CN104569624A - Full lightning cloud cloud-to-ground lightning recognition method - Google Patents

Abstract

The invention relates to a full lightning cloud cloud-to-ground lightning recognition method. The method can be used for recognizing different lightning types, includes intracloud discharging and cloud-to-ground discharging recognition and recognition of a special cloud lightning event (NBE) and can be used for conventional cloud-to-ground lightning and position cloud lightning. A specific waveform parameter extraction method is adopted to extract collected lightning field waveform parameters, the extracted lightning waveform parameters are utilized for comprehensive judgment, and lightning discharging types are given according to judgment results.

Description

A kind of full lightning Ground flash recognition methods

Technical field

The invention belongs to electric field, especially relate to a kind of full lightning Ground flash recognition methods.

Background technology

In " IDNDR " that the United Nations in 1987 determines, thunder and lightning is endanger one of ten kinds of maximum disasters to the mankind.The material progress that the thunder and lightning natural resources of depending on for existence to the mankind and the mankind create for a long time forms and threatens greatly, especially today of microelectronic device widespread use, direct and the indirect disaster that thunder and lightning causes is day by day serious, therefore the research of thunder and lightning is also more and more come into one's own, the lighting location network LLS that China runs covers the most area of China, can dodge over the ground and well monitor.But cloud twinkle SM can not be provided to cease and can not observe early stage Lightning electromagnetic radiation development processes such as cloud sudden strains of a muscle, affect and limit for the rich understanding of thunder activities.In order to better study the generation development mechanism of thunder and lightning, need the three-dimensional detection technical research having carried out thunder and lightning.The three-dimensional detection technical research of a thunder and lightning wherein gordian technique is exactly full lightning Ground flash Waveform Identification Technology.

Summary of the invention

The present invention mainly solves the technical matters existing for prior art; Provide the identification that a kind of the method can be used for different lightning types, comprising intracloud discharge, dodge electric discharge and to identify and a kind of special cloud dodges the identification of electric discharge event (NBE), can carry out dodging traditionally, also can dodge to cloud the one full lightning Ground flash recognition methods positioned.

Above-mentioned technical matters of the present invention is mainly solved by following technical proposals:

A kind of full lightning Ground flash recognition methods, is characterized in that, comprise the steps:

Step 1: adopt specific 9 waveform parameter extracting method to extract the radiation of lightening discharge electric field waveform feature parameter collected; The definition of described 9 waveform parameters and following Lightning radiation electric field waveform characteristic quantity:

Characteristic quantity one: rise time: Tr=Tp1-Ta1, Ta1 is poor to time to peak Tp1 for waveform 10% peak value rising time;

Characteristic quantity two: fall time: Tf=Tb1-Tp1, time to peak Tp1 is poor to waveform 10% peak value negative edge time Tb1;

Characteristic quantity three: pulse width: Td=Tb1-Ta1,10% peak value negative edge time Tb1 is poor to waveform 10% peak value rising time Ta1;

Characteristic quantity four: forward direction negative peak compares: R10=-V0/P1, the ratio between forward direction negative peak V0 and peak-peak;

Characteristic quantity five: backward negative peak ratio: R11=-V1/P1, the ratio between backward negative peak V1 and peak-peak;

Characteristic quantity six: secondary peak compares: R12=P2/P1, the ratio between the peak-peak P2 after peak-peak and peak-peak P1;

Characteristic quantity seven: signal to noise ratio snr: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of wave-average filtering power beyond this 20 μ s; Defining whole waveform data points is N number of point, and peak point is positioned at P point, and pulse height is An;

$\mathrm{SNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\Σ}}}{A}_n^2}{\underset{n=0}{\overset{p-20}{\mathrm{\Σ}}}{A}_n^2+\underset{n=P+20}{\overset{N}{\mathrm{\Σ}}}{A}_n^2}\·\frac{N-40}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An;

Characteristic quantity eight: forward direction signal to noise ratio (S/N ratio) preSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s before waveform peak;

$\mathrm{preSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\Σ}}}{A}_n^2}{\underset{n=P-400}{\overset{p-20}{\mathrm{\Σ}}}{A}_n^2}\·\frac{380}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An,

