CN103149457A - Space electromagnetic intensity distribution analysis method - Google Patents

Abstract

The invention discloses a space electromagnetic intensity distribution analysis method, which comprises the following steps of: 1, determining an observation and test space region according to space electromagnetic intensity analysis requirements, and meshing the region, wherein a test point in subsequent steps can be selected from mesh regions; 2, calculating a relative distance and a relative direction between the point and each piece of equipment according to the position of the test point; 3, calculating a time-domain signal of the test point according to a formula for a composite signal by utilizing calculation results obtained by the step 2; 4, performing Fourier transform on the time-domain composite signal obtained by the step 3 to obtain the frequency-domain energy distribution of the space composite signal at the test point; and 5, repeating the steps 2 to 4 for the whole observation and test region to obtain the composite electromagnetic radiation intensity data of a space radiation source of the observation and test region. According to the method, the distribution of the space electromagnetic intensity can be analyzed more accurately and efficiently.

Description

Space electromagnetism intensity distributional analysis method

Technical field

The invention belongs to space electromagnetic environment monitoring and Electromagnetic Situation perception field, space, specifically, relate to a kind of space electromagnetism intensity distributional analysis method.

Background technology

Under Information Condition, electromagnetic environment has unprecedented complicacy, the difficult property surveyed.Electromagnetic environment is invisible, can't direct feel, and analyze it and consist of with feature most important for the understanding electromagnetic environment.The key element that consists of electromagnetic environment is a lot, but artificial electromagnetic activity is most active factor.Taking " four territories " describing method of spatial domain, time domain, frequency domain and energy gap in the electromagnetism science, delineate out the morphological feature of electromagnetic environment, is a kind of effectively research method.

Space electromagnetism distribution monitoring is for civil aviaton's aircraft and lay special stress on protecting electronic equipment and how to avoid strong electromagnetic etc., and how various aircraft to avoid strong electromagnetic in motion process, so that inherently safe arrives at the destination etc.

The present relevant space electromagnetism intensity analytical approach that exists is mainly used in civilian electromagnetic radiation intensity and detects, and some power that is used for electronic countermeasure synthesizes, and still for the electromagnetism distributional analysis in target spatial domain, yet there are no effective monitoring and analytical approach.

Summary of the invention

In order to solve the problems of the technologies described above, the invention provides a kind of space electromagnetism intensity distributional analysis method, the analysis that the space electromagnetism is distributed is more accurate, efficient.Its technical scheme is as follows:

A kind of space electromagnetism intensity distributional analysis method comprises following steps:

1) analyze requirement according to the space electromagnetism intensity, determine the observation test area of space, and grid is carried out in the zone divide.Wherein the test point in subsequent step can be selected in the net region of dividing, as the grid element center location point etc.;

2) according to the position of test point, calculate relative distance and relative orientation between this point and each equipment, utilize relative distance to calculate the transmission attenuation coefficient of signal, utilize relative orientation calculated direction figure weighted value;

$R_{\mathrm{ci}}=\sqrt{{(x_{\mathrm{ci}}-x)}^2+{(y_{\mathrm{ci}}-y)}^2+{(z_{\mathrm{ci}}-z)}^2}$

$R_{\mathrm{ri}}=\sqrt{{(x_{\mathrm{ri}}-x)}^2+{(y_{\mathrm{ri}}-y)}^2+{(z_{\mathrm{ri}}-z)}^2}$

$R_{\mathrm{ji}}=\sqrt{{(x_{\mathrm{ji}}-x)}^2+{(y_{\mathrm{ji}}-y)}^2+{(z_{\mathrm{ji}}-z)}^2}$

Subscript c wherein, r, j represent respectively communication transmitter, radar transmitter, jamming transmitter, other not clear and definite emissive source can be referred in above-mentioned three kinds of radiation sources according to its attribute.

According to each transmitter coordinate and attitude, can try to achieve observation station with respect to position angle and the pitching angle theta of each transmitter by coordinate transform _ci, θ _ri, θ _ji,

With

Then contrast its directional diagram information and can obtain the directional diagram weighted value P that observation station receives each transmitter signal _ci, P _riAnd P _ji,

Find the solution when sky propagate after, the centre frequency f that the observation station place respectively transmits _0iStack Doppler frequency f _diAfter the observation signal center frequency value:

f _i=f _0i+f _di

3) utilize step 2) result of calculation, calculate the time-domain signal of test point according to the formula of composite signal;

