Lightning positioning enhancement system and method based on site spatial configuration

Abstract

The invention discloses a lightning positioning enhancement system and method based on site spatial configuration, relates to the technical field of lightning monitoring, and solves the problems that in the prior art, a comprehensive and effective evaluation means for a final positioning result is lacked, and when the spatial structure participating in sites is relatively poor, some calculation results with poor effects are very easy to introduce; and the positioning accuracy is influenced. The method comprises the following steps: acquiring thunder and lightning information detected by networking of each detection station; screening the detection station networking according to the collected thunder and lightning information to obtain candidate detection station networking; extracting coordinates of each detection station in the candidate detection station network and the detected lightning arrival time, calculating a GDOP value based on the coordinates of each detection station and the lightning arrival time, and determining an optimal detection station network; calculating thunder and lightning coordinates according to the coordinates and thunder and lightning arrival time of each detection site in the optimal detection site network; the precision of a positioning result is effectively improved, and the reliability of a positioning system is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of lightning monitoring, and in particular relates to a lightning location enhancement system and method based on site spatial configuration. Background Art

[0002] Globally, thunderstorm disasters are listed as one of the ten most serious natural disasters announced by the United Nations International Decade for Disaster Reduction. Every year, the direct economic losses caused by thunderstorms exceed US$1 billion, and the indirect losses are as high as tens of billions. The number of casualties caused by lightning strikes exceeds 50,000, making it the third largest killer in natural disasters. With the rapid development of electronic technology, modern electronic equipment such as measurement, monitoring, protection, communication, and computer networks have been widely infiltrated into key fields such as electricity, aviation, national defense, and communications. These highly integrated electronic devices are extremely sensitive to transient overvoltage and overcurrent. Once struck by lightning, it will not only cause equipment failure, but also may cause huge economic losses and social impacts.

[0003] Faced with this severe challenge, the existing means of lightning detection and forecasting are very limited. Meteorological departments and related units mainly use atmospheric electric field instruments supplemented by meteorological radars, satellite cloud images and other methods to monitor and warn lightning. However, these technical means still have great application limitations, such as small detection range, high price, and inability to form a large-scale network. In response to this situation, many companies and units have developed lightning positioning methods based on time difference and magnetic direction detection. For example, patent CN114034936 introduces a lightning positioning system based on distributed sites. The system uses LF / VLF lightning signals detected by multiple sites to obtain the time difference (TDOA) of lightning reaching each site, and combines GPU parallel computing technology to greatly improve the positioning speed of the central processor, realizing real-time monitoring of lightning in the area covered by the station network.

[0004] However, this method also has its shortcomings, mainly because it lacks a comprehensive and effective evaluation method for the final positioning results. When the spatial structure of the participating sites is poor, it is easy to introduce some poor solution results that are difficult to eliminate. Considering the danger and mobility of lightning, it is difficult to measure the exact location where it occurs. When locating lightning through some observations, the main consideration is to use residuals to evaluate the solution results. However, for the nonlinear equations constructed by sites with poor spatial structures, even if the residual of the solution result is very small, it may deviate greatly from the actual position. There are mainly the following reasons. First, the TDOA method depends on the geometric configuration of the receiving station. If the receiving stations are too concentrated or arranged along a straight line, the information collection direction may be insufficient, affecting the geometric accuracy of the measurement. Second, in numerical calculations, the sensitivity of the solution refers to the impact of a small change in the input on the output solution. Poor geometric conditions will greatly increase the sensitivity of the solution, and even a small input error (such as time difference measurement error) may cause a large change in the solution. This means that a small residual does not necessarily guarantee the accuracy of the solution. Therefore, how to select a reliable site combination to participate in positioning and ensure the availability and stability of the positioning results is an important research direction for multi-station lightning positioning systems. Therefore, the present invention provides a lightning location enhancement system and method based on site spatial configuration. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a lightning location enhancement system and method based on the spatial configuration of the site, which is used to solve the technical problem that the prior art lacks a comprehensive and effective evaluation method for the final positioning result, and when the spatial structure of the participating sites is poor, it is easy to introduce some poor solution results, thereby affecting the positioning accuracy.

