CN104569913A - High-precision full-lightning positioning method - Google Patents

Abstract

The invention relates to a high-precision full-lightning positioning method. The method can be applied to three-dimensional positioning of lightning, can realize high-precision positioning of the spatial position and height of the inter-cloud and intracloud lightning and can realize high-precision positioning of the ground position of cloud-to-ground lightning as well. According to the method, a five-station three-dimensional positioning algorithm is adopted to transformer a nonlinear equation system into a linear matrix equation so as to obtain a unique solution, a time window, a waveform cross-correlation extraction time difference method and a Levenberg-Marquardt(L-M) least square optimization algorithm are adopted to solve the problems about automatic matching of data waveforms of different sounding stations, accurate extraction of time difference and three-dimensional positioning optimization solution of non-plane sounding stations, and accurate three-dimensional geographical information and time information of the lightning can be obtained.

Description

The full lightning positioning method of a kind of high precision

Technical field

The invention belongs to electric field, especially relate to the full lightning positioning method of a kind of high precision.

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 gordian technique of the three-dimensional detection technical research of thunder and lightning is exactly the research of the full lightning positioning method of high precision.This patent proposes the full lightning positioning method of a kind of high-precision three-dimensional, and the method can be used for the three-dimensional localization to lightning, can position dodging traditionally, also can dodge cloud and position.The process employs five station three-dimensional location, Nonlinear System of Equations is converted into linear matrix equation and can obtains unique solution, propose time window, waveform cross-correlation extracts time difference method and Levenberg – Marquardt (L-M) least square method optimized algorithm, planar detector station three-dimensional localization Optimization Solution problems such as solving different detection site data waveform Auto-matching, the mistiming accurately extracts, be non-, obtains accurate lightning three-dimensional geographic information and temporal information.

Summary of the invention

The planar detector station three-dimensional localization Optimization Solution problems such as the present invention mainly solves different detection site data waveform Auto-matching existing for prior art, the mistiming accurately extracts, non-; Provide a kind of three-dimensional localization that can be used for lightning, the hi-Fix of locus and height can be carried out lightning between cloud and in cloud, also can dodge the full lightning positioning method of a kind of high precision carrying out ground location hi-Fix over the ground.

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

The full lightning positioning method of a kind of high precision, is characterized in that, comprise the steps:

Step 1: by the radiated electric field waveform digitization of full lightning location detection site, adopt waveform cross correlation algorithm accurately to extract each website to each website waveform poor in the writing time at each station for identical lightning discharge event, concrete grammar is as follows:

Step 1.1: adopt time window to screen waveform to the true response of identical radiation event from the time, each station waveform be simultaneously in time window is likely just the response to same radiation signal.

Step 1.2: be normalized power waveform by Hilbert Rapid Variable Design by original electric field waveform, eliminates the difference of polarity of wave that each website causes due to the difference of distance radiation source distance and amplitude

Step 1.3: calculate the linearly dependent coefficient of allowing stations available power waveform in window, waveform related coefficient being greater than setting, as the threshold value belonging to similar events response, gets best, the up to standard combination at most of similarity as the preliminary matches result to identical lightning event waveform.

Step 1.4: adopt cross-correlation method to extract each website waveform time poor, cross-correlation is relative time function between signal is not the absolute time difference of certain pulse concrete from time delay averaging time that waveform character reflects, thus eliminates different website environment and route of transmission causes waveform small differences.

Whether step 1.5: after the mistiming obtaining each website, use geometric model to detect the mistiming sequence obtained reasonable.

Step 2: non-linear orientation distance algorithm system of equations is converted to linear matrix equation group and tries to achieve just solution, concrete grammar is as follows:

Step 2.1: according to waveform transfer equation, lists each website waveform transfer equation.

$t_i=t+\frac{1}{c}\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2}$

Wherein c is the light velocity in vacuum, (x _i, y _i, z _i) be i-th localizer station point coordinate, t _ifor lightning arrives the time of i-th acquisition station.

