CN106324325A - Methods for remote sensing on initial continuous current of artificially triggered lightning applying low-frequency magnetic field antenna - Google Patents

Abstract

The invention discloses a methods for remote sensing on initial continuous current of artificially triggered lightning applying low-frequency magnetic field antenna. By applying the responsing frequecy characteristics of low-frequency magnetic field antenna outside the effective detected frequency band, adopt numerical integration method to process mathematically the waveform of magnetic field obtained near channel of artificially triggered lightning, which can effectively remove the influence of noise signal in measuring process and obtain the characteristic discharging process in experiment of artificially trigered lightning, namely the high time solution waveform of initial continuous current. The manufacturing and erection of low-frequency magnetic field antenna is relatively easy and with low cost, whose parameters such as gain can be adjusted based on different experimental requirements, with strong practibility; besides, the result of artificially triggered lightning of inversion demonstrates high signal-to-noise ratio, which means during the experiment, the sensor doesn't need to be deployed on current path, and under situations when no lightning current such as natural lightning can be directly measured, this inversion method can help obtain the time-varying waveform in process of continuous discharging.

Description

The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning

Technical field

The invention belongs to artificially triggered lightning discharge process field of measuring technique, particularly relate to one and utilize low frequency magnetic field antenna distant The initial continuous current of sensed quantity artificially triggered lightning (and high constructure initiation lightning) and closely remote sensing survey Return stroke of ground flash connect The method of continuous electric current.

Background technology

Artificially triggered lightning is the important technical of research Lightning Process physical mechanism.By pulling tinsel from ground launch Mouse, ground zero potential can be incorporated in the high electric field environment at the bottom of thunder cloud, thus form lasting discharge process, Ultimately form lightning.As the lightning measurement means that a kind of controllability is higher, the method has been used for studying in lightning discharge Physical process (the particularly feature description of ground connection process) and the experimental verification of lightning guard technology.Observation with natural lightning Compare, artificially triggered lightning experiment a big advantage be conducting lightning currents import ground passage be known, therefore can by design Place observation experiment measures conducting lightning currents waveform.Since 20 research team of century 70 France development artificially triggered lightning technology, Current measurement is always one of research contents important in experimentation.Real at the artificially channel braided carried out all over the world at present In testing, typically by coaxial shunt is connected on conducting lightning currents from drainage bar be connected to ground discharge path realize lightning Directly measuring of electric current, and by realizing conducting lightning currents is carried out to the measurement of the electromagnetic intensity on Pearson coil Indirectly inverting.The conducting lightning currents result that two kinds of methods obtain is basically identical, is therefore generally mated use for measuring not homotype Enclose interior channel bottom current intensity.Above two traditional measurement method is required to measurement equipment is placed in known lightning in advance Electric current enters ground channel circumference, it is impossible to measure, in the range of certain distance, the conducting lightning currents flowing through unknown discharge channel.People Work is drawn channel bottom in thunder experiment and recorded lightning different stages of development or electric current corresponding to various process.Due to manually Draw conducting lightning currents in thunder experimental design and measure the range of equipment the most greatly (such as 40kA and 2kA two kinds setting) so that measure and set Standby resolution is less, and the initial continuous current stage is generally attended by the weak current process of order of amps, surveys in conventional current In amount result, these weak currents are superimposed with measuring noise, are therefore difficult to identify that in initial continuous current, amplitude is relatively exactly Weak part, such as, measured a bigger M component of amplitude, but M component that before and after it, several amplitudes are less then and Noise is superimposed, and is difficult to identify.Therefore, equipment continuous current initial to lightning lack of resolution is measured for conducting lightning currents Problem, need development on the basis of existing channel bottom current measurement means to have the detection method of higher sensitivity.

In sum, in existing channel bottom current measuring method, sensor need to be placed on the office on conducting lightning currents path Sex-limited and not enough to lightning weak current resolution capability, it is impossible to realize exactly initial continuous current minutia is reconstructed.

