CN104101869B - A kind of ground wave radar moving target simulation modeling method under polar coordinate - Google Patents

Abstract

The present invention relates to the ground wave radar moving target simulation modeling method under a kind of polar coordinate.By the ground wave radar moving target simulation method under polar coordinate, thus the performance of the methods such as targetpath tracking, fusion is analyzed, verifies and evaluates.Its detailed process is: step one, target is set up the corresponding motion model of even acceleration model under the polar coordinate with radar station as limit, obtains the real motion parameter of target the most in the same time；Step 2, the real motion parameter that step one is obtained by the measurement error of introducing ground wave radar system is modified, and emulation obtains target observation kinematic parameter；Step 3, introduces environment clutter on the basis of the target observation kinematic parameter of step 2, and emulation obtains moving target point mark data.

Description

A kind of ground wave radar moving target simulation modeling method under polar coordinate

Technical field

The present invention is applied to movement overseas targeted surveillance monitoring field, it is proposed that the ground wave radar motion under a kind of polar coordinate Target simulator modeling method, the method can be simulated and generate the target data that ground wave radar is measured, can be used for Track In Track, fusion Research and evaluation etc. method.

Background technology

High-frequency ground wave radar utilizes shortwave (3～30MHz) in the conduction ocean surface diffraction propagation little feature of decay, uses Vertical polarized antenna radiation electric wave, naval vessel, aircraft, iceberg and guided missile etc. that energy over-the-horizon detection sea level sight line appears below are transported Moving-target, operating distance is up to more than 300km.Meanwhile, high-frequency ground wave radar utilizes the ocean surface single order to frequency electromagnetic waves Scattering and second order dispersion mechanism, can extract the sea situation information such as wind field, Lang Chang, flow field, it is achieved to ocean ring from radar return Border on a large scale, high accuracy and round-the-clock real-time monitoring.

When radio wave is towards emission of sea surface, a kind of electromagnetic wave propagation model, referred to as earthwave can be there is in seawater surface (Ground Wave), is a kind of surface wave (Surface Wave), and therefore high-frequency ground wave radar is also referred to as high frequency surface wave radar (HF Surface Wave Radar).The propagation of ground wave in medium wave and short-wave band seawater surface is decayed the least, and earthwave is one Determine to propagate along the earth surface of bending in degree, arrive the place that below horizon is far, i.e. realize over-the-horizon propagation.Cause This high-frequency ground wave radar utilizing earthwave over-the-horizon propagation characteristic to carry out detecting is also referred to as ground wave OTHR (Over-The- Horizon Radar), detection range can be usually reached 200～500km according to the difference launching power and frequency.Other two kinds The over-the-horizon radar of type is sky-wave OTH radar and the microwave radar utilizing atmospheric duct feature respectively, and the former is by ionization High frequency radio wave reflect the detection realized thousands of miles target outward by layer, the latter can to 100 kilometers outside target Detect.

Chinese patent CN101206260 discloses the processing method of radar target information in navigating tube automatization system, and this is special Profit mainly solves the processing accuracy of Target Tracking System, utilizes air traffic control radar polar coordinate (distance, orientation, highly) report and locate Conversion between reason plane rectangular coordinates, reduces the calculating error of usual transfer algorithm.

Chinese patent CN102508238 discloses a kind of radar tracking method based on Rotating Transition of Coordinate, it based on Machine variant correlation coefficient and Rotating Transition of Coordinate principle, to reach the measurement equation in quantitative measurement radar filtering system model Nonlinear degree on the basis of, reduce the measurement equation nonlinear degree in radar filtering system model, thus improve radar Tracking effect.

But above-mentioned technology is all not directed to how the movement overseas target of earthwave radar detection be set up corresponding phantom, So that the method such as Track In Track, fusion is analyzed, evaluates.

Summary of the invention

The purpose of the present invention is exactly for solving to put down Moving Target Exploitation shortage simulation modeling in earthwave Radar Sea at present The problem of platform, by the ground wave radar moving target simulation modeling method under polar coordinate, thus to targetpath tracking, fusion etc. The performance of method is analyzed, verifies and evaluates offer foundation.