Step 2.2: the transmission equation of step 2.1 is carried out transposition process, afterwards the transmission equation of different website is subtracted each other between two, obtain linear equation.

c ²(t ²+t _i ²-2tt _i)＝x ²+x _i ²-2xx _i+y ²+y _i ²-2yy _i+z ²+z _i ²-2zz _i

Wherein define:

r _i ²＝x _i ²+y _i ²+z _i ²

r ²＝x ²+y ²+z ²

Can obtain: c ²t ²+ c ²t _i ²-r _i ²=r ²-2 (xx _i+ yy _i+ zz _i-c ²tt _i)

In a jth website, following equation can be obtained equally:

c ²t ²+c ²t _j ²-r _j ²＝r ²-2(xx _j+yy _j+zz _j-c ²tt _j)

Two formulas are subtracted each other and can be obtained:

c ²(t _i ²-t _j ²)-(r _i ²-r _j ²)＝-2(x(x _i-x _j)+y(y _i-y _j)+z(z _i-z _j)-c ²t(t _i-t _j))

Same definition:

t _ij＝t _i-t _j,x _ij＝x _i-x _j,y _ij＝y _i-y _j,z _ij＝z _i-z _j,

$b_{\mathrm{ij}}=\frac{(r_i^2-r_j^2)-c^2(t_i^2-t_j^2)}{2}$

Obtain linear equation xx _ij+ yy _ij+ zz _ij-c ²tt _ij=b _ij

Tij is the mistiming that i, j two websites reach

Step 2.3: for station, any 5 stations or more observed reading, subtract each other with all the other 4 stations and wherein 1 station, can obtain the matrix be made up of the independent linearity equation of 4 similar steps 2.2, wherein tij obtains by adopting cross-correlation method to extract each website waveform time difference tij in step 1.4;

$\left[\begin{array}{cccc}{x}_{\mathrm{ij}}& y_{\mathrm{ij}}& z_{\mathrm{ij}}& -c^2{t}_{\mathrm{ij}}\\ x_{\mathrm{ik}}& y_{\mathrm{ik}}& z_{\mathrm{ik}}& -c^2{t}_{\mathrm{ik}}\\ x_{\mathrm{il}}& y_{\mathrm{il}}& z_{\mathrm{il}}& -c^2{t}_{\mathrm{il}}\\ x_{\mathrm{im}}& y_{\mathrm{im}}& z_{\mathrm{im}}& -c^2{t}_{\mathrm{im}}\end{array}\right]\·\left[\begin{array}{c}x\\ y\\ z\\ t\end{array}\right]=\left[\begin{array}{c}{b}_{\mathrm{ij}}\\ b_{\mathrm{ik}}\\ b_{\mathrm{il}}\\ b_{\mathrm{im}}\end{array}\right]$

Step 2.4: get radiation source three-dimensional position and time is calculated in the matrix equation of the formation of any 5 station linear combinations.

Step 3: according to the first solution obtained, adopt L-M least square method optimized algorithm to calculate accurate anchor point, concrete grammar is:

Step 3.1: the radiation source three-dimensional position calculated by step 2 and time, inverting lightning discharge event reaches the time of each website, based on following formula:

${\mathrm{TOA}}_i^{\mathrm{fit}}=\frac{1}{c}\sqrt{{(x^{\mathrm{fit}}-x_i)}^2+{(y^{\mathrm{fit}}-y_i)}^2+{(z^{\mathrm{fit}}-z_i)}^2}$

that inverting is at inverting position (x ^fit, y ^fit, z ^fit) the transmission of lightning discharge course of event simple path after arrive matching time of arrival of website i.

Step 3.2: determine to weigh Optimal calculation factor χ ², obtain possible initial estimation analytic solution in 5 station steps 2, redundant sites obtains numerical solution, χ the most at last for coordinating nonlinear iteration to retrain ²be worth minimum solution vector as unique accurate solution vector.

${\mathrm{\χ}}^2=\underset{N-5}{\overset{N}{\mathrm{\Σ}}}{\left[\frac{{\mathrm{TOA}}_i^{\mathrm{obs}}-{\mathrm{TOA}}_i^{\mathrm{fit}}}{{\mathrm{\σ}}_t^2}\right]}^2$

Wherein, N is current stations available sum, and σ is the standard deviation of each acquisition station data, is a fixed value, for the time of arrival that website i observes.

Therefore, tool of the present invention has the following advantages: can be used for the three-dimensional localization to lightning, can carry out the hi-Fix of locus and height, also can dodge over the ground and carry out ground location hi-Fix lightning between cloud and in cloud.

Accompanying drawing explanation

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

Fig. 2 is the method flow schematic diagram differed from the cross correlation algorithm extraction time related in the present invention.