Summary of the invention

It is an object of the invention to provide one and utilize the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning Method, it is intended to solve sensor in existing channel bottom current measuring method and need to be placed on the limitation on conducting lightning currents path Property, and not enough to lightning weak current resolution capability, it is impossible to realize exactly initial continuous current minutia reconstruct is asked Topic.

In order to solve above-mentioned technical problem, the present invention relates to one and utilize at the beginning of low frequency magnetic field antenna remote sensing survey artificially triggered lightning The method of beginning continuous current, described method utilizes low frequency magnetic field antenna frequency-response characteristic outside effectively detection band limits, Now actual measure is rate of change of magnetic (dB/dt) signal to magnetic field antenna, and the method that this signal uses numerical integration can To obtain true field (B) signal, the white noise being simultaneously superimposed upon on effective magnetic field signal mutually supports during numerical integration Disappear so that the Signal-to-Noise after Mathematical treatment is the highest.Nearer in view of observation station distance artificially triggered lightning lightning channel (78m), the field signal now measured is mainly induction field, and has coefficient between magnetic field induction field and electric current and close System, therefore obtains this coefficient by field calibration and i.e. can be used for characteristic discharge process during inverting artificially triggered lightning is tested, the most initially The high time resolution waveform of continuous current.

Further, described low frequency magnetic field antenna includes:

Magnetic Sensor, uses close around plain conductor coil, and coaxial metal lead loop is close to be wound on a relative permeability and exist 10²On the soft magnetic materials bar magnet of magnitude, Magnetic Sensor is encapsulated in high-strength PVC plasticity sleeve pipe, uses T-shaped connection pipe fitting to combine Be orthogonal sensor；Densely packed coil is equivalent to by the circuit of resistance R, electric capacity C and inductance L composition；

Magnetic Sensor is connected with signal processing circuit, and signal processing circuit includes copped wave resistance, a two-stage amplifying circuit With a high pass filter；Wherein copped wave resistance makes this magnetic field measurement system bandwidth adjustable；Two-stage amplifying circuit makes to measure system System adjustable gain；High pass filter is used for filtering industrial frequency noise；

Magnetic Sensor and signal processing circuit board are encapsulated in composition magnetic field antenna outdoor section in unmasked box, and to shielding Box does water-proofing treatment.

Further, described low frequency magnetic field antenna three dB bandwidth is 6kHz-340kHz, surveys at this frequency band internal magnetic field sensor Amount is magnetic field B signal；Less than in the frequency of 6kHz, magnetic field antenna is actual, and measure is rate of change of magnetic dB/dt signal.

Further, the magnetic field B that described magnetic field antenna measures includes induction field B_iWith measurement white noise B_n, meet in magnetostatics Biot-Savart law:

$B\left(t\right)=\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{dB}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′}=\mathrm{\α}\·h\left(t\right)\·I\left(t\right);$

Wherein h (t) is the lightning channel length of time t, and h (t) processes as constant, and α is proportionality coefficient undetermined；Owing to surveying Amount white noise B_nCancel out each other in numerical integration computing, make β=α h (t), then formula is rewritable is from closely magnetic signal The relational expression of acquisition channel bottom current waveform:

$I\left(t\right)=\mathrm{\β}\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{{\mathrm{dB}}_i}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′};$

Constant beta is obtained by field calibration.

