RU2524208C1 - Method for radar detection of manoeuvre of ballistic target on passive trajectory section - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method comprises estimating the rate of change of the product of range and radial velocity in the middle of a sliding window-type observation interval on two fixed samples of the product of range and radial velocity, wherein the sample of a lower volume is part of the sample of a larger volume, and then calculating the ratio of the absolute increment of velocity estimates to the root-mean-square estimation error. A decision on detection of manoeuvre is made at a moment in time when the ratio of the absolute increment of velocity estimates to the root-mean-square error of the velocity estimate becomes greater than a given threshold.

EFFECT: high probability of detecting manoeuvre of a ballistic target by avoiding measurement of the elevation angle and azimuth from processed samples.

2 dwg, 3 tbl

Description

The invention relates to devices for the processing path of radar information and can be used in radar and in automated control systems of radar units.

The detection of a ballistic target maneuver (BC) on a passive trajectory (PUT) is very important from both tactical and technical points of view. Untimely detection of a maneuver can lead to large methodological errors in predicting the point of incidence, since during a maneuver the BC flight range can increase by tens of kilometers. In technical terms, BC maneuvering can significantly impair the accuracy of determining its motion parameters and the stability of automatic tracking.

In connection with the aforementioned circumstances, it is advisable to include special maneuver detectors (OM) in the radar in order to exclude measurements made at the maneuver site from the sample being processed.

Known methods for detecting maneuvers based on estimating the acceleration and rate of change of the coordinate of the target, using algorithms for parametric identification of the estimated parameters with their a priori values, using techniques for detecting the divergence of the filtering process, etc. (Kuzmin SZ Digital processing of radar information. - M .: "Radio and communications, 1967. - S.310-311, S.346-347. Estimation of range and speed in radar systems. Part 2. / Under the editorship of V.I. Merkulov. - M .:" Radio engineering " , 2007. - S.194-214). The main disadvantage of these methods is the low sensitivity of maneuver detection in rough measurements of azimuth and elevation of the target.

The closest in essence to the claimed method, that is, the prototype, is a method for detecting maneuver by the absolute value of the speed increment. (Kuzmin SZ. Digital processing of radar information. - M.: “Radio and communications”, 1967. - S.346-347). In relation to a ballistic target, a maneuver can be detected by the absolute value of the increment of the rate of change of the horizontal Cartesian coordinate, since the motion of the rocket along the horizontal axis of the Cartesian coordinate system is uniform and the velocity component will be constant. (Zhakov A.M., Pigulevsky F.A. Ballistic missile control. - M.: Military Publishing House of the USSR Ministry of Defense, 1965 - S.12-13). In the maneuver section, the velocity component along the horizontal axis will be variable, since accelerations appear due to the action of forces and moments of the maneuver devices.

и в предыдущем обзоре $${\widehat{V}}_{x_{n-1}}$$

по одинаковым выборкам типа «скользящего окна» значений координаты и вычисляют их разность, то есть абсолютную величину приращения скорости:First, estimates of the rate of change of the Cartesian coordinate, for example, the x coordinate, are found in the current review $${\widehat{V}}_{x_n}$$

and in the previous review $${\widehat{V}}_{x_{n-\mathrm{one}}}$$

based on the same samples of the “sliding window” type of coordinate values and calculate their difference, that is, the absolute value of the speed increment:

$$|\; |\; |\Delta {\widehat{V}}_x|\; |\; |=|\; |\; |{\widehat{V}}_{x_n}-{\widehat{V}}_{x_{n-\mathrm{one}}})|\; |\; |$$

и сравнивают с некоторым наперед заданным порогом (числом а) в каждом новом положении «скользящего окна».Then, this absolute value of the speed increment is divided by the standard error (RMS) of the speed estimate $${\sigma }_{{\widehat{V}}_x}$$

and compared with a certain predetermined threshold (number a) in each new position of the “sliding window”.