[0006] To achieve the above-mentioned object, the first aspect of the present invention provides a lightning location enhancement system based on site spatial configuration, including a data acquisition module, a GPS or BDS satellite timing module, a network transmission module, a station group configuration evaluation module, a central processing and calculation module, and a storage and publishing module;

[0007] Data acquisition module: used to collect lightning information; the lightning information includes lightning signals and lightning arrival time; the lightning information is detected by a network of several distributed detection sites; the lightning arrival time is the time when the detection site detects the lightning signal;

[0008] Station group configuration evaluation module: used to select candidate detection site networks from a number of detection site networks; calculate the GDOP value of the candidate detection site networks; based on the GDOP value, select the best detection site network from the candidate detection site networks;

[0009] Central processing calculation module: used to extract the coordinates of each detection site in the best detection site network; calculate the lightning coordinates according to the coordinates of each detection site in the best detection site network.

[0010] Preferably, the data acquisition module includes a GPS antenna, a whip antenna and a bidirectional magnetic ring, a signal processor, a GPS signal acquisition card, a high-speed digital signal acquisition card and an acquisition system;

[0011] The GPS antenna is connected to the GPS signal acquisition card in communication; the GPS signal acquisition card is connected to the high-speed digital signal acquisition card in communication; the whip antenna and the bidirectional magnetic ring are connected to the signal processor in communication, and the signal processor includes a signal amplifier, a filter and an analog / digital signal converter; the signal processor is connected to the high-speed digital signal acquisition card in communication; the GPS signal acquisition card and the high-speed digital signal acquisition card are both connected to the acquisition system in communication.

[0012] Preferably, the GPS or BDS satellite timing module is constructed based on a high-speed digital signal acquisition card and a GPS acquisition card; the GPS acquisition card outputs one serial port NEMA83 signal, one 5MHz clock pulse, and one PPS second signal pulse.

[0013] Preferably, the method for acquiring the lightning arrival time includes:

[0014] The GPS signal acquisition card outputs one serial port NEMA83 signal to the acquisition system; the GPS signal acquisition card outputs one PPS second signal pulse and one 5MHz clock pulse to the high-speed digital signal acquisition card; the signal processor outputs the processed digital signal to the high-speed digital signal acquisition card, and by matching it with one PPS second signal pulse and one 5MHz clock pulse, the time when the lightning signal arrives at each detection site is obtained and marked as the lightning arrival time.

[0015] Preferably, the calculating the GDOP value of the candidate detection site network and obtaining the candidate detection site network includes:

[0016] Step P1: Preliminary screening of the detection site network based on the waveform characteristics of the lightning signal; wherein the waveform characteristics include polarity, waveform parameters and change trends; the waveform parameters include rise time, fall time, pulse width and recoil amplitude;

[0017] Step P2: Perform secondary screening on the detection site network according to the triangle principle; wherein, any three sites in the detection site network must satisfy the triangle principle; the triangle principle is that the sum of the two sides is greater than the third side, and the difference between the two sides is less than the third side;

[0018] Step P3: After two rounds of screening, several detection site networks are obtained and marked as candidate detection site networks; the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time are extracted, and based on the coordinates of each detection site and the lightning arrival time, the initial coordinates of the lightning are calculated and marked as the initial value of the lightning coordinates; based on the initial value of the lightning coordinates, the GDOP value of the candidate detection site network is calculated;

[0019] Step P4: Determine whether the GDOP value is less than the preset minimum threshold and less than the preset threshold of the current detection site network; if yes, the candidate detection site network is marked as the best detection site network; if no, the detection site network is not marked.