The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning that the present invention provides, Ke Yike Take channel bottom and measure the equipment problem to lightning weak current resolution capability deficiency, can relatively accurately realize initial continuous The reconstruct of electric current.The present invention, based on measuring the wide-band magnetic field that artificially triggered lightning lightning channel is closely located, obtains a kind of initial The inversion method of continuous current waveform, traditional channel bottom current measurement is by using coaxial shunt or Pearson Coil realizes, and is the standard method in artificially triggered lightning and high constructure initiation lightning research, and measures phase with conventional current Ratio, the low frequency magnetic field antenna that in the present invention, the method for remote-sensing inversion electric current is used makes and sets up relatively easy, and cost is relatively low (cost of manufacture of front end sensors is about 10 yuan, and rear end amplifying circuit cost is less than 100 yuan), and can want according to experiment The parameters such as the different adjustment magnetic field antenna gain asked, operability is higher.The more important thing is, at the beginning of being obtained by the method inverting Beginning continuous current result to-noise ratio is the highest, and the supplementary means can measured as artificially triggered lightning experiment conducting lightning currents, even all In the case of not having conducting lightning currents measured directly such as natural lightning etc., conducting lightning currents can be obtained by this inversion method and extremely may be used The result leaned on.

The present invention non-classical formula artificially triggered lightning (the most so-called draw thunder in the air): draw in thunder test in this form, rocket The steel wire of towing connects with big earthed conductor with nylon wire (or cotton thread), and therefore lightning grounding passage has randomness, therefore traditional Current metering sensor cannot measure current waveform.In this case, the remote sensing technique of the present invention can effectively obtain and draw ray process In initial continuous current time-varying waveform that may be present.High constructure causes lightning: high constructure typically connects because of its lightning protection demand Ground, the wire that during therefore high constructure is similar to artificially triggered lightning, rocket tows, earth conductor can be incorporated into thunder cloud equally High electric field region.Owing to the design of high constructure is the most complex, therefore measure the electricity hitting high constructure inflow surface Flow relatively difficult.The remote sensing technique of the present invention will effectively solve this difficult problem, contribute to obtaining distance magnetic field sensor one spacing In the range of from, high constructure causes the continuous current time-varying waveform that lightning may cause.Continuous current mistake present in Return stroke of ground flash Journey: Return stroke of ground flash course location is difficult to prediction, the time-varying waveform of continuous current in therefore cannot dodging with directly measuring.The present invention's Remote sensing technique need not place a sensor on current channel, in the range of therefore can obtaining distance magnetic field sensor certain distance The continuous current time-varying waveform that natural lightning causes.

Accompanying drawing explanation

Fig. 1 be the embodiment of the present invention provide current measuring method use low frequency magnetic field sensor construction figure (antenna is adopted It is wound around soft magnetism rod with bare copper wire to make).

Fig. 2 is the operation principle signal of current measuring method the used low frequency magnetic field sensor that the embodiment of the present invention provides Figure.

Fig. 3 is that the vertical conducting lightning currents of the certain time yardstick that the embodiment of the present invention provides produces at 78 meters of horizontal ranges Magnetic field (have chosen the lightning channel of five differing heights) schematic diagram.

Fig. 4 is the frequency response curve of the low frequency magnetic field sensor that the embodiment of the present invention provides.

Fig. 5 is an artificially triggered lightning measurement result schematic diagram in 23 days Augusts in 2014 that the embodiment of the present invention provides；

In figure: the measured waveform (horizontal direction passage) of low frequency magnetic field antenna at (a) 78 meters；Low frequency magnetic field at (b) 78 meters The measured waveform (vertical direction passage) of antenna；C initial continuous current waveform that () is obtained by numerical integration and same passage thereof The comparison of bottom measurement result.

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearer, below in conjunction with embodiment, to the present invention It is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not used to Limit the present invention.

The method bag using the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning that the embodiment of the present invention provides Include following steps:

Step 1, making Magnetic Sensor.Use the close scheme around plain conductor coil, in order to improve described Magnetic Sensor Sensitivity, can by increase coil radius and increase wire circle realize, but such that magnetic field antenna size relatively Greatly, not meeting portable basic demand, and wire circle is the most, coil self-resistance is the biggest, and the thermal noise that wire introduces is also The strongest, therefore the present invention is wound on relative permeability by close for coaxial metal lead loop higher (Effective permeability is 10²Amount Level) soft magnetic materials bar magnet on, not only increase the sensitivity of Magnetic Sensor, controlled in rational size range simultaneously (length 20cm, diameter 1cm), it is contemplated that soft magnet material is the most fragile, easy fracture, the Magnetic Sensor will made in the present invention It is encapsulated in high-strength PVC plasticity sleeve pipe (containing casing diameter about 1.8cm), and uses T-shaped connection pipe fitting to be combined into orthogonal sensing Device, it is ensured that it uses intensity and portability, as shown in Figure 1.

