulse data processing center station is used to receive, decompress, and downsample data transmitted from short-baseline and long-baseline lightning electromagnetic pulse detection equipment in real time, and to perform homogeneous event filtering and location calculation on the data.

[0165] The display terminal is used to display the real-time operating status of short-baseline and long-baseline lightning electromagnetic pulse detection equipment and electromagnetic pulse data processing center station.

[0166] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the storage device and processing device described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0167] Those skilled in the art will recognize that the modules and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the invention.

[0168] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0169] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0170] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A lightning localization method based on hybrid baselines, characterized in that, The method includes: Step S10: Monitor the electromagnetic pulse signal of lightning radiation in real time using short-baseline lightning detection equipment and long-baseline lightning detection equipment; Step S20: The detection device records the original waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold, and marks the trigger time of the original waveform data. Step S30: The marked raw waveform data is encoded and compressed, and sent to the data processing center. After the data processing center decodes the data, it performs the fusion positioning calculation of short baseline lightning detection data and long baseline detection data. Step S40: The data processing center outputs the location information of the hybrid baseline lightning event; The method for fusing short-baseline lightning detection data and long-baseline detection data to calculate the location is as follows: Step S31: Upsample the electromagnetic pulse waveform data decoded in the data center to make the sampling rate and data dimension of the short baseline detection data consistent with those of the long baseline detection data. Step S32: Calculate the sequence correlation of the upsampled data and filter electromagnetic pulse waveform data with sequence correlation greater than a set threshold to form a waveform sequence of lightning events from the same source. Step S33: Based on the waveform sequence of the same-source lightning event, the arrival time of the electromagnetic pulse waveform data at each detection device is calculated using the time sliding window sequence arrival time extraction method. The method is as follows: Step S331: Arrange the data according to the chronological order of the marked times of the electromagnetic pulse waveform data to obtain... A waveform sequence of a homogeneous lightning event composed of electromagnetic pulse waveform data. Dimensions of each electromagnetic pulse waveform data All ; Step S332: Select the electromagnetic pulse waveform data with the earliest marking time. As a benchmark, electromagnetic pulse waveform data The time corresponding to the pulse peak As a reference time, the electromagnetic pulse waveform data Expand to : in, For dimensions and An array of all zeros with consistent dimensions; Step S333, calculate sequentially and correlation coefficient , Indicates selection From the middle The initial length is Continuous data , The dimension is obtained as Related queues ; Step S334, calculate the relevant queue The index value corresponding to the maximum value and based on the index value Calculate electromagnetic pulse waveform data Arrival time ; Step S335: Traverse the waveform sequence of the same-source lightning events using the methods corresponding to steps S332-S334. For each data point, the time it takes for the electromagnetic pulse waveform data to reach each detection device is obtained; Step S34: Based on the arrival time of the electromagnetic pulse waveform data at each detection device, solve for the location information of the lightning event.

2. The lightning localization method based on hybrid baselines according to claim 1, characterized in that, The original waveform data is obtained by the following method: The electromagnetic pulse signal sensed at the antenna end of the detection device is converted into a digital signal through an analog-to-digital conversion circuit; The converted signals are formatted into a data file according to a set format to obtain the original waveform data.

3. The lightning localization method based on hybrid baselines according to claim 1, characterized in that, The trigger time of the original waveform data is marked using the following method: Obtain real-time high-precision time through satellite navigation and timing systems; The trigger time is marked based on the real-time high-precision time.

4. The lightning localization method based on hybrid baselines according to claim 1, characterized in that, In step S30, the marked raw waveform data is encoded and compressed, and the data processing center decodes the data. The method is as follows: in, , representing the original waveform data, This represents the number of sampling points for the original waveform data. It is a dimension of eigenvectors, For feature vectors The transpose of the matrix, For encoded and compressed waveform data, For feature vector-based Waveform data after encoding and compression The original waveform data obtained after decoding Similar data.