[0020] Preferably, the calculating the initial coordinates of the lightning based on the coordinates of each detection site and the lightning arrival time includes:

[0021] The arrival time difference of lightning at each detection site is calculated; based on the arrival time difference and the coordinates of each detection site, the initial value of the lightning coordinate is calculated.

[0022] Preferably, the calculating of the GDOP value of the candidate detection site network based on the initial value of the lightning coordinates includes:

[0023] The GDOP value of the i-th candidate detection site network is calculated as follows:

[0024]

[0025] Wherein, i is the number of the candidate detection site network, i=0,1,…,N, N is a positive integer, k is the number of base stations in each detection site network; (x,y,z) is the initial value of the lightning coordinate, fk1, fk2, fk3 respectively refer to the first-order derivatives of the k-th site to the lightning coordinate component; (Axk,Ayk,Azk) is the three-dimensional coordinate of the k-th base station; dk is the distance from the lightning to the k-th base station; the G matrix is ​​the combination of fk1,fk2,fk3 of the k-th site; tr is the trace of the matrix; T is the transpose.

[0026] Preferably, the calculating of lightning coordinates according to the coordinates of the best detection site network includes:

[0027] The three-dimensional coordinates of the kth base station in the best detection site network are extracted and marked as Pk; the lightning coordinates Pf are obtained by the following calculation formula:

[0028] e j = dis(Pk,Pf)-c(t j -t);

[0029] Where j is the number of the candidate detection site network, j = 0, 1, ..., M, M is a positive integer; ej is the positioning error of the jth candidate detection site network; c is the propagation speed of electromagnetic waves along the earth's surface; t is the time when lightning occurs, t j is the lightning arrival time of the jth detection site network; the dis(Pk,Pf) function is used to calculate the spherical distance between points Pk and Pf;

[0030] The following nonlinear equations are constructed by networking several detection sites:

[0031]

[0032] The minimum value of the nonlinear equation group E is solved by GPU traversal method to obtain the lightning coordinates Pf.

[0033] Preferably, the network transmission module is used to establish a TCP / UDP connection and send the trigger data collected by the front-end site to the central processing and calculation module; when the central processing and calculation module completes the calculation of a detection site network, the calculation result is sent to the storage and publishing module.

[0034] Preferably, the second aspect of the present invention provides a method for enhancing lightning location based on site spatial configuration, comprising the following steps:

[0035] Step 1: Obtain lightning information detected by each detection site network;

[0036] Step 2: Preliminary screening of the detection site network based on the waveform characteristics of the collected lightning signals; secondary screening of the detection site network based on the triangle principle to obtain candidate detection site networks;

[0037] Step 3: Extract the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time, and calculate the initial value of the lightning coordinates based on the coordinates of each detection site and the lightning arrival time;

[0038] Step 4: Based on the initial value of the lightning coordinates, calculate the GDOP value of the candidate detection site network; based on the GDOP value, determine the best detection site network;

[0039] Step 5: Calculate the lightning coordinates based on the coordinates of each detection site in the best detection site network and the lightning arrival time.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention cleverly introduces the GDOP (geometric dilution of precision) index to implement strict screening and filtering of the site spatial configuration, ensuring that only reasonable and healthy site combinations are included in the positioning process, significantly improving the accuracy of the positioning results, and by streamlining the calculation process, eliminating unnecessary calculation steps, thereby enhancing the positioning efficiency, especially in periods of frequent lightning activity, to ensure the efficient and stable operation of the system. In addition, the present invention also uses advanced GPU traversal technology to efficiently solve the multi-site time difference observation model, greatly shortening the positioning calculation time and reducing the energy consumption of the system. This method can not only ensure that the final positioning result reaches the global optimal, but also has a better positioning accuracy than traditional methods; more importantly, this method does not rely on the accuracy of the initial value, effectively avoiding the dilemma of falling into the local optimal solution, thereby greatly improving the overall stability and availability of the lightning positioning system; the present invention achieves high-precision positioning capabilities in various complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 This is a structural diagram of a data acquisition module of the present invention;