Step 2, modulated signal.Densely packed coil can be equivalent to by the circuit of resistance R, electric capacity C and inductance L composition, and by The magnetic field antenna of coil composition has certain specific resonant frequency, and this is determined by its intrinsic attribute, and its computing formula isWhen signal frequency increases to resonant frequency, Magnetic Sensor is the strongest, and signal frequency continues During increase, owing to the induction reactance of coil increases, thus equiva lent impedance increase makes signal pass through Magnetic Sensor phase should die down.This Bright Magnetic Sensor is connected in order to modulated signal with signal processing circuit, described signal processing circuit mainly include copped wave resistance, One two-stage amplifying circuit and a high pass filter, wherein copped wave resistance can make this magnetic field measurement system bandwidth adjustable, and two It is adjustable that level amplifying circuit enables to measure system gain, and high pass filter is used for filtering industrial frequency noise, circuit design structure figure As shown in Figure 2.

Step 3, system calibrating.After magnetic field antenna and circuit production thereof complete, need whole system is carried out at laboratory Strict demarcation, its ultimate principle is to be produced the signal of a fixed frequency by signal generator, and this signal has transmitted to one Know the big hollow magnetic field coil of parameter, and then be calculated its internal magnetic field intensity, little magnetic field antenna to be calibrated is put Enter inside it, realize the demarcation of signal under this fixed frequency by reading oscillographic signal, change signal generator afterwards Frequency repeat this calibration process until completing the signal scaling to whole required frequency range.By repeatedly testing, the present invention is final Achieve a set of working frequency range and contain the magnetic field antenna of low-frequency range: its three dB bandwidth is 6kHz-340kHz, magnetic in this frequency band What field sensor was measured is magnetic field (B) signal；Less than in the frequency of 6kHz, magnetic field antenna is actual, and measure is changes of magnetic field Rate (dB/dt) signal, the frequency width curve demarcated is as shown in Figure 3.

Step 4, system encapsulate.Magnetic field antenna is formed in Magnetic Sensor and signal processing circuit board are encapsulated in unmasked box Outdoor section, and described shielding box is done water-proofing treatment.

In view of lightning, there is space-time randomness, its radiation produce field signal direction uncertain, therefore this Two orthogonal magnetic field antennas of bright middle employing receive signal, and circuit board uses the dual pathways simultaneously, and by antenna and circuit board package It is positioned over outdoor in unmasked box,

Step 5, inner and outer system joint debugging.By shielding coaxial cable, magnetic field antenna outdoor section is adopted with control room internal magnetic field Collecting system is connected, and whole system realizes the high accuracy time service of submicrosecond magnitude, described GPS time service device by GPS time service device Its antenna is placed in outdoor.

Step 6, data analysis.In artificially triggered lightning is tested, the data obtained by above-mentioned low frequency magnetic field antenna be can be used to The initial continuous current of inverting.

Below in conjunction with specific embodiment, the application effect of the present invention is explained in detail.

In the Shandong Zhanhua lightning observation experiment in summer in 2014, utilize high sensitivity wide-band magnetic field antenna away from drawing thunder The remote sensing survey to artificially triggered lightning current course has been carried out in the distance of point 78 meters.5 artificially triggered lightnings of period are tested by analysis INTEGRATED SIGHT data, find magnetic remote sensing technique initial continuous current distinctive in artificially triggered lightning is had good efficiency of inverse process. By 78 meters of magnetic measurement signal apart from upper acquisition being integrated process, it is possible to effectively remove and measure effect of noise, from And inverting obtains the low noise time-varying waveform of initial continuous current.The method is to obtain the initial electricity continuously that high-altitude is drawn in thunder test Stream waveform provides a kind of new method, simultaneously can be used for the time-varying waveform of continuous current in closely inverting natural lightning.