Fig. 3 is that what relate in the present invention is the schematic diagram of normalized power waveform by Hilbert Rapid Variable Design by original electric field waveform.

Fig. 4 is whether reasonably the use geometric model related in the present invention detects the mistiming sequence detection method curve synoptic diagram obtained.

Embodiment

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

Embodiment:

Lightning positioning method as complete in Fig. 1 high precision, first adopts waveform cross correlation algorithm accurately to extract each website poor at the record at each station for identical lightning discharge event; Secondly adopt equation conversion Nonlinear System of Equations to be converted to linear matrix equation group and try to achieve just solution; The first solution that last basis obtains, adopts L-M least square method optimized algorithm to calculate exact solution.

Cross correlation algorithm extraction time differs from method as shown in Figure 2:

The first step: adopt time window to screen waveform to the true response of identical radiation event from the time, each station waveform be simultaneously in time window is likely just the response to same radiation signal.

Second step: be normalized power waveform by Hilbert Rapid Variable Design by original electric field waveform, eliminates the difference of polarity of wave that each website causes due to the difference of distance radiation source distance and amplitude as shown in Figure 3.

3rd step: calculate the linearly dependent coefficient of allowing stations available power waveform in window, waveform related coefficient being greater than setting, as the threshold value belonging to similar events response, gets best, the up to standard combination at most of similarity as the preliminary matches result to identical lightning event waveform.

4th step: adopt cross-correlation method to extract each website waveform time poor, cross-correlation is relative time function between signal is not the absolute time difference of certain pulse concrete from time delay averaging time that waveform character reflects, thus eliminates different website environment and route of transmission causes waveform small differences.

Whether the 5th step: after the mistiming obtaining each website, use geometric model to detect the mistiming sequence obtained reasonable.As Fig. 4, d ₁for lightning time gap S _ithe distance of website, d ₂for lightning time gap S _jthe distance of website, d ₃for S _iand S _jdistance between two websites.Obviously, d ₁-d ₂< d ₃, two ends, simultaneously divided by light velocity c, can obtain t _i-t _j< d ₃/ c, i.e. DTOA _ij< d ₃/ c, the mistiming therefore obtained between all websites is less than propagation delay between respective stations.

Adopt equation conversion Nonlinear System of Equations to be converted to linear matrix equation group and try to achieve just solution, comprise the steps:

Step 1: list each website waveform transfer equation.

$t_i=t+\frac{1}{c}\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2}$

(wherein c is the light velocity in vacuum, (x _i, y _i, z _i) be i-th localizer station point coordinate, t _ifor lightning arrives the time of i-th acquisition station).

Step 2: the transmission equation of step one is carried out transposition process, afterwards the transmission equation of different website is subtracted each other between two, obtain linear equation.

c ²(t ²+t _i ²-2tt _i)＝x ²+x _i ²-2xx _i+y ²+y _i ²-2yy _i+z ²+z _i ²-2zz _i

Wherein define:

r _i ²＝x _i ²+y _i ²+z _i ²

r ²＝x ²+y ²+z ²

Can obtain: c ²t ²+ c ²t _i ²-r _i ²=r ²-2 (xx _i+ yy _i+ zz _i-c ²tt _i)

In a jth website, following equation can be obtained equally:

c ²t ²+c ²t _j ²-r _j ²＝r ²-2(xx _j+yy _j+zz _j-c ²tt _j)

Two formulas are subtracted each other and can be obtained:

c ²(t _i ²-t _j ²)-(r _i ²-r _j ²)＝-2(x(x _i-x _j)+y(y _i-y _j)+z(z _i-z _j)-c ²t(t _i-t _j))

Same definition:

t _ij＝t _i-t _j,x _ij＝x _i-x _j,y _ij＝y _i-y _j,z _ij＝z _i-z _j,

$b_{\mathrm{ij}}=\frac{(r_i^2-r_j^2)-c^2(t_i^2-t_j^2)}{2}$

Obtain linear equation xx _ij+ yy _ij+ zz _ij-c ²tt _ij=b _ij

Tij is the mistiming that i, j two websites reach

Step 3: for station, any 5 stations or more observed reading, subtract each other with all the other 4 stations and wherein 1 station, can obtain the matrix be made up of the independent linearity equation of 4 similar steps 2, wherein tij can be obtained by the step of claim 2 correspondence.

