CN103116083A - Very low frequency (VLF) / low frequency (LF) frequency range ground lightening detection positioning system - Google Patents

Abstract

The invention discloses a very low frequency (VLF) / low frequency (LF) frequency range ground lightening detection positioning system which is capable of accurately estimating direction of arrival of a ground (DOA) lightening signal transmitted along the ground face generated by a ground lightening radiating source. A signal waveform data file calculated by different detection processing substations is uploaded to a central processing station through a wide area network, time difference of arrival (TDOA estimate) between any two probe processing stations corresponding with the same ground lightening signal is calculated in the central processing station, then the two-dimensional plane coordination position of the ground lightening radiating source is determined by utilizing the DOA information and the TDOA information in a combination mode. The VLF/LF frequency range ground lightening detection positioning system is capable of carrying out high-accuracy super-resolution observation of the direction of arrival of the ground lightening signal transmitted along the ground surface generated by the ground lightening radiating source, greatly reducing consistency requirement of channel range characteristics of a receiver, and solving the TDOA estimating difference problem caused by the difference of time delay of different probe processing substation channel groups.

Description

A kind of VLF/LF frequency range ground dodges the lightening detection positioning system

Technical field

Dodge lightning monitoring early warning technology research field with the invention belongs to, relate to a kind of very low frequency (VLF)/low frequency (VLF/LF) frequency range ground and dodge the lightening detection positioning system.

Background technology

Lightning location system originates from late 1970s, the U.S. has realized large-scale lightning location system (LLS based on modern thunder and lightning remote measurement location technology, Lightning Location System) build, and the lightning location system networking that will be distributed in each state has formed the National Lightning Detecting Network (NLDN of the current U.S., National Lightning Detection Network), realized comprehensively, intactly monitoring overlay area lightening activity situation.20th century the mid-80, French Vaisala company develops SAFIR3000V2 ground and dodges lightning location system, and comes into operation in a plurality of countries and regions.

Lightning location system also successfully dodges in late 1980s with developing in China, and start throughout the country to dodge thunder and lightning position monitor net the end of the nineties in last century with building, development through more than 20 years, the monitoring system of China has covered national most of zone at present, for the departments such as national electrical network transmission, weather monitoring provide a large amount of utility datas.

Summary of the invention

The object of the invention is to design and realize that a kind of VLF/LF frequency range ground dodges the lightening detection positioning system, native system can dodge over the ground the generation of radiation of lightening discharge source and accurately estimate along the ground sudden strain of a muscle thunder and lightning signal direction of arrival (DOA) of ground surface propagation.

A kind of VLF/LF frequency range provided by the invention ground dodges the lightening detection positioning system, it is characterized in that, this system comprises a center processing station and a plurality of detection processing substation that is positioned at diverse location; Substation is processed in different detections and the center processing station all forms the system of an associating by wireless or wired mode access wide area network;

Each survey to process that substation be used for the time service of GPS/ big-dipper satellite and clock synchronous, system channel group delay are calculated, dodge the reception of thunder and lightning signal and synchronous acquisition, the calibration of channel amplitude inconsistency, dodge that thunder and lightning detects and the estimation of signal direction of arrival, after the lightning wave of sudden strain of a muscle in real time graphic data, direction finding angle information, system state parameter information and the time tag information that then will obtain carries out framing, form ground and dodge thunder and lightning signal waveform data file, by wide area network, this data file is uploaded to the center processing station;

The center processing station realizes each is surveyed to the remote monitoring of processing the substation duty by wide area network; Data file that upload processing substation is also surveyed for receiving each in the center processing station, and each ground of survey processing substation dodges thunder and lightning signal waveform data file and calculates and dodge the thunder and lightning signal and arrive any two and survey the mistimings of processing substations according to the same period samely, re-use each survey process substation corresponding to same direction of arrival information of dodging the thunder and lightning signal and time of arrival poor information dodge the planimetric coordinates position in radiation of lightening discharge source with calculating.

The present invention can dodge over the ground the radiation of lightening discharge source and produce the ground of propagating along ground surface and dodge thunder and lightning signal direction of arrival and carry out the observation of high precision, super-resolution; Greatly alleviated the coherence request to receiver channel amplitude characteristic; Solved because difference is surveyed the different TDOA evaluated error problems of bringing of substation system passage group delay of processing; The present invention can also dodge the lightning wave graphic data to VLF/LF frequency range ground for a long time and carry out continuous recording, for VLF/LF frequency range ground dodges the thunder and lightning signature analysis, provides full and accurate basic data.Particularly, system of the present invention has following characteristics:

(1) form a complete VLF/LF frequency range ground and dodge the lightening detection positioning system, can realize to VLF/LF frequency range ground dodge the thunder and lightning signal continuously, uninterruptedly observe and locate.The time that record dodges the thunder and lightning signal continuously is a few hours and obliterated data not;

(2) the system hardware complexity is low, and networking cost and systematic running cost are low, and extensibility is strong;

(3) survey the processing substation and adopt incoherent energy measuring, improved the detection efficiency that dodges over the ground the thunder and lightning signal;

(4) survey processing substation can dodge over the ground thunder and lightning signal arrival bearing and carry out the observation of high precision, super-resolution, ground is dodged to thunder and lightning signal waveform data file simultaneously and be uploaded to the center processing station, then stand erectly to connect in center processing and dodge the mistimings (TDOA) that the thunder and lightning signal arrives any two detection processing substations with resolving, do not need to survey (TOA) information time of arrival that the thunder and lightning signal is provided in substation of processing with providing;

(5) surveying the processing substation effectively estimates the system channel group delay, and system channel group delay information is dodged in thunder and lightning signal waveform data file with adding and is uploaded to the center processing station, center processing stands in while carrying out TDOA calculating, utilize each to survey the system channel group delay information of processing substation, the time tag information that ground for carrying out TDOA calculating is dodged to the lightning wave graphic data compensates, thereby can farthest reduce because difference is surveyed the different positioning errors of bringing of processing substation system passage group delay;

(6) the center processing station adopts combination DOA and TDOA information to dodge the two dimensional surface coordinate in radiation of lightening discharge source with calculating; Also can only by TDOA information, calculate the position that ground dodges the radiation of lightening discharge source, and differentiate and reject the false bearing point by DOA information.