[0044] Figure 2 Schematic diagram of waveform data of different sites of the present invention;

[0045] Figure 3 This is a schematic diagram of the GDOP calculation results of the present invention;

[0046] Figure 4 It is a schematic diagram of the CUDA structure of the present invention;

[0047] Figure 5 It is a schematic diagram of the GPU traversal method of the present invention;

[0048] Figure 6 The figure is a schematic diagram of the flow of the lightning locating method of the present invention. DETAILED DESCRIPTION

[0049] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The first aspect of the present invention provides a lightning location enhancement system based on site spatial configuration, including a data acquisition module, a GPS or BDS satellite timing module, a network transmission module, a station group configuration evaluation module, a central processing and calculation module, and a storage and publishing module;

[0051] The data acquisition module collects lightning signals and lightning arrival time, which is the time when the detection station detects the lightning signal, that is, the lightning arrival time;

[0052] Among them, lightning information is detected through a network of several distributed detection sites. The detection process is as follows:

[0053] See also Figure 1 ,The data acquisition module includes GPS antenna, whip antenna and bidirectional magnetic ring, signal processor, GPS signal acquisition card, high-speed digital signal acquisition card and acquisition system;

[0054] The GPS antenna is connected to the GPS signal acquisition card; the GPS signal acquisition card is connected to the high-speed digital signal acquisition card; the whip antenna and the bidirectional magnetic ring are connected to the signal processor, which includes a signal amplifier, a filter and an analog / digital signal converter; the signal processor is connected to the high-speed digital signal acquisition card; the GPS signal acquisition card and the high-speed digital signal acquisition card are connected to the acquisition system;

[0055] The frequency bands of the front-end amplifier are 300Hz-400KHz and 800Hz-400KHz respectively. During the lightning discharge process, broadband electronic radiation of several Hz to several GHz can be generated, and its main energy is concentrated in the LF or VLF band, which can be transmitted for thousands of kilometers. Therefore, the present invention adopts a working frequency band of 300Hz-400Khz to cope with the deployment of a large-scale lightning detection network.

[0056] Since the stations set up in coastal areas will be interfered by the navigation signal (100KHz) of the Loran-c coastal station chain, causing a large number of data false triggers, a third-order Butterworth low-pass filter with a -3dB at 70KHz was selected to preprocess the collected raw data. The filtered data was used to trigger lightning events, which can not only filter out the interference of the Loran-c signal on the trigger event, but also filter out the signal interference of other high-frequency bands. Furthermore, during the operation of the station, the design of the trigger threshold directly affects the sensitivity of the acquisition end to the lightning signal, and further affects the positioning efficiency. When using an operational amplifier to amplify the signal, the offset voltage of the operational amplifier itself will affect the reference level of the output signal. At the same time, environmental factors such as ambient temperature and electric field will also affect the reference level of the signal. Therefore, a floating threshold that changes with historical data is designed. The average value of the first N untriggered data is taken as the reference level for judging this trigger. The trigger threshold is set based on the reference level, which largely eliminates the influence of system errors on lightning triggering. By comparing the waveform data of different stations after sorting, the waveform type and characteristics and the correlation between them can be further analyzed, such as Figure 2 shown.

[0057] GPS or BDS satellite timing module enables several distributed detection sites to form a network and detect lightning at the same time;

[0058] The GPS or BDS satellite timing module of the present invention is designed based on a high-speed data acquisition card and a GPS training clock module. The GPS training clock outputs a serial port NEMA83 signal, a 5MHz clock pulse, and a PPS second signal pulse. The time signal is transmitted to the computer through the serial port, and a PPS second signal pulse is output to the fourth channel of the acquisition card for matching the accurate second time, and a constant temperature crystal oscillator clock (5M) is output as the sampling clock of the acquisition card to ensure the accuracy and stability of the sampling rate. Through this timing mode, it can be ensured that the stations in the station network are at the same time reference and accurately synchronized.

