CN102269807A - Realization method of radar anti-jamming technology based on AIS (automatic identification system) information - Google Patents

Abstract

The invention relates to a realization method of radar anti-jamming technology based on AIS (automatic identification system) information. The method comprises the following steps: 1, respectively converting coordinates of position information of a radar observation target and position information relative to the observation target provided by the AIS; 2, computing a membership degree from a radar flight path to an AIS flight path by a fuzzy c-means (FCM) clustering algorithm; 3, judging a target related to the AIS information according to the AIS information of a tracking target obtained in the step 2, namely, the required tracking target; 4, computing a first relevance distance between the AIS information of the tracking target and a radar echo generated by the tracking target, and computing a second relevance distance between the AIS information of the tracking target and a radar echo generated by a high-voltage power transmission line. By combining the AIS information and the radar information, an algorithm for reducing the target exchange by the AIS information is proposed, the simulation experiment shows that the radar cannot lose the tracking target, and the anti-jamming ability of the radar to the 220 KV high-voltage power transmission line is improved.

Description

Implementation method based on the Anti-jamming Technology for Radar of AIS information

Technical field

The present invention relates to the technical field of the anti-ultra-high-tension power transmission line electromagnetic interference (EMI) of marine vessel electronic equipment, specifically is a kind of implementation method of the Anti-jamming Technology for Radar based on AIS information.

Background technology

Generally all be provided with 220KV high-tension cable over strait on the main channel of ocean, ultra-high-tension power transmission line can constantly produce some electromagnetic pulses, to the various wide band frequency electromagnetic waves of aerial radiation as a kind of electromagnetic radiation source when operation.This electromagnetic wave is along the horizontal transmission of transmission line of electricity both sides, the waveforms amplitude and the phase place of the useful signal that the radio receiving equipment in the certain limit along the line received when operate as normal are affected, cause these radio receiving equipments not reach the needed signal to noise ratio (S/N ratio) of operate as normal.Simultaneously, the 220KV high voltage transmission line also can produce reflection to electromagnetic wave, and then disturbs the equipment that generates electromagnetic waves.Particularly modern ships is all got up with advanced electronic equipment and system equipment, comprises radar, outside and intercommunication, data transmission and processing, navigation, remote measurement, undersea detection, various electronic such as location, meteorology under water.So numerous electronic systems is concentrated and is equipped in the narrow space of boats and ships, makes the use density of electronic equipment increase day by day.Laying or the like of the expansion of the increase of crowded frequency spectrum, the antenna that stands in great numbers, launching electrical level, raising, data and the weak signal transmission quantity of receiving sensitivity and the antenna of various hardwares and non-antenna effect, a large amount of bunched cableses provides condition and approach all for the generation of electromagnetic interference (EMI) and propagation.

Radar is the indispensable communication navigation set of modern ships, and radar beam shines object can produce corresponding radar return again.The power of radar return is except the influence of fading that is subjected to sea situation and weather phenomenon, and is also relevant with visual angle, shape, size, surface structure and the composition material of target.Ultra-high-tension power transmission line is the less cylindrical metal conductor in line footpath, and the area of radar beam irradiation is less, and the radar reflection ability is relatively poor, particularly do not leading under the situation of high-tension electricity, its effective scattering area is very little, and echo is very weak naturally, and general marine radar can't detect this radar return.But, after passing through the 220KV high-tension electricity on the plain conductor, will change effective scattering area of plain conductor, make effective scattering area increase, in the actual measurement process, it is found that near the 220KV ultra-high-tension power transmission line in the thousands of rice, radar can detect the echo of ultra-high-tension power transmission line really.

At of radiation and the interference of 220KV ultra-high-tension power transmission line to the radar generation, multiple Anti-Jamming Technique is arranged in the prior art, select technology, low secondary lobe and Ultralow Sidelobe Antenna technology, side-lobe blanking and sidelobe cancellation technology, antenna self-adaptive Anti-Jamming Technique, power countermeasure techniques, frequency to select technology and CFAR treatment technology as waveform.Using at present more is the method for selecting filtering, and it requires the form of selecting filter according to the system of radar transmitter, type etc., simultaneously, and the measure that antenna system is set up suppressed sidelobes, improved antenna gain.These Anti-Jamming Techniques respectively have characteristics, overcome the electromagnetic interference (EMI) that the 220KV ultra-high-tension power transmission line produces radar to a certain extent, but the radar return that ultra-high-tension power transmission line is produced is to blocking that ship return forms, and then may cause radar to lose this problem of tracking target also not having good solution.