The accompanying drawing explanation

Fig. 1 is the overall architecture that the VLF/LF frequency range ground of indication of the present invention dodges the lightening detection positioning system;

Fig. 2 surveys to process substation functional unit block diagram;

Fig. 3 is VLF/LF frequency range ultra broadband receiving antenna structural drawing;

Fig. 4 is system channel group delay computation process;

Fig. 5 is center processing station functional unit block diagram;

Fig. 6 surveys to process substation digital processing subsystem function unit block diagram;

Fig. 7 surveys to process substation analog channel functional unit block diagram.

Embodiment

A kind of VLF/LF frequency range ground that the present invention proposes dodges the lightening detection positioning system, utilize VLF/LF frequency range ultra broadband receiving antenna, VLF/LF frequency range hyperchannel to receive and the synchronous acquisition unit, receive and gather ground and dodge the VLF/LF ground sudden strain of a muscle thunder and lightning signal that the radiation of lightening discharge source gives off, the reception bandwidth is 0～2.5MHz, carry out corresponding digital signal processing after analog to digital conversion, then the ground of extraction is dodged to lightning parameter be uploaded to the center processing station and dodge the positioning calculation of thunder and lightning signal with carrying out.

As shown in Figure 1, a kind of VLF/LF frequency range ground that the present invention proposes dodges the lightening detection positioning system, comprise detection that a center processing station 20 and N are positioned at diverse location process substation 11,12,13 ..., 1N forms, N is more than or equal to 3 positive integer, means to survey the number of processing substation. Detection processing substation 11,12,13 ..., between 1N, and each surveys the geographic position of processing between substation and center processing station apart from reaching several hundred kilometers. Detection processing substation 11,12,13 ..., 1N respectively or wired mode wireless by 3G/4G wireless base station, wired route etc. be linked into wide area network, center processing station 20 is by optical fiber access via telephone line wide area network, and the ground that forms an associating dodges the lightening detection positioning system.

Each is surveyed the processing substation and completes the time service of GPS/ big-dipper satellite and clock synchronous, the system channel group delay is calculated, the ultra broadband that VLF/LF frequency range ground dodges the thunder and lightning signal receives at a high speed, synchronous acquisition, the calibration of channel amplitude inconsistency, ground dodges the thunder and lightning input and the signal direction of arrival is estimated, the thunder and lightning of the sudden strain of a muscle in real time signal waveform data that then will obtain, the direction finding angle information, after system state parameter information and time tag information etc. carry out framing, be buffered in the sdram memory bar, upload to survey by the PXI interface again and process in the local hard drive of surveying processing substation embedded controller in substation, form ground and dodge thunder and lightning signal waveform data file, finally by wide area network, adopt file transfer protocol (FTP) (FTP) mode that above-mentioned data file is uploaded to the center processing station.

Center processing station 20 receives each and surveys processing substation 11, 12, 13, after the ground that 1N uploads dodges thunder and lightning signal waveform data file, form according to Frame dodges in the lightning data storehouse with depositing in, and then survey corresponding to each ground sudden strain of a muscle lightning wave graphic data of processing substation in the same period of taking-up and calculate samely and dodge the mistimings that the thunder and lightning signal arrives any two detection processing substations from this database, then with each, survey and process substation and set up the integrated positioning equation corresponding to same DOA information and TDOA information of dodging the thunder and lightning signal, finally dodge the planimetric coordinates position in radiation of lightening discharge source with calculating.

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described further.It should be noted that at this, for the explanation of these embodiments, for helping to understand the present invention, but do not form limitation of the invention.In addition, below in each embodiment of described the present invention involved technical characterictic as long as form each other conflict, just can mutually not combine.

As shown in Figure 2, each detection processing substation at least comprises with lower unit: substation digital processing subsystem 104, detection processing substation embedded controller 105 are processed in temporal frequency unit 101, VLF/LF frequency range ultra broadband receiving antenna unit 102, the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit 103, detection.

Temporal frequency unit 101 adopts GPS/ big-dipper satellite time service simultaneous techniques, and the analogy and digital circuit of processing substation for the detection that is arranged in diverse geographic location provides 50MHz synchronizing clock signals, standard second pulse signal (1PPS pulse) and general universal time coordinated information (UTC information).Wherein, 1PPS pulse and UTC information adopt USB (universal serial bus) to flow to and survey processing substation digital processing subsystem 104; The rising edge shake average of 1PPS pulse is less than 50ns, make the time mark resolution of surveying the processing substation reach 20ns, each is surveyed the clock synchronization accuracy of processing between substation and is better than 50ns, thereby guarantees entirely to dodge the net synchronization capability of lightening detection positioning system.

The structured flowchart of VLF/LF frequency range ultra broadband receiving antenna unit 102 as shown in Figure 3, three symmetrical support bars 33 of placing, support respectively three kinds of different receiving antennas: monopole antenna 34 is vertical with surface level, for receiving the electric field channel signal; GPS/ big-dipper satellite antenna 35, for receiving the GPS/ Big Dipper satellite signal; Two orthogonal loop antennas 31 and 32 square crossings, each plane of a loop is vertical with surface level, and wherein, loop antenna 31 overlaps with geographical east-west direction, loop antenna 32 overlaps with geographical North and South direction, and the two receives respectively magnetic field thing ring channel signal and north and south, magnetic field ring channel signal; Adopt concentric cable magnetic field thing ring channel signal, north and south, magnetic field ring channel signal and electric field channel signal are offered to the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit 103, also adopt concentric cable to give temporal frequency unit 101 by the GPS/ Big Dipper satellite signal simultaneously; As shown in Figure 7, also comprise that for the concentric cable of magnetic field thing ring channel signal, north and south, the magnetic field ring channel signal of transmission and electric field channel signal impedance matching, lightening surge preventing, the difference of series connection successively turn single-ended, low-pass filtering and impedance inverter circuit in VLF/LF frequency range ultra broadband receiving antenna unit 102.

