A magnetic field identification method based on lightning positioning

Abstract

The application discloses a magnetic field identification method based on lightning positioning, which adopts the method of independent timing of each time condition to accurately mark and determine the time point based on global clock information, detects and identifies different operation states of the data magnetic field signal sent by a lightning detection station, and waits for the state of the over-threshold effective signal; when the over-threshold effective signal exists, the method starts to find the peak value and records the time point information of the current trigger threshold; after the peak value is determined, the peak point time information is recorded and the method is transferred to the detection of the falling time and the detection of the subsequent peak value intensity. Through the circulation of the method, the lightning signal can be continuously identified and processed.

Description

Technical Field

[0001] This invention relates to the field of lightning location technology, and in particular to a magnetic field identification method based on lightning location. Background Technology

[0002] Previous lightning location systems used fixed models to distinguish between ground flashes and cloud-to-ground flashes. These models had fixed parameters and logic, resulting in traditional binary logic: signals that matched the predictions were recognized, while those that didn't were not. However, based on existing literature, our understanding of lightning discharge processes needs further development, and the changing characteristics of the wide-area propagation waveform of lightning electromagnetic waves require further research. Even considering all previous logic recognition conditions, the possibility of signal misinterpretation still exists.

[0003] Multivalued logic is a logical calculus with more than two possible truth values. In wide-area lightning ground flash monitoring, based on the basic model design, multiple definitions and calculations are performed on the possible signal characteristics to provide a more tolerant identification logic to acquire a large amount of wide-area lightning activity monitoring data. The waveform data is then stored and transmitted remotely to establish a waveform database for subsequent systems, providing a foundation for data analysis and improving the understanding of lightning electromagnetic wave characteristics.

[0004] In addition, due to the inherent characteristics of multi-valued logic signal processing algorithms and high background noise lightning electromagnetic wave signal detection, the amount of signal processing increases dramatically in a short period of time, and the signal processing methods become more complex. Traditional lightning signal processing methods cannot meet the real-time processing of signal data streams. Therefore, it is necessary to design a new magnetic field identification method for lightning location to overcome the challenges of continuous processing and storage of bursty, high-density lightning signals. Summary of the Invention

[0005] This invention provides a magnetic field identification method based on lightning location, which at least solves the technical problem in related technologies that lack the ability to continuously process lightning signals.

[0006] According to one aspect of the present invention, a magnetic field identification method based on lightning location is provided, comprising:

[0007] Using global clock information as a reference, a method of independent timing for each time condition is employed to accurately calibrate and determine time points. The data magnetic field signals transmitted by the lightning detection station are then detected and identified to identify different operating states. This includes the following steps:

[0008] The state of waiting for a valid threshold signal;

[0009] When a valid signal that has exceeded the threshold is found, peak search begins and the time information of the current threshold trigger is recorded.

[0010] Once the peak value is determined, the peak time information is recorded, and the process transitions to fall time detection and subsequent peak intensity detection.

[0011] Optionally, the threshold-crossing valid signal is when the current threshold-crossing signal is high.

[0012] Optionally, the peak finding includes an ascent process and a peak point confirmation process.

[0013] Optionally, the rising process includes: setting a temporary peak register as a temporary storage for the current maximum value, and initially the data in the temporary peak register is the threshold value;

[0014] After the threshold signal is valid, the current input signal data is compared point by point. If the value of the current input data is greater than the data in the temporary peak register, the current data is stored in the temporary peak register and used as the comparison object for the next data, until the input data is less than the data in the temporary peak register. When the input data is less than the data in the peak register, a judgment is made on whether the falling state is valid.

[0015] Optionally, the peak point confirmation process includes: after input data less than the data in the temporary peak register appears, starting a timer for valid confirmation;

[0016] If, within the effective judgment time of the timer, the current input data is all less than the data in the temporary peak register and all greater than the threshold value, then the data in the temporary peak register is the peak point. The peak time is determined based on the time when the peak point is input into the temporary peak register, and it is confirmed that the waveform decline phase has begun, i.e., the decline time detection and subsequent peak intensity detection are initiated.

[0017] If, within the valid judgment period, the input data is greater than the data in the peak temporary register, the current larger value will still be transferred to the peak temporary register, and the judgment will continue from the falling state to the rising state.

[0018] Optionally, the fall time detection includes: in the valid judgment of the fall state, a specific time period is set according to the characteristics of the actual signal. If no data greater than the temporary peak register appears within this time period, it is determined that the subsequent stage of fall has been entered.

[0019] Optionally, the descent time is an immediate jump condition, and the subsequent peak intensity is a delayed jump condition.

[0020] According to another aspect of the present invention, a magnetic field identification system based on lightning location is also provided. Using global clock information as a reference, a method of independently timing each time condition is employed for precise calibration and determination of time points. The system detects and identifies different operating states of the data magnetic field signals sent by lightning detection stations, including:

[0021] The initial state module is used to initialize all temporary registers and control signals in the lightning-based magnetic field identification unit, and then immediately jump to the trigger waiting state.