$\left[\begin{array}{cccc}{x}_{\mathrm{ij}}& y_{\mathrm{ij}}& z_{\mathrm{ij}}& -c^2{t}_{\mathrm{ij}}\\ x_{\mathrm{ik}}& y_{\mathrm{ik}}& z_{\mathrm{ik}}& -c^2{t}_{\mathrm{ik}}\\ x_{\mathrm{il}}& y_{\mathrm{il}}& z_{\mathrm{il}}& -c^2{t}_{\mathrm{il}}\\ x_{\mathrm{im}}& y_{\mathrm{im}}& z_{\mathrm{im}}& -c^2{t}_{\mathrm{im}}\end{array}\right]\&CenterDot;\left[\begin{array}{c}x\\ y\\ z\\ t\end{array}\right]=\left[\begin{array}{c}{b}_{\mathrm{ij}}\\ b_{\mathrm{ik}}\\ b_{\mathrm{il}}\\ b_{\mathrm{im}}\end{array}\right]$

Step 4: get radiation source three-dimensional position and time is calculated in the matrix equation of the formation of any 5 station linear combinations.

Adopt L-M least square method optimized algorithm to calculate exact solution, comprise the steps:

Step 1: by the radiation source three-dimensional position that calculates in claim 3 and time.Inverting lightning discharge event reaches the time of each website.

${\mathrm{TOA}}_i^{\mathrm{fit}}=\frac{1}{c}\sqrt{{(x^{\mathrm{fit}}-x_i)}^2+{(y^{\mathrm{fit}}-y_i)}^2+{(z^{\mathrm{fit}}-z_i)}^2}$

that inverting is at inverting position (x ^fit, y ^fit, z ^fit) the transmission of lightning discharge course of event simple path after arrive matching time of arrival of website i.

Step 2: determine to weigh Optimal calculation factor χ ², obtain possible initial estimation analytic solution in 5 station claims 3, redundant sites obtains numerical solution, χ the most at last for coordinating nonlinear iteration to retrain ²be worth minimum solution vector as unique accurate solution vector.

${\mathrm{\&chi;}}^2=\underset{N-5}{\overset{N}{\mathrm{\&Sigma;}}}{\left[\frac{{\mathrm{TOA}}_i^{\mathrm{obs}}-{\mathrm{TOA}}_i^{\mathrm{fit}}}{{\mathrm{\&sigma;}}_t^2}\right]}^2$

Wherein, N is current stations available sum, and σ is the standard deviation of each acquisition station data, is a fixed value, for the time of arrival that website i observes.

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. the full lightning positioning method of high precision, is characterized in that, comprise the steps:

Step 1: by the radiated electric field waveform digitization of full lightning location detection site, adopt waveform cross correlation algorithm accurately to extract each website to each website waveform poor in the writing time at each station for identical lightning discharge event, concrete grammar is as follows:

Step 1.1: adopt time window to screen waveform to the true response of identical radiation event from the time, each station waveform be simultaneously in time window is likely just the response to same radiation signal;

Step 1.2: be normalized power waveform by Hilbert Rapid Variable Design by original electric field waveform, eliminates the difference of polarity of wave that each website causes due to the difference of distance radiation source distance and amplitude

Step 1.3: calculate the linearly dependent coefficient of allowing stations available power waveform in window, waveform related coefficient being greater than setting, as the threshold value belonging to similar events response, gets best, the up to standard combination at most of similarity as the preliminary matches result to identical lightning event waveform;

Step 1.4: adopt cross-correlation method to extract each website waveform time poor, cross-correlation is relative time function between signal is not the absolute time difference of certain pulse concrete from time delay averaging time that waveform character reflects, thus eliminates different website environment and route of transmission causes waveform small differences;

Whether step 1.5: after the mistiming obtaining each website, use geometric model to detect the mistiming sequence obtained reasonable;

Step 2: non-linear orientation distance algorithm system of equations is converted to linear matrix equation group and tries to achieve just solution, concrete grammar is as follows:

Step 2.1: according to waveform transfer equation, lists each website waveform transfer equation;

$t_i=t+\frac{1}{c}\sqrt{{(x_i-x)}^2+{(y_i-y)}^2+{(z_i-z)}^2}$

Wherein c is the light velocity in vacuum, (x _i, y _i, z _i) be i-th localizer station point coordinate, t _ifor lightning arrives the time of i-th acquisition station;