Summary of the invention

Technical matters to be solved by this invention is the implementation method that a kind of Anti-jamming Technology for Radar based on AIS information is provided at above-mentioned prior art, and this implementation method can accurately be distinguished the radar return of tracking target, and then reduces radar and produce the target exchange.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: be somebody's turn to do the implementation method based on the Anti-jamming Technology for Radar of AIS information, comprise the steps:

(1) positional information of relevant this observed object that the positional information of radar observation target and AIS are provided is carried out coordinate transform respectively, and both are in the same coordinate system;

(2) calculate the degree of membership of radar track with fuzzy c-means clustering algorithm, to judge whether the AIS information in the radar tracking window is the AIS information of the tracking target of being wanted to the AIS flight path;

(3) judge target with this AIS associating information, the i.e. tracking target that will ask for by the AIS information of the tracking target of trying to achieve in the step (2);

(4) calculate first correlation distance between the radar return that the AIS information and the tracking target of tracking target produced, and calculate second correlation distance between the radar return that the AIS information of above-mentioned tracking target and ultra-high-tension power transmission line produce, judge the echoed signal of tracking target by the size of more above-mentioned first correlation distance and second correlation distance.

Further, it is polar coordinate system on the north orientation of initial point that the same coordinate system described in the step (1) adopts with this ship, and the position angle is for just clockwise, and the position angle is for bearing counterclockwise.

Further improvement project is, the positional information of the radar observation target described in the step (1) adopts the target ship to indicate with respect to the distance and bearing of this ship, and described AIS provides longitude and the latitude of the positional information employing of relevant this observed object based on the WGS84 geographic coordinate system.

Further, step (3) comprises the steps:

(3a) obtain the range-azimuth that radar is carved measured target at a time;

(3b) by the range-azimuth of AIS in the positional information reckoning target of this this target that provides constantly;

(3c) range-azimuth that the range-azimuth that records in the step (3a) is come with middle reckoning of step (3b) carries out related detection, and related the detection set up distance function between sample;

(3d) judge the tracking target that to ask for by above-mentioned distance function.

Compared with prior art, because when the radar return that the 220KV ultra-high-tension power transmission line produces blocks the echo of boats and ships, target exchange phenomenon may appear in radar, cause losing correct tracking target, the present invention is in conjunction with AIS information and radar information, the AIS information of utilizing that proposes reduces the algorithm of target exchange, by experiment simulation as can be known radar can not lose tracking target, improved the antijamming capability of radar to the 220KV ultra-high-tension power transmission line.

Description of drawings

Fig. 1 is the 220KV of an embodiment of the invention ultra-high-tension power transmission line synoptic diagram over strait;

Fig. 2 is the 220KV ultra-high-tension power transmission line straight line point-like echo synoptic diagram of the embodiment of the invention;

Fig. 3 is that the 220KV ultra-high-tension power transmission line echo and the incident angle of the embodiment of the invention concerns synoptic diagram;

Fig. 4 blocks the synoptic diagram of ship echo for the echo of the 220KV ultra-high-tension power transmission line of the embodiment of the invention;

Fig. 5 is the radar tracking window synoptic diagram of the embodiment of the invention;

Fig. 6 is two ship trajectory diagrams in the simulation algorithm of the embodiment of the invention;

Fig. 7 is two ship course figure in the simulation algorithm of the embodiment of the invention;

Fig. 8 is two ship speed of a ship or plane figure in the simulation algorithm of the embodiment of the invention.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

Present embodiment is chosen under as shown in Figure 1 Zhoushan-continent networking transmission line of electricity over strait and is carried out on-the-spot test, is equipped with the JRC-JMA-2344 radar on the research ship, and research ship crosses 220KV ultra-high-tension power transmission line over strait along course line shown in Figure 1.The distance and the characteristics of the appearance of 220KV ultra-high-tension power transmission line echo are also observed and are measured in the variation of images such as observation radar echo, radar clutter, interference, and the ultra-high-tension power transmission line peripheral electromagnetic field is to the influence of other echo.