[0022] The trigger light strip status module is used to wait for a valid signal after the threshold is exceeded, i.e., it is in a trigger waiting state;

[0023] The peak search status module is used to start peak search and record the time point information of the current trigger threshold when a valid signal exceeding the threshold is found; and

[0024] The descent state module is used to record the peak time information after the peak is determined and then proceed to descent time detection and subsequent peak intensity detection.

[0025] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to execute the magnetic field identification method based on lightning location as described above.

[0026] According to another aspect of the present invention, a processor is also provided, the processor being configured to run a program, wherein the program, when running, executes the magnetic field identification method based on lightning location as described in any of the preceding embodiments.

[0027] Compared with existing technologies, the present invention has the following advantages:

[0028] In this embodiment of the invention, the method uses global clock information as a reference and employs an independent timing method for each time condition to accurately calibrate and determine the time point. It detects and identifies different operating states of the data magnetic field signal sent by the lightning detection station, waiting for a valid threshold signal. When a valid threshold signal is found, peak value searching begins and the current trigger threshold time point information is recorded. Once the peak value is determined, the peak value time information is recorded, and the process transitions to fall time detection and subsequent peak intensity detection. By repeating this method, lightning signals can be continuously identified and processed. Attached Figure Description

[0029] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart of a magnetic field identification method based on lightning location according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of peak finding according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram illustrating the process of determining peak data and peak point time data according to an embodiment of the present invention;

[0033] Figure 4 This is a simulation waveform diagram of the functional verification test according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the starting segment of the waveform rise process captured according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of intermediate process 1 of the rising process according to an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of intermediate process 2 of the rising process according to an embodiment of the present invention;

[0037] Figure 8 This is the peak confirmation process according to an embodiment of the present invention. Figure 1 ;

[0038] Figure 9 This is the peak confirmation process according to an embodiment of the present invention. Figure 2 ;

[0039] Figure 10 This refers to the state change and numerical storage state after peak confirmation according to an embodiment of the present invention. Detailed Implementation

[0040] 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.

[0041] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0042] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] Example 1

[0044] According to an embodiment of the present invention, an embodiment of a magnetic field identification method based on lightning location is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0045] Magnetic field signal identification is the detection and recognition of magnetic field signals. It is the unit for determining the time reference point in the lightning location system and the main control unit of the entire identification system. Digital lightning detectors are designed to be compatible with the data processing methods of traditional detectors. They adopt the same data sample processing method as traditional detectors, using the larger of the absolute values ​​of the east-west and north-south magnetic field signals as the identification object. Therefore, all data entering the magnetic field signal identification process are absolute value signals. According to the processing requirements of the identification method, the magnetic field signal identification condition is the primary discrimination condition. Therefore, the magnetic field signal identification unit is designed to operate in an active mode, providing relevant control signals to the identification system, especially the electric field signal identification unit, while simultaneously responding to the status feedback signals from the electric field signal identification unit.

[0046] like Figure 1 This is a flowchart of a magnetic field identification method based on lightning location according to an embodiment of the present invention, as follows: Figure 1As shown, this method uses global clock information as a reference and employs an independent timing method for each time condition to accurately calibrate and determine the time point. It detects and identifies different operating states of the data magnetic field signals sent by the lightning detection station, including the following steps:

[0047] Step S1: Wait for the threshold valid signal, that is, always monitor the threshold signal.

[0048] Step S2: When a valid signal that has exceeded the threshold exists, start peak search and record the time information of the current threshold trigger.

[0049] As an optional embodiment, the threshold valid signal is when the current threshold signal is high.

[0050] The design specifies that input data exceeding a certain set value is considered threshold-crossing data, and the threshold-crossing signal is high. Conversely, input data below the set value is considered non-threshold-crossing data, and the threshold-crossing signal is low. When the current threshold-crossing signal is high, and its previous state was low, a threshold crossing is considered to have occurred, and the threshold-crossing signal is deemed valid. When the threshold-crossing signal is valid, the trigger wait state immediately jumps to the peak search state, and the rise time timer starts. When the threshold-crossing signal is invalid, the identification unit clock operates in a wait state, and all relevant parameter registers and flag signals are at their initial values.

