RU2231084C2 - Device for recognition of firing systems - Google Patents

Abstract

FIELD: radar equipment, applicable in reconnaissance radars for identification of the class of the enemy firing systems according to the results of measurement of the current co-ordinates of the shell (mine, rocket) in the trajectory.

SUBSTANCE: the known device, having series-connected smoothing unit, unit for conversion of the smoothed out target motion parameters, the first threshold device, storage unit maximum determination unit, as well as the second threshold unit, additionally uses a storage, series-connected comparison device, unit analyzing the growth of the values of Doppler frequency, and the third threshold device.

EFFECT: enhanced probability of correct recognition of firing systems, enhanced precision of development of the requirement to the quantity and type of the used ammunition at raising the task for destruction of the reconnoitered target.

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Description

The invention relates to the field of radar technical means of recognizing the class of firing artillery systems of the enemy by measuring the current coordinates of the projectile (mines, missiles) on the trajectory.

As it follows from well-known sources, in the radar of reconnaissance of artillery firing positions [1], recognition of firing systems is carried out with the classification of targets as mortars, artillery and missile launchers, but there is no separation of the class of multiple launch rocket systems (MLRS), which in foreign radars is classified as artillery .

A recognition device is known that is implemented in an adopted product in the Russian Army — a radar for detecting the positions of enemy shooting systems by a shot — Zoo-1 (see [2, 3]).

In the known device, measured as a result of auto tracking of a projectile (missiles, mines) on the trajectory, its current coordinates on the ascending branch of the trajectory are smoothed, as a result of which coordinates are estimated, horizontal components of speed and acceleration at any point in the tracking interval. After that, the horizontal components of velocity and acceleration are calculated for the middle of the observation interval. Further, according to the obtained estimates of the horizontal components of velocity and acceleration for the middle of the observation interval, the value of the ballistic function is determined [2].

Determining the nature of the trajectory section - active or passive - is carried out by the sign of the ballistic function. For an active site, according to a preselected threshold of ballistic function, the target is assigned to classes 5 or 6: class 5 - tactical missiles (active site), class 6 - active-rockets, active-reactive mines (ARS, AWP). For a passive section of the trajectory, the values of horizontal velocities and accelerations are used to determine the conditional probability densities of the observed ballistic target in each of four classes:

Grade 1 - howitzers;

Grade 2 - mortars;

Grade 3 - MLRS;

Grade 4 - tactical missiles (passive section).

The assignment of an object to one or another class is carried out according to the maximum of the conditional probability density of belonging of the observed ballistic target to one of the four classes.

In essence, the technical solution closest to the proposed device is a recognition device implemented in the product "Zoo-1" [2, 3] and selected for the prototype. The recognition device selected for the prototype is shown in figure 1 in the form of a flowchart describing the sequence of solving individual problems [2] when recognizing the class of shooting systems.

In figure 1:

1 - block smoothing the obtained rectangular coordinates of the projectile flight path;

2 - block conversion of smooth coordinates;

3 - the first threshold device;

4 - memory block of conditional probability densities of the target belonging to each of the four classes;

5 - a unit for determining the maximum of the conditional probability density of a target belonging to one of four classes;

6 - second threshold device.

The device adopted for the prototype works as follows.

In block 1, the smoothed estimates of the rectangular coordinates, velocities and accelerations of the projectile for the end of the observation interval are calculated by the incoming current rectangular coordinates of the projectile’s flight path by filtering with a second-order polynomial ([4], [2] p. 3.8).

In the conversion unit 2 is performed:

- recount ([2] p. 3.9) obtained for the end of the observation interval of smoothed estimates of rectangular coordinates, velocities and accelerations in the middle of the observation interval for a polynomial of the second degree:

N _cp = N _n -V _{con con} · (N-1) / 2 + W _{n con} · (N-1) ^2/2;

V _nsr = (V _{n con} -W _{n con} · (N-1) / 2) / Δt;

W _nsr = W _{n con} / Δt ² ;

where H _con , V _{n con} , W _{n con} - estimates of the rectangular coordinates, velocities and accelerations of the projectile for the end of the observation interval, obtained after smoothing;

Δt is the step of taking coordinates on the path;

N is the number of smoothed points on the observation interval.

For the coordinates X _cf and Y _cf, all calculations are similar.

- calculation of recognition parameters - horizontal components of speed V _g and acceleration W _g for the middle of the observation interval:

W _g = (V · W _{HSR HSR} + V _{SIS SIS} · W) / V _g.