Thus, the maneuver detector by the prototype method is a threshold device and operates according to the following algorithm:

- маневр обнаружен;if $$\frac{|\; |\; |\Delta {\widehat{V}}_x|\; |\; |}{{\sigma }_{{\widehat{V}}_x}}>a$$

- maneuver detected;

- маневр отсутствует.if $$\frac{|\; |\; |\Delta {\widehat{V}}_x|\; |\; |}{{\sigma }_{{\widehat{V}}_x}}\le a$$

- no maneuver.

:By a similar rule, a maneuver is detected when using the absolute increment of the estimate of the rate of change of another horizontal Cartesian coordinate $$|\; |\; |\Delta {\widehat{V}}_y|\; |\; |=|\; |\; |{\widehat{V}}_{y_n-}{\widehat{V}}_{y_{n-\mathrm{one}}}|\; |\; |$$

:

- маневр обнаружен;if $$\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}>a$$

- maneuver detected;

- маневр отсутствует.if $$\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}\le a$$

- no maneuver.

The probability of detecting a maneuver is calculated by the formula:

. $$R_{m\mathrm{but}n.}=2F_0\left(\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}\right)=\frac{2}{\sqrt{2\pi }}{\displaystyle {\int }_0^{\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}}{e}^{\frac{-{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="00000057.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{2}}dt}$$

.

Values of the normalized Laplace function Ф ₀ (.) Are given in table 1.1.2.6.2. (Bronshtein I.N., Semendyaev K.A. Handbook of mathematics for engineers and students of technical colleges. - M .: "Science", 1980, S. 92-93).

The threshold value is selected according to a predetermined probability of detecting a maneuver. For example, at the threshold a = 2, the probability of detecting a maneuver will be equal to p _man. = 0.954, and for a = 3 - p _man. = 0.997.

Estimates of the rate of change of the horizontal Cartesian coordinates and the standard deviation of these estimates are calculated by the formulas for the linear trajectory by the optimal weighted summation of the values of the Cartesian coordinates:

; $${\widehat{V}}_y=\frac{{\widehat{\Delta }}_{1}y}{T_0}=\frac{1}{T_0}{\displaystyle \sum _{i=1}^n\eta (i)y_i}$$

, $${\widehat{V}}_x=\frac{{\widehat{\Delta }}_{\mathrm{one}}x}{T_0}=\frac{\mathrm{one}}{T_0}{\displaystyle \sum _{i=\mathrm{one}}^n\eta (i)x_i}$$

; $${\widehat{V}}_y=\frac{{\widehat{\Delta }}_{\mathrm{one}}y}{T_0}=\frac{\mathrm{one}}{T_0}{\displaystyle \sum _{i=\mathrm{one}}^n\eta (i)y_i}$$

,

, $${\widehat{\Delta }}_{1}y$$

- оценки первого приращения координаты за период обзора;Where $${\widehat{\Delta }}_{\mathrm{one}}x$$

, $${\widehat{\Delta }}_{\mathrm{one}}y$$

- estimates of the first increment of the coordinate for the review period;

- весовые коэффициенты оценки первого приращения (скорости); $$\eta (i)=\frac{12i-6-6n}{n(n^2-\mathrm{one})}$$

- weighting coefficients of the estimation of the first increment (speed);

T ₀ - radar survey period;

n is the number of measurements in the processed sample (sample size) (Kuzmin SZ Digital processing of radar information. - M: "Radio and communications", 1967, S.300-301).

The values of the standard deviation of the velocity estimates are calculated by the formulas (ibid., P. 308):

, $${\sigma }_{{\widehat{V}}_y}=\frac{{\sigma }_y}{T_0}\sqrt{\frac{12}{n(n^2-1)}}$$

, $${\sigma }_{{\widehat{V}}_x}=\frac{{\sigma }_x}{T_0}\sqrt{\frac{12}{n(n^2-\mathrm{one})}}$$

, $${\sigma }_{{\widehat{V}}_y}=\frac{{\sigma }_y}{T_0}\sqrt{\frac{12}{n(n^2-\mathrm{one})}}$$