Characteristic quantity nine: backward signal to noise ratio (S/N ratio) postSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s after waveform peak;

$\mathrm{postSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\Σ}}}{A}_n^2}{\underset{n=P+20}{\overset{p+400}{\mathrm{\Σ}}}{A}_n^2}\·\frac{380}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An,

Step 2: utilize the radiation of lightening discharge electric field wave shape parameter that extracts to carry out comprehensive descision, provide typeo f lightning discharge according to comprehensive descision result, described in go out typeo f lightning discharge comprise cloud dodge, dodge and NBE, wherein,

The identification of described Return stroke of ground flash waveform character is based on following Rule of judgment:

Condition 211: waveform rise time is short, Tr<8 μ s;

Condition 212: waveform fall time is long, Tf>15 μ s, simultaneously the ratio Tf/Tr>2 of fall time and rise time;

Condition 213: the forward direction signal to noise ratio (S/N ratio) of waveform is comparatively large, preSNR>500, simultaneously the ratio preSNR/postSNR>50 of forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio);

Condition 204: secondary peak is larger, R12>0.4;

The identification of described NBE waveform character is based on following Rule of judgment:

Condition 221: waveform rise time is short, Tr<7 μ s;

Condition 222: waveform fall time is short, Tf<5 μ s;

Condition 223: the signal to noise ratio (S/N ratio) of waveform is comparatively large, SNR>100, backward signal to noise ratio (S/N ratio) postSNR>100, forward direction signal to noise ratio (S/N ratio) preSNR>1500;

Condition 224: backward negative peak compares R11>0.2.

Described general cloud dodges waveform character identification based on following Rule of judgment:

Condition 231: waveform fall time is short, Tf<15 μ s;

Condition 232: waveform noise is smaller, forward direction signal to noise ratio (S/N ratio) preSNR<400, forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio) ratio preSNR/postSNR<10.

Therefore, tool of the present invention has the following advantages: can be used for the identification to different lightning types, comprising intracloud discharge, dodge electric discharge and to identify and a kind of special cloud dodges the identification of electric discharge event (NBE), can carry out dodging traditionally, also can dodge cloud and position.

Accompanying drawing explanation

Fig. 1 is method flow schematic diagram of the present invention.

Fig. 2 is thunder and lightning electric field wave shape parameter extracting method schematic diagram involved in the present invention.

Fig. 3 a is the first typical discharges type waveforms schematic diagram (dodge).

Fig. 3 b is the first typical discharges type waveforms schematic diagram (cloud sudden strain of a muscle).

Fig. 3 c is the third typical discharges type waveforms schematic diagram (NBE).

Embodiment

Below by embodiment, and by reference to the accompanying drawings, technical scheme of the present invention is described in further detail.

Embodiment:

Further illustrate below in conjunction with drawings and Examples:

Lightning Ground flash as complete in Fig. 1 recognition methods, first adopts specific waveform parameter extracting method to extract the thunder and lightning electric field wave shape parameter collected.Then the lightning waveform parameter extracted is utilized to carry out weight comprehensive descision.Typeo f lightning discharge is provided according to judged result.

Thunder and lightning electric field wave shape parameter extracting method is as shown in Figure 2:

(1) rise time: Tr=Tp1-Ta1, Ta1 is poor to time to peak Tp1 for waveform 10% peak value rising time;

(2) fall time: Tf=Tb1-Tp1, time to peak Tp1 is poor to waveform 10% peak value negative edge time Tb1;

(3) pulse width: Td=Tb1-Ta1,10% peak value negative edge time Tb1 is poor to waveform 10% peak value rising time Ta1;

(4) forward direction negative peak ratio: R10=-V0/P1, the ratio between forward direction negative peak V0 and peak-peak;

(5) backward negative peak ratio: R11=-V1/P1, the ratio between backward negative peak V1 and peak-peak;

(6) secondary peak ratio: R12=P2/P1, the ratio between the peak-peak P2 after peak-peak and peak-peak P1;