- calculation of the value of E ([5], [2], clause 3.9), called the ballistic function in [2]:

E = -W _g / V _g

Then, in the first threshold device 3, the sign of the ballistic function E is analyzed ([2], clause 3.13.1).

If E≥0, the control is transferred to memory block 4, where the constants are stored, the values of which are equal to the conditional probability densities of the obtained values of the horizontal components of speed and acceleration to each of the four classes ([2], table of clause 3.13.2). In the block for determining the maximum 5, the target belongs to the corresponding class according to the maximum of the conditional probability density ([2], clause 3.13.2).

If E≥0, control is transferred to memory block 4, where the constants are stored, the values of which are equal to the conditional probability densities of the obtained values of the horizontal components of speed and acceleration to each of the four classes ([2], clause 3.13.2). In the block for determining the maximum of 5, the target belongs to the corresponding class according to the maximum conditional probability density of the probability that the target belongs to one of four classes.

If E <0, control is transferred to the second threshold device 6, where, in accordance with a preselected threshold of the ballistic function, the target is assigned to class 5 or 6.

However, the significance of the recognition class of the firing system is significantly affected by the mean square errors of determining the horizontal components of velocity and acceleration. First of all, this concerns the horizontal component of acceleration, the root mean square error of the determination of which can be up to 40% of its true value. In addition, modern artillery shells have initial flight speeds that are comparable to the speeds of rockets at the end of the active section, which, together with errors in determining horizontal speeds and accelerations, leads to errors in determining the class of firing systems (mixing up classes). The disadvantages of the prototype are the above facts, leading to a decrease in the probability of recognition of firing systems belonging to 1 or 3 classes.

The aim of the present invention and the technical result is to increase the reliability of recognition of goals related to 1 or 3 classes.

This goal is achieved by the fact that as an additional sign of recognition are considered a sign of increasing (decreasing) the flight speed of the projectile and its value at the midpoint of the observation site. The missile projection observation section falls either at the end of the active section and in this case the projectile speed increases, which clearly indicates that the target belongs to the third class, or on the passive missile observation section immediately following the projectile's maximum speed. In the latter case, the shell artillery shells, upon reaching the same observation site, lose up to 30% of their initial velocity (firing speed).

If the preliminary recognition, according to the well-known technical solution [2], by the value of the ballistic function and the maximum conditional probability density of the target’s belonging to one of the four classes showed that the target belongs to the 2nd, 4th, 5th or 6th class, additional recognition is not performed, so as the probability of recognition of these classes, as experience has shown, is quite high. If preliminary recognition showed that the target belongs to the first (artillery) or third (MLRS) classes, an additional refinement of the target's belonging to the first or third classes is made.

During auto tracking, the determination of the radial velocity of the projectile on the trajectory relative to the radar is carried out by the value of the Doppler frequency of the signal. The values of the Doppler frequency increase with increasing values of the velocity, which unambiguously indicates the presence of an active section of the trajectory (during engine operation, an increase in the flight speed of the projectile occurs), i.e. about the belonging of the goal to the third class. If the Doppler frequency decreases - the target is on the passive section of the trajectory - an additional analysis of the projectile speed at the midpoint of the observation section is performed. If the velocity of the projectile in the middle of the observation area is less than the threshold value, the target belongs to class 1, otherwise the target class is taken equal to that obtained after preliminary recognition.

Figure 2 shows a diagram of the proposed device, which allows the recognition of the class of explored targets.

The device includes the following blocks:

1 - block smoothing the obtained rectangular coordinates of the projectile flight path;

2 - block conversion of smooth coordinates;

3 - the first threshold device;

4 - memory block of conditional probability densities of the target belonging to each of the four classes;

5 - a unit for determining the maximum of the conditional probability density of a target belonging to one of four classes;

6 - second threshold device;

7 - storage device;

8 is a comparison device;

9 is a block analysis of increasing values of the Doppler frequency;

10 - the third threshold device.

The inventive device operates as follows.

During auto tracking, the current rectangular coordinates of the projectile’s flight path and the signal’s Doppler frequency are fed to the input of block 7, where the values of the Doppler frequency of the signal are stored and transmitted from the first output to the second input of the analysis unit for increasing the Doppler frequency 9, and the rectangular coordinates of the projectile’s flight from the second the outputs of block 7 are transferred to the input of smoothing block 1. Next, in block 1, the rectangular coordinates of the projectile's flight path are smoothed, resulting in Xia smoothed estimates of rectangular coordinates, velocity and acceleration of the projectile at the end of the observation interval. In conversion block 2, the rectangular coordinates of the projectile’s flight path, projectile velocities and accelerations are recalculated in the middle of the observation interval, the horizontal components of the velocities and accelerations in the middle of the observation interval are calculated, and the ballistic function E is calculated. Then, the sign of the ballistic function is analyzed in the first threshold device 3 E.