[0051] As an optional implementation, the peak finding process mainly includes two stages: the rising phase and the peak point confirmation process. Since the lightning location system is a highly real-time lightning monitoring system, the digital detection station for lightning signal detection is designed and developed based on real-time requirements for signal processing. As a real-time detection device, it can only analyze and process current and past data samples. The location of the peak point is uncertain without a comprehensive understanding of all data characteristics. To accurately find the peak point while meeting certain real-time requirements, a data buffering operation mode is adopted in the design to determine the peak point. First, based on the known characteristics of lightning electromagnetic waves, the waveform rises after passing a threshold. Therefore, a temporary register is set as a temporary storage for the current maximum value. Initially, the data in this register is the threshold value. After the threshold signal is valid, the current input data is compared point by point. If the current input value is greater than the data in the temporary peak register, the current data is stored in the temporary peak register and used as the comparison object for the next data. The identification unit continues to operate in the rising judgment process until the input data is less than the data in the temporary peak register. When the input data is less than the peak register, a peak may have already occurred, and the recognition unit will then determine whether the descent state is valid. In the valid descent state determination, a specific time period is set based on the characteristics of the actual signal. If no data greater than the temporary peak register appears within this time period, the system will determine that it has entered the subsequent descent stage. Following this logic, after input data less than the data in the temporary peak register appears, a valid confirmation timer will be started. If, within the timer, all currently input data are less than the data in the temporary peak register and all are greater than the threshold value, the recognition unit will determine the peak point, the peak time, and confirm entry into the subsequent descent stage of the waveform. However, if, within the valid determination time period, the previous input data is greater than the data in the peak temporary register, the current larger value will still be transferred to the peak temporary register, and the system will exit the valid descent state determination state and continue with the rising state determination. It should be noted that in the valid descent state determination state, if the current input data is already below the threshold value, then even if other data are not greater than the value in the temporary peak register, the magnetic field recognition unit will generate an immediate initialization signal, determining that the current input data does not meet the lightning strike condition requirements. Based on the above description of the design and operation of the peak state, in addition to satisfying the state transition conditions, all conditions form a complete peak finding and identification loop to ensure that the system does not abnormally exit.

[0052] When confirming peak values, that is, during the valid determination of a declining state, there are two methods for determining peak points: 1. Determining the declining trend; 2. Determining extreme points. Determining the declining trend involves judging whether the current input data meets a certain declining trend. Two temporary registers are used: a temporary peak register and a temporary minimum register. When the input data is less than the data in the temporary peak register, the data in the peak register is locked, and the current input data is transferred to the temporary minimum register. When new data arrives, it is compared with the data in the temporary minimum register. If the new data is less than the data in the temporary minimum register, the new data is written to the temporary minimum register. Following this method, if a continuous series of small-amplitude data inputs occur within a certain period, the current state is considered to have entered the declining phase, and the data in the temporary peak register is identified as the peak point. Determining extreme points is essentially the method for determining maximum values. When the input data is less than the data in the temporary peak register, the determination of a valid declining state begins. Each input data is compared with the data in the temporary peak register. If, within a certain period, the input data is consistently less than the data in the temporary register, the point corresponding to the data in the temporary register is determined to be the peak point. Both methods can locate peak values ​​in waveform data. However, the first method, which compares adjacent data point by point, is highly sensitive to abnormal signal fluctuations. If spikes are superimposed on the waveform, it will affect the accurate determination of peak points, leading to uncertainty about the peak point within a certain time period. The length of this time period varies depending on the waveform data. Such time uncertainty is unacceptable for lightning location systems that rely on precise time.

[0053] like Figure 2 This is a simplified diagram illustrating the peak finding process. As shown, each stage has a maximum or minimum time limit. Therefore, if the corresponding process is not completed within the specified time, the identification system will automatically initialize. The diagram also shows the comparison of peak confirmation with data of equal amplitude in a temporary register. This raises the question of determining the peak time point when the input signal amplitude has not exceeded the measurement range and the signal itself exhibits a flat-top characteristic at the peak point. Considering the characteristics of actual lightning electromagnetic wave signals and the system's requirements, the design adopts a method of using the midpoint as the time calibration point.

[0054] Figure 3This diagram illustrates the process of determining peak data and peak point time data, using the identification process of a standard lightning signal as an example. Other complex signals are simply state cycle transitions based on this process. The diagram shows two levels of temporary registers. During the transition from the rising state to the peak point confirmation state, it indicates that the maximum value has been found. Simultaneously, the identification unit sends the current maximum value to temporary peak register 1 and the corresponding time point to temporary peak point time register 1. After the confirmation process in the peak point confirmation stage, the identification unit sends a confirmation signal to control the data lines between the first and second level registers, allowing first-level data to enter the second level register. The second level register is actually a protective storage register; its data is only modified when the peak confirmation signal or initialization signals such as reset are valid. The diagram also shows the flat-top processing process marked with dashed lines; this process addresses the previously mentioned problem of determining the flat-top peak point time. When the input data immediately adjacent to the peak point is equal to the peak data, the system will clock and count samples during this process, calculate the time offset of the midpoint, and then correct the peak point time after the peak point is confirmed.

[0055] Step S3: After determining the peak value, record the peak value time information and proceed to the detection of the descent time and subsequent peak intensity, i.e., enter the descent state judgment.