For achieving the above object, the present invention adopts the following technical scheme that

A kind of ground wave radar moving target simulation modeling method under polar coordinate, its detailed process is:

Step one, sets up the corresponding motion model of even acceleration model under the polar coordinate with radar station as limit to target, Obtain the real motion parameter of target the most in the same time；

Step 2, the real motion parameter that step one is obtained by the measurement error of introducing ground wave radar system is modified, Emulation obtains target observation kinematic parameter；

Step 3, introduces environment clutter on the basis of the target observation kinematic parameter that step 2 obtains, and emulation is moved Targets Dots data.

In described step one, under polar coordinate, the motion model of target is as follows:

$\left\{\begin{array}{c}{r}_t=\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2+2r_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos \mathrm{\α}}\\ {\mathrm{\θ}}_t=\mathrm{\Φ}-\mathrm{arc}\sin (r_0\sin (\mathrm{\Φ}-{\mathrm{\θ}}_0)/r_t)\\ v_{\mathrm{rt}}=(v_0+\mathrm{at})\cos \left(\mathrm{arc}\sin (r_0\sin (\mathrm{\Φ}-{\mathrm{\θ}}_0)/r_t)\right)\end{array}\right.$

Wherein, r_tFor the radial distance between t target location and radar station；r₀For initial time target location and thunder Reach the radial distance between station；Move the moment t sweep spacing using radar as ultimate unit；A is acceleration；α represents initial Angle between moment target travel direction and target radial speed direction；θ_tFor t target location vector and radar normal direction Angle；Ф is target travel direction and radar normal direction angle ,-π≤Ф≤π；θ₀For target initial orientation angle；v₀At the beginning of target Beginning speed；v_rtRadial velocity for t target；Target travel direction and target radial speed angular separation are β=arcsin (r₀sin(π-Φ+θ₀)/r_t), corresponding β is acute angle 0 ° < β < 90 °；Target travel direction and target radial speed angular separation are β =π-arcsin (r₀sin(π-Φ+θ₀)/r_t), corresponding β is 90 ° < β < 180 ° of obtuse angle；

According to target in radar method to the right or left side motion, it is simultaneously acute angle or obtuse angle according to β angle, determines motion The condition that model is revised accordingly:

(1) 90 ° > Φ > 0 ° time,

(2) 180 ° > Φ > 90 ° time, critical angle δ=Φ-90 ° > 0, work as θ₀During ＜ δ,

(3)-90 °>Φ>-180 ° time, critical angle δ=Φ+90 °<0, work as θ₀During ＞ δ,

(4) 0 > Φ >-90 ° time,

In above-mentioned four kinds of situations, when β is acute angle, modus ponens β=arcsin (r₀sin(π-Φ+θ₀)/r_t) expression-form, When β is obtuse angle, modus ponens β=π-arcsin (r₀sin(π-Φ+θ₀)/r_t) expression-form, described motion model is repaiied Just.

In described step 2, it is assumed that the observation noise Gaussian distributed that ground wave radar measures, then the target observed is joined Number is expressed as:

$\left\{\begin{array}{c}{r}_{\mathrm{observe}}=r_{\mathrm{orignal}}+{\mathrm{\&sigma;}}_{r}n\\ v_{\mathrm{observe}}=v_{\mathrm{original}}+{{\mathrm{\&sigma;}}_v}^{}n\\ {\mathrm{\&theta;}}_{\mathrm{observe}}={\mathrm{\&theta;}}_{\mathrm{original}}+{\mathrm{\&sigma;}}_{\mathrm{\&theta;}}n\end{array}\right.$

Wherein, r_observe、v_observe、θ_observeRepresent radial distance, radial velocity and azimuthal observation respectively, r_original、v_original、θ_originalRepresent the actual value of three, σ respectively_r、σ_v、σ_θRepresent respectively radial distance, radial velocity with And the standard deviation of azimuth measurement error, n represents that average is zero, and variance is the normally distributed random variable of 1, is measured by adjustment Error criterion extent, changes the disturbance to each measurement parameter, obtains the observation of ground wave radar detection target under polar coordinate.