As shown in Figure 2, because the influence of alternating electromagnetic field on the ultra-high-tension power transmission line, the radar return of 220KV high voltage transmission line is not continuous linear pattern target, forms straight line point-like echo, and the intensity of echo changes with the incident angle and the weather conditions of distance, radar return.

As shown in Figure 3, when radar electromagnetic wave became the vertical incidence angle with the 220KV ultra-high-tension power transmission line, the echo of ultra-high-tension power transmission line was the strongest.And along with the increase of the axial incident angle θ of radar, effective scattering area of ultra-high-tension power transmission line will reduce, and radar return also weakens thereupon.

As shown in Figure 4, when the 220KV ultra-high-tension power transmission line from the distance of this ship during less than the maximum detectable range of 220KV ultra-high-tension power transmission line, the 220KV ultra-high-tension power transmission line can produce echo to the electromagnetic wave of boat-carrying radar emission on this ship, this radar return can be presented on the radar screen, at this moment, if radar has also detected target, then the echo of this target also will be presented on the screen of this radar, thereby the radar return that makes the 220KV ultra-high-tension power transmission line has produced the echo of this target and has blocked, a plurality of different targets appear on the radar screen, promptly be equivalent to a plurality of targets and intersect, the target exchange may appear in radar, and then loses correct tracking target.At this phenomenon, present embodiment has proposed the algorithm that a kind of AIS of utilization information reduces the radar target exchange, in this algorithm, when 220KV ultra-high-tension power transmission line echo and ship echo are overlapping, can also be used as a target to the ultra-high-tension power transmission line echo, this situation is handled as the situation that two ships intersect.The concrete steps of algorithm are as follows:

1) coordinate conversion of AIS and track window

As shown in Figure 5, radar is to be the center with this ship to the observation of target, indicates with respect to this bearing and distance with the target ship, and radar changes into azimuth-range matrix in the internal memory to the target video echo volume on the screen.The target position information that AIS broadcasts is based on the longitude and the latitude of WGS84 geographic coordinate system.For AIS information and radar information are well combined, need carry out coordinate transform, they are in the same coordinate system.Employing is polar coordinate system on the north orientation of initial point with this ship, and the position angle is for just clockwise, and the position angle is for bearing counterclockwise.ARPA is to implement the flight path of target is carried out relevant treatment with track window to the tracking of target, and the polar coordinates system as shown in Figure 5 on the track window of radar and the north orientation.Δ A, Δ R are respectively the width and the degree of depth of track window, R _RAnd B _RBe the distance and bearing of radar site, R _AAnd B _AIt is the distance and bearing of AIS position.

Radar is the longitude and latitude of boats and ships by the target position data that AIS obtains, and need convert longitude and latitude to the azran of sphere, and the longitude and latitude of establishing the AIS target is λ, and φ promptly adopts Gauss Kru﹠4﹠ger projection longitude and latitude to be converted to planimetric rectangular coordinates x earlier, y:

Planimetric rectangular coordinates x, y converts to respect to polar coordinates on the north orientation of this ship position then, and the rectangular coordinate of establishing the AIS target is (x _T, y _T), the rectangular coordinate of this ship position is (x _O, y _O), conversion formula is as follows:

$\left\{\begin{array}{c}R=\sqrt{{(x_T-x_o)}^2+{(y_T-y_o)}^2}\\ B=\left\{\begin{array}{cc}\frac{\mathrm{\&pi;}}{2}-\arg \mathrm{tg}\frac{y_T-y_o}{x_T-x_o}& (x_T-x_o>0)\\ \frac{3\mathrm{\&pi;}}{2}-\arg \mathrm{tg}\frac{y_T-y_o}{x_T-x_o}& (x_T-x_o<0)\end{array}\right.\end{array}\right.---\left(4\right)$

2) calculate degree of membership with fuzzy c-means clustering algorithm (FCM)

The effect of this step is exactly to judge whether the AIS information in the track window is the AIS information of the tracking target of wanting.