,

- СКО вычисления декартовой координаты x;Where $${\sigma }_x=\sqrt{{(r\text{cos}\epsilon \text{cos}\beta {\sigma }_{\beta })}^2+{(r\text{sin}\epsilon \sin \beta {\sigma }_{\epsilon })}^2}$$

- RMSE for calculating the Cartesian coordinate x;

- СКО вычисления декартовой координаты y; $${\sigma }_y=\sqrt{{(r\text{cos}\epsilon \text{sin}\beta {\sigma }_{\beta })}^2+{(r\text{sin}\epsilon \text{cos}\beta {\sigma }_{\epsilon })}^2}$$

- RMSE for calculating the Cartesian coordinate y;

σ _β , σ _ε - standard deviation of azimuth and elevation measurements. RMSE range measurements are not taken into account, since they have an insignificant effect.

We consider the essence of maneuver detection by the prototype method using the example of the maneuver detector using samples of five values of the Cartesian coordinate y. The structural diagram of OM is presented in figure 1. It consists of a unit 1 for converting the measured polar coordinates, that is, the calculation of the Cartesian y coordinate, a unit 2 for estimating the first increment of the y coordinate for the survey period, a divider for estimating the first increment for the survey period (block 3), a delay line for the survey period (block 4) , inverter (block 5), adder 6 for calculating the absolute increment of the speed estimates, a calculator of the standard error of the speed estimate (block 8), a divider 7 of the absolute increment of the speed estimates by the standard error of the estimate and threshold devices about 9.

The y coordinate values calculated in block 1 are supplied to the input of the storage device by blocks 2, consisting of 4 delay lines. The current value of the coordinate y ₅ , multiplied by the weight coefficient (0.2) and fed to the input of the adder. Coordinate values y ₁ -y ₄ calculated from the data of range, azimuth and elevation in previous surveys, after a delay of the required number of viewing periods and multiplication by the corresponding weight coefficient, are fed simultaneously to the current weighted coordinate value to the adder input. Thus, at the input of the adder, fixed surveys of 5 weighted coordinate values are generated in each survey, and the optimal estimates of the first increment of the coordinate are obtained at the output of the adder. After dividing this increment in block 3 by the review period, a current estimate of the coordinate change rate is obtained and fed to the input of adder 6. The velocity estimate obtained in the previous review and multiplied by (-1) is received at the other input of the adder. At the output of the adder, an absolute increment of the speed estimates is obtained, divided by the standard deviation of the speed estimate and fed to the threshold device 9. The decision to detect a maneuver is made at the time when the absolute increment of the speed estimate to the standard deviation of the estimate becomes greater than the set threshold a.

As an example, we calculate the probability of detecting an Atakms-type maneuver on a trajectory with a firing range of 290 km. Table 1 shows the following parameters of this trajectory:

time to the moment of the fall of the rocket T _pad. ;

;measured polar coordinates: range r, elevation angle ε, radial velocity $$\dot{r}$$

;

.transformed coordinates: height z _i = r _i sinε _i , Cartesian horizontal coordinates x _i = r _i cosε _i sinβ _i , y _i = r _i cosε _i cosβ _i , range product by radial speed $$r_i{\dot{r}}_i$$

.

, угла места и азимута σ_β=σ_ε=90 мин (Вооружение ПВО и РЭС России. Альманах. - М.: Издательство НО «Лига содействия оборонным предприятиям», 2011. - С.356-361).Radar "Resonance-NE" is located in the plane of the trajectory 200 km from the point of impact. The azimuth of the BC is 45 °. RMS errors of coordinate measurement: range σ _r = 300 m, radial velocity $${\sigma }_{\dot{r}}=\mathrm{1,5}m/\mathrm{from}$$

, elevation angle and azimuth σ _β = σ _ε = 90 min (Armament of air defense and RES of Russia. Almanac. - M.: Publishing House of the Non-Commercial Partnership “League for Assistance to Defense Enterprises”, 2011. - P.356-361).