Three simulation receiving cables in the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit 103, through lightening surge preventing, bandpass filtering, programme-controlled gain, active power filtering, amplify, the magnetic field thing ring channel signal of VLF/LF frequency range ultra broadband receiving antenna unit 102 outputs, north and south, magnetic field ring channel signal and electric field channel signal are carried out to the ultra broadband simulation and receive and amplify, signal bandwidth is 0～2.5MHz; Then after the ADC analog to digital conversion circuit carries out 50MHz synchronized sampling and quantification (quantization digit is not less than 10bit), the VLF/LF digital signal that to obtain frequency range be 0～2.5MHz, be input to survey in the mode of serial and process substation digital processing subsystem 104 Zhong， tri-road serial digital signal streaming rates and all be not less than 500Mbps.

As shown in Figure 6, survey to process substation digital processing subsystem 104 at least comprise time mark module 401, digital pretreatment module 402, system channel group delay computing module 403, channel amplitude inconsistency calibration module 404, dodge thunder and lightning signal detection module 405, signal direction of arrival estimation module 406, data framing buffer memory and transmission control module 407.

Time mark module 401, the serial 1PPS pulse and the UTC information that mainly complete 101 outputs of temporal frequency unit are received and are resolved, and obtain date Hour Minute Second information; The 50MHz clock signal of frequency cells 101 outputs service time is counted simultaneously, and with the rising edge of 1PPS pulse to counter O reset, thereby obtain precision, it is the synchronous pulse per second (PPS) count value of 20ns, together with date Hour Minute Second information, form complete time tag information, for subsequent module.In addition, the time mark module also completes the frequency division of 50MHz clock signal and process of frequency multiplication, produces the homology clock signal of surveying the different frequency of processing the required use of substation digital processing other modules of subsystem.

The numeral pretreatment module mainly completes to be processed synchronous reception and the filtering extraction of magnetic field thing ring passage (EW), north and south, magnetic field ring passage (NS), electric field passage (EF) three tunnel highspeed serial data stream, obtains the digital signal x that three circuit-switched data speed are 5Msps _eW(n), x _nS(n), x _{eF (}n).X wherein _eW(n), x _nS(n), x _eF(n) be respectively through the magnetic field of pretreated n the sampled point of numeral thing ring channel signal, north and south, magnetic field ring channel signal and electric field channel signal.Detailed process is as follows:

1. the synchronous reception of three tunnel highspeed serial data stream: at first carry out test pattern and obtain the clock phase deviation between three tunnel highspeed serial data stream, then by the bit clock phase place of clock phase freqency fine adjustment machine lockmaking Ding Mei road serial data stream receiver, realization is not less than the synchronous reception of the serial digital signal of 500Mbps speed to three tunnels, through string-also conversion, obtain the parallel digital signal of three road 50Msps speed again.

2. filtering extraction is processed: at first the aforementioned three-channel parallel digital signal obtained is gone to DC component treatment; Then carry out low-pass filtering and 5 times of extractions, obtaining speed is the parallel digital signal that 10Msps, bandwidth are 0～5M; Then, to this further low-pass filtering of three railway digitals signal and 2 times of extractions, obtaining speed is the parallel digital signal that 5Msps, bandwidth are 0～2.5M; Last Zai Dui tri-road signals carry out high-pass filtering, and obtaining speed is the three railway digital preprocessed signal x that 5Msps, bandwidth are 10K～2.5M _eW(N), x _nS(N), x _eF(N).

This example can adopt flow process as shown in Figure 4 to carry out the calculating of system channel group delay: by the 1PPS pulse of temporal frequency unit 101 outputs, sent into respectively pulse-series generator and surveyed the time mark module 401 of processing in substation digital processing subsystem 104; Pulse-series generator can produce the VLF/LF pulse-modulated signal, and it produces the VLF/LF pulse-modulated signal under the synchronous modulation of 1PPS rising edge of a pulse, then via the signal emitting antenna, to space, carries out electromagnetic radiation; Emitting antenna is the loop antenna turned to by copper core, and the VLF/LF pulse-modulated signal is input to two input ends of emitting antenna can be to space radiation; VLF/LF frequency range ultra broadband receiving antenna unit 102 is by the space electromagnetic induction, the VLF/LF pulse-modulated signal received is given to VLF/LF frequency range hyperchannel receives and synchronous acquisition unit 103 carries out synchronous acquisition and reception, finally in survey processing substation digital processing subsystem 104 after digital pretreatment module, enter system channel group delay computing module; System channel group delay module is used the 1PPS rising edge of a pulse synchronously to detect, and the moment of thresholding pulse-modulated signal and the mistiming that the 1PPS rising edge of a pulse arrived between the moment detected, is the group delay of whole signal loop.In the situation that ignore the emission path of pulse-modulated signal and receive the difference between path, the group delay result of the aforementioned whole signal loop recorded, divided by 2, can be obtained to system channel group delay value.