If E≥0, control is transferred to memory block 4, where the constants are stored, the values of which are equal to the conditional probability densities of the obtained values of the horizontal components of speed and acceleration to each of the four classes (1, 2, 3, or 4) [2]. In the block for determining the maximum 5, the target belongs to the corresponding class according to the maximum conditional probability density of the probability that the target belongs to one of the four classes, after which control is transferred to the comparison device 8.

If E <0, control is transferred to the second threshold device 6, where, in accordance with a pre-selected threshold of the ballistic function, the target is assigned to class 5 or 6, after which control is also transferred to the comparison device 8.

The comparison device 8 analyzes the belonging of the target to 1 or 3 classes. If the target belongs to the 2nd, 4th, 5th or 6th classes, recognition of the target's class is considered completed. If the target belongs to class 1 or 3, control is transferred to the first input of block 9, where the presence of an increase in the Doppler frequency values received at the second input of block 9 from the first output of memory device 7 is analyzed. If the Doppler frequency increases, the target belongs to class 3 and recognition target class deemed to be met, otherwise control is passed to a third threshold device 10, where a comparison is made of the projectile velocity at the midpoint of the observation portion V _cp with a threshold value V _pore .

If V _cp <V _threshold - the target belongs to class 1 and recognition of the target class is considered fulfilled, otherwise (V _cp ≥ V _threshold ) - target recognition is considered fulfilled, the target class does not change and remains equal to that obtained at the preliminary recognition stage. The threshold value of the V _threshold speed is determined using mathematical modeling and according to the results of experimental tests (firing) taking into account tactics of warfare (relative positions of firing positions and radar, the method of firing, etc.).

The use of the inventive device, as shown by the calculations performed on the model, and according to the authors' records of real trajectory measurements of projectile flight, increases the recognition efficiency of the class of enemy shooting systems compared to a similar device (prototype) by 30% due to the fact that additional signs of recognition:

- increase (decrease) in the values of the Doppler frequency of the signal from a moving object;

- analysis of the speed of a moving object at the midpoint of the observation site.

Increasing the reliability of recognition of the class of enemy shooting systems makes it possible to more accurately develop requirements for the quantity and type of ammunition consumed when setting a task to defeat an explored target. This all reduces the ammunition consumption when firing to defeat a proven target.

Sources of information

1. Jane's IDR, July 1997, C.37-42; ADJ: ASIAN DEFENSE JOURNAL, March 2001, p.20-23.

2. The database. 00001-03 13 01 LU, p.105-112, p.125-131.

3. Weapons of Russia, catalog, vol. I, Armament of the Ground Forces, 1996-1997, JSC Military Parade, 1996-1997, Moscow, pp. 106-107.

4. Amiantov I.N. Selected Issues of the Statistical Theory of Communication, Moscow: Soviet Radio, 1971, p.142-144.

5. Dmitrievsky A.A. External ballistics, M.: Mechanical Engineering, 1979, p. 321.

Claims (1)

Recognition device for shooting systems, containing a series-connected smoothing unit, a unit for converting smoothed target motion parameters, a first threshold device, a memory unit, a maximum determining unit, and a second threshold device, the input of which is connected to the second output of the first threshold device, and the first and second outputs the second threshold device and the output of the maximum determination unit are interconnected, characterized in that a storage device is inserted into it, sequentially connected a comparison device, an analysis unit for increasing the value of the Doppler frequency and a third threshold device, wherein the input of the storage device is an input for the measured current coordinates and for the values of the Doppler frequency, the first output of the storage device is connected to the second input of the analysis unit for increasing the values of the Doppler frequency, and the second output connected to the input of the smoothing unit, the input of the comparison device is connected to the combined outputs of the maximum determination unit and the second threshold device, p the first output of the comparison device is connected to the first input of the analysis unit for increasing the values of the Doppler frequency, the first output of which is connected to the input of the third threshold device, while the second output of the comparison device is combined with the second output of the unit for analyzing the values of the Doppler frequency, the first and second outputs of the third threshold device device output.

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