1, measurement and data

Data used in the present invention obtain in the Shandong artificially triggered lightning experiment in summer in 2014, the lightning of channel bottom Electric current uses the 5m Ω coaxial shunt series connection drainage bar with a width of 0-3.2MHz directly to measure acquisition.Drawing thunder steel wire is preferably It is buckled on drainage bar.Additionally, go back around a Pearson coil (carrying a width of 0.9Hz～1.5MHz) to obtain bottom drainage bar The kiloampere magnitude electric current that the process such as must fight back causes.Magnetic field at 78 meters is by intersecting magnetic coil measurement.According in laboratory Calibration result, the three dB bandwidth of Magnetic Sensor is 6kHz to 340kHz.Less than in the frequency of 6kHz, the gain of Magnetic Sensor Increase (this intrinsic attribute depending primarily on magnetic coil) along with the increase of frequency, be the initial continuous current introduced of the present invention The closely working frequency range of remote sensing technique.

In artificially triggered lightning is tested, rocket towing metal wire (uses diameter 0.2mm, unit length in SHATLE observes Resistance is the steel wire of 7 Ω/m) rise with the desin speed of 100m/s.Owing to steel wire remains ground state, and more than ground Electromotive force be constantly the least (considering the situation of negative polarity artificially triggered lightning).Therefore, the electric field near rising steel wire terminal reaches During to breakdown threshold, the positive guide of a persistence will be formed and with 2 × 10⁴M/s to 1.8 × 10⁵The speed of m/s upwardly propagates. General after positive guide originates 5-10 millisecond, positive leader channel continues visible on high-speed camera, electric charge transmission the most over the ground Enter the initial continuous current stage.The positive guide of 5 artificially triggered lightnings in 2014 originates height and the initial continuous current stage is visible Passage length (including drawing thunder cable segments) as listed in table 1.The present invention is with artificially triggered lightning of 16:11:06UTC on August 23 Experiment is embodiment, but is not necessarily limited by this embodiment.Due to the sensitivity that used low frequency magnetic field antenna is higher, except August 18 Outside the experiment of day 04:17:18UTC, all there is a certain degree of saturated phenomenon in other horizontal channel magnetic-field measurement drawing thunder for 4 times, And the signal in vertical channel direction is more weak and unsaturation, but the measurement Signal-to-Noise of vertical direction is relatively low.

The table positive guide of artificially triggered lightning in 1 2014 year summer originates channel height time seen from height and lightning channel continuous illumination

2, method and theoretical basis

During the artificially triggered lightning of SHATLE Experimental Base, when lasting upward positive leader occurs in plain conductor head Time, draw thunder rocket and generally have increased to the height of more than 150 meters.By thunder cloud body and week thereof during just guide upwardly propagates Negative charge transport in collarette border is to ground, and corresponding current elements is transmitted downwards along approximately perpendicular thunder lead channels of drawing, its Electromagnetic radiation model as it is shown on figure 3, wherein h be current source original position distance ground height, c be electromagnetic wave in an atmosphere Spread speed (approximation is taken as the light velocity in vacuum, and i.e. 3 × 10⁸M/s), v is the current elements speed along lightning channel travel downward, l Horizontal range (unification takes 78m in discussion of the present invention) for magnetic field antenna with drainage bar.