In described step 3, the preparation method of moving target point mark data is:

On the basis of observation of a certain moment moving target data that step 2 obtains, add certain in the range of target acquisition The clutter point of number.Wherein, the number of clutter point obeys Poisson distribution, and the average of Poisson distribution is by the detection area of radar and list In plane is long-pending, the product of clutter number determines, the clutter number (i.e. noise intensity) in unit are can set according to actual needs；Miscellaneous The kinematic parameter stochastic generation of wave point.

The present invention, in order to preferably study the methods such as the tracking of ground wave radar targetpath, fusion, verifies its effectiveness, proposes Ground wave radar moving target simulation modeling method under a kind of polar coordinate, has the following characteristics that

(1) Targets Dots under polar coordinate can be directly generated, it is to avoid Coordinate Conversion and the error thus introduced, practical Property is strong；

(2) can emulate plurality of target forms of motion, above-described embodiment is as a example by uniformly accelrated rectilinear motion, by other fortune After movable model or model combination are replaced, i.e. can get the target travel result of multi-form, such as target maneuver etc.；

(3) observation noise, the addition of environment clutter have taken into full account the feature of ground wave radar target acquisition so that emulation Target is closer to real ground wave radar result of detection；

(4) observation noise and environment noise intensity can be changed flexibly, to emulate the target acquisition result under varying environment.

Accompanying drawing explanation

The Track In Track flow process that Fig. 1 models based on ground wave radar moving target simulation；

Fig. 2 target motion model (direction of motion and radar normal direction acutangulate) under polar coordinate；

Fig. 3 target motion model (direction of motion becomes obtuse angle with radar normal direction) under polar coordinate；

Five moving target real motion track emulation results of Fig. 4 a；

The partial enlarged drawing of Fig. 4 b Fig. 4 a；

Five moving target observation simulation results of Fig. 5 a；

The partial enlarged drawing of Fig. 5 b Fig. 5 a；

The simulation result of Fig. 6 target 1；

Fig. 7 target velocity change curve；

Fig. 8 a comprises the moving target simulation result of clutter；

The partial enlarged drawing of Fig. 8 b Fig. 8 a；

Fig. 9 clutter point and impact point simulation result；

Figure 10 targetpath follows the tracks of result example.

Detailed description of the invention

The present invention will be further described with embodiment below in conjunction with the accompanying drawings.

Track In Track handling processes based on ground wave radar moving target simulation data are as shown in Figure 1.Wherein, dashed rectangle Inside it show moving target simulation flow process (not to be the emulation modelling method of the present invention outside dotted line frame, generally can use prior art Realize, repeat no more).Set the goal initial motion parameter (position, speed etc.), utilize motion model (linear uniform motion, even Accelerate linear motion, maneuver modeling etc.) target can be obtained in real motion parameter the most in the same time；In view of ground wave radar system The measurement error of system, adds corresponding measurement error in target true motion parameter, can emulate the motion obtaining target observation Parameter；On the basis of target observation kinematic parameter, introduce environment clutter, just can get simulation objectives point mark.Utilization emulation obtains Moving target point mark data, utilize Track In Track Processing Algorithm to process the flight path of available target.The targetpath that will obtain Contrast with the movement locus of real goal, can be the analysis of Track In Track algorithm performance, offer foundation is provided.

Generally, the kinestate of movement overseas target does not have the biggest motor-driven situation, therefore, is generally transported Movable model is assumed to linear uniform motion.In order to reflect moving target more accurately it is possible that less motor-driven situation, with The derivation of target state is carried out as a example by even acceleration model (Constant Acceleration, CA).

Fig. 2 show moving target motion schematic diagram under polar coordinate.The original state assuming target is: radially Distance r₀, azimuth angle theta₀, speed v₀, acceleration a, does even acceleration straight line fortune along becoming Φ (-π≤Φ≤π) angle with radar normal direction Dynamic.

