RU2615784C1 - Method and device for radar detection of ballistic facility manoeuvre by sampling of range squares - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: they measure the range of ballistic facilities (BF) in digital form and at intervals of time T0 determine the range squares when the BF is auto-tracked in the "sliding window" containing a sample of N range squares with the duration time of (N-1)T₀, assess the second increment of the range square by optimum weighted summation of N range squares and calculate the mean square deviation (MSD) of the assessment, the manoeuvre detection signal is sent, if the ratio of the inverted estimate of the second increment of the range square to the MSE assessment becomes greater than the threshold corresponding to the set probability of manoeuvre detection . Then, via the optimum weighted summation of N range squares in the "sliding window" they determine the absolute difference between the assessment of the second increment at the sample with the duration time of (N-1)T₀ and assessment of the second increment at the sample with the duration time of (N-2m-1)T₀, where mT₀ is time deleting of the beginning and the end of the sample from the beginning and the end of the "sliding window", compute the MSE of the assessment of the second increment in the range square at the sample and the ratio of the absolute difference to the MSE of the assessment. The manoeuvre detection signal is sent, if the ratio of the absolute difference between the assessments to the MSE of the assessment becomes greater than the threshold, and the decision to accept the manoeuvre is taken if one of the threshold devices or both threshold devices generate a manoeuvre detection signal. Device for implementing the method consists of a range input multiplier, a digital nonrecursive filter as a part of the memory device, the first and second blocks of the multipliers, the first and second adders and the first and second dividers, the first and second threshold devices, an MSE calculator, inverter and adder for signals of threshold devices connected in a certain manner.

EFFECT: increased probability of ballistic facility manoeuvre detection in both active and the passive phases of their flight trajectory.

2 cl, 6 dwg

Description

The invention relates to radar and can be used in radar stations (radar) to detect the maneuver of ballistic objects (BO). The task of determining the maneuver must be solved in order to prevent the appearance of methodological errors in determining the parameters of the ballistic trajectory and disruption of the auto tracking of the BO. In particular, the coordinates of the point of impact of BOs of the type of short- and medium-range missiles, calculated from the radar measurements made in the maneuver sections, can be determined with a short flight or flight from several tens to several hundred kilometers.

Three sections can be distinguished on the BO trajectory:

- the active section of the trajectory (AUT), on which the BO moves under the action of the traction force of the engines and makes a maneuver of high intensity;

- a passive section of the trajectory (PUT), starting after turning off the engines, in which the BO moves by inertia under the influence of a known force of attraction to the Earth, there is no maneuver, therefore the BO trajectory and the coordinates of its point of incidence can be determined with high accuracy;

- the maneuver section, as a rule, on the descending branch of the PUT, where the BO moves under the action of the control forces of the aerodynamic rudders or special rocket engines, therefore the trajectory differs from the ballistic one and its parameters are determined with methodological errors.

Known methods for detecting maneuver by the absolute value of the increment of speed [1, S. 346-347]. With respect to BO, a maneuver can be detected by the absolute value of the increment of the rate of change of the horizontal Cartesian coordinate, since the rocket’s motion along the horizontal axis of the Cartesian coordinate system is uniform and the velocity component will be constant [2, P. 12, 13]. In the maneuver section, the rate of change of the horizontal Cartesian coordinate will be variable, since accelerations appear due to the action of the forces of the maneuver devices.

The main disadvantage of these methods is the low probability of detecting maneuver with rough measurements of azimuth and elevation.

A known method for determining the end time of the ATF by sampling the range products by the radial speed [3] and the device for determining the end time of the ATF described in this patent. The decision to terminate the automatic control, that is, to end the BO maneuver, is made if the estimate of the rate of change of the product of the range by the radial speed becomes greater than the standard error (RMS) of the estimate.

There is a method of radar detection of maneuver BO on the ITB by sampling range products by radial speed [4] and the maneuver detection device (UOM) described in this patent. In this method, the decision on the presence of a BO maneuver is made if the absolute difference between the estimates of the rate of change of the product of the range by the radial speed, calculated from samples of larger and smaller volumes, becomes larger than the standard deviation of the sample from a smaller volume.

In these methods, a high probability of detecting the BO maneuver is achieved due to elimination of the influence of azimuth and elevation angle measurement errors. However, these methods can only be implemented in radars with high-precision radial velocity measurements.

The closest analogue to the claimed invention, that is, the prototype, is a method for radar determination of the end time of the ATF, that is, the end time of the maneuver, by selecting the squares of the range [5] and the device for determining the end time of the ATF described in this patent.