For observation station receives the directional diagram weighted value of i communication transmitter signal and the ratio that i communication transmitter arrives the distance of observation station, represent that i communication transmitter signal on the impact of observation station electromagnetic radiation intensity, in like manner can get

With

Be i communication transmitter to the distance of observation station and the ratio of the light velocity, namely the transmission delay between observation station observation signal and i communication transmitter, in like manner can get

With

Therefore the composite signal that space test point P=(x, y, z) is located is:

$S(P,t)=\underset{i=1}{\overset{M_c}{\mathrm{\Σ}}}\frac{P_{\mathrm{ci}}}{R_{\mathrm{ci}}}{S}_c(i,t-\frac{R_{\mathrm{ci}}}{c},f_{\mathrm{ci}})+\underset{R_{\mathrm{ri}}}{\overset{M_r}{\mathrm{\Σ}}}\frac{P_{\mathrm{ri}}}{R_{\mathrm{ri}}}{S}_r(i,t-\frac{R_{\mathrm{ri}}}{c},f_{\mathrm{ri}})+\underset{i=1}{\overset{M_j}{\mathrm{\Σ}}}\frac{P_{\mathrm{ji}}}{R_{\mathrm{ji}}}{S}_j(i,t-\frac{R_{\mathrm{ji}}}{c},f_{\mathrm{ji}})$ ；

4) the 3rd step is calculated the time domain composite signal that obtains and carry out Fourier transform (FFT), can obtain the frequency domain energy distribution of test point place space composite signal;

FFT(S(P，t))

5) to whole observation area repeating step 2) to step 4), can obtain the synthetic electromagnetic radiation intensity data in space radiation source in observation test zone.

Beneficial effect of the present invention: a kind of space electromagnetism intensity distributional analysis method provided by the invention, problem analysis for the distribution of space electromagnetism, a kind of new analytical model and implementation method have been provided, for resisting, the attacking and defending both sides of electronic warfare implement and countermeasure effectiveness is provided by analysis and the test method that provides near the actual electromagnetic environment, power in electronic countermeasure is synthetic also not just for the electromagnetism intensity in target spatial domain, and the while also distributes for the electromagnetism of designated flying zone.

Description of drawings

Fig. 1 is space electromagnetism intensity distributional analysis method realization flow figure of the present invention;

Fig. 2 is spacing electromagnetic radiation intensive analysis geometric representation.

Embodiment

Below in conjunction with the drawings and specific embodiments, technical scheme of the present invention is described in more detail.

As shown in Figure 1, a kind of space electromagnetism intensity distributional analysis method comprises the following steps:

1) analyze requirement according to the space electromagnetism intensity, determine the observation test area of space, and grid is carried out in the zone divide, wherein the test point in subsequent step can be selected in the net region of dividing, as the grid element center location point etc.

2) determine the radiation sources such as radar transmitter, communication transmitter and jamming transmitter quantity, type, emissive power, transmission frequency, transmit, the data such as speed and directional diagram:

At first the space radiation source is sorted out.Usually the space radiation source roughly can be classified as three classes according to its radiation characteristic: communication transmitter, radar transmitter and jamming transmitter.The commercial communication signal transmitting tower can be classified as communication transmitter etc. such as us.

M is arranged in hypothesis space _cIndividual communication facilities, wherein the position vector of each communication facilities is P _c(i)=[x _ci, y _ci, z _ci] ^T, transmitting is S _c(i, t), wherein i represents the sequence number of communication facilities, and i=1 ..., M _rIn same space, M is arranged _rIndividual radar equipment, wherein the position vector of each radar equipment is P _r(i)=[x _ri, y _ri, z _ri] ^T, transmitting is S _r(i, t), wherein i represents the sequence number of radar equipment, and i=1 ..., M _rIn same space, M is arranged _jIndividual jamming equipment, wherein the position vector of each jamming equipment is P _j(i)=[x _ji, y _ji, z _ji] ^T, transmitting is S _j(i, t), wherein i represents the sequence number of jamming equipment, and i=1 ..., M _j

If the position of electromagnetic radiation intensity observation test point is P=(x, y, z).

3) determine above-mentioned data after, calculate test point to each transmitter distance (R _ci, R _riAnd R _ji), test point receives the directional diagram weighted value (P of each transmitter signal _ci, P _riAnd P _ji) and the Doppler frequency f of the relative observation station of each transmitter _dEtc. data:

Step 3) can be specially following operation:

A) calculate test point and arrive each transmitter distance:

$R_{\mathrm{ci}}=\sqrt{{(x_{\mathrm{ci}}-x)}^2+{(y_{\mathrm{ci}}-y)}^2+{(z_{\mathrm{ci}}-z)}^2}---\left(1\right)$

Wherein: (x _ci, y _ci, z _ci) be the position coordinates of i communication transmitter, (x, y, z) is observation station position coordinates, R _ciBe that i communication transmitter is to the Euclidean distance of observation station.