[0056] As an optional implementation, the system enters a descent state once the peak point is confirmed. In the descent state, based on design conditions, there are two main confirmation conditions: descent time and subsequent peak intensity. Descent time is the immediate jump condition, while subsequent peak intensity is the delayed jump condition. It is required that the first time below the threshold during the descent process must not be less than the minimum descent time. If any data point falls below the threshold within the minimum required time, the system is immediately transferred to the initialization state. It should be noted that since the necessary time requirement for peak confirmation occupies part of the descent time, adjustments to the descent time timing need to be considered. Regarding subsequent peak intensity, it is required that no point in the entire subsequent process has an excessively large amplitude intensity. If such an intensity exists, the system will not issue a lightning confirmation signal after the subsequent process time is completed, but will directly jump to the initial state.

[0057] Example 2

[0058] According to another aspect of the present invention, a magnetic field identification unit based on lightning location is also provided. Using global clock information as a reference, it employs a method of independent timing for each time condition to accurately calibrate and determine time points, and detects and identifies different operating states of the data magnetic field signals sent by the lightning detection station, including:

[0059] The initial state module is used to initialize all temporary registers and control signals in the lightning-based magnetic field identification unit, and then immediately jump to the trigger wait state.

[0060] Specifically, when the initial state module is working, it puts the lightning-based magnetic field identification unit into an initial state. The initial state is an instantaneous state, controlled by the system control signals and the identification and confirmation signals of the electromagnetic field identification unit. Once any of these signals is set to valid, the system will immediately enter the initial state. In the initial state, all temporary registers and control signals within the magnetic field identification unit will be initialized, and then the system will immediately jump to the trigger wait state.

[0061] The trigger light strip status module is used to wait for a valid signal after the threshold is exceeded, i.e., it is in the trigger waiting state.

[0062] Specifically, when the trigger light strip status module is working, it puts the lightning-based magnetic field identification unit into a triggered state. The trigger waiting state is the starting state of the magnetic field identification process, and its state transition is based solely on the crossing from below the threshold value to above the threshold value. Therefore, in this state, the identification unit constantly monitors the threshold crossing signal. The design specifies that when the input data is higher than a certain set value, it is considered threshold-crossing data, and the threshold crossing signal is high; conversely, when the input data is lower than the set value, it is considered non-threshold-crossing data, and the threshold crossing signal is low. When the current threshold crossing signal is high, and the previous state of the threshold crossing signal was low, it is considered that a threshold crossing process has occurred, and the threshold crossing signal is deemed valid. When the threshold crossing signal is valid, the trigger waiting state will immediately jump to the peak search state and start the rise time timer. When the threshold crossing signal is invalid, the identification unit clock operates in a waiting state, and all relevant parameter registers and flag signals are at their initial values.

[0063] The peak search status module is used to start peak search and record the time point information of the current trigger threshold when there is a valid signal that has exceeded the threshold.

[0064] Specifically, when the peak search module is working, it puts the magnetic field identification unit based on lightning location into a peak search state. The peak search state mainly includes two processes: the rising process and the peak point confirmation process. Since the lightning location system is a highly real-time lightning monitoring system, the digital detection station for lightning signal detection is designed and developed based on real-time requirements for signal processing. As a real-time detection device, it can only analyze and process current and past data samples. The location of the peak point is uncertain without a comprehensive understanding of all data characteristics. To accurately identify the peak point while meeting certain real-time requirements, a data buffering operation mode is adopted in the design to determine the peak point. First, based on the known characteristics of lightning electromagnetic waves, the waveform rises after exceeding a threshold. Therefore, a temporary register is set up to temporarily store the current maximum value. Initially, the data in this register is the threshold value. After the threshold signal is valid, the current input data is compared point by point. If the current input value is greater than the data in the temporary peak register, the current data is stored in the temporary peak register and used as the comparison object for the next data. The recognition unit continues to operate in the rising judgment process until the input data is less than the data in the temporary peak register. When the input data is less than the peak register, a peak may have occurred, and the recognition unit will then determine whether the falling state is valid. In the valid falling state judgment, a specific time period is set according to the characteristics of the actual signal. If no data greater than the data in the temporary peak register occurs within this time period, the system will determine that it has entered the subsequent falling stage. Following the above approach, after input data less than the data in the temporary peak register occurs, a valid confirmation timer will be started. If, within the timer, all current input data are less than the data in the temporary peak register and all are greater than the threshold value, the recognition unit will determine the peak point, the peak time, and confirm that it has entered the subsequent falling stage of the waveform. During the valid judgment period, if the input data is greater than the data in the peak temporary register, the current larger value will still be transferred to the peak temporary register, and the system will exit the falling state valid judgment state and continue to the rising state judgment state. It should be noted that in the falling state valid judgment state, if the current input data is already below the threshold value, then even if other data is not greater than the value in the temporary peak register, the magnetic field recognition unit will generate an immediate initialization signal, determining that the current input data does not meet the lightning strike condition requirements. Through the above design and operation description of the peak state, in addition to meeting the state transition conditions, all conditions form a complete peak search and recognition loop to ensure that the system does not abnormally exit.