(7) signal to noise ratio snr: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of wave-average filtering power beyond this 20 μ s.Suppose that whole waveform data points is N number of point, peak point is positioned at P point, and pulse height is An;

$\mathrm{SNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=0}{\overset{p-20}{\mathrm{\&Sigma;}}}{A}_n^2+\underset{n=P+20}{\overset{N}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{N-40}{40}$

(8) forward direction signal to noise ratio (S/N ratio) preSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s before waveform peak;

$\mathrm{preSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=P-400}{\overset{p-20}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{380}{40}$

(9) backward signal to noise ratio (S/N ratio) postSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s after waveform peak;

$\mathrm{postSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=P+20}{\overset{p+400}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{380}{40}$

Here, rise time Tr, fall time these three parameters of Tf and pulse width T d reflect the basic configuration of pulse waveform, forward direction negative peak reflects the bipolarity feature to amplitude of variation and pulse waveform before and after pulse waveform than R10 and backward negative peak R11, secondary peak reflects the degree of irregularity of waveform decline process than R12, and signal to noise ratio snr, forward direction signal to noise ratio (S/N ratio) preSNR and backward signal to noise ratio (S/N ratio) postSNR then reflect the overall signal amplitude of pulse waveform and the front and back magnitude aspect to pulse.

Cloud dodges radiation field feature and dodges different with ground as shown in Figure 3, and sudden strain of a muscle radiation field in ground has steep rising edge and negative edge more slowly, and cloud sudden strain of a muscle radiation waveform is then rising edge and quick negative edge relatively slowly; Cloud dodges radiation field waveform forward direction signal to noise ratio (S/N ratio) and is far smaller than Return stroke of ground flash forward direction signal to noise ratio (S/N ratio), and the former is less than the latter's 1/10; Cloud dodges signal to noise ratio (S/N ratio), forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio) and is in the same order of magnitude, and has marked difference to Return stroke of ground flash three; Cloud dodges radiation field waveform and is mostly fast-pulse, and the duration of pulse is shorter, and fight back ground sudden strain of a muscle waveform and then have slower negative edge, the duration is longer.There is larger secondary peak than being fight back the obvious feature of of radiation signal.

NBE waveform character and Return stroke of ground flash and general cloud dodge electric discharge significant difference, NBE is as a kind of special intracloud discharge, and radiation intensity is often beyond Return stroke of ground flash, and NBE waveform pulse width time is shorter, and Return stroke of ground flash pulsewidth mean value is comparatively large, the former is less than the latter 1/5th.

According to dodging with fighting back, cloud dodges and the notable difference of special intracloud discharge event NBE tri-class waveform, can be distinguished based on radiated electric field waveform character, and this patent sums up that to propose full lightning class discharge-type identification method of discrimination as follows:

(1) Return stroke of ground flash waveform recognition

---waveform rise time is short, Tr<8 μ s;

---waveform fall time is long, Tf>15 μ s, simultaneously the ratio Tf/Tr>2 of fall time and rise time;

---the forward direction signal to noise ratio (S/N ratio) of waveform is comparatively large, preSNR>500, simultaneously the ratio preSNR/postSNR>50 of forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio);

---secondary peak is larger, R12>0.4.

(2) NBE waveform recognition

---waveform rise time is short, Tr<7 μ s;

---waveform fall time is short, Tf<5 μ s;

---the signal to noise ratio (S/N ratio) of waveform is comparatively large, SNR>100, backward signal to noise ratio (S/N ratio) postSNR>100, forward direction signal to noise ratio (S/N ratio) preSNR>1500;

---backward negative peak compares R11>0.2.

(3) general cloud dodges waveform recognition

---waveform fall time is short, Tf<15 μ s;

---waveform noise is smaller, forward direction signal to noise ratio (S/N ratio) preSNR<400, forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio) ratio preSNR/postSNR<10.

Specific embodiment described herein is only to the explanation for example of the present invention's spirit.Those skilled in the art can make various amendment or supplement or adopt similar mode to substitute to described specific embodiment, but can't depart from spirit of the present invention or surmount the scope that appended claims defines.