Step 2.2: the transmission equation of step 2.1 is carried out transposition process, afterwards the transmission equation of different website is subtracted each other between two, obtain linear equation;

c ²(t ²+t _i ²-2tt _i)＝x ²+x _i ²-2xx _i+y ²+y _i ²-2yy _i+z ²+z _i ²-2zz _i

Wherein define:

r _i ²＝x _i ²+y _i ²+z _i ²

r ²＝x ²+y ²+z ²

Can obtain: c ²t ²+ c ²t _i ²-r _i ²=r ²-2 (xx _i+ yy _i+ zz _i-c ²tt _i)

In a jth website, following equation can be obtained equally:

c ²t ²+c ²t _j ²-r _j ²＝r ²-2(xx _j+yy _j+zz _j-c ²tt _j)

Two formulas are subtracted each other and can be obtained:

c ²(t _i ²-t _j ²)-(r _i ²-r _j ²)＝-2(x(x _i-x _j)+y(y _i-y _j)+z(z _i-z _j)-c ²t(t _i-t _j))

Same definition:

t _ij＝t _i-t _j,x _ij＝x _i-x _j,y _ij＝y _i-y _j,z _ij＝z _i-z _j,

$b_{\mathrm{ij}}=\frac{({r_i}^2-{r_j}^2)-c^2({t_i}^2-{t_j}^2)}{2}$

Obtain linear equation xx _ij+ yy _ij+ zz _ij-c ²tt _ij=b _ij

Tij is the mistiming that i, j two websites reach

Step 2.3: for station, any 5 stations or more observed reading, subtract each other with all the other 4 stations and wherein 1 station, can obtain the matrix be made up of the independent linearity equation of 4 similar steps 2.2, wherein tij obtains by adopting cross-correlation method to extract each website waveform time difference tij in step 1.4;

$\left[\begin{array}{cccc}{x}_{\mathrm{ij}}& y_{\mathrm{ij}}& z_{\mathrm{ij}}& {-c}^2{t}_{\mathrm{ij}}\\ x_{\mathrm{ik}}& y_{\mathrm{ik}}& z_{\mathrm{ik}}& {-c}^2{t}_{\mathrm{ik}}\\ x_{\mathrm{il}}& y_{\mathrm{il}}& z_{\mathrm{il}}& {-c}^2{t}_{\mathrm{il}}\\ x_{\mathrm{im}}& y_{\mathrm{im}}& z_{\mathrm{im}}& {-c}^2{t}_{\mathrm{im}}\end{array}\right].\left[\begin{array}{c}x\\ y\\ z\\ t\end{array}\right]=\left[\begin{array}{c}{b}_{\mathrm{ij}}\\ b_{\mathrm{ik}}\\ b_{\mathrm{il}}\\ b_{\mathrm{im}}\end{array}\right]$

Step 2.4: get radiation source three-dimensional position and time is calculated in the matrix equation of the formation of any 5 station linear combinations;

Step 3: according to the first solution obtained, adopt L-M least square method optimized algorithm to calculate accurate anchor point, concrete grammar is:

Step 3.1: the radiation source three-dimensional position calculated by step 2 and time, inverting lightning discharge event reaches the time of each website, based on following formula:

${\mathrm{TOA}}_i^{\mathrm{fit}}=\frac{1}{c}\sqrt{{(x^{\mathrm{fit}}-x_i)}^2+{(y^{\mathrm{fit}}-y_i)}^2+{(z^{\mathrm{fit}}-z_i)}^2}$

that inverting is at inverting position (x ^fit, y ^fit, z ^fit) the transmission of lightning discharge course of event simple path after arrive matching time of arrival of website i;

Step 3.2: determine to weigh Optimal calculation factor χ ², obtain possible initial estimation analytic solution in 5 station steps 2, redundant sites obtains numerical solution, χ the most at last for coordinating nonlinear iteration to retrain ²be worth minimum solution vector as unique accurate solution vector;

${\mathrm{\&chi;}}^2=\underset{N-5}{\overset{N}{\mathrm{\&Sigma;}}}{\left[\frac{{\mathrm{TOA}}_i^{\mathrm{obs}}-{\mathrm{TOA}}_i^{\mathrm{fit}}}{{\mathrm{\&sigma;}}_t^2}\right]}^2$

Wherein, N is current stations available sum, and σ is the standard deviation of each acquisition station data, is a fixed value, for the time of arrival that website i observes.