The essence of detecting maneuver by the prototype method is as follows. In the radar, the BO range is measured in digital form, at equal time intervals T ₀ , the range signals are multiplied and squares are obtained. BO auto-tracking is carried out in a "sliding window" containing a sample of N squares of a range of duration (N-1) T ₀ . In a “sliding window”, a fixed sample of N squares of a range determines the acceleration estimate by the square of the range and the standard deviation of this estimate is calculated. The decision on the end of the ATF, that is, on the end of the maneuver, is taken at the time when the value of the acceleration estimate by the squared range becomes larger than the standard deviation of this estimate.

The block diagram of the prototype device in which maneuver is detected using samples of three and five squares of range is shown in FIG. one.

The UOM prototype contains a series-connected input signal multiplier (block 1), a digital non-recursive filter (TsNRF, block 2), which includes a sequentially connected memory device from N-1 delay lines (block 2.1), a weight multiplier block (block 2.2), and the adder (block 2.3), the divider (block 3), the threshold device (block 4), the second input of which is connected to the RMS calculator (block 5), the input of which is connected to the input range signals, the output signals of the threshold device are the output signals of the UOM prototype.

The prototype device operates as follows. In block 1, at equal time intervals T _{0, the} digital range signals arriving at its input are multiplied, squares of the range are obtained and fed to the input of memory device 2.1.

умножают в блоке 2.2 на весовой коэффициент, равный

и подают на вход сумматора 2.3. Одновременно с этим сигналом на вход сумматора подают сигналы квадратов дальности, задержанные в блоке 2.1 на 1, 2, 3 и 4 обзора РЛС и умноженные в блоке 2.2 на свои весовые коэффициенты

и

. В итоге на входе сумматора 2.3 получают фиксированную выборку из 5 взвешенных значений квадратов дальности, а на его выходе - оценку второго приращения квадрата дальности:The current value of the squared range

multiply in block 2.2 by a weight coefficient equal to

and served at the input of the adder 2.3. Simultaneously with this signal, the squares of the range, delayed in block 2.1 by 1, 2, 3 and 4 of the radar survey and multiplied in block 2.2 by their weights, are fed to the input of the adder

and

. As a result, at the input of adder 2.3, a fixed sample of 5 weighted values of the squares of the range is obtained, and at its output, an estimate of the second increment of the square of the range is obtained:

и подают ее на пороговое устройство 4.This estimate is divided in block 3 by the square of the review period; an estimate of the acceleration by the square of the range is obtained

and feed it to the threshold device 4.

, где σ_r - СКО измерения дальности. Если оценка ускорения по квадрату дальности

меньше СКО

то пороговое устройство выдает сигнал о том, что БО находится на участке маневра, то есть на АУТ. Если оценка

больше СКО

, то пороговое устройство выдает сигнал об окончании маневра БО (АУТ) и о начале невозмущенного пассивного участка траектории.In block 5 calculate the standard deviation of the acceleration of the square squared range by the formula

where σ _r is the standard deviation of the range measurement. If the estimate of acceleration by the squared range

less standard deviation

then the threshold device gives a signal that the BO is located on the maneuver site, that is, at the AUT. If the score

more standard deviation

, then the threshold device gives a signal about the end of the BO maneuver (AUT) and about the beginning of the unperturbed passive section of the trajectory.

As shown in table 4 of the description of patent No. 2510861, acceleration scores on the ATE are negative (less than zero), and on the STB are several times more positive and more than the standard deviation. Therefore, the prototype is characterized by a high probability of detecting the end time of the AUT, that is, the BO maneuver.

However, the prototype cannot be used to detect a maneuver on a firearm, since the estimates of acceleration by the square of the range can be positive both on an unperturbed fire hazard and on a maneuver site on a fire hazard. In addition, the acceleration estimates can be positive for the OUT if the BO moves away from the radar. Therefore, in these cases, it is either impossible to identify the maneuver, or the probability of its detection will be low.

The technical result of the invention is to increase the likelihood of detecting a maneuver of ballistic objects along the entire path of their flight.

The specified technical result is achieved by the fact that in the claimed method of radar detection of maneuver BO, as in the prototype, in the radar measure the range of the BO in digital form. At equal time intervals T ₀ multiply the range signals and get the squares of the range. BO auto-tracking is carried out in a “sliding window” containing a sample of N squares of a range of duration (N-1) T ₀ .

