CN-120254378-B - Space-time clustering analysis-based electric parameter measurement system for ground flash active path

CN120254378BCN 120254378 BCN120254378 BCN 120254378BCN-120254378-B

Abstract

The invention discloses a space-time clustering analysis-based electric parameter measurement system for a ground flash active path, which relates to the technical field of ground flash active path electric parameter measurement and comprises a data acquisition module, an electric parameter measurement module and a sensor, wherein the data acquisition module is used for acquiring ground flash data, the ground flash data comprises time, longitude and latitude information of ground flash, the electric parameter measurement module is used for measuring electric parameters on the ground flash active path, the electric parameters comprise electric field intensity, current intensity and voltage, the sensor is used for monitoring an area on the ground flash active path in real time to acquire accurate electric parameter data, the sensor is used for measuring the electric field intensity, the current intensity is measured through a current transformer, and the voltage is measured through a voltage sensor.

Inventors

JIN SHI
Amur Sana'a
CHAO LU

Assignees

呼和浩特市气象灾害防御中心(呼和浩特市决策气象服务中心、呼和浩特市雷电防御中心)

Dates

Publication Date: 20260505
Application Date: 20250331

Claims (7)

1. A system for measuring electrical parameters of a ground flash active path based on space-time clustering analysis is characterized by comprising, The data acquisition module is used for acquiring ground flash data, wherein the ground flash data comprises time, longitude and latitude information of ground flash; The electric parameter measuring module is used for measuring electric parameters on the ground flash moving path, wherein the electric parameters comprise electric field intensity, current intensity and voltage; The sensor monitors the area on the ground flash moving path in real time to acquire accurate electric parameter data, adopts the sensor to measure the electric field intensity, measures the current intensity through the current transformer, and measures the voltage through the voltage sensor; in the electric parameter measurement module, a data fusion algorithm is adopted to measure the electric field intensity, the current intensity and the voltage value; The electric parameter measurement system also comprises a region division module which is used for dividing regions into three regions of mountain areas, grasslands and deserts by analyzing altitude, topography and geomorphology features and determining region boundaries; the region dividing module is used for further dividing the three regions according to the gradient and the slope direction; The gradient region is divided into an extremely steep region, a steep gradient region, a medium gradient region and a slow gradient region; The system comprises a space-time database establishing module, a data processing module and a data processing module, wherein the space-time database establishing module is used for establishing collected ground flash data into a three-dimensional space-time database, determining the dimensionality of the three-dimensional space-time database as time, longitude and latitude, converting each ground flash data record into an object point form, and recording all object points into the database according to a time sequence; the space-time clustering analysis module is used for performing space-time clustering analysis on data in the space-time database and comprises a threshold setting unit, a core object judging unit, an adjacent point searching unit and a cluster perfecting unit; the threshold setting unit is used for setting a time interval threshold, a space distance threshold and a space-time object quantity threshold; The method comprises the steps of obtaining regional characteristic information from a regional division module, extracting ground flash data characteristics from a space-time database, adopting a self-adaptive algorithm, and adjusting a threshold value by a feedback-based dynamic adjustment algorithm, wherein the adjustment weights are w t 、w s 、w Min-Pts respectively, and the formula is as follows, w t +w s +w min-Pts min-pts=C; Wherein w t represents the threshold weight of the time distance to the ground flash data point, w s represents the threshold weight of the space distance factor to the ground flash data point, w Min-Pts represents the threshold weight of the number of space-time objects in the ground flash data point, min-Pts represents the cluster analysis starting point, and C represents the target value of the space-time cluster analysis; the core object judging unit is used for taking one object point from all the ground flash data and judging a ground flash path; selecting an object point, wherein P= { id, x, y and t }, wherein id is an object point unique identifier, x and y are longitude information and latitude information respectively, and t is time information; judging whether the object point belongs to the existing cluster, if so, re-selecting the next object point, otherwise, judging whether the object point is a space-time core object, if not, returning to the object point selecting step to re-select the next object point, if so, searching adjacent points; The adjacent point searching unit is used for searching all the space-time adjacent points of the space-time core object point, taking time, longitude and latitude information as reference for the point determined as the space-time core object, and determining that the point is the space-time adjacent point in the space dimension if the time difference between the other point and the core object point is not more than a set time distance threshold value; The cluster perfecting unit is used for judging whether the ground flash data are space-time core objects or not, and judging whether the number of neighbors in a given range is not less than the space-time object quantity threshold according to the time distance threshold, the space distance threshold and the space-time object quantity threshold, wherein the given range is a time period with a time difference not greater than the time distance threshold in the time dimension and is a region with a space distance not greater than the space distance threshold in the space dimension; In the adjacent point searching unit, a K-D tree data structure is adopted to search the space adjacent points, for a given space-time core object point, adjacent points meeting the space distance threshold range are found in the K-D tree, a fuzzy clustering algorithm is introduced in the cluster perfecting unit, the attribution of the newly added object point is judged according to the fuzzy membership degree between the newly added object point and the existing cluster center, the object point P= { id, x, y, t } is set, the existing cluster center is C= { x c ,y c ,t c }, and the fuzzy membership degree calculation formula is as follows: Wherein u ij is the model membership degree of the object point i belonging to the cluster j, d ij is the distance from the object point i to the cluster center j, C is the number of clusters, m is the fuzzy index, and whether the object point is a core object and the cluster to which the object point belongs is determined according to the fuzzy membership degree, wherein d kj is the Euclidean distance from the kth ground flash data object point to the center of the jth cluster, and the Euclidean distance is calculated based on longitude and latitude data of the object point in a space-time database.