[0065] When confirming peak values, that is, during the valid determination of a declining state, there are two methods for determining peak points: 1. Determining the declining trend; 2. Determining extreme points. Determining the declining trend involves judging whether the current input data meets a certain declining trend. Two temporary registers are used: a temporary peak register and a temporary minimum register. When the input data is less than the data in the temporary peak register, the data in the peak register is locked, and the current input data is transferred to the temporary minimum register. When new data arrives, it is compared with the data in the temporary minimum register. If the new data is less than the data in the temporary minimum register, the new data is written to the temporary minimum register. Following this method, if a continuous series of small-amplitude data inputs occur within a certain period, the current state is considered to have entered the declining phase, and the data in the temporary peak register is identified as the peak point. Determining extreme points is essentially the method for determining maximum values. When the input data is less than the data in the temporary peak register, the determination of a valid declining state begins. Each input data is compared with the data in the temporary peak register. If, within a certain period, the input data is consistently less than the data in the temporary register, the point corresponding to the data in the temporary register is determined to be the peak point. Both methods can locate peak values ​​in waveform data. However, the first method, which compares adjacent data point by point, is highly sensitive to abnormal signal fluctuations. If spikes are superimposed on the waveform, it will affect the accurate determination of peak points, leading to uncertainty about the peak point within a certain time period. The length of this time period varies depending on the waveform data. Such time uncertainty is unacceptable for lightning location systems that rely on precise time.

[0066] like Figure 2 This is a simplified diagram illustrating the peak finding process. As shown, each stage has a maximum or minimum time limit. Therefore, if the corresponding process is not completed within the specified time, the identification system will automatically initialize. The diagram also shows the comparison of peak confirmation with data of equal amplitude in a temporary register. This raises the question of determining the peak time point when the input signal amplitude has not exceeded the measurement range and the signal itself exhibits a flat-top characteristic at the peak point. Considering the characteristics of actual lightning electromagnetic wave signals and the system's requirements, the design adopts a method of using the midpoint as the time calibration point.

[0067] Figure 3This diagram illustrates the process of determining peak data and peak point time data, using the identification process of a standard lightning signal as an example. Other complex signals are simply state cycle transitions based on this process. The diagram shows two levels of temporary registers. During the transition from the rising state to the peak point confirmation state, it indicates that the maximum value has been found. Simultaneously, the identification unit sends the current maximum value to temporary peak register 1 and the corresponding time point to temporary peak point time register 1. After the confirmation process in the peak point confirmation stage, the identification unit sends a confirmation signal to control the data lines between the first and second level registers, allowing first-level data to enter the second level register. The second level register is actually a protective storage register; its data is only modified when the peak confirmation signal or initialization signals such as reset are valid. The diagram also shows the flat-top processing process marked with dashed lines; this process addresses the previously mentioned problem of determining the flat-top peak point time. When the input data immediately adjacent to the peak point is equal to the peak data, the system will clock and count samples during this process, calculate the time offset of the midpoint, and then correct the peak point time after the peak point is confirmed.

[0068] The descent state module is used to record the peak time information after the peak is determined and then proceed to descent time detection and subsequent peak intensity detection.

[0069] Specifically, when the descent state module operates, it puts the lightning-based magnetic field identification unit into a descent state. Once the peak point is confirmed, it enters the descent state. In the descent state, based on design conditions, there are two main confirmation conditions: descent time and subsequent peak intensity. The descent time is the immediate jump condition, while the subsequent peak intensity is the delayed jump condition. It is required that the first time below the threshold during the descent process must not be less than the minimum descent time. If any data point falls below the threshold within the minimum required time, the system is immediately transferred to the initialization state. It should be noted that since the necessary time requirement for peak confirmation occupies part of the descent time, a correction to the descent time timing needs to be considered. Regarding the subsequent peak intensity, it is required that no point in the entire subsequent process has an excessively large amplitude intensity. If such an intensity exists, the system will not issue a lightning confirmation signal after the subsequent process time is completed, but will directly jump to the initial state.

[0070] Next, we will conduct tests and verifications based on the different processes described above.

[0071] Figure 4This is a simulated waveform used for functional verification testing. The original sample of this waveform comes from measured lightning strike waveform data. In this test, to clearly represent the function and logical judgment of the recognition unit, plus or minus 32 points of noise were superimposed on the original sample to test the handling of noise or anomalies during the rise process. For clarity, a local method description is provided at the starting point of the waveform's rise.

[0072] Figure 5 This is the starting segment of the waveform's rising phase. Relevant information in the diagram includes: the identification unit's operating clock clk_5M, the threshold indicator overTH and its own delay line overTHreg (delayed by one time unit), the rise time counter riseTime_Cnt, and its backup register riseTime_Cnt1. The identification unit is triggered by the rising edge of the clock. Therefore, from... Figure 5 As shown, when overTH is high and overTHreg is low at the same time point, a valid threshold crossing signal exists, and the magnetic field recognition unit will begin judging the rising process. The rise timer will begin counting. During the rise phase, unless there are other situations where the input signal does not meet the set conditions, the timer should maintain a valid count throughout the entire rise process. Figure 5 As can be seen, in the first half of the process, there are multiple valid threshold crossing signals, but due to other conditions, the system jumps, causing the rising counter to reset to zero. At any given point, as long as a valid rising process exists, the counter continues to accumulate counts. Figure 5 The latter half of it.