Table 1

$$\dot{r},\text{m / s}$$

T _{pad., S} r, km ε, deg z, km x, y, km $$r_i{\dot{r}}_i,\mathrm{to}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000057.png"\; state="\{\{state\}\}">m</figure-callout>}}^2/{\mathrm{from}}^2$$

one 2 3 four 5 6 7 246 321.1 8.81 -1051 49.18 224.37 -337.38 236 310.53 8.0 -1063 43.22 217.44 -330.03 226 299.86 6.96 -1069 36.34 210.47 -320.55 216 289.18 5.65 -1065 28.47 203.47 -307,977 206 278.62 4.06 -1043 19.73 196.52 -290.60 196 268.5 2.19 -965 10.26 189.72 -259.10 186 258.65 1,5 -910 6.77 182.83 -235.35 176 250.85 1,52 -948 6.65 177.31 -162.60 166 245.45 2.01 -448 8.61 173.45 -109.96 156 241.58 2,57 -383 10.83 170.65 -81.73

The maneuver begins 196 seconds before the point of impact of the rocket. To detect the maneuver, samples of five coordinate values are generated. The calculation results are presented in table 2.

table 2 The moment of assessment, with 206 196 186 176 166 156

$${\widehat{V}}_{y_n}({\widehat{V}}_{x_n}),\text{m / s}$$

-697 -694 -690 -660 -585 -475 $$|\; |\; |\Delta {\widehat{V}}_y|\; |\; |,\text{m / s}$$

- 3 four thirty 75 110 $${\sigma }_{{\widehat{V}}_y},\text{m / s}$$

174 169 163 157 152 147 $$\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}$$

0 0.02 0.02 0.19 0.49 0.75 $$R_{m\mathrm{but}n.}=2F_0\left(\frac{|\; |\; |\Delta {\widehat{V}}_y|\; |\; |}{{\sigma }_{{\widehat{V}}_y}}\right)$$

0 0 0 0.15 0.38 0.55

As can be seen from the above example, due to large errors in azimuth measurement in the Resonance-NE radar, maneuver is practically not detected. In order to detect a maneuver with a probability of at least 0.95 at the 176th second (2 reviews after the start of the maneuver), it is necessary to set the threshold a = 2 and reduce the azimuth measurement error by more than an order of magnitude (from σ _β = 90 min to σ _β = 9 min).

Thus, the main disadvantage of the prototype is the low probability of detecting maneuver with rough measurements of azimuth and elevation. Therefore, in radars, the antenna dimensions of which are commensurate with the wavelength, primarily in the radar meter wavelength range, to use this method is impractical.

The technical result of the present invention is the development of a new method, the use of which increases the probability of detecting maneuver by excluding measurements of azimuth and elevation from the processed samples.

. В заявляемом изобретении вычисляют оценки скорости изменения произведения дальности r_i на радиальную скорость $${\dot{r}}_i$$

путем оптимального взвешенного суммирования фиксированной выборки типа «скользящего окна» значений произведений дальности на радиальную скорость $$r_i{\dot{r}}_i$$

:To achieve this result, high-precision measurements of the range r _i and radial velocity (rate of change of range) are used. $${\dot{r}}_i$$

. In the claimed invention, the estimates of the rate of change of the product of the range r _i by the radial speed are calculated $${\dot{r}}_i$$

by optimal weighted summation of a fixed sample of the “sliding window” type of range products by radial speed $$r_i{\dot{r}}_i$$

:

$${\widehat{V}}_{r_i{\dot{r}}_i}=\frac{{\widehat{\Delta }}_{\mathrm{one}}r\dot{r}}{T_0}=\frac{\mathrm{one}}{T_0}{\displaystyle \sum _{i=\mathrm{one}}^n\eta (i)r_i{\dot{r}}_i}$$

RMSE ratings are calculated as in the prototype:

, $${\sigma }_{{\widehat{V}}_{rr}}=\frac{{\sigma }_{r\dot{r}}}{T_0}\sqrt{\frac{12}{n(n^2-\mathrm{one})}}$$

,

- СКО вычисления произведения дальности на радиальную скорость;Where $${\sigma }_{r\dot{r}}=\sqrt{{(r{\sigma }_{\dot{r}})}^2+{(\dot{r}{\sigma }_r)}^2}$$

- RMSE for calculating the product of range by radial speed;

- измеренные значения дальности и радиальной скорости;r _i $${\dot{r}}_i$$

- measured values of range and radial velocity;

- среднеквадратические ошибки измерения дальности и радиальной скорости.σ _r $${\sigma }_{\dot{r}}$$

- root mean square errors of measuring range and radial velocity.