In Fig. 2, θ_tFor the angle of t target location vector Yu radar normal direction, r_tFor t target location and radar station Between radial distance, v_tFor the true velocity of t target, v_rtRadial velocity for t target.Wherein, t is with radar Sweep spacing is as ultimate unit.

As shown in Figure 2,

α=Φ-θ₀, ω=π-α=π-(Φ-θ₀) (1)

α represents the angle between initial time target travel direction and target radial speed direction.

R can be tried to achieve by the cosine law_t,

$\begin{array}{c}{r}_t=\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2-{2r}_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos \mathrm{\&omega;}}\\ =\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2-{2r}_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos (\mathrm{\&pi;}-(\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0))}\\ =\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2+{2r}_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos (\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0)}\end{array}---\left(2\right)$

Wherein, t=(n-1) T, T are integration time, and n is scanning times, n=1,2,3 ... and, n is natural number.

It is apparent from θ_t=Φ-β.β can be tried to achieve by sine:

$\frac{r_t}{\sin \mathrm{\&omega;}}=\frac{r_0}{\sin \mathrm{\&beta;}}---\left(3\right)$

Meanwhile, v can be obtained_rt,

v_rt=v_tCos β=(v₀+at)cosβ (5)

$\begin{array}{c}{v}_{\mathrm{rt}}=(v_0+\mathrm{at})\cos \left(\mathrm{arc}\sin (r_0\sin (\mathrm{\&pi;}-\mathrm{\&Phi;}+{\mathrm{\&theta;}}_0)/r_t)\right)\\ =(v_0+\mathrm{at})\cos \left(\mathrm{arc}\sin (r_0\sin (\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0)/r_t)\right)\end{array}---\left(6\right)$

Thus, show that under polar coordinate, the motion model of target is as follows:

$\left\{\begin{array}{c}{r}_t=\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2+2r_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos \mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_t=\mathrm{\&Phi;}-\mathrm{arc}\sin (r_0\sin (\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0)/r_t)\\ v_{\mathrm{rt}}=(v_0+\mathrm{at})\cos \left(\mathrm{arc}\sin (r_0\sin (\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0)/r_t)\right)\end{array}\right.---\left(7\right)$

During model above is set up, owing to the calculating of angle relates to arcsin function, the needs of choosing of angle value divide Different situations is discussed.

The definition territory of arcsin function is [-1 ,+1], and codomain is [0, pi/2], therefore, during above-mentioned model inference according to Formula β=arcsin (r₀sin(π-Φ+θ₀)/r_t) carry out the situation that value simply corresponding β is acute angle (0 ° < β < 90 °).

When β is obtuse angle (90 ° < β < 180 °), its value should be

β=π-arcsin (r₀sin(π-Φ+θ₀)/r_t) (8)

Fig. 3 is 180 ° > Φ > 90 ° time, β is situation during obtuse angle, now,

β=π-arc sin (r (0) sin (π-Φ+θ (0))/r (t)) (9)

In like manner, when target is moved to the left in radar method, also should consider in two kinds of situation.

Being analyzed by above, (its schematic diagram is identical with Fig. 2 and Fig. 3 principle, no longer draws at this to obtain following four kinds of situations Go out):

(1) 90 ° > Φ > 0 ° time,

(2) 180 ° > Φ > 90 ° time, critical angle δ=Φ-90 ° > 0 °, work as θ₀During ＜ δ,

(3)-90 °>Φ>-180 ° time, critical angle δ=Φ+90 °<0 °, work as θ₀During ＞ δ,

(4) 0 ° > Φ >-90 ° time,

In above-mentioned four kinds of situations, when β is acute angle, the expression-form of modus ponens (3), when β is obtuse angle, the table of modus ponens (8) Reach form.Just the ideal goal simulation result under different motion situation can be obtained by model above.