Channel amplitude inconsistency calibration module comprises amplitude inconsistency coefficients calculation block and channel amplitude Inconsistency compensation module;

1. amplitude inconsistency coefficients calculation block, when build a station in each detection processing substation, utilize random signal generator to produce the white Gaussian noise signal, send into north and south, 102 magnetic field, VLF/LF frequency range ultra broadband receiving antenna unit ring passage and magnetic field thing ring passage concentric cable connector by the one-to-two power splitter, then to the digital pretreated digital signal x of process _eW(n), x _nS(n) calculating magnetic field binary channels amplitude inconsistency factor alpha

$\mathrm{\α}=\sqrt{\frac{P_{\mathrm{nEW}}}{P_{\mathrm{nNS}}}}=\sqrt{\frac{\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{x}_{\mathrm{EW}}^2\left(n\right)}{\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{x}_{\mathrm{NS}}^2\left(n\right)}}$

Wherein, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200; x _eW(n), x _nS(n)) be respectively in a sampled data piece, through the magnetic field of pretreated n the sampled point of numeral thing ring channel signal and north and south, magnetic field ring channel signal; P _nEWand P _nNSbe respectively the short-time energy of magnetic field thing ring channel signal and north and south, magnetic field ring channel signal in a sampled data piece;

2. in channel amplitude Inconsistency compensation module, according to the following equation the amplitude of three road signals of digital pretreatment module output is carried out to Inconsistency compensation, obtain the digital signal after compensation for calibrating errors

$\left\{\begin{array}{c}{y}_{\mathrm{EW}}\left(n\right)=1\·x_{\mathrm{EW}}\left(n\right)\\ y_{\mathrm{NS}}\left(n\right)=\mathrm{\α}\·x_{\mathrm{EW}}\left(n\right)\\ y_{\mathrm{EF}}\left(N\right)=1\·x_{\mathrm{EF}}\left(n\right)\end{array}\right.$

Wherein, y _eW(n) be the digital signal of magnetic field thing ring channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is 1; y _nS(n) be the digital signal of north and south, magnetic field ring channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is α; y _eF(n) be the digital signal of electric field channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is 1.Here why magnetic field thing ring channel signal and electric field channel signal also being carried out to the amplitude Inconsistency compensation, is in order to guarantee synchronization through digital pretreated magnetic field thing ring channel signal x _eWand north and south, magnetic field ring channel signal x (n) _nSand electric field channel signal x (n) _eF(n) the strict data between are synchronous.

Ground dodges the thunder and lightning signal detection module and comprises state switching controls module, background noise energy computing module, short-time energy computing module, dynamic over-threshold detection module;

1. state switching controls module is calculated according to default background noise energy and normal sampling time of reception ratio, between the calculating of background noise energy and normal sampling accepting state, carries out periodic switching controls; The present embodiment system is per hour automatically switched once, and it is 1s that each background noise energy calculates state duration, and other times are normal sampling accepting state;

2. background noise energy computing module is for during background noise energy computing mode, to the digital signal y after compensation for calibrating errors _eW(n), y _nS(n) carry out according to the following equation the short-time energy statistical computation

$E_{\mathrm{noise}}=\underset{n=0}{\overset{K\×M}{\mathrm{\Σ}}}[y_{\mathrm{EW}}^2\left(n\right)+y_{\mathrm{NS}}^2\left(n\right)]$

Wherein, E _noisefor the background noise energy, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200, and K is positive integer, means that the span of K is [1,1024] for calculating the number of background noise energy sampled data piece used; Here why will add up the cumulative sum value of K * M point, be the general statistical law that obtains the background noise energy in long-time section for as much as possible.

3. the short-time energy computing module is under normal sampling accepting state, to the digital signal y after compensation for calibrating errors _eW(n), y _nS(n) carry out according to the following equation short-time energy calculating

$E_{\mathrm{sample}}=\underset{n=0}{\overset{M}{\mathrm{\Σ}}}[y_{\mathrm{EW}}^2\left(n\right)+y_{\mathrm{NS}}^2\left(n\right)]$

Wherein, E _samplefor short-time energy, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200;

4. dynamic over-threshold detection module is by the background noise energy value E calculated _noisecarry out relevant treatment with detection threshold signal-to-noise ratio settings value, obtain the dynamic power detection threshold

E _ref＝k*E _noise/K

Wherein, k is detection threshold signal-to-noise ratio settings value, E _reffor the dynamic power detection threshold; By short-time energy E _samplewith detection threshold E _refcompare, work as E _sample>=E _refthe time, judge that this data block dodges the lightening pulse signal with comprising, otherwise do not dodge the lightening pulse signal with comprising.

Signal direction of arrival estimation module to the data segment that dodges the lightening pulse signal detected under normal sampling accepting state with comprising carry out the tangent angle calculation, the quadrant fuzzy Judgment is tabled look-up, gone to the arc tangent angle, thereby obtain direction of arrival information:

1. tangent angle computing module, utilize following formula to calculate the tangent value information of direction of arrival

$\left|\tan \mathrm{\θ}\right|=\frac{\left|\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{y}_{\mathrm{EW}}\left(n\right)\right|}{\left|\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{y}_{\mathrm{NS}}\left(n\right)\right|}$

Wherein, θ is direction of arrival, | tan θ | be the absolute value of its tangent value, M is positive integer, means total sampling number that each sampled data piece comprises, M >=200;

2. arc tangent table look-up module, according to what obtain in aforementioned tangent angle computing module | tan θ | carry out the one dimension arc tangent and table look-up, obtain the projection of direction of arrival θ at first quartile | θ |, wherein independent variable is tangent value, functional value is angle, functional value covers 0 °～90 °, and in the present embodiment, the step-length of angle is 0.5 °;

3. go in quadrant fuzzy Judgment module, amplitude cumulative sum value by calculating magnetic field thing ring channel signal, north and south, magnetic field ring channel signal and electric field channel signal, obtain the positive-negative polarity information of triple channel signal, then according to following rule, gone the quadrant fuzzy Judgment to obtain real direction of arrival result of calculation θ:

Wherein, for magnetic field thing ring channel signal amplitude cumulative sum value,

for north and south, magnetic field ring channel signal amplitude cumulative sum value,

for electric field channel signal amplitude cumulative sum value, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200.

Data framing buffer memory and transmission control module dodge detected electric field channel signal data y corresponding to data segment that dodges the lightening pulse signal in the thunder and lightning signal detection module by aforementioned with comprising _eF(n), the direction of arrival and the positive-negative polarity information that together with aforementioned signal direction of arrival estimation module, calculate, and system channel group delay information, detection threshold signal-to-noise ratio settings value, the background noise energy value carries out framing, and the split-second precision label information of being exported by the time mark module on mark, form complete ground and dodge thunder and lightning signal waveform data frame, and then by its buffer memory to the sdram memory bar, when the Frame size reaches 640KB by the time, upload control by PXI, be uploaded to survey and process in the local hard drive of surveying processing substation embedded controller 105 in substation, form a ground and dodge thunder and lightning signal waveform data file.