In like manner have:

$R_{\mathrm{ri}}=\sqrt{{(x_{\mathrm{ri}}-x)}^2+{(y_{\mathrm{ri}}-y)}^2+{(z_{\mathrm{ri}}-z)}^2}---\left(2\right)$

$R_{\mathrm{ji}}=\sqrt{{(x_{\mathrm{ji}}-x)}^2+{(y_{\mathrm{ji}}-y)}^2+{(z_{\mathrm{ji}}-z)}^2}---\left(3\right)$

Wherein: (x _ri, y _ri, z _ri) be the position coordinates of i radar transmitter, (x _ji, y _ji, z _ji) be the position coordinates of i jamming transmitter, (x, y, z) is observation station position coordinates, R _riAnd R _jiBe respectively i radar transmitter and i jamming transmitter to the Euclidean distance of observation station.

B) calculate test point position angle and the angle of pitch of each transmitter relatively, draw the directional diagram weighted value that receives signal:

If antenna array installation parallel with bearer plane, carrier heading are position angle 0 degree direction, departing from head to right flank is forward; Bearer plane is the angle of pitch 0 degree direction, is forward below carrier.

As shown in Figure 2, O-XYZ is the carrier geographic coordinate system at some O place.The coordinate of observation station is (x, y, z), coordinate (the x of observation station in take i communication transmitter as the carrier geographic coordinate system of initial point _oci, y _oci, z _oci) be:

$\left(\begin{array}{c}{x}_{\mathrm{oci}}\\ y_{\mathrm{oci}}\\ z_{\mathrm{oci}}\end{array}\right)=\left(\begin{array}{c}x\\ y\\ z\end{array}\right)-\left(\begin{array}{c}{x}_{\mathrm{ci}}\\ y_{\mathrm{ci}}\\ z_{\mathrm{ci}}\end{array}\right)---\left(4\right)$

Consider the attitude of carrier impact, can solve the coordinate of observation station in the carrier coordinate system that i communication transmitter is initial point according to the coordinate transform relation is (x _bci, y _bci, z _bci).

Observation station can be tried to achieve according to the coordinate transform relation with respect to the position angle of i communication transmitter and the angle of pitch and is respectively θ _ciWith

Directional diagram and θ according to i communication transmitter _ciWith

Comparison draws the directional diagram weighted value P that observation station is accepted i communication transmitter signal _ciIn like manner can try to achieve P _riAnd P _ji

C) the Doppler frequency f of the relative observation station of each transmitter _d

At first calculating the projection speed v of each transmitter velocity of displacement on transmitter and observation station line, for just, is negative when deviating from observation station when projection speed is pointed to observation station.

Calculate formula according to Doppler frequency, substitution relative velocity v easily tries to achieve Doppler frequency f _d

4) calculate the time-domain signal of test point according to the formula of composite signal:

The Doppler frequency f that first brings with the relative observation station motion of each transmitter of trying to achieve _dCentre frequency f to each transmitter signal S self ₀Revise.Observation station receives the frequency f of i communication transmitter signal _ciFor:

f _ci=f _0ci+f _dci (5)

In like manner try to achieve f _riAnd f _ji

For observation station receives the directional diagram weighted value of i communication transmitter signal and the ratio that i communication transmitter arrives the distance of observation station, represent that namely i communication transmitter signal is on the impact of observation station electromagnetic radiation intensity.

In like manner,

Be i radar transmitter signal on the impact of observation station electromagnetic radiation intensity,

Be that i jamming transmitter is on the impact of observation station electromagnetic radiation intensity.

Be i communication transmitter to the distance of observation station and the ratio of the light velocity, i.e. transmission delay between observation station observation signal and i communication transmitter.

In like manner,

Be the transmission delay between observation station observation signal and i radar transmitter,

Be the transmission delay between observation station observation signal and i jamming transmitter.