[0059] The station group configuration evaluation module selects candidate detection site networks from a number of detection site networks; calculates the GDOP values ​​of the candidate detection site networks; and selects the best detection site network from the candidate detection site networks based on the GDOP values;

[0060] The selection of candidate detection site networks specifically includes the following processing steps:

[0061] Step P1: Preliminary screening of the detection site network based on the waveform characteristics of the lightning signal; wherein the waveform characteristics include polarity, waveform parameters and change trends; the waveform parameters include rise time, fall time, pulse width and recoil amplitude;

[0062] It should be noted that lightning signals with the same polarity, similar waveform parameters and the same change trend are screened out, and the similar waveform parameters refer to the same waveform parameter values ​​whose difference is less than the corresponding preset difference threshold.

[0063] Step P2: Perform secondary screening on the detection site network according to the triangle principle; wherein, any three sites in the detection site network must satisfy the triangle principle; the triangle principle is that the sum of the two sides is greater than the third side, and the difference between the two sides is less than the third side;

[0064] Step P3: After two rounds of screening, several detection site networks are obtained and marked as candidate detection site networks; the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time are extracted, and the arrival time difference of lightning at each detection site is calculated; based on the arrival time difference and the coordinates of each detection site, the initial value of the lightning coordinate is calculated; based on the initial value of the lightning coordinate, the GDOP value of the candidate detection site network is calculated;

[0065] Specifically, for each detection site pair (for example, site A, site B, and site C), assuming that the time for the lightning signal to reach site A is tA, the time for the lightning signal to reach site B is tB, and the time for the lightning signal to reach site C is tC, then the time differences of the lightning signals reaching the three sites are ΔtAB = |tA-tB|, ΔtAC = |tA-tC|, and ΔtBC = |tB-tC|; based on the propagation speed of electromagnetic waves in a vacuum being the speed of light c (approximately equal to 3×10 8 m / s) to calculate the distance between each detection site, which are dBA, dBC, and dBC respectively; where dBA is the distance from the lightning signal to site A minus the distance to site B, dAC is the distance from the lightning signal to site A minus the distance to site C, and dBC is the distance from the lightning signal to site B minus the distance to site C. For each pair of sites, the distance equations between the lightning signal and the site can be obtained. Solving the three sets of equations can obtain the initial value of the lightning coordinates; if there are N sites, then N equations can be obtained.

[0066] Assumptions

[0067]

[0068] Wherein, i is the number of the candidate detection site network, i=0,1,…,N, N is a positive integer, k is the number of base stations in each detection site network; (x,y,z) is the initial value of the lightning coordinate, fk1, fk2, fk3 respectively refer to the first-order derivatives of the k-th site to the lightning coordinate component; (Axk,Ayk,Azk) is the three-dimensional coordinate of the k-th base station; dk is the distance from the lightning to the k-th base station; the G matrix is ​​the combination of fk1,fk2,fk3 of the k-th site; tr is the trace of the matrix; T is the transpose.

[0069] It should be noted that the initial value of the lightning coordinate may be significantly different from the actual position, but it is still small enough compared to the transmission distance of hundreds or thousands of kilometers and can be used to calculate the GDOP value.

[0070] Step P4: Determine whether the GDOP value is less than the preset minimum threshold and less than the preset threshold of the current detection site network; if yes, the candidate detection site network is marked as the best detection site network; if no, the detection site network is not marked.

[0071] To further illustrate the screening effect of GDOP index on site combination, the present invention conducted a simulation experiment, using 6 sites in our site network, simulating 100,000 initial values ​​of lightning coordinates in a given area, and calculating GDOP for these lightning positions. The results are as follows: Figure 3 As shown in the figure, it can be clearly seen that the GDOP index clearly distinguishes lightning with better spatial configuration inside the station network from lightning with poor spatial configuration outside the station network (the smaller the GDOP value, the better the spatial configuration), proving that it can be used as one of the indicators for site combination screening.