In contrast to the prototype, according to the invention, in the “sliding window”, the estimate of the second increment of the square of the range is determined by the optimal weighted summation of N squares of the range and the standard deviation of this estimate is calculated. A maneuver detection signal is issued if the ratio of the inverted estimate of the second increment of the square of the distance to the standard deviation of the estimate becomes greater than the threshold corresponding to the specified probability of detecting the maneuver. Then, by the optimal weighted summation of N squares of the range in the “sliding window”, the absolute difference between the estimate of the second increment in the sample of duration (N-1) T ₀ and the estimate of the second increment in the sample of duration (N-2m-1) T ₀ , where mT ₀ - removal by time of the beginning and end of this sample from the beginning and end of the “sliding window”. Then calculate the standard deviation of the second increment of the squared range for this sample and the ratio of the absolute difference to the standard deviation of the estimate. A maneuver detection signal is issued if the ratio of the absolute difference between the estimates to the standard deviation of the estimate becomes greater than the threshold, and a decision to detect a maneuver is made if one of the threshold devices or both threshold devices issued a signal about the detection of the maneuver.

A BO maneuvering radar detection device implementing this method based on range square samples contains, as in the prototype, a series-connected multiplier, the input of which is connected to the range input signals, and a digital non-recursive filter (TsNRF) including a series-connected memory device from N-1 delay lines, a block of multipliers by weighting factors and an adder, as well as an RMS calculator, the input of which is connected to the input range signals, and a divider, the output of which is connected to the first input thresholds of the device.

In contrast to the prototype, according to the invention, the first output of the TsNRF is connected to the input of an additionally introduced inverter, the output of which is connected to the first input of the first divider. The second input of the divider is connected to the first output of the RMS calculator. The second input of the first threshold device is connected to the source of the threshold, and the output is connected to the first input of the adder signals of the threshold devices. A second block of multipliers by weighting factors and a second adder, the output of which, which is the second output of the TsNRF, is connected to the first input of an additionally introduced second divider, are additionally included in the TsNRF. The second input of this divider is connected to the second output of the RMS calculator, and the output is connected to the first input of an additionally entered second threshold device. The second input of this device is connected to the source of the second threshold, and the output is connected to the second input of the adder signals of the threshold devices, the output of which is the output of the claimed device.

The essence of the claimed invention is illustrated by the scheme of the detection device maneuver BO on samples of 5 and 3 squares of the range shown in FIG. 2, where the following notation is introduced:

1 - multiplier of input range signals;

2 - TsNRF;

2.1 - storage device

2.2 - the first block of multipliers;

2.3 - the first adder;

2.4 - the second block of multipliers;

2.5 - second adder;

3 - the first divider;

4 - the first threshold device (PU-1);

5 - calculator RMS;

6 - inverter;

7 - the second divider;

8 - the second threshold device (PU-2);

9 - adder signals threshold devices.

In the multiplier 1, the digital range signals arriving at its input are multiplied, the squares of the range are obtained and fed to the input of the TsNRF. The storage device, the first weighting factor multiplier and the first adder work in the same way as in the prototype. As a result, at the output of the first adder (block 2.3), an estimate of the second increment of the squared range is obtained from a sample of N squared ranges:

Unlike the prototype, this estimate is inverted in the inverter 6 and divided in the divider 3 by the standard deviation of the estimate, calculated in the same way as in the prototype. The ratio of the estimate to the standard deviation is compared in PU-1 with the first threshold (P ₁ ), the value of which is selected in accordance with the given probability of detecting the maneuver. According to the probability integral for P ₁ = 1, the probability is 0.68, and for P ₁ = 2, the probability is at least 0.95 [6, C. 658-660].

. Для этого во второй блок умножителей 2.5, в отличие от прототипа, вводят другие весовые коэффициенты

At the output of the additionally introduced second adder 2.5, the absolute difference | δ | between the estimate of the second increment of the square of the range obtained from a sample of 5 squares of range and the estimate of the second increment of the square of the range obtained from a sample of 3 squares of range:

. To do this, in the second block of multipliers 2.5, in contrast to the prototype, other weights are introduced

Then, at the output of the second divider 7, the ratio of the absolute difference to the standard deviation of the estimate is obtained from a sample of 3 squares of the range, which is fed to the second threshold device 8.

If the ratio of the absolute difference to the standard deviation of the estimate is greater than the threshold, a signal is issued indicating the detection of a maneuver.

To combine the signals of the first and second threshold devices, the adder of the signals of the threshold devices 9 is introduced into the UOM circuit. The decision to detect a maneuver is made if signals about the presence of a maneuver from one of the threshold devices or from both threshold devices are received at the input of the adder 9.

To prove the feasibility of the claimed technical result in the graphs of FIG. 3-6 shows the results of comparing the probability of detecting a maneuver of operational tactical missiles of the claimed method and its analogue. RMSE coordinate measurements are equal: in range - σ _r = 50 m; in angular coordinates - 0.25 ° (15 angular minutes).