[0073] like Figure 6 The image shows the intermediate stage of the ascent process. Several typical questions need to be considered here. If a brief amplitude drop occurs during the ascent, how can its impact on the overall ascent be avoided? If a smooth step occurs during the ascent, how can its impact on the overall ascent be avoided? Furthermore, if the smooth step appears at the peak, how can its ascent termination point be determined? For typical single-peak waveform signals, the ascent process ends with the determination of the peak point. Utilizing this characteristic, and combining it with lightning waveform features, assuming that the amplitude continues to decrease for a certain period, the peak can be confirmed. Based on this, when there are transient amplitude changes during the ascent process, because the duration of the amplitude decrease trend is very short, the ascent counter can be protected from interference from such signals through the shielding function of an effective counter. Figure 6In the example, the counter Paffirm_Cnt is this type of counter. We can see that when riseTime_Cnt reaches 20, a decreasing process occurs. At this point, Paffirm_Cnt counts to 1 when the next clock arrives. However, when riseTime_Cnt reaches 22, the waveform rises again. Due to the shielding effect, riseTime_Cnt continues to count, while Paffirm_Cnt resets to zero and waits for the next decreasing point. Between 19 and 22, although a dip occurs, the counter remains stable. This phenomenon is also reflected between 24 and 33. It should be further noted that the FPGA design employs a state-change design philosophy. Paffirm_Cnt should not affect the timing of the rising process during operation. Any extra timing time, since it is fixed, can be handled later. Figure 7 This reflects the impact of different working states of Paffirm_Cnt on riseTime_Cnt.

[0074] Figure 7 As can be seen, when Paffirm_Cnt is working, riseTime_Cnt exhibits a count hold phenomenon. The longer Paffirm_Cnt works, the longer riseTime_Cnt holds. Although the system does not interrupt the operation of riseTime_Cnt, the count hold causes a serious deviation in the determination of the waveform rise time. If this transient decline process does not occur before the peak point is confirmed, then this method with count hold characteristics can conveniently time the rise time. However, precisely because of the uncertainty of signal characteristics, although the continuous counting method increases the rise time length, the increase is predictable. Therefore, it is only necessary to eliminate the corresponding increment in subsequent processes.

[0075] Regarding the smoothing step process, according to the design concept, the main peak can be divided into two parts: an upward movement and a downward movement. Considering the signal characteristics, the first downward point after confirming the peak is taken as the dividing point. Therefore, for the upward movement, there are two possibilities: the current value is greater than the past value, and the current value is equal to the past value. It is desirable for the current value to be greater than the past value, while the current value being equal to the past value—the so-called smoothing step process—requires further processing. This process can occur in the entire peak portion and at the rising edge. Here, we will first discuss the case where the smoothing step occurs at the rising edge; the case where it occurs in the peak portion will be further explained during the peak finding process. At the rising edge, due to the real-time nature of the system, the identification unit itself is unaware of the distribution of subsequent data. As a condition for judgment, when equal data appears, the identification unit will enter the plateau process timing. Due to the state transition, the rise time count will be interrupted. To avoid this situation, the plateau phase time needs to be accumulated when the rise restarts. However, since the rise process also restarts, the same register cannot be written to twice at the same time point. Therefore, the number of plateau phases needs to be counted to ensure effective timing. However, this method increases the system's judgment and transition between different states, increasing the risk of timing conflicts and potentially causing system unexpected events. To avoid this phenomenon, a simple method is adopted: the rise process counting is only interrupted after the peak is confirmed. This way, only the plateau situation at the peak needs to be considered. The specific handling method is similar to the handling method for transient drops.