In the case of surface conductivity is infinitely-great hypothetically, the magnetic field that magnetic field antenna receives can be passed through formula (1) and calculate:

$\begin{array}{c}B\left(t\right)=\frac{1}{2{\mathrm{\π\ϵ}}_0{c}^2}\underset{0}{\overset{H}{\∫}}\left(\frac{\sin \mathrm{\α}\left(z^{\′}\right)}{R^2\left(z^{\′}\right)}i\right(z^{\′},t-\frac{R\left(z^{\′}\right)}{c})\\ +\frac{\sin \mathrm{\α}\left(z^{\′}\right)}{cR\left(z^{\′}\right)}\frac{\∂i(z^{\′},t-R(z^{\′})/c)}{\∂t}){\mathrm{dz}}^{\′}\end{array}---\left(1\right)$

Wherein Section 1 on the right of equation and Section 2 are called the induction field in lightning magnetic field and (are designated as B_i) and spoke Penetrate field component and (be designated as B_r), the value of H is equal to drawing thunder conductor length h.Owing to the initial continuous current of artificially triggered lightning typically lasts for tens To hundreds of millisecond, the initial continuous current change of superposition on it and the full width at half maximum of M component also hundreds of delicate to several millis Second-time, therefore these electric currents comprise more low-frequency component, it is contemplated that electric current spread speed on steel wire is 10⁸M/s number Magnitude, and the horizontal range of magnetic field antenna and drainage bar is only 78m, during so electromagnetic field propagation delay is much smaller than conducting lightning currents Between yardstick.In this case, the initial continuous current stage be can assume that the electric current on passage at any time is all phase With, Charge Source is positioned at the top of thunder cloud internal channel.

As it can be seen from table 1 positive guide originates and is the most substantially distributed between 140～400 meters in artificially triggered lightning experiment, and When initial continuous current initially forms, conductor length is by longer (more than 400 meters).Result of calculation based on line mode shows, When in wire the time scale of electric current and M component quite or longer time, no matter conductor length, the magnetic that current emissions produces Its induction field of field is occupied an leading position all the time, and radiation field is negligible.Additionally, conductor length increases induction field Impact more and more less, when conductor length is more than 400 meters, 78 meters at, the induction field that arrives of measurement is not the most with conductor length Increase and change.

Understanding based on the above results, the magnetic field B that magnetic field antenna measures only has induction field B_i(it is designated as B with measuring white noise_n) group Become, meet the Biot-Savart law in magnetostatics:

$B\left(t\right)=\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{dB}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′}=\mathrm{\α}\·h\left(t\right)\·I\left(t\right)---\left(2\right)$

Wherein h (t) is the lightning channel length of time t, has already described above when initial continuous current is formed, and wire is long Spending the least on the impact in magnetic field, therefore h (t) can process as constant, and α is proportionality coefficient undetermined.White in view of measuring Noise meets relational expressionAnd setting β=α h (t), then formula (2) is rewritable for obtain from closely magnetic signal The relational expression of channel bottom current waveform:

$I\left(t\right)=\mathrm{\β}\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{{\mathrm{dB}}_i}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′}---\left(3\right)$

Wherein the value of constant beta is with the distance dependent bottom Magnetic Sensor to lightning channel.Understand according to formula (3), just The inverting of beginning continuous current can by magnetic field antenna measurement to magnetic field carry out time integral method realize.

3, result

During said method is applied to 5 artificially triggered lightnings that 2014 obtain, all obtain more satisfactory result. The inversion result of the inventive method is introduced below with artificially triggered lightning experiment of 16:11:06UTC on August 23 for embodiment.