Suppose X={x ₁, x ₂..., x _nThe expression radar flight path, n represents element number, c is an AIS flight path number, also is the cluster centre number, 1＜c＜n.d _Ij=|| x _i-v _j|| be the Euclidean distance of i bar radar track to j bar AIS flight path, 1＜j＜c.u _IjBe x _iTo v _jDegree of membership, promptly i bar radar track is to the degree of membership of j bar AIS flight path.Then fuzzy clustering problem can be expressed as following mathematical programming problem.

$\min J_m(U,V)=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{c}{\mathrm{\&Sigma;}}}{u}_{\mathrm{ij}}^{\mathrm{<figure-callout\; id="2"\; label="m\; d\; ij"\; filenames="HSA00000487626100011.png,HSA00000487626100032.png"\; state="\{\{state\}\}">m</figure-callout>}}{d}_{\mathrm{ij}}^{}{}_2^{}$

Wherein: $\underset{j=1}{\overset{c}{\mathrm{\&Sigma;}}}{u}_{\mathrm{ij}}=1$ 1≤i≤n

0≤u _ij≤1 1≤i≤n，1≤j≤c

$0<\underset{j=1}{\overset{c}{\mathrm{\&Sigma;}}}{u}_{\mathrm{ij}}<\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HSA00000487626100011.png,HSA00000487626100032.png"\; state="\{\{state\}\}">n</figure-callout>}$ 1≤j≤c

The m here is a weight coefficient, m＞1.By minimized method, solve best degree of membership.

Degree of membership:

$u_{\mathrm{ij}}=\frac{1}{\underset{r=1}{\overset{c}{\mathrm{\&Sigma;}}}{\left(\frac{d_{\mathrm{ij}}}{d_{\mathrm{ir}}}\right)}^{\frac{2}{m-1}}}\&ForAll;i,r$

Calculate the degree of membership of radar prediction position and two AIS of place information respectively, but bigger that is the AIS information that the subject of knowledge and the object of knowledge will mate, here degree of membership can be set a threshold epsilon, when that bigger degree of membership during greater than ε, can finally conclude the AIS information of tracking target.

3) AIS is related with radar site

After having determined the AIS information of the tracking target of wanting, we just can determine which is a target associated therewith with it.Because we can only obtain the range-azimuth information of two targets, so related herein these two information that also can only use AIS.

If R _Rk, B _RkBe the range-azimuth of radar in k measured target of the moment, R _Ak, B _AkThe k range-azimuth of the target extrapolated of the target position information that provides of AIS constantly is provided.Here need carry out related the detection m time in order to improve related quality, detects between sample in association and set up distance function ρ _Ij, i represents the data of i group AIS, and j represents the data of j group radar, and i and j are independent incoherent.ρ _IjBe defined as follows:

${\mathrm{\&rho;}}_{\mathrm{ij}}=\frac{1}{2}[\frac{{\left(\underset{n=1}{\overset{m}{\mathrm{\&Sigma;}}}{(R_{\mathrm{Rjn}}-R_{\mathrm{Ain}})}^2\right)}^{\frac{1}{2}}}{m}+\frac{{\left(\underset{n=1}{\overset{m}{\mathrm{\&Sigma;}}}{(B_{\mathrm{Rjn}}-B_{\mathrm{Ain}})}^2\right)}^{\frac{1}{2}}}{m}]$

For the i group AIS data of determining, find for the pairing data of the radar of same target so, as long as find j, this j makes apart from ρ _IjObtain minimum value, promptly pairing that target of this minimum value is the target that will follow the tracks of.

4) judgement of AIS information

Calculate the degree of membership of pre-measured center and two AIS of place respectively, obtain two degree of membership u ₁₁And u ₂₁Compare u earlier ₁₁And u ₂₁, obtain bigger one (u for example ₁₁), if u ₁₁＞ε, then u ₁₁Pairing AIS is the AIS of tracking target.