[0076] Now, let's describe the functional verification process for peak confirmation. For example... Figure 8 and Figure 9As shown, the first figure is the corresponding waveform state diagram, and the second figure is the corresponding waveform data diagram. For easier viewing, a portion of the main peak has been cropped, omitting its rising edge. The relevant parameters are: signal input data_in, threshold z1, overthreshold signal overTH, overthreshold signal delay overTHreg, peak confirmation counter Paffirm_Cnt, peak register P1reg, peak maximum value temporary registers PmaxTemp1 and PmaxTemp2, and peak point time registers PmaxTimeTemp1 and PmaxTimeTemp2. ​​When the recognition unit enters the rising phase, the synchronous peak confirmation process will also begin. As mentioned earlier, the only criterion for peak point confirmation is the appearance of a decrease in amplitude. Therefore, during the rising phase, a temporary maximum value register is established to store the maximum value of the current phase. When a valid threshold-crossing signal exists, since the signal cannot undergo abrupt changes, the temporary maximum value register PmaxTemp1 is initialized to the threshold value. After entering the rising phase, each input value data_in is compared with the data currently registered in PmaxTemp1. Starting with data_in as 517 (a scalar value) as a reference, PmaxTemp1 is also initialized to 517. At the next clock moment, if the input value data_in is 619, since 619 is greater than 517, 619 is transferred to PmaxTemp1 and used as the comparison object for the next input data. At this time, the corresponding global clock value will also be locked in the peak point time register PmaxTimeTemp1 to ensure that the time points corresponding to the data points are synchronously one-to-one. When the current data_in input value is less than the value in PmaxTemp1, the recognition unit will enter a decreasing confirmation state. At this time, Paffirm_Cnt starts counting. Taking a typical data_in value of 947 as an example, when data_in is 947, since it is greater than 929 in PmaxTemp1, 947 is transferred to PmaxTemp1, while Paffirm_Cnt remains 0. After the next clock cycle, the new data_in value is 854, which is less than the value in PmaxTemp1. At this time, Paffirm_Cnt starts counting to 1. Simultaneously, due to the decrease in amplitude, to ensure the validity and reliability of the peak data, the value in PmaxTemp1 is saved to PmaxTemp2 for backup, and the corresponding peak time information is also saved to PmaxTimeTemp2 for backup. Since the subsequent 8 input data values ​​are all less than the values ​​in PmaxTemp1, the peak confirmation state continues, and the value of the Paffirm_Cnt counter continues to increase due to the relatively small input data.It should be noted that digital lightning detection stations are real-time systems, and the FPGA data stream also has high real-time performance. Although the left and right ends of the data can be seen during analysis and verification, in the actual identification unit, the system never knows the state of the next data. Therefore, necessary data backup and retention are required. When Paffirm_Cnt counts up to 8, since the data_in of the next clock is 962, which is once again greater than 947 in PmaxTemp1, and this falling process only lasts for 8 clock cycles, it does not meet the condition for confirming the peak. Therefore, the identification unit switches to the rising state and continues to search for the peak point. Returning to the first figure, we can see that the signal waveform experienced a brief dip during this period, but quickly recovered to the rising state.

[0077] To avoid the current peak confirmation counter affecting the next confirmation state, the peak confirmation counter is immediately reset to zero when the recognition unit exits the descent confirmation process, ensuring the accuracy of the count for each descent confirmation process. As data continues to be input, the recognition unit will cyclically perform the above process based on the state of the current input data until the peak point is confirmed.

[0078] like Figure 8 and Figure 9 As shown, when the input data is 947, the signal waveform shows a clear downward inflection point. At this time, Paffirm_Cnt is restarted for confirmation timing. The currently saved peak value and peak time information have been backed up to a temporary register. As data continues to be input, the current input data data_in is always less than the value in PmaxTemp1. When the Paffirm_Cnt count is greater than 16, the data in the design parameter PmaxTemp2 is confirmed as the peak value, and the corresponding time information PmaxTimeTemp2 is the peak moment. In the figure, when Paffirm_Cnt is 17, the peak value is confirmed, the peak value and its corresponding time are locked, and the value in the peak register P1reg becomes valid. During this process, to avoid timing races and hazards, valid data is only saved when the next clock arrives.

[0079] like Figure 10The diagram shows the state changes and value storage status after peak confirmation. In the diagram, "state" represents the state information, with 2 representing the rising and peak search state, and 4 representing the falling judgment state. Clearly, when the confirmation time arrives, the recognition unit's state jumps from 2 to 4. Simultaneously, the peak information is saved to P1reg, the falling start signal T307begin is set high, and the rising time is locked in riseTime_Cnt1. Since the peak point clock information uses an instantaneous transfer method, the peak time is stored in PmaxTimeTemp1 and PmaxTimeTemp2.

[0080] After the peak is confirmed, the subsequent descent process is then judged. The judgment of the descent process is based on the basic identification model, which involves comparing the data point by point in the subsequent time period. The algorithm is simple and will not be described in detail.

[0081] Example 3

[0082] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to execute any of the above-described methods for identifying magnetic fields based on lightning location.

[0083] Optionally, in this embodiment, the computer-readable storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals, and the computer-readable storage medium includes a stored program.

[0084] Optionally, during program execution, the device containing the computer-readable storage medium performs the following functions: using global clock information as a reference, and employing an independent timing method for each time condition to accurately calibrate and determine time points, and detecting and identifying different operating states of the data magnetic field signals sent by the lightning detection station, including the following steps: waiting for the state of a valid threshold signal; when a valid threshold signal exists, starting peak search and recording the current trigger threshold time point information; after determining the peak value, recording the peak value time information and proceeding to fall time detection and subsequent peak intensity detection.

[0085] Example 4

[0086] According to another aspect of the present invention, a processor is also provided for running a program, wherein the program executes any of the above-described methods for identifying magnetic fields based on lightning location.