In order to simulate the measurement of ground wave radar more truly, need the observation noise in view of radar system.In emulation In model, it is assumed that the observation noise Gaussian distributed that ground wave radar measures, then the target component observed can be expressed as:

$\left\{\begin{array}{c}{r}_{\mathrm{observe}}=r_{\mathrm{orignal}}+{\mathrm{\&sigma;}}_{r}n\\ v_{\mathrm{observe}}=v_{\mathrm{original}}+{{\mathrm{\&sigma;}}_v}^{}n\\ {\mathrm{\&theta;}}_{\mathrm{observe}}={\mathrm{\&theta;}}_{\mathrm{original}}+{\mathrm{\&sigma;}}_{\mathrm{\&theta;}}n\end{array}\right.---\left(10\right)$

Wherein, r_observe、v_observe、θ_observeRepresent radial distance, radial velocity and azimuthal observation respectively, r_original、v_original、θ_originalRepresent the actual value of three, σ respectively_r、σ_v、σ_θRepresent respectively radial distance, radial velocity with And the standard deviation of azimuth measurement error, n represents that average is zero, and variance is the normally distributed random variable of 1.Measured by adjustment Error criterion extent, thus it is possible to vary the disturbance to each measurement parameter.

The observation of ground wave radar detection target under polar coordinate is i.e. can get by (10) formula.

2, emulation experiment

(1) real goal emulation

In order to verify the correctness of the moving target analogy method of proposition, respectively to 5 mesh with different motion parameter Mark emulates.The direction of motion of 5 targets is respectively 0 °, 90 °, 10 °, 120 ° ,-150 °, i.e. with the angle Φ of radar normal direction Respectively along radar normal direction and radar normal direction vertical direction, radar normal axis clockwise direction, radar normal axis counterclockwise fortune Dynamic, utilize the target movement model set up to carry out moving target simulation, result is as shown in Fig. 4 a, 4b.

(2) observed object emulation

Measure to simulate real ground wave radar, when producing target observation value, take into full account the measurement of radar system Error.Knowable to feature in conjunction with the measurement of earthwave radar target and the statistical analysiss to a large amount of actual measurement ground wave radar data, its speed Certainty of measurement is the highest, and measurement error is about 0.02m/s；Radial distance precision is taken second place, and measurement error is about 3km；Azimuth Precision is minimum, and measurement error is about 3 °.The statistical value of reference measure error, sets the measurement noise of different motion target component Variance.

On the basis of real goal, measurement noise is taken into account, obtain target observation result as shown in Fig. 5 a, 5b.

In order to compare the kinestate clearly displaying target, the kinestate of target 1 is individually shown as shown in Figure 6.

Fig. 7 gives the speed change curves of target, and understanding this target from the change curve of speed actual value is to make even adding Speed motion, matches with the even acceleration model set up.Velocity measurement value fluctuates near actual value, can recognize on overall trend For being the uniformly accelerated motion of band noise.

(3) target simulator in clutter environment

Clutter in high-frequency ground wave radar object detection results is counted and is obeyed Poisson distribution in scanning every time.If uniformly dividing The clutter density of cloth is λ/km², then equally distributed number of echoes in investigative range can be obtained.

The clutter of emulation and Targets Dots are distributed as shown in Fig. 8 a, 8b.

In order to compare the kinestate clearly displaying target, the kinestate of the target 1 comprising clutter point is individually shown Show in fig .9.

(4) Track In Track result

Utilize the phantom set up to obtain the actual value of target and the simulation result of measuring value, this simulation result is applied In Track In Track is tested, obtain an embodiment.Figure 10 is the tracking result of the target 1 utilizing Track In Track algorithm to obtain. Track In Track experiment can be carried out for different targets.