Detection processing substation, substation embedded controller 105 is processed in detection in Fig. 2 will be stored in the ground sudden strain of a muscle thunder and lightning signal waveform data file in local hard drive, according to file transfer protocol (FTP) (FTP) mode, be uploaded to the center processing station 20 in Fig. 1.

As shown in Figure 5, the center processing station at least comprises with lower unit: router two 01, fire wall 202, communication and monitoring server 203, switch 204, dodge lightning data storehouse 205, TDOA calculation server 206 and ground and dodge thunder and lightning positioning calculation server 207.

Each detection processing substation 11,12,13 ..., the ground that obtains of 1N dodges the lightening detection data file and passes through wide area network, via the high speed fibre special line, transfer to router two 01, after the invalid IP packet of fire wall 202 isolation, effective IP packet is delivered to communication and monitoring server 203, then through switch 204, dodge lightning data storehouse 205 with depositing in.

TDOA calculation server 206 dodges lightning data storehouse 205 by switch 204 access, obtains the ground sudden strain of a muscle thunder and lightning signal waveform data frame with time tag information, dodges the thunder and lightning signal with then calculating and arrives any two mistiming Δ τ that survey processing substation p, q _pq, TDOA information, the DOA information that then will be positioned at the same time period is put in data and concentrates, and obtains TDOA/DOA data acquisition (the Δ τ that dodges the radiation of lightening discharge source corresponding to same _pq, θ _p), wherein, θ _pmean that the ground that p detection processing substation records dodges the direction of arrival of thunder and lightning signal, and this result of calculation is dodged in lightning data storehouse 205 again with being stored in.In the present embodiment, the duration of each time period is 40us.

Ground dodges thunder and lightning positioning calculation server 207 and dodges lightning data storehouse 205 by switch 204 access, read DOA and TDOA data wherein, then use these data set up based on ground dodge the thunder and lightning signal direction of arrival DOA and time of arrival poor TDOA information the integrated positioning equation, dodge the two dimensional surface coordinate (x, y) in radiation of lightening discharge source by iterative computation with obtaining.The integrated positioning equation of setting up comprises following two classes:

1. dodge the thunder and lightning signal based on ground and arrive any two Rotational Symmetry Hyperbolic Equations of surveying the time difference information of processing substation and setting up:

$\sqrt{{(x_p-x)}^2+{(y_p-y)}^2}-\sqrt{{(x_q-x)}^2+{(y_q-y)}^2}=c\·{\mathrm{\Δ\τ}}_{\mathrm{pq}},$ p，q＝1，2，…，p≠q

2. dodge the thunder and lightning signal based on ground and arrive the azimuth information of surveying arbitrarily the processing substation and the aximuthpiston equation of setting up:

(x-x _p)sinθ _p-(y-y _p)cosθ _p＝0， p＝1，2，…

Wherein, (x, y) dodges the two dimensional surface coordinate in radiation of lightening discharge source, (x with being _p, y _p), (x _q, y _q) be p and q the two dimensional surface position coordinates of surveying the processing substation, Δ τ _pqfor dodging the thunder and lightning signal, ground arrives p and q the mistiming of surveying the processing substation, θ _pbe p and survey the ground sudden strain of a muscle thunder and lightning signal direction of arrival that the processing substation obtains, c means electromagnetic wave propagation speed.

In a word, system of the present invention utilizes VLF/LF frequency range ultra broadband receiving antenna, VLF/LF frequency range hyperchannel to receive and the ground of the completes such as synchronous acquisition plate, the digital signal processing hardware platform be comprised of FPGA, SDRAM, pci controller etc. and PXI built-in industrial control machine dodges lightening detection processing substation, completes reception, processing, transmission and control that VLF/LFF frequency range ground is dodged to the thunder and lightning signal.System is dodged over the ground the generation of radiation of lightening discharge source and is accurately estimated along the ground sudden strain of a muscle thunder and lightning signal direction of arrival (DOA) of ground surface propagation.In addition, system also adopts GPS/ big-dipper satellite high precision Service of Timing and file transfer protocol (FTP) (FTP) network transmission technology will dodge with the ground of split-second precision label information thunder and lightning waveform and aforementioned ground of trying to achieve to dodge the thunder and lightning signal wave and reach directional data and be uploaded to the center processing station.Then calculate any two at the center processing station and survey to process between substations corresponding to estimating same time of arrival poor (TDOA) of dodging the thunder and lightning signal, and the two dimensional surface based on DOA and TDOA information realization dodge the radiation of lightening discharge source is over the ground located.The center processing station adopts many interconnected multi-purpose computers to form, survey between processing substation and center processing station and adopt file transfer protocol (FTP) (FTP) mode to dodge the transmission of lightning wave graphic data file with completing, adopt transmission control protocol/Internet Interconnection agreement (TCP/IP) mode to complete and dodges over the ground the bidirectional monitoring information that lightening detection is processed substation.

The present invention not only is confined to above-mentioned embodiment; persons skilled in the art are according to content disclosed by the invention; can adopt other multiple embodiment to implement the present invention; therefore; every employing structural design of the present invention and thinking; do some simple designs that change or change, all fall into the scope of protection of the invention.