. Поэтому реализовать высокие вероятности обнаружения маневра БО с использованием способа-аналога проблематично даже в РЛС с относительно высокоточными измерениями угла места и азимута, а в РЛС с грубыми измерениями угловых координат - практически невозможно.As can be seen from the graphs of FIG. 3, in the maneuver section, the absolute differences between the estimates of the rate of change of the horizontal Cartesian coordinate in the neighboring positions of the “sliding window” are less than the standard deviation

. Therefore, realizing high probabilities of detecting a BO maneuver using the analogue method is problematic even in radars with relatively high-precision measurements of elevation and azimuth, and in radars with rough measurements of angular coordinates, it is practically impossible.

и по выборкам из 7 и 3 квадратов дальности

In the graphs of FIG. Figure 4 shows the values of the absolute differences between the estimates of the second increment of the square of the range for samples of 5 and 3 squares of range

and from samples of 7 and 3 squares of range

In the given example, the values of these differences are more than twice the value of the standard deviation of the estimate. Therefore, the beginning of the BO maneuver on the PUT is detected with a probability close to unity.

In the graphs of FIG. Figure 5 shows that as the length of the “sliding window” increases, the probability of detecting the end time of the maneuver increases.

Как видно из графика, в отличие от предыдущих примеров, маневр обнаруживается на всем активном участке траектории.In the graphs of FIG. Figure 6 shows the values of the inverted estimate of the second increment of the squared range

As can be seen from the graph, unlike the previous examples, the maneuver is detected on the entire active section of the trajectory.

Thus, the technical result of the claimed invention is achieved: the likelihood of detecting a maneuver of ballistic objects both at the PUT and at the PLC is increased.

Information sources

1. Kuzmin S.Z. Digital processing of radar information. - M.: “Radio and Communications”, 1967, 395 p.

2. Zhakov A.M., Pigulevsky F.A. Ballistic missile control. - M.: “Military Publishing House of the Ministry of Defense of the USSR”, 1965, 278 p.

3. Patent RU No. 2509319. A method for determining the end time of an active section of a ballistic missile trajectory.

4. Patent RU No. 2524208. Method for radar detection of ballistic target maneuver in a passive section of a trajectory.

5. Patent RU No. 2510861. A method for determining the end time of an active section of a ballistic missile trajectory.

6. Sigorsky V.P. Mathematical apparatus of an engineer. Kiev, "Technics", 1977, 768 p.

Claims (2)

1. The method of radar detection of the maneuver of a ballistic object (BO) from a range of squares, which consists in the fact that the radar station measures the BO range in digital form, at regular intervals T ₀ multiply the range signals and obtain the squares of the range, BO auto-tracking is carried out in " “sliding window” containing a sample of N squares of a range of duration (N-1) T ₀ , characterized in that the “sliding window” determines the estimate of the second increment of the square of the range by optimal weight total sum of N squared ranges and calculate the standard error (RMSE) of this estimate, a maneuver detection signal is issued if the ratio of the inverted estimate of the second increment of the squared range to the standard deviation becomes greater than the threshold corresponding to the specified probability of detecting the maneuver, then by the optimal weighted summation of N squared ranges a "sliding window" is determined absolute difference between the estimate of the second increment of sample length (N-1) T ₀ and the estimate of the second increment of choice e duration (N-2m-1) T _0, where mT ₀ - removal of the start and end of the sample from the beginning and end of the "sliding window", was calculated MSE estimate the second distance square increment on this sample and the ratio of the absolute difference to the MSE estimates , a maneuver detection signal is issued if the ratio of the absolute difference between the estimates to the standard deviation of the estimate becomes greater than the threshold, and a decision to detect a maneuver is made if one of the threshold devices or both threshold devices issued a maneuver detection signal. 2. A device for radar detection of a maneuver of a ballistic object from range squares, containing a series-connected multiplier, the input of which is connected to the input range signals, a digital non-recursive filter (TsNRF), including a series-connected memory device from N-1 delay lines, a block of multipliers by weight coefficients and an adder, an RMS calculator, the input of which is connected to the input range signals, and also a divider, the output of which is connected to the first input of the threshold device TWA, characterized in that the first output of the CINRF, which is the output of the first adder, is connected to the input of an additionally introduced inverter, the output of which is connected to the first input of the first divider, the second input of which is connected to the first output of the RMS calculator, the second input of the first threshold device is connected to the threshold source and the output is connected to the first input of the adder of the signals of the threshold devices, in the Central Research Center of Russia additionally included are the second block of multipliers by weight coefficients and the second adder, in addition m the inputs of the second block of multipliers by weighting factors are connected to the outputs of the storage device, the output of the second adder, which is the second output of the TsNRF, is connected to the first input of the additionally introduced second divider, the second input of which is connected to the second output of the RMS calculator, and the output is connected to the first input of the additionally introduced the second threshold device, the second input of which is connected to the source of the second threshold, and the output is connected to the second input of the adder signals of the threshold devices, the output of which is is the output of the device.

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