2. The system for measuring the electrical parameters of the earth flash moving path based on the space-time clustering analysis of claim 1, wherein the data acquisition module is used for carrying out earth flash data acquisition by adopting a distributed sensor network, carrying out real-time data preprocessing on the acquired data, including abnormal value detection and elimination, and carrying out abnormal value judgment by adopting a Laida criterion, namely, if the difference between a data point and an average value is more than three times of standard deviation, the data point is identified as an abnormal value and the abnormal value is eliminated.
3. The system for measuring the electrical parameters of the ground flash moving path based on the space-time clustering analysis of claim 1 is characterized in that in a mountain area, a gradient is greater than 60 degrees and is an extremely steep area, a gradient is 45-60 degrees and is a steep slope area, a gradient is 30-45 degrees and is a medium gradient area, a gradient is less than 20 degrees and is a gentle slope area, slope direction division is used for analyzing the influence of vegetation coverage conditions and soil humidity differences of the slope directions on the ground flash moving path, and the slope directions are divided into a sunny slope and a cloudy slope; in the grassland, the slope division is divided into a steep slope area with a slope of more than 10 degrees and a gentle slope area with a slope of less than 10 degrees, and the slope division is used for analyzing the influence of vegetation coverage conditions and soil humidity differences of the slope on a ground flash moving path and is divided into a sunny slope and a cloudy slope; In the desert, the gradient of the sand hill is larger than 30 degrees and is a steep slope area, the gradient of the sand hill is smaller than 30 degrees and is a gentle slope area, the slope direction is divided, the windward side of the sand hill is a sunny slope, the leeward side of the sand hill is a cloudy slope, and the influence of the sand compaction degree and the humidity difference of different slope directions on the ground flash moving path is analyzed.
4. The system for measuring electrical parameters of a ground flash path based on space-time clustering analysis as set forth in claim 3, wherein the area dividing module introduces a topographic relief index for further division of mountain areas, and the topographic relief calculation formula is as follows Wherein H max is the highest point elevation in the area, H min is the lowest point elevation in the area, D is the difference between the average elevation in the area and the average elevation in the neighborhood, S is the area of the area, and the mountain area is subdivided into a high-relief mountain area, a medium-relief mountain area and a low-relief mountain area according to the relief degree of the topography, and the flash moving paths of the mountain areas with different relief degrees can be affected by the topography to different degrees.
5. The system for measuring electrical parameters of a ground flash path based on space-time clustering analysis according to claim 1, wherein the core object judging unit is configured to increase time series analysis for the judgment of the ground flash path, to use an autoregressive moving average model to model and predict time series data, and to consider that the point may belong to the same ground flash path if the deviation between the predicted value and the actual value is within a certain range, and to set the time series of the selected object points as { t 1 ,t 2 ,…,t n }, and the model formula is: Wherein the method comprises the steps of For autoregressive coefficients, θ j is the moving average coefficient, ε t is the white noise sequence, where P is the average distance of the ground flash data point to other ground flash data points in the same terrain area, and q is the average distance of the ground flash data point to the ground flash data point in the nearest different terrain area.
6. The system for measuring electrical parameters of a ground flash path based on space-time clustering analysis as set forth in claim 4, wherein in the region division module, validity evaluation is performed on the division result of the region by using a cluster evaluation index coefficient, wherein the data point P= { id, x, y, t }, a (P) is an average distance from a point P to other points in the same region, and the contour coefficient is Where s (P) is the contour coefficient of the ground flash data point P, a (P) is the average distance from the ground flash data point P to the ground flash data point in the same terrain area, b (P) is the average distance from the ground flash data point P to the ground flash data point in the nearest different terrain area, and the evaluation value of the whole area division result is obtained by averaging according to the contour coefficients of all the data points.
7. The system for measuring electrical parameters of a ground flash path based on space-time clustering analysis as set forth in claim 1, wherein the information entropy calculation formula of the electric field intensity measurement value is Wherein the method comprises the steps of Information entropy of current intensity and voltage measured values is obtained by the same method, wherein H (E) represents information entropy of electric field intensity measured values, n is the number of the electric field intensity measured values, E i is the ith electric field intensity measured value, p (E i ) represents the proportion of the ith electric field intensity measured value in the sum of all measured values, E j is the first j electric field intensity measured value, weight coefficients are calculated according to the information entropy, and a weight coefficient calculation formula is Wherein ωe i represents a weight coefficient corresponding to the electric field strength measurement value E i , H (E i ) is an information entropy of the electric field strength measurement value E i , n is a number of electric field strength measurement values, k is an index for summing, all electric field strength measurement values are traversed from 1 to n to calculate a denominator value, and the weight coefficients of the current strength and the voltage are calculated in a same way, and the determined weight coefficients are subjected to weighted average fusion to obtain a fusion value of the electric field strength, the current strength and the voltage.