[0072] The central processing calculation module extracts the coordinates of each detection site in the best detection site network; and calculates the lightning coordinates according to the coordinates of each detection site in the best detection site network.

[0073] It should be noted that the central processing module is the core module of the entire system. All the detection site network detection data are filtered by the station group configuration evaluation module and then transmitted to the central computing module for solution. When the central processing module completes the calculation of a site combination, it will push the result to the data publishing thread, and then push it to the storage publishing module when certain conditions are met.

[0074] Specifically, the three-dimensional coordinates of the kth base station in the best detection site network are extracted and marked as Pk; the lightning coordinates Pf are obtained by the following calculation formula:

[0075] e j = dis(Pk,Pf)-c(t j -t);

[0076] Where j is the number of the candidate detection site network, j = 0, 1, ..., M, M is a positive integer; ej is the positioning error of the jth candidate detection site network; c is the propagation speed of electromagnetic waves along the earth's surface; t is the time when lightning occurs, t j is the lightning arrival time of the jth detection site network; the dis(Pk,Pf) function is used to calculate the spherical distance between points Pk and Pf;

[0077] The following nonlinear equations are constructed by networking several detection sites:

[0078]

[0079] The minimum value of the nonlinear equation group E is solved by GPU traversal method to obtain the lightning coordinates Pf.

[0080] It should be noted that GPU refers to the product launched by NVIDIA that supports CUDA computing. CUDA provides a three-level hierarchy to configure and call threads running on GPU, namely GRID, BLOCK and THREAD, see Figure 4 . First, we build multi-level grid models with different resolutions in the coverage area of ​​the station network. There are several grid points in each level of the grid, and each point represents a coordinate. Substitute this coordinate into the above equations to obtain E, and then each thread substitutes different grid points to perform the same operation, and finally obtains a minimum E at the current resolution. Then we step into the next level of grid with this grid point as the center until we reach the grid resolution we want.

[0081] Each time the grid is traversed, all threads run the same function, but process different data streams. It should be noted that only threads in the same block can interact with each other, so all threads in each block need to compare the points with the smallest error within themselves, and then use the CPU to compare the points with the smallest error between blocks. In order to speed up the minimum value comparison between multiple threads, the present invention uses a parallel reduction algorithm to speed up. Figure 5 As shown in the figure, in the recursive structure, at each step, all threads are divided into two equal groups, and each thread in group A compares its calculation result with the result of the relative position in group B, passes the smaller result to group A and discards the result of group B. After the threads are synchronized, all threads in group A enter the next round of operation until there is only one thread result left in group A, which is the minimum value of the current block.

[0082] A simulation experiment was used to compare the optimization algorithm, CPU traversal and GPU traversal methods to calculate 100 lightning events. The optimization algorithm uses the LM algorithm and adds 100 annealing mechanisms; the CPU traversal uses XEON E3-1230; the GPU traversal sets the traversal grid to 3000*3000 and the graphics card is GTX780. In the end, the positioning error of each algorithm is within 3KM, which ensures that the final effects of several positioning algorithms are similar. Then the time consumption becomes an important indicator for evaluating the availability of real-time positioning algorithms. The results are as follows:

[0083]

[0084] Judging from the experimental results, the GPU traversal method has obvious efficiency advantages over other traditional methods in the location calculation process of 100 lightning events, proving its high application value in lightning location scenarios that require a large amount of parallel computing.

[0085] The network transmission module transmits the data collected by the front-end site back to the central processing module in a timely manner. After the trigger data is collected, the system will first store it in the FIFO buffer of the acquisition card. When the buffer is full, the data in the entire stack will be sent to the specific port of the central processing module by establishing a TCP / UDP connection. When data transmission is blocked, the system will clear the stack and reconnect to give priority to ensuring the normal transmission of data.