In contrast to the prototype, the magnitude of the standard deviation depends only on the errors of measuring the radial speed and range. The errors in measuring radial velocity and range are independent of the size of the antenna and can be reduced to several meters per second and up to several tens or hundreds of meters.

The essence of the detection of maneuver by the claimed method, we consider the example of the operation of the maneuver detector on samples of three and five values of range products by radial speed. The structural diagram of OM is presented in figure 2. It consists of unit 1 for converting the measured polar coordinates, that is, calculating the product of the range by the radial speed, unit 2 for estimating the first increment of the product of the range by the radial speed for the review period, two dividers (blocks 3 and 6) for estimating the first increment for the survey period, line delays for the review period (block 4), an inverter (block 5), an adder for calculating the absolute increment of the velocity estimates (block 7), block 9 for calculating the standard error of the velocity estimate, divider 8 of the absolute increment of estimates scab on the mean square error rate estimation and threshold device 10.

The values calculated in the first block of range products at a radial speed are fed to the input of the storage device of block 2, which consists of 4 delay lines.

умножают на весовой коэффициент, равный 0,2, и подают на вход первого сумматора. Одновременно с этим сигналом на вход сумматора подаются значения произведений, задержанные на 1, 3 и 4 обзора РЛС и умноженные на свои весовые коэффициенты. В итоге, как и в прототипе, на выходе сумматора получают оценку первого приращения по выборке из 5-ти значений произведений дальности на радиальную скорость:present value $$r_5{\dot{r}}_5$$

multiplied by a weight coefficient equal to 0.2, and fed to the input of the first adder. Simultaneously with this signal, the values of products delayed by 1, 3 and 4 of the radar survey and multiplied by their weight coefficients are fed to the input of the adder. As a result, as in the prototype, at the output of the adder, an estimate of the first increment is obtained from a sample of 5 values of the range products by the radial speed:

. $${\widehat{\Delta }}_{\mathrm{one}}r\dot{r}(5)=\frac{2r_5{\dot{r}}_5+r_{\mathrm{four}}{\dot{r}}_{\mathrm{four}}-r_2{\dot{r}}_2-2r_{\mathrm{one}}{\dot{r}}_{\mathrm{one}}}{10}$$

.

. Для этого на вход второго сумматора подают задержанные на период обзора и на три периода обзора взвешенные значения произведений дальности на радиальную скорость. Как видно из приведенных формул, в отличие от прототипа оценки скорости вычисляют по выборкам разного объема для одной точки траектории ракеты (для середины интервала наблюдения).In block 2, the first increment is also estimated from a sample of 3 values of the product of the range by the radial speed: $${\widehat{\Delta }}_{\mathrm{one}}r\dot{r}(3)=\frac{r_{\mathrm{four}}{\dot{r}}_{\mathrm{four}}-r_2{\dot{r}}_2}{2}$$

. For this purpose, delayed for the period of review and for three periods of review weighted range products and radial speed are fed to the input of the second adder. As can be seen from the above formulas, in contrast to the prototype, velocity estimates are calculated from samples of different volumes for one point of the missile trajectory (for the middle of the observation interval).