Claims (1)

1. a full lightning Ground flash recognition methods, is characterized in that, comprise the steps:

Step 1: adopt specific 9 waveform parameter extracting method to extract the radiation of lightening discharge electric field waveform feature parameter collected; The definition of described 9 waveform parameters and following Lightning radiation electric field waveform characteristic quantity:

Characteristic quantity one: rise time: Tr=Tp1-Ta1, Ta1 is poor to time to peak Tp1 for waveform 10% peak value rising time;

Characteristic quantity two: fall time: Tf=Tb1-Tp1, time to peak Tp1 is poor to waveform 10% peak value negative edge time Tb1;

Characteristic quantity three: pulse width: Td=Tb1-Ta1,10% peak value negative edge time Tb1 is poor to waveform 10% peak value rising time Ta1;

Characteristic quantity four: forward direction negative peak compares: R10=-V0/P1, the ratio between forward direction negative peak V0 and peak-peak;

Characteristic quantity five: backward negative peak ratio: R11=-V1/P1, the ratio between backward negative peak V1 and peak-peak;

Characteristic quantity six: secondary peak compares: R12=P2/P1, the ratio between the peak-peak P2 after peak-peak and peak-peak P1;

Characteristic quantity seven: signal to noise ratio snr: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of wave-average filtering power beyond this 20 μ s; Defining whole waveform data points is N number of point, and peak point is positioned at P point, and pulse height is An;

$\mathrm{SNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=0}{\overset{p-20}{\mathrm{\&Sigma;}}}{A}_n^2+\underset{n=P+20}{\overset{N}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{N-40}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An;

Characteristic quantity eight: forward direction signal to noise ratio (S/N ratio) preSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s before waveform peak;

$\mathrm{preSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=P-400}{\overset{p-20}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{380}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An,

Characteristic quantity nine: backward signal to noise ratio (S/N ratio) postSNR: to be defined as from peak point forward 10 μ s and average power backward in 10 μ s, with the ratio of the average power of waveform in 200 μ s after waveform peak;

$\mathrm{postSNR}=\frac{\underset{n=P-20}{\overset{p+20}{\mathrm{\&Sigma;}}}{A}_n^2}{\underset{n=P+20}{\overset{p+400}{\mathrm{\&Sigma;}}}{A}_n^2}\&CenterDot;\frac{380}{40}$

Wherein N is whole waveform data points, and peak point is positioned at P point, and the pulse height of n-th is An,

Step 2: utilize the radiation of lightening discharge electric field wave shape parameter that extracts to carry out comprehensive descision, provide typeo f lightning discharge according to comprehensive descision result, described in go out typeo f lightning discharge comprise cloud dodge, dodge and NBE, wherein,

The identification of described Return stroke of ground flash waveform character is based on following Rule of judgment:

Condition 211: waveform rise time is short, Tr<8 μ s;

Condition 212: waveform fall time is long, Tf>15 μ s, simultaneously the ratio Tf/Tr>2 of fall time and rise time;

Condition 213: the forward direction signal to noise ratio (S/N ratio) of waveform is comparatively large, preSNR>500, simultaneously the ratio preSNR/postSNR>50 of forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio);

Condition 204: secondary peak is larger, R12>0.4;

The identification of described NBE waveform character is based on following Rule of judgment:

Condition 221: waveform rise time is short, Tr<7 μ s;

Condition 222: waveform fall time is short, Tf<5 μ s;

Condition 223: the signal to noise ratio (S/N ratio) of waveform is comparatively large, SNR>100, backward signal to noise ratio (S/N ratio) postSNR>100, forward direction signal to noise ratio (S/N ratio) preSNR>1500;

Condition 224: backward negative peak compares R11>0.2.

Described general cloud dodges waveform character identification based on following Rule of judgment:

Condition 231: waveform fall time is short, Tf<15 μ s;

Condition 232: waveform noise is smaller, forward direction signal to noise ratio (S/N ratio) preSNR<400, forward direction signal to noise ratio (S/N ratio) and backward signal to noise ratio (S/N ratio) ratio preSNR/postSNR<10.