Utilize the geometric relationship of each radiation source and test point and top required data can try to achieve the composite signal of locating in space test point P=(x, y, z) to be:

$S(P,t)=\underset{i=1}{\overset{M_c}{\mathrm{\Σ}}}\frac{P_{\mathrm{ci}}}{R_{\mathrm{ci}}}{S}_c(i,t-\frac{R_{\mathrm{ci}}}{c},f_{\mathrm{ci}})+\underset{i=1}{\overset{M_r}{\mathrm{\Σ}}}\frac{P_{\mathrm{ri}}}{R_{\mathrm{ri}}}{S}_r(i,t-\frac{R_{\mathrm{ri}}}{c},f_{\mathrm{ri}})+\underset{i=1}{\overset{M_j}{\mathrm{\Σ}}}\frac{P_{\mathrm{ji}}}{R_{\mathrm{ji}}}{S}_j(i,t-\frac{R_{\mathrm{ji}}}{c},f_{\mathrm{ji}})---\left(6\right)$

5) step 4) is calculated the time domain composite signal that obtains and carries out Fourier transform (FFT), and above step is repeated in whole observation area, can obtain the synthetic electromagnetic radiation intensity data in space radiation source in observation test zone:

S (P, t) is carried out Fourier transform, can obtain the frequency domain data of the reception signal at Space View measuring point P place.Each point in the test analysis space is carried out aforesaid operations successively can realize analysis to given spacing electromagnetic radiation intensity.

The above is only best mode for carrying out the invention, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses, and the simple change of the technical scheme that can obtain apparently or equivalence are replaced and all fallen within the scope of protection of the present invention.

Claims (1)

1. a space electromagnetism intensity distributional analysis method, is characterized in that, comprises following steps:

1) analyze requirement according to the space electromagnetism intensity, determine the observation test area of space, and grid is carried out in the zone divide, wherein the test point in subsequent step can be selected in the net region of dividing;

2) according to the position of test point, calculate relative distance and relative orientation between this point and each equipment,

Utilize relative distance to calculate the transmission attenuation coefficient of signal, utilize relative orientation calculated direction figure weighted value;

$R_{\mathrm{ci}}=\sqrt{{(x_{\mathrm{ci}}-x)}^2+{(y_{\mathrm{ci}}-y)}^2+{(z_{\mathrm{ci}}-z)}^2}$

$R_{\mathrm{ri}}=\sqrt{{(x_{\mathrm{ri}}-x)}^2+{(y_{\mathrm{ri}}-y)}^2+{(z_{\mathrm{ri}}-z)}^2}$

$R_{\mathrm{ji}}=\sqrt{{(x_{\mathrm{ji}}-x)}^2+{(y_{\mathrm{ji}}-y)}^2+{(z_{\mathrm{ji}}-z)}^2}$

According to each transmitter coordinate and attitude, can try to achieve observation station with respect to position angle and the pitching angle theta of each transmitter by coordinate transform _ci, θ _ri, θ _ji,

With

Then contrast its directional diagram information and can obtain the directional diagram weighted value P that observation station is accepted each transmitter signal _ci, P _riAnd P _ji,

Find the solution the Doppler frequency of the relative observation station of each transmitter:

f _i=f _0i+f _di

3) utilize step 2) result of calculation, calculate the time-domain signal of test point according to the formula of composite signal;

For observation station receives the directional diagram weighted value of i communication transmitter signal and the ratio that i communication transmitter arrives the distance of observation station, represent that i communication transmitter signal on the impact of observation station electromagnetic radiation intensity, in like manner can get

With

Be i communication transmitter to the distance of observation station and the ratio of the light velocity, namely the transmission delay between observation station observation signal and i communication transmitter, in like manner can get

With

Therefore the composite signal that space test point P=(x, y, z) is located is:

$S(P,t)=\underset{i=1}{\overset{M_c}{\mathrm{\Σ}}}\frac{P_{\mathrm{ci}}}{R_{\mathrm{ci}}}{S}_c(i,t-\frac{R_{\mathrm{ci}}}{c},f_{\mathrm{ci}})+\underset{i=1}{\overset{M_r}{\mathrm{\Σ}}}\frac{P_{\mathrm{ri}}}{R_{\mathrm{ri}}}{S}_r(i,t-\frac{R_{\mathrm{ri}}}{c},f_{\mathrm{ri}})+\underset{i=1}{\overset{M_j}{\mathrm{\Σ}}}\frac{P_{\mathrm{ji}}}{R_{\mathrm{ji}}}{S}_j(i,t-\frac{R_{\mathrm{ji}}}{c},f_{\mathrm{ji}});$

4) the 3rd step was calculated the time domain composite signal that obtains and carry out Fourier transform (FFT), can obtain

The frequency domain energy distribution of test point place space composite signal;

FFT(S(P，t))

5) to whole observation area repeating step 2) to step 4), can obtain the synthetic electromagnetic radiation intensity data in space radiation source in observation test zone.

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