Claims (3)

1. the ground wave radar moving target simulation modeling method under polar coordinate, is characterized in that, its detailed process is:

Step one, sets up the corresponding motion model of even acceleration model under the polar coordinate with radar station as limit to target, obtains The real motion parameter of target the most in the same time；

Step 2, the real motion parameter that step one is obtained by the measurement error of introducing ground wave radar system is modified, emulation Obtain target observation kinematic parameter；

Step 3, introduces environment clutter on the basis of the target observation kinematic parameter of step 2, and emulation obtains moving target point mark Data；In described step one, under polar coordinate, the motion model of target is as follows:

$\left\{\begin{array}{c}{r}_t=\sqrt{r_0^2+{(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)}^2+2r_0(v_{0}t+\frac{1}{2}{\mathrm{at}}^2)\cos \mathrm{\&alpha;}}\\ {\mathrm{\&theta;}}_t=\mathrm{\&Phi;}-\mathrm{arc}sin\left(r_0\sin \right(\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0)/r_t)\\ v_{rt}=(v_0+at)\cos \left(arc\sin \right(r_0\sin \left(\mathrm{\&Phi;}-{\mathrm{\&theta;}}_0\right)/r_t\left)\right)\end{array}\right.$

Wherein, r_tFor the radial distance between t target location and radar station；r₀For initial time target location and radar station Radial distance, t is the motion moment, using the sweep spacing of radar as ultimate unit；A is acceleration；α represents initial time mesh Angle between the mark direction of motion and target radial speed direction；θ_tAngle for t target location vector Yu radar normal direction； Ф is target travel direction and radar normal direction angle ,-π≤Ф≤π；Initial orientation angle θ₀；Initial velocity V₀；V_rtFor t mesh Target radial velocity；Target travel direction and target radial speed angular separation are β=arc sin (r₀sin(π-Φ+θ₀)/ r_t), corresponding β is acute angle 0 ° < β < 90 °；Target travel direction and target radial speed angular separation are β=π-arc sin (r₀sin (π-Φ+θ₀)/r_t), corresponding β is 90 ° of obtuse angle ＜ β ＜ 180 °；

According to target in radar method to the right or left side motion, it is simultaneously acute angle or obtuse angle according to β angle, determines motion model The condition revised accordingly,

During (1) 90 ° of ＞ Φ ＞ 0 °,

During (2) 180 ° of ＞ Φ ＞ 90 °, critical angle δ=Φ-90 ° ＞ 0 °, works as θ₀During ＜ δ,

During (3)-90 ° of ＞ Φ ＞-180 °, critical angle δ=Φ+90 ° ＜ 0 °, works as θ₀During ＞ δ,

During (4) 0 ° of ＞ Φ ＞-90 °,

In above-mentioned four kinds of situations, when β is acute angle, modus ponens β=arc sin (r₀sin(π-Φ+θ₀)/r_t) expression-form, work as β During for obtuse angle, modus ponens β=π-arc sin (r₀sin(π-Φ+θ₀)r_t) expression-form, described motion model is modified.

2. the ground wave radar moving target simulation modeling method under polar coordinate as claimed in claim 1, is characterized in that, described step In rapid two, it is assumed that the observation noise Gaussian distributed that ground wave radar measures, then the target component observed is expressed as:

$\left\{\begin{array}{c}{r}_{observe}=r_{orignal}+{\mathrm{\&sigma;}}_{r}n\\ v_{observe}=v_{original}+{\mathrm{\&sigma;}}_{v}n\\ {\mathrm{\&theta;}}_{observe}={\mathrm{\&theta;}}_{original}+{\mathrm{\&sigma;}}_{\mathrm{\&theta;}}n\end{array}\right.$

Wherein, r_observe、v_observe、θ_observeRepresent radial distance, radial velocity and azimuthal observation, r respectively_original、 v_original、θ_originalRepresent the actual value of three, σ respectively_r、σ_v、σ_θRepresent radial distance, radial velocity and azimuth respectively The standard deviation of measurement error, n represents that average is zero, and variance is the normally distributed random variable of 1, by adjusting measurement error standard Extent, changes the disturbance to each measurement parameter, obtains the observation of ground wave radar detection target under polar coordinate.

3. the ground wave radar moving target simulation modeling method under polar coordinate as claimed in claim 1, is characterized in that, clutter point Number obey Poisson distribution, the average of Poisson distribution is by the product of clutter number in the detection area of radar and unit are certainly Fixed, the clutter number i.e. noise intensity in unit are sets according to actual needs；The kinematic parameter stochastic generation of clutter point.