Description

Space-time clustering analysis-based electric parameter measurement system for ground flash active path Technical Field The invention relates to the technical field of electric parameter measurement of a ground flash active path, in particular to a space-time clustering analysis-based electric parameter measurement system of the ground flash active path. Background In lightning research, it is important to accurately measure electrical parameters on the ground flash path of activity. The ground flash is a powerful natural discharge phenomenon, and the carried electric parameters such as electric field intensity, current intensity, voltage and the like play a key role in understanding the physical mechanism of lightning deeply and evaluating the influence of lightning on various facilities and environments. To this end, CN107271793B discloses an automated lightning early warning system, which uses a thunderstorm cluster as a lightning early warning unit, predicts the next occurrence place and time of the thunderstorm cluster according to the historical path and time of the thunderstorm cluster movement, is favorable for avoiding the trouble of singly calculating the movement of the thunder spot, simplifies the calculation workload, and improves the prediction efficiency. According to the method, the statistics of the thunderstorm group historical paths and the prediction of the next occurrence places are carried out by setting the coordinate system and combining the coordinate system, so that the accuracy and the intuitiveness of the predicted paths and places are improved. However, the prior art has obvious disadvantages. Some electric field intensity measuring methods are easy to be interfered by environment, the accuracy of measuring results is difficult to ensure, the performance of a measuring sensor is seriously affected by external factors, so that larger deviation of measuring data occurs, and in the aspect of measuring the current intensity, when the traditional equipment measures large current, the current change in the flash moment cannot be accurately captured due to limited measuring range or insufficient response speed. For voltage measurement, due to the instantaneity and complexity of the ground flash voltage, the existing voltage measurement means have difficulty in accurately measuring the peak value and the change process of the voltage measurement means. To solve the above problems, a system for measuring electrical parameters of a ground flash active path based on space-time cluster analysis is provided. Disclosure of Invention The invention aims to provide a space-time clustering analysis-based earth flash active path electrical parameter measurement system, which solves the problem of poor electrical parameter measurement accuracy in the background technology. In order to achieve the purpose, the invention provides a technical scheme that the earth flash active path electrical parameter measurement system based on space-time clustering analysis comprises, The data acquisition module is used for acquiring ground flash data, wherein the ground flash data comprises time, longitude and latitude information of ground flash; The electric parameter measuring module is used for measuring electric parameters on the ground flash moving path, wherein the electric parameters comprise electric field intensity, current intensity and voltage; The sensor monitors the area on the ground flash moving path in real time to acquire accurate electric parameter data, adopts the sensor to measure the electric field intensity, measures the current intensity through the current transformer, and measures the voltage through the voltage sensor; In the electric parameter measurement module, a data fusion algorithm is adopted to measure the electric field intensity, the current intensity and the voltage value. Preferably, the electric parameter measurement system further comprises a region division module, wherein the region division module is used for dividing regions into three regions of mountain areas, grasslands and deserts by analyzing altitude, topography and geomorphology characteristics to determine region boundaries; the region dividing module is used for further dividing the three regions according to the gradient and the slope direction; The gradient region is divided into an extremely steep region, a steep slope region, a medium gradient region and a slow slope region; The system comprises a space-time database establishing module, a data processing module and a data processing module, wherein the space-time database establishing module is used for establishing collected ground flash data into a three-dimensional space-time database, determining the dimensionality of the three-dimensional space-time database as time, longitude and latitude, converting each ground flash data record into an object point form, and recording all object points into the database according to a time sequence; the space-time c