5. The lightning localization method based on hybrid baselines according to claim 4, characterized in that, The feature vector The calculation method is as follows: Get Original waveform data The dataset Perform each raw waveform data separately. Decentralization, obtaining decentralized data Decentralized dataset ; Based on decentralized data and the corresponding transpose matrix Calculate the matrix eigenvalues and the corresponding feature vector Among them, the eigenvalue vector With eigenvalues The elements correspond one-to-one; eigenvalues Arrange in descending order and select The eigenvectors corresponding to the largest eigenvalues ​​constitute the eigenvectors. .

6. The lightning localization method based on hybrid baselines according to claim 1, characterized in that, Step S34 includes: Step S341: Assuming the lightning electromagnetic pulse signal propagates uniformly along the sphere, the two-dimensional position of the lightning event on the sphere is calculated using the signal arrival time difference positioning calculation method. and the resolved distance of the lightning event relative to the first detection device involved in the location. ,in Longitude of the sphere y Latitude is spherical; Step S342, based on the position of the first detection device participating in the positioning. For reference, calculate and The actual geographical distance between two points ; Step S343, to resolve distance Actual geographical distance and the height of lightning events Construct a triangular relationship to calculate the height of a lightning event. This allows us to obtain the location information of the lightning event.

7. The lightning localization method based on hybrid baselines according to claim 6, characterized in that, The height of the lightning event The calculation method is as follows: Among them, analytical distance Let be the hypotenuse of the triangle in the constructed triangular relationship.

8. A lightning positioning system based on a hybrid baseline, characterized in that, The system includes: The signal acquisition module is configured to monitor the electromagnetic pulse signal of lightning radiation in real time through short-baseline lightning detection equipment and long-baseline lightning detection equipment; The signal marking module is configured to record the raw waveform data of electromagnetic pulse signals with an intensity exceeding a set threshold by the detection device, and to mark the trigger time of the raw waveform data; The positioning module is configured to encode and compress the marked raw waveform data and send it to the data processing center. The data processing center decodes the data and performs a fusion positioning calculation of the short baseline lightning detection data and the long baseline detection data. The output module is configured to output the location information of the hybrid baseline lightning event through the data processing center; The method for fusing short-baseline lightning detection data and long-baseline detection data to calculate the location is as follows: Step S31: Upsample the electromagnetic pulse waveform data decoded in the data center to make the sampling rate and data dimension of the short baseline detection data consistent with those of the long baseline detection data. Step S32: Calculate the sequence correlation of the upsampled data and filter electromagnetic pulse waveform data with sequence correlation greater than a set threshold to form a waveform sequence of lightning events from the same source. Step S33: Based on the waveform sequence of the same-source lightning event, the arrival time of the electromagnetic pulse waveform data at each detection device is calculated using the time sliding window sequence arrival time extraction method. The method is as follows: Step S331: Arrange the data according to the chronological order of the marked times of the electromagnetic pulse waveform data to obtain... A waveform sequence of a homogeneous lightning event composed of electromagnetic pulse waveform data. Dimensions of each electromagnetic pulse waveform data All ; Step S332: Select the electromagnetic pulse waveform data with the earliest marking time. As a benchmark, electromagnetic pulse waveform data The time corresponding to the pulse peak As a reference time, the electromagnetic pulse waveform data Expand to : in, For dimensions and An array of all zeros with consistent dimensions; Step S333, calculate sequentially and correlation coefficient , Indicates selection From the middle The initial length is Continuous data , The dimension is obtained as Related queues ; Step S334, calculate the relevant queue The index value corresponding to the maximum value and based on the index value Calculate electromagnetic pulse waveform data Arrival time ; Step S335: Traverse the waveform sequence of the same-source lightning events using the methods corresponding to steps S332-S334. For each data point, the time it takes for the electromagnetic pulse waveform data to reach each detection device is obtained; Step S34: Based on the arrival time of the electromagnetic pulse waveform data at each detection device, solve for the location information of the lightning event.

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