[0086] See also Figure 6 The second aspect of the present invention provides a method for enhancing lightning location based on site spatial configuration, comprising the following steps:

[0087] Step 1: Obtain lightning information detected by each detection site network;

[0088] Step 2: Preliminary screening of the detection site network based on the waveform characteristics of the collected lightning signals; secondary screening of the detection site network based on the triangle principle to obtain candidate detection site networks;

[0089] Step 3: Extract the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time, and calculate the initial value of the lightning coordinates based on the coordinates of each detection site and the lightning arrival time;

[0090] Step 4: Based on the initial value of the lightning coordinates, calculate the GDOP value of the candidate detection site network; based on the GDOP value, determine the best detection site network;

[0091] Step 5: Calculate the lightning coordinates based on the coordinates of each detection site in the best detection site network and the lightning arrival time.

[0092] Part of the data in the above formula is calculated by removing the dimension and taking its numerical value. The formula is a formula closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by technical personnel in this field according to actual conditions or obtained through simulation of a large amount of data.

[0093] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A lightning location enhancement system based on site spatial configuration, characterized in that: It includes data acquisition module, GPS or BDS satellite timing module, network transmission module, station group configuration evaluation module, central processing and calculation module and storage and release module; Data acquisition module: used to collect lightning information; the lightning information includes lightning signals and lightning arrival time; the lightning information is detected by a network of several distributed detection sites; the lightning arrival time is the time when the detection site detects the lightning signal; Station group configuration evaluation module: used to select candidate detection site networks from a number of detection site networks; calculate the GDOP value of the candidate detection site networks; based on the GDOP value, select the best detection site network from the candidate detection site networks; Central processing calculation module: used to extract the coordinates of each detection site in the best detection site network; calculate the lightning coordinates according to the coordinates of each detection site in the best detection site network.

2. A lightning location enhancement system based on site spatial configuration according to claim 1, characterized in that: The network transmission module is used to establish a TCP / UDP connection and send the trigger data collected by the front-end site to the central processing and calculation module; when the central processing and calculation module completes the calculation of a detection site network, it sends the calculation result to the storage and publishing module.

3. The lightning location enhancement system based on site spatial configuration according to claim 1, characterized in that: The data acquisition module includes a GPS antenna, a whip antenna and a bidirectional magnetic ring, a signal processor, a GPS signal acquisition card, a high-speed digital signal acquisition card and an acquisition system; The GPS antenna is connected to the GPS signal acquisition card in communication; the GPS signal acquisition card is connected to the high-speed digital signal acquisition card in communication; the whip antenna and the bidirectional magnetic ring are connected to the signal processor in communication, and the signal processor includes a signal amplifier, a filter and an analog / digital signal converter; the signal processor is connected to the high-speed digital signal acquisition card in communication; the GPS signal acquisition card and the high-speed digital signal acquisition card are both connected to the acquisition system in communication.

4. A lightning location enhancement system based on site spatial configuration according to claim 3, characterized in that: The GPS or BDS satellite timing module is constructed based on a high-speed digital signal acquisition card and a GPS acquisition card; the GPS acquisition card outputs one serial port NEMA83 signal, one 5MHz clock pulse, and one PPS second signal pulse.

5. The lightning location enhancement system based on site spatial configuration according to claim 4, characterized in that: The method for obtaining the lightning arrival time includes: The GPS signal acquisition card outputs one serial port NEMA83 signal to the acquisition system; the GPS signal acquisition card outputs one PPS second signal pulse and one 5MHz clock pulse to the high-speed digital signal acquisition card; the signal processor outputs the processed digital signal to the high-speed digital signal acquisition card, and by matching it with one PPS second signal pulse and one 5MHz clock pulse, the time when the lightning signal arrives at each detection site is obtained and marked as the lightning arrival time.