делят в блоке 6 на период обзора и получают оценку скорости $${\widehat{V}}_{r\dot{r}}(5)$$

. Эту оценку подают на вход сумматора 7. Оценку первого приращения $${\widehat{\Delta }}_{1}r\dot{r}(3)$$

, полученную по выборке меньшего объема, делят в блоке 3 на период обзора и получают оценку скорости $${\widehat{V}}_{r\dot{r}}(3)$$

. Чтобы оценка $${\widehat{V}}_{r\dot{r}}(3)$$

поступала на вход сумматора 7 одновременно с оценкой $${\widehat{V}}_{r\dot{r}}(5)$$

, ее задерживают на период обзора в блоке 3. Чтобы получить приращение оценок, $${\widehat{V}}_{r\dot{r}}(3)$$

умножают на (-1) в блоке 5.First increment score $${\widehat{\Delta }}_{\mathrm{one}}r\dot{r}(5)$$

divided in block 6 for the review period and get a speed estimate $${\widehat{V}}_{r\dot{r}}(5)$$

. This estimate is fed to the input of the adder 7. Evaluation of the first increment $${\widehat{\Delta }}_{\mathrm{one}}r\dot{r}(3)$$

, obtained from a sample of a smaller volume, is divided in block 3 by the review period and a speed estimate is obtained $${\widehat{V}}_{r\dot{r}}(3)$$

. To score $${\widehat{V}}_{r\dot{r}}(3)$$

arrived at the input of the adder 7 simultaneously with the assessment $${\widehat{V}}_{r\dot{r}}(5)$$

, it is delayed for the review period in block 3. In order to obtain an increment in the estimates, $${\widehat{V}}_{r\dot{r}}(3)$$

multiply by (-1) in block 5.

делят в блоке 8 на СКО ки $${\sigma }_{{\widehat{V}}_{r\dot{r}}}$$

, вычисленную в блоке 9 для выборки меньшего объема, и подают на пороговое устройство 10. Решение об обнаружении маневра принимают в момент времени, когда отношение абсолютного приращения оценок скорости к СКО оценки становится больше заданного порога.Received at the output of the adder 7 value of the absolute increment of the estimates of speed $$|\; |\; |\Delta {\widehat{V}}_{r\dot{r}}|\; |\; |=|\; |\; |{\widehat{V}}_{r\dot{r}}(5)-{\widehat{V}}_{r\dot{r}}(3)|\; |\; |$$

divided in block 8 on the standard deviation $${\sigma }_{{\widehat{V}}_{r\dot{r}}}$$

calculated in block 9 for sampling a smaller volume, and served on the threshold device 10. The decision to detect a maneuver is made at a time when the ratio of the absolute increment of the speed estimates to the standard deviation of the estimate becomes greater than a predetermined threshold.

As an example, we calculate the probability of detecting a maneuver of the Atakms type of the inventive method according to the initial data of table 1. The calculation results are shown in table 3.

Table 3 166 The moment of assessment, with 216 206 196 186 176 0.846 1,1 1,494 2.45 2.76 4.82

$${\widehat{V}}_{r_i{\dot{r}}_i}(3),{\widehat{V}}_{r_i{\dot{r}}_i}(5),{\text{<figure-callout id="2" label="Km" filenames="00000057.png" state="{{state}}">Km</figure-callout>}}^{\text{2}}{\text{/from}}^{\text{2}}$$

0.867 1.16 1,717 3.33 3.46 3,58 $$|\; |\; |\Delta {\widehat{V}}_{r\dot{r}}|\; |\; |,{\text{<figure-callout id="2" label="Km" filenames="00000057.png" state="{{state}}">Km</figure-callout>}}^{\text{2}}{\text{/from}}^{\text{2}}$$

0.02 0.05 0.22 0.88 0.70 1.24 $${\sigma }_{{\widehat{V}}_{r\dot{r}}},{\text{<figure-callout id="2" label="Km" filenames="00000057.png" state="{{state}}">Km</figure-callout>}}^{\text{2}}{\text{/from}}^{\text{2}}$$

0.04 0.04 0,038 0,037 0,036 0,035 $$\frac{|\; |\; |\Delta {\widehat{V}}_{r\dot{r}}|\; |\; |}{{\sigma }_{{\widehat{V}}_{r\dot{r}}}}$$

0.5 1.25 5.9 24 19 35 $$R_{m\mathrm{but}n.}=2F_0\left(\frac{|\; |\; |\Delta {\widehat{V}}_{r\dot{r}}}{{\sigma }_{{\widehat{V}}_{r\dot{r}}}}\right)$$