[0087] This invention provides a device including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of a magnetic field identification method based on lightning location.

[0088] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0089] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interface, and the indirect coupling or communication connection of units or modules may be electrical or other forms.

[0091] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0093] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic field identification method based on lightning location, characterized in that, Using global clock information as a reference, a method of independent timing for each time condition is employed to accurately calibrate and determine time points. The data magnetic field signals transmitted by the lightning detection station are then detected and identified to identify different operating states. This includes the following steps: The state of waiting for a valid threshold signal; When a valid signal that has exceeded the threshold is found, peak search begins and the time information of the current threshold trigger is recorded. Once the peak value is determined, the peak time information is recorded, and the process transitions to fall time detection and subsequent peak intensity detection. The peak finding process includes an upward process and a peak point confirmation process. The rising process includes: setting a temporary peak register as a temporary storage for the current maximum value, and initially the data in the temporary peak register is the threshold value; After the threshold signal is valid, the current input signal data is compared point by point. If the value of the current input data is greater than the data in the temporary peak register, the current data is stored in the temporary peak register and used as the comparison object for the next data, until the input data is less than the data in the temporary peak register. When the input data is less than the data in the peak register, a judgment is made on whether the falling state is valid. The peak point confirmation process includes: after input data with a value less than that in the temporary peak register is received, a timer for valid confirmation is started; If, within the effective judgment time of the timer, the current input data is all less than the data in the temporary peak register and all greater than the threshold value, then the data in the temporary peak register is the peak point. The peak time is determined based on the time when the peak point is input into the temporary peak register, and it is confirmed that the waveform decline phase has begun, i.e., the decline time detection and subsequent peak intensity detection are initiated. Among them, if the current input data is greater than the data in the temporary peak register during the effective judgment period, the current large value will still be transferred to the temporary peak register, and the effective judgment state will jump out of the falling state and continue to the rising state judgment. If the current input data is below the threshold value, even if other data is not greater than the value in the temporary peak register, an immediate initialization signal will be generated to determine that the current input data does not meet the requirements for lightning to ground flash.

2. The magnetic field identification method based on lightning location according to claim 1, characterized in that, The threshold-crossing valid signal is when the current threshold-crossing signal is high.

3. The magnetic field identification method based on lightning location according to claim 1, characterized in that, Fall time detection includes: in the valid judgment of the fall state, a specific time period is set according to the characteristics of the actual signal. If no data greater than the temporary peak register appears within this time period, it is determined that the subsequent stage of fall has been entered.

4. The magnetic field identification method based on lightning location according to claim 1, characterized in that, The descent time is the immediate jump condition, and the subsequent peak intensity is the delayed jump condition.

5. A magnetic field identification unit based on lightning location, characterized in that, Based on global clock information, a method of independent timing for each time condition is used to accurately calibrate and determine time points. This method detects and identifies different operating states of the data magnetic field signals transmitted by the lightning detection station, including: The initial state module is used to initialize all temporary registers and control signals in the lightning-based magnetic field identification unit, and then immediately jump to the trigger waiting state. The trigger light strip status module is used to wait for a valid signal after the threshold is exceeded, i.e., it is in a trigger waiting state; The peak search status module is used to start peak search and record the time point information of the current trigger threshold when there is a valid signal that has exceeded the threshold. The descent state module is used to record the peak point time information after the peak is determined and then proceed to the descent time detection and subsequent peak intensity detection. The peak finding process includes an upward process and a peak point confirmation process. The rising process includes: setting a temporary peak register as a temporary storage for the current maximum value, and initially the data in the temporary peak register is the threshold value; After the threshold signal is valid, the current input signal data is compared point by point. If the value of the current input data is greater than the data in the temporary peak register, the current data is stored in the temporary peak register and used as the comparison object for the next data, until the input data is less than the data in the temporary peak register. When the input data is less than the data in the peak register, a judgment is made on whether the falling state is valid. The peak point confirmation process includes: after input data with a value less than that in the temporary peak register is received, a timer for valid confirmation is started; If, within the effective judgment time of the timer, the current input data is all less than the data in the temporary peak register and all greater than the threshold value, then the data in the temporary peak register is the peak point. The peak time is determined based on the time when the peak point is input into the temporary peak register, and it is confirmed that the waveform decline phase has begun, i.e., the decline time detection and subsequent peak intensity detection are initiated. Among them, if the current input data is greater than the data in the temporary peak register during the effective judgment period, the current large value will still be transferred to the temporary peak register, and the effective judgment state will jump out of the falling state and continue to the rising state judgment. If the current input data is below the threshold value, even if other data is not greater than the value in the temporary peak register, an immediate initialization signal will be generated to determine that the current input data does not meet the requirements for lightning to ground flash.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the magnetic field identification method based on lightning location as described in any one of claims 1 to 4.

7. A processor, characterized in that, The processor is used to run a program, wherein the program executes the magnetic field identification method based on lightning location as described in any one of claims 1 to 4.

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