Claims (10)

1. a VLF/LF frequency range ground dodges the lightening detection positioning system, it is characterized in that, this system comprises a center processing station and a plurality of detection processing substation that is positioned at diverse location; Substation is processed in different detections and the center processing station all forms the system of an associating by wireless or wired mode access wide area network;

Each survey to process that substation be used for the time service of GPS/ big-dipper satellite and clock synchronous, system channel group delay are calculated, dodge the reception of thunder and lightning signal and synchronous acquisition, the calibration of channel amplitude inconsistency, dodge that thunder and lightning detects and the estimation of signal direction of arrival, after the lightning wave of sudden strain of a muscle in real time graphic data, direction finding angle information, system state parameter information and the time tag information that then will obtain carries out framing, form ground and dodge thunder and lightning signal waveform data file, by wide area network, this data file is uploaded to the center processing station;

The center processing station realizes each is surveyed to the remote monitoring of processing the substation duty by wide area network; Data file that upload processing substation is also surveyed for receiving each in the center processing station, and each ground of survey processing substation dodges thunder and lightning signal waveform data file and calculates and dodge the thunder and lightning signal and arrive any two and survey the mistimings of processing substations according to the same period samely, re-use each survey process substation corresponding to same direction of arrival information of dodging the thunder and lightning signal and time of arrival poor information dodge the planimetric coordinates position in radiation of lightening discharge source with calculating.

2. a kind of VLF/LF frequency range according to claim 1 ground dodges the lightening detection positioning system, it is characterized in that, each is surveyed the processing substation and all at least comprises with lower unit: temporal frequency unit (101), and VLF/LF frequency range ultra broadband receiving antenna unit (102), the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit (103), detection are processed substation digital processing subsystem (104) and are surveyed processing substation embedded controller (105);

VLF/LF frequency range ultra broadband receiving antenna unit (102) for dodging thunder and lightning signal and GPS/ Big Dipper satellite signal with receiving, ground is dodged to the thunder and lightning signal and offer the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit (103), the GPS/ Big Dipper satellite signal is offered to temporal frequency unit (101);

Temporal frequency unit (101) is resolved the GPS/ Big Dipper satellite signal received, and obtains standard second pulse signal and UTC information, and offers detection processing substation digital processing subsystem (104); Also the local clock signal is synchronously processed, synchronizing clock signals is offered respectively to the reception of VLF/LF frequency range hyperchannel and synchronous acquisition unit (103) and detection and process substation digital processing subsystem (104);

VLF/LF frequency range hyperchannel receives and synchronous acquisition unit (103) carry out synchronized sampling and quantification treatment according to synchronizing clock signals to the ground sudden strain of a muscle thunder and lightning signal received, and dodges the thunder and lightning digital signal with obtaining and sends into detection processing substation digital processing subsystem (104);

Survey processing substation digital processing subsystem (104) the ground sudden strain of a muscle thunder and lightning digital signal of input is carried out to digital processing, dodge lightning wave graphic data file with obtaining, be cached in and survey in processing substation embedded controller (105);

The ground sudden strain of a muscle lightning wave graphic data file that detection processing substation embedded controller (105) will be stored in local hard drive is uploaded to the center processing station in file transfer protocol (FTP) (FTP) mode.

3. a kind of VLF/LF frequency range according to claim 1 ground dodges the lightening detection positioning system, it is characterized in that, the center processing station at least comprise router (201), fire wall (202), communication and monitoring server (203), switch (204), dodge lightning data storehouse (205), TDOA calculation server (206) and ground and dodge thunder and lightning positioning calculation server (207);

Communication and monitoring server (203) receive each detection by router (201) and fire wall (202) and process the ground sudden strain of a muscle thunder and lightning signal waveform data file that substation provides, the lightening detection data are dodged in parsing with obtaining, this ground dodges the lightening detection data and comprises that the ground with time tag information dodges lightning wave graphic data and DOA data, and dodge lightning data storehouse (205) storage of classifying by switch (204) with offering, communication also surveys to each remote monitoring of processing the substation duty for completing with monitoring server (203);

TDOA calculation server (206) dodges lightning data storehouse (205) by switch (204) access, obtain dodging the lightning wave graphic data with the ground of time tag information, then calculate ground and dodge the mistimings that the thunder and lightning signal arrives any two detection processing substations, obtain the TDOA data, and again dodge in lightning data storehouse (205) by the TDOA data with being stored in;

Ground dodges thunder and lightning positioning calculation server (207) and dodges lightning data storehouse (205) by switch (204) access, read DOA and TDOA data wherein, dodge the two dimensional surface coordinate of thunder and lightning origination point or area of space according to read data with calculating.

4. a kind of VLF/LF frequency range according to claim 1 and 2 ground dodges the lightening detection positioning system, it is characterized in that, VLF/LF frequency range ultra broadband receiving antenna unit (102) comprises the magnetic loop antenna (31,32) of monopole antenna (34), GPS/ big-dipper satellite antenna (35) and two quadratures, wherein two orthogonal loop antennas (31,32) overlap with geographical east-west direction and North and South direction respectively, for receiving magnetic field thing ring channel signal and north and south, magnetic field ring channel signal, monopole antenna (34) is vertical with surface level, receives the electric field channel signal; And adopt concentric cable and magnetic field thing ring channel signal, north and south, magnetic field ring channel signal and electric field channel signal are offered to VLF/LF frequency range hyperchannel receive and synchronous acquisition unit (103); That impedance matching, lightening surge preventing, the difference that magnetic field thing loop antenna passage, north and south, magnetic field loop antenna passage and electric field antenna channels include successively series connection turns is single-ended, low-pass filtering and impedance inverter circuit; VLF/LF frequency range hyperchannel receives and synchronous acquisition unit (103) middle three corresponding simulation receiving cables include series connection successively lightening surge preventing, bandpass filtering, programme-controlled gain, active power filtering amplify and the ADC analog to digital conversion circuit;

GPS/ big-dipper satellite antenna (35) is for receiving the GPS/ Big Dipper satellite signal, and offers temporal frequency unit (101).

5. a kind of VLF/LF frequency range according to claim 1 and 2 ground dodges the lightening detection positioning system, it is characterized in that, after detection processing substation digital processing subsystem (104) carries out digital pre-service to the three railway digital signals of inputting, obtain magnetic field thing ring passage numeral preprocessed signal, the digital preprocessed signal of north and south, magnetic field ring passage and the digital preprocessed signal of electric field passage; Then carry out the calibration of channel amplitude inconsistency, dodge thunder and lightning input, the estimation of signal direction of arrival, time mark, data buffer storage and control, obtain dodging in real time lightning wave graphic data, magnetic field passage inconsistency calibration factor and signal wave and reach directional data, then after the framing buffer memory, upload to survey and process substation embedded controller (105).