0.38 0.78 one one one one

) и дальности (σ_r=300 м) и устранения влияния грубых измерений азимута и угла места (σ_β=σ_ε=90 мин).As can be seen from the above example, the inventive method is characterized by high sensitivity. Unlike the prototype, the maneuver is detected in the Resonance-NE radar with a probability close to unity at the very beginning, that is, at the 196th second of the missile’s flight. This effect is achieved through the use of high-precision measurements of radial velocity ( $${\sigma }_{\dot{r}}=\mathrm{1,5}\text{m / s}$$

) and range (σ _r = 300 m) and eliminating the influence of rough measurements of azimuth and elevation (σ _β = σ _ε = 90 min).

The claimed invention meets the conditions of novelty and inventive step. The features of the invention, matching the features of the prototype, are the following operations:

conversion of measured polar coordinates;

calculation of estimates of the rate of change of the transformed coordinates from fixed samples of the values of the transformed coordinates and the standard deviation of these estimates;

calculating the absolute increment of speed estimates;

dividing the absolute increment of speed estimates by the standard deviation of estimates;

making a decision to detect a maneuver at a time when the ratio of the absolute increment of the speed estimates to the standard deviation of the speed estimate exceeds a predetermined threshold, the value of which is selected based on a given probability of detecting the maneuver.

Distinctive features of the claimed invention.

When converting the measured polar coordinates, the range products are calculated by the radial velocity, and not the Cartesian coordinates.

They form fixed samples of values of range products by radial speed, and not samples of Cartesian coordinates.

Estimates of the rate of change of the product of the range by the radial speed are calculated for one point of the trajectory (for the middle of the observation interval) from fixed samples of the products of the range by the radial speed of different volumes. Estimates of the rate of change of Cartesian coordinates are calculated from samples of Cartesian coordinates of the same volume in adjacent viewing periods.

In the claimed invention does not use the results of measurements of azimuth and elevation. The probability of detecting a maneuver depends on errors in measuring radial velocity and range. The prototype does not use the results of measurements of radial velocity. The likelihood of detecting a maneuver depends on the errors of azimuth and elevation measurements, and the errors in measuring ranges have a negligible effect.

Using the proposed method for radar detection of a ballistic maneuver in a passive section of a trajectory will increase the likelihood of detecting a maneuver in a radar with rough measurements of azimuth and elevation. Timely detection of the maneuver will eliminate methodological errors in determining the parameters of the rocket’s movement, extrapolating the ballistic trajectory and predicting the point of incidence of the rocket by eliminating the measurements of range, azimuth, elevation, radial velocity made on the maneuver site from the processed samples.

Thus, the method of radar detection of a ballistic target’s maneuver in a passive section of the trajectory consists in converting the measured polar coordinates of the ballistic target, forming fixed samples of the “sliding windows” type of the converted coordinate values, calculating the rate of change of the converted coordinates and the standard error of the speed estimate, calculating absolute increment of speed estimates, calculate the ratio of the absolute increment of speed estimates to rms If the error of the speed estimate, the decision to detect the maneuver is made at the time when the ratio of the absolute increment of the speed estimates to the standard error of the speed estimate becomes greater than the threshold, the value of which is selected in accordance with the specified probability of detecting the maneuver, the products of the measured range are calculated when converting the measured polar coordinates to the measured values of the radial velocity, form two fixed samples of the products of the range by the radial velocity, at ohm, one of the samples is part of another sample, they find the estimates of the rate of change of the product of the range by the radial speed for the middle of the observation interval from two samples, calculate the absolute increment of the speed estimates and divide it by the standard error of the speed estimate in a smaller sample, make the decision to detect the maneuver at the time when the ratio of the absolute increment of the velocity estimates to the standard error of the velocity estimate becomes greater than the threshold.

Claims (1)

A method for radar detection of a ballistic target’s maneuver on a passive path segment, which consists in converting the measured polar coordinates of the ballistic target, forming fixed samples of the “sliding window” type of the converted coordinate values, calculating the rate of change of the converted coordinates and its standard error, calculating the ratio of the absolute increment of estimates