And then calculate the correlation distance ρ of this AIS information and two radar returns ₁₁And ρ ₁₂, less that is exactly the echoed signal of our institute's tracking target.

In the present embodiment, this algorithm is given following emulation experiment:

On PC, write the target following program of using this algorithm with VC++, and on radar simulator, carried out emulation experiment.

If this ship's head 0 degree, speed 10 joints.3.51 nautical miles of A ship initial distances, orientation 60.5 degree, the speed of a ship or plane 10 saves relatively, virtual course 200 degree.3.09 nautical miles of B ship initial distances, orientation 50.0 degree, the speed of a ship or plane 10 saves relatively, virtual course 180 degree.In the process that intersection is met, to the observation of target and their data such as Fig. 6 to shown in Figure 8: A-ARPA, B-ARPA represent the A ship that radar records and the data of B ship; A-Real, B-Real represent the True Data of A ship and B ship; A-Paper, B-Paper represent through the data after this paper algorithm process.

Fig. 6 is the trajectory diagram of two ships.Therefrom as can be seen, two ships are located to meet in (2.271,0.086).Occur the target exchange herein, the flight path of B ship disappears, and the flight path saltus step of A ship is the flight path of B ship, all can correctly be followed the tracks of through A ship after this algorithm process and B ship.Fig. 7 is two ship's head figure, and therefrom as can be seen, from 420s, B loses the ship's head, and the saltus step of A ship's head is the B ship's head.Through after this algorithm process, two ship's heads can both correctly obtain.Fig. 8 is the speed of a ship or plane figure of two ships, and therefrom as can be seen, from 420s, the speed of a ship or plane of B ship is lost, and the speed of a ship or plane saltus step of A ship is the speed of a ship or plane of B ship.Through after the algorithm process of this case, the speed of a ship or plane of two ships can both correctly obtain.

Claims (4)

1. the implementation method based on the Anti-jamming Technology for Radar of AIS information is characterized in that this method comprises the steps:

(1) positional information of relevant this observed object that the positional information of radar observation target and AIS are provided is carried out coordinate transform respectively, and both are in the same coordinate system;

(2) calculate the degree of membership of radar track with fuzzy c-means clustering algorithm, to judge whether the AIS information in the radar tracking window is the AIS information of the tracking target of being wanted to the AIS flight path;

(3) judge target with this AIS associating information, the i.e. tracking target that will ask for by the AIS information of the tracking target of trying to achieve in the step (2);

(4) calculate first correlation distance between the radar return that the AIS information and the tracking target of tracking target produced, and calculate second correlation distance between the radar return that the AIS information of above-mentioned tracking target and ultra-high-tension power transmission line produce, judge the echoed signal of tracking target by the size of more above-mentioned first correlation distance and second correlation distance.

2. the implementation method of the Anti-jamming Technology for Radar based on AIS information according to claim 1, it is characterized in that: it is polar coordinate system on the north orientation of initial point that the same coordinate system described in the step (1) adopts with this ship, and clockwise the position angle is for just, and the position angle is for bearing counterclockwise.

3. the implementation method of the Anti-jamming Technology for Radar based on AIS information according to claim 1 is characterized in that:

The positional information of the radar observation target described in the step (1) adopts the target ship to indicate with respect to the distance and bearing of this ship, and described AIS provides longitude and the latitude of the positional information employing of relevant this observed object based on the WGS84 geographic coordinate system.

4. according to the implementation method of any one described Anti-jamming Technology for Radar based on AIS information in the claim 1 to 3, it is characterized in that: step (3) comprises the steps:

(3a) obtain the range-azimuth that radar is carved measured target at a time;

(3b) by the range-azimuth of AIS in the positional information reckoning target of this this target that provides constantly;

(3c) range-azimuth that the range-azimuth that records in the step (3a) is come with middle reckoning of step (3b) carries out related detection, and related the detection set up distance function between sample;

(3d) judge the tracking target that to ask for by above-mentioned distance function.

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