6. The lightning location enhancement system based on site spatial configuration according to claim 1, characterized in that: The calculating the GDOP value of the candidate detection site network and obtaining the candidate detection site network includes: Step P1: Preliminary screening of the detection site network based on the waveform characteristics of the lightning signal; wherein the waveform characteristics include polarity, waveform parameters and change trends; the waveform parameters include rise time, fall time, pulse width and recoil amplitude; Step P2: Perform secondary screening on the detection site network according to the triangle principle; wherein, any three sites in the detection site network must satisfy the triangle principle; the triangle principle is that the sum of the two sides is greater than the third side, and the difference between the two sides is less than the third side; Step P3: After two rounds of screening, several detection site networks are obtained and marked as candidate detection site networks; the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time are extracted, and based on the coordinates of each detection site and the lightning arrival time, the initial coordinates of the lightning are calculated and marked as the initial value of the lightning coordinates; based on the initial value of the lightning coordinates, the GDOP value of the candidate detection site network is calculated; Step P4: Determine whether the GDOP value is less than the preset minimum threshold and less than the preset threshold of the current detection site network; if yes, the candidate detection site network is marked as the best detection site network; if no, the detection site network is not marked.

7. A lightning location enhancement system based on site spatial configuration according to claim 6, characterized in that: The calculating of the initial coordinates of the lightning based on the coordinates of each detection site and the lightning arrival time includes: The arrival time difference of lightning at each detection site is calculated; based on the arrival time difference and the coordinates of each detection site, the initial value of the lightning coordinate is calculated.

8. The lightning location enhancement system based on site spatial configuration according to claim 7, characterized in that: The calculating of the GDOP value of the candidate detection site network based on the initial value of the lightning coordinates includes: The GDOP value of the i-th candidate detection site network is calculated as follows: Wherein, i is the number of the candidate detection site network, i=0,1,…,N, N is a positive integer, k is the number of base stations in each detection site network; (x,y,z) is the initial value of the lightning coordinate, fk1, fk2, fk3 respectively refer to the first-order derivatives of the k-th site to the lightning coordinate component; (Axk,Ayk,Azk) is the three-dimensional coordinate of the k-th base station; dk is the distance from the lightning to the k-th base station; the G matrix is ​​the combination of fk1,fk2,fk3 of the k-th site; tr is the trace of the matrix; T is the transpose.

9. The lightning location enhancement system based on site spatial configuration according to claim 8, characterized in that: The step of calculating the lightning coordinates according to the coordinates of the optimal detection site network includes: The three-dimensional coordinates of the kth base station in the best detection site network are extracted and marked as Pk; the lightning coordinates Pf are obtained by the following calculation formula: e j =dis(Pk,Pf)-c(t j -t); Where j is the number of the candidate detection site network, j = 0, 1, ..., M, M is a positive integer; ej is the positioning error of the jth candidate detection site network; c is the propagation speed of electromagnetic waves along the earth's surface; t is the time when lightning occurs, t j is the lightning arrival time of the jth detection site network; the dis(Pk,Pf) function is used to calculate the spherical distance between points Pk and Pf; The following nonlinear equations are constructed by networking several detection sites: The minimum value of the nonlinear equation group E is solved by GPU traversal method to obtain the lightning coordinates Pf.

10. A lightning location enhancement method based on site spatial configuration, based on the operation of a lightning location enhancement system based on site spatial configuration according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Obtain lightning information detected by each detection site network; Step 2: Preliminary screening of the detection site network based on the waveform characteristics of the collected lightning signals; secondary screening of the detection site network based on the triangle principle to obtain candidate detection site networks; Step 3: Extract the coordinates of each detection site in the candidate detection site network and the detected lightning arrival time, and calculate the initial value of the lightning coordinates based on the coordinates of each detection site and the lightning arrival time; Step 4: Based on the initial value of lightning coordinates, calculate the GDOP value of the candidate detection site network; Based on the GDOP value, determine the best detection site network; Step 5: Calculate the lightning coordinates based on the coordinates of each detection site in the best detection site network and the lightning arrival time.

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