Fig. 5 is magnetic-field measurement result at 78 meters of the initial continuous current of described embodiment (horizontally and vertically two The most as shown in figure 5 a and 5b, wherein horizontal direction measurement result signal to noise ratio is higher for the measurement result of individual passage) and electric current survey Amount and inversion result (Fig. 5 c), it is saturated that the horizontal direction field signal that wherein recorded indicates the time period to exist in fig 5 a.As In Fig. 5 c shown in imaginary point line, in utilizing horizontal direction field signal inversion result, although on the saturated time period closely The numerical integration in magnetic field cannot obtain current waveform, but in section At All Other Times, inverting current waveform embodies actual measurement well Most features of current waveform, including the initial electricity continuously that the initial continuous current change procedure of part and some intensity are more weak Stream pulse, owing to signal is saturated, inversion result and measured result there will be certain translation.Make for field signal is saturated The incomplete problem of inversion result become, the surveyed letter of vertical channel and horizontal channel of the available designed magnetic field antenna of the present invention Number proportionate relationship, vertical direction unsaturation field signal is replaced horizontal direction saturation magnetic field signal, reconstructed horizontal passage Field signal, and then inverting obtains the time-varying waveform of initial continuous current, shown in solid in its result such as Fig. 5 c, it can be seen that Electric current inversion result essentially coincides with measured result waveform, and due in magnetic field observation result the white noise of superposition in inverting side Method is cancelled out each other by numerical integration so that the current waveform that inverting obtains is more smooth, it is possible to preferably resolve weak current.

The foregoing is only embodiments of the invention, not in order to limit the present invention, all in the spirit and principles in the present invention Within any amendment, equivalent and the improvement etc. made, should be included within the scope of the present invention.

Claims (4)

1. the method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning, it is characterised in that described The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning utilizes low frequency magnetic field antenna in effectively detection Frequency-response characteristic outside band limits, uses the method for numerical integration to obtain at distance artificially triggered lightning lightning channel closely place Field waveform carry out Mathematical treatment, can effectively remove the impact of noise signal during measurement, it is thus achieved that artificially triggered lightning is tested Middle characteristic discharge process, the high time resolution waveform of i.e. initial continuous current.

The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning the most as claimed in claim 1, its Being characterised by, described low frequency magnetic field antenna includes:

Magnetic Sensor, uses close around plain conductor coil, and coaxial metal lead loop is close is wound on a relative permeability 10²Amount On the soft magnetic materials bar magnet of level, Magnetic Sensor is encapsulated in high-strength PVC plasticity sleeve pipe, uses T-shaped connection pipe fitting to be just combined into Hand over sensor；Densely packed coil is equivalent to by the circuit of resistance R, electric capacity C and inductance L composition；

Magnetic Sensor is connected with signal processing circuit, and signal processing circuit includes copped wave resistance, a two-stage amplifying circuit and Individual high pass filter；Wherein copped wave resistance makes this magnetic field measurement system bandwidth adjustable；Two-stage amplifying circuit makes measurement system increase Benefit is adjustable；High pass filter is used for filtering industrial frequency noise；

Magnetic Sensor and signal processing circuit board are encapsulated in composition magnetic field antenna outdoor section in unmasked box, and do shielding box Water-proofing treatment.

The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning the most as claimed in claim 1, its Being characterised by, described low frequency magnetic field antenna three dB bandwidth is 6kHz-340kHz, at this frequency band internal magnetic field sensor measurement is Magnetic field (B) signal；Less than in the frequency of 6kHz, magnetic field antenna is actual, and measure is rate of change of magnetic (dB/dt) signal.

The method utilizing the low frequency magnetic field antenna initial continuous current of remote sensing survey artificially triggered lightning the most as claimed in claim 3, its Being characterised by, the magnetic field B that described magnetic field antenna measures includes induction field B_iWith measurement white noise B_n, meet the Biot-in magnetostatics Savart law:

$B\left(t\right)=\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{dB}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′}=\mathrm{\α}\·h\left(t\right)\·I\left(t\right);$

Wherein h (t) is the lightning channel length of time t, and h (t) processes as constant, and α is proportionality coefficient undetermined；White owing to measuring Noise B_nCancel out each other in numerical integration computing, make β=α h (t), then formula is rewritable for obtain from closely magnetic signal The relational expression of channel bottom current waveform:

$I\left(t\right)=\mathrm{\β}\underset{t^{\′}=t_0}{\overset{t}{\∫}}\frac{{\mathrm{dB}}_i}{{\mathrm{dt}}^{\′}}{\mathrm{dt}}^{\′};$

Constant beta is obtained by field calibration.