6. a kind of VLF/LF frequency range according to claim 3 ground dodges the lightening detection positioning system, it is characterized in that, the concrete processing procedure that TDOA calculation server (206) and ground dodge thunder and lightning positioning calculation server (207) is respectively:

TDOA calculation server (206) dodges lightning data storehouse (205) by switch (204) access, obtain dodging thunder and lightning signal waveform data frame with the ground of time tag information, then calculate ground sudden strain of a muscle thunder and lightning signal and arrive the mistiming Δ τ that substation p, q are processed in any two detections _pq, TDOA information, the DOA information that then will be positioned at the same time period is put in data and concentrates, and obtains TDOA/DOA data acquisition (the Δ τ that dodges the thunder and lightning signal corresponding to same _pq, θ _p), wherein, θ _pthe direction of arrival that means the ground sudden strain of a muscle thunder and lightning signal that p detection processing substation records, and by this data acquisition (Δ τ _pq, θ _p) again dodge in lightning data storehouse (205) with being stored in;

Ground dodge thunder and lightning positioning calculation server (207) utilize direction of arrival DOA and time of arrival poor TDOA information set up based on ground dodge the thunder and lightning signal direction of arrival DOA and time of arrival poor TDOA information the integrated positioning equation, finally resolve the two dimensional surface coordinate of sudden strain of a muscle thunder and lightning origination point or area of space with obtaining;

Described integrated positioning system of equations comprises following two class positioning equations:

1. dodge the thunder and lightning signal based on ground and arrive any two Rotational Symmetry Hyperbolic Equations of surveying the time difference information of processing substation and setting up:

$\sqrt{{(x_p-x)}^2+{(y_p-y)}^2}-\sqrt{{(x_q-x)}^2+{(y_q-y)}^2}=c\·{\mathrm{\Δ\τ}}_{\mathrm{pq}},$ p，q＝1，2，…，p≠q

P, q are for surveying the sequence number of processing substation;

2. dodge the thunder and lightning signal based on ground and arrive the azimuth information of surveying arbitrarily the processing substation and the aximuthpiston equation of setting up:

(x-x _p)sinθ _p-(y-y _p)cosθ _p＝0， p＝1，2，…

Wherein, (x, y) dodges the two dimensional surface coordinate in radiation of lightening discharge source, (x with being _p, y _p), (x _q, y _q) be p and q the two dimensional surface position coordinates of surveying the processing substation, Δ τ _pqfor dodging the thunder and lightning signal, ground arrives p and q the mistiming of surveying the processing substation, θ _pbe p and survey the ground sudden strain of a muscle thunder and lightning signal direction of arrival that the processing substation obtains, c means electromagnetic wave propagation speed.

7. a kind of VLF/LF frequency range according to claim 5 ground dodges the lightening detection positioning system, it is characterized in that, survey to process substation digital processing subsystem (104) at least comprise time mark module (401), digital pretreatment module (402), system channel group delay computing module (403), channel amplitude inconsistency calibration module (404), dodge thunder and lightning signal detection module (405), signal direction of arrival estimation module (406), data framing buffer memory and transmission control module (407);

Numeral pretreatment module (402) is carried out synchronous the reception and the filtering extraction processing for the three railway digital signals that complete input, and the data after processing are offered to channel amplitude inconsistency calibration module (404) and system channel group delay computing module (403);

The magnetic field thing ring passage numeral preprocessed signal of channel amplitude inconsistency calibration module (404) to obtaining, the amplitude of north and south, magnetic field ring passage numeral preprocessed signal and electric field passage numeral preprocessed signal is carried out the Inconsistency compensation processing, obtain digital signal and magnetic field binary channels amplitude inconsistency coefficient after compensation for calibrating errors, and the magnetic field thing ring channel digital signal after compensation for calibrating errors and north and south, magnetic field ring channel digital signal are dodged to thunder and lightning signal detection module (405) with offering, simultaneously by the magnetic field thing ring passage numeral preprocessed signal after compensation for calibrating errors, north and south, magnetic field ring passage numeral preprocessed signal and electric field passage numeral preprocessed signal offer signal direction of arrival estimation module (406),

Ground sudden strain of a muscle thunder and lightning signal detection module (405) utilizes magnetic field thing ring passage numeral preprocessed signal and north and south, the magnetic field ring passage numeral preprocessed signal after compensation for calibrating errors to carry out short-time energy calculating, obtain the detection of dynamic thresholding Mobile state over-threshold detection of going forward side by side, and testing result is offered to signal direction of arrival estimation module (406);

The signal that signal direction of arrival estimation module (406) utilization receives carries out arctangent computation, obtains direction of arrival information, and offers data framing buffer memory and transmission control module (407);

Data framing buffer memory and transmission control module (407) are by direction of arrival information, together with corresponding electric field passage numeral preprocessed signal and temporal information, and magnetic field binary channels amplitude inconsistency coefficient, dynamic monitoring threshold information carry out framing, local cache, then upload to survey and process substation embedded controller (105);

Time mark module (401) receives from temporal frequency unit (101) output 1PPS pulse and UTC information, and above-mentioned detecting dodged to lightening pulse signal data segment mark temporal information with comprising; Time mark module (401) also receives the synchronous clock information from temporal frequency unit (101) output, for surveying other modules of processing substation digital processing subsystem, provides clock signal.

8. a kind of VLF/LF frequency range according to claim 7 ground dodges the lightening detection positioning system, it is characterized in that, channel amplitude inconsistency calibration module (404) comprises amplitude inconsistency coefficients calculation block and channel amplitude Inconsistency compensation module;

Amplitude inconsistency coefficients calculation block is used for calculating magnetic field binary channels amplitude inconsistency factor alpha:

$\mathrm{\α}=\sqrt{\frac{P_{\mathrm{nEW}}}{P_{\mathrm{nNS}}}}=\sqrt{\frac{\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{x}_{\mathrm{EW}}^2\left(n\right)}{\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{x}_{\mathrm{NS}}^2\left(n\right)}}$

Wherein, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200; x _eW(n), x _nS(n)) be respectively in a sampled data piece, through the magnetic field of pretreated n the sampled point of numeral thing ring channel signal and north and south, magnetic field ring channel signal; P _nEWand P _nNSbe respectively the short-time energy of magnetic field thing ring channel signal and north and south, magnetic field ring channel signal in a sampled data piece;

Channel amplitude Inconsistency compensation module is carried out Inconsistency compensation for the amplitude of the three railway digital signals to digital pretreatment module output

$\left\{\begin{array}{c}{y}_{\mathrm{EW}}\left(n\right)=1\·x_{\mathrm{EW}}\left(n\right)\\ y_{\mathrm{NS}}\left(n\right)=\mathrm{\α}\·x_{\mathrm{EW}}\left(n\right)\\ y_{\mathrm{EF}}\left(N\right)=1\·x_{\mathrm{EF}}\left(n\right)\end{array}\right.$

Wherein, y _eW(n) be the digital signal of magnetic field thing ring channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is 1; y _nS(n) be the digital signal of north and south, magnetic field ring channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is α, y _eF(n) be the digital signal of electric field channel signal after the amplitude Inconsistency compensation, its Amplitude Compensation coefficient is 1; x _eWand x (n) _nS(n) channel signal, x are encircled in the pretreated magnetic field of representative digit thing ring channel signal and north and south, magnetic field respectively _eF(n) the pretreated electric field channel signal of representative digit.

9. a kind of VLF/LF frequency range according to claim 7 ground dodges the lightening detection positioning system, it is characterized in that, ground dodges thunder and lightning signal detection module (405) and comprises state switching controls module, background noise energy computing module, short-time energy computing module and dynamic over-threshold detection module;

State switching controls module is calculated according to default background noise energy and normal sampling time of reception ratio, between the calculating of background noise energy and normal sampling accepting state, carries out periodic switching controls;

Background noise energy computing module is for during background noise energy computing mode, to the digital signal y after compensation for calibrating errors _eW(n), y _nS(n) carry out according to the following equation the short-time energy statistical computation

$E_{\mathrm{noise}}=\underset{n=0}{\overset{K\×M}{\mathrm{\Σ}}}[y_{\mathrm{EW}}^2\left(n\right)+y_{\mathrm{NS}}^2\left(n\right)]$

Wherein, E _noisefor the background noise energy, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200, and K is positive integer, means that the span of K is [1,1024] for calculating the number of background noise energy sampled data piece used;

The short-time energy computing module is under normal sampling accepting state, to the digital signal y after compensation for calibrating errors _eW(n)), y _nS(n) carry out according to the following equation short-time energy calculating

$E_{\mathrm{sample}}=\underset{n=0}{\overset{M}{\mathrm{\Σ}}}[y_{\mathrm{EW}}^2\left(n\right)+y_{\mathrm{NS}}^2\left(n\right)]$

Wherein, E _samplefor short-time energy, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200;

Dynamically the over-threshold detection module is by the background noise energy value E calculated _noisecarry out relevant treatment with detection threshold signal-to-noise ratio settings value, obtain the dynamic power detection threshold

E _ref＝k*E _noise/K

Wherein, k is detection threshold signal-to-noise ratio settings value, E _reffor the dynamic power detection threshold; By short-time energy E _samplewith detection threshold E _refcompare, work as E _sample>=E _refthe time, judge that this data block dodges the lightening pulse signal with comprising, otherwise do not dodge the lightening pulse signal with comprising;

1PPS pulse and the UTC temporal information of mark temporal information module frequency cells service time (101) output, temporal information on electric field channel signal mark after the corresponding compensation for calibrating errors of data segment that is sudden strain of a muscle lightening pulse by aforementioned detection forms ground and dodges the lightening detection data with comprising.

10. a kind of VLF/LF frequency range according to claim 7 ground dodges the lightening detection positioning system, it is characterized in that, signal direction of arrival estimation module (406) comprises tangent angle computing module, arc tangent angle table look-up module and goes quadrant fuzzy Judgment module;

Tangent angle computing module utilizes following formula to calculate the absolute value information of the tangent value of direction of arrival θ | tan θ |

$\left|\tan \mathrm{\θ}\right|=\frac{\left|\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{y}_{\mathrm{EW}}\left(n\right)\right|}{\left|\underset{n=1}{\overset{M}{\mathrm{\Σ}}}{y}_{\mathrm{NS}}\left(n\right)\right|}$

Wherein, θ is direction of arrival, | tan θ | be the absolute value of its tangent value, M is positive integer, means total sampling number that each sampled data piece comprises, M >=200;

The arc tangent table look-up module is according to obtaining in aforementioned tangent angle computing module | tan θ | carry out the one dimension arc tangent and table look-up, obtain the absolute value of direction of arrival | θ |, wherein independent variable is tangent value, and functional value is angle, and functional value covers 0 °～90 °;

Go in quadrant fuzzy Judgment module, the amplitude cumulative sum value of magnetic field thing ring channel signal, magnetic field north and south ring channel signal and the electric field channel signal of calculating after the amplitude Inconsistency compensation, obtain the positive-negative polarity information of triple channel signal, then according to following rule, gone the quadrant fuzzy Judgment to obtain real direction of arrival result of calculation θ:

Wherein,

for the magnetic field thing ring channel signal amplitude cumulative sum value after the amplitude Inconsistency compensation,

for the ring channel signal amplitude cumulative sum value of the north and south, magnetic field after the amplitude Inconsistency compensation,

for the electric field channel signal amplitude cumulative sum value after the amplitude Inconsistency compensation, M is positive integer, means total sampling number that each sampled data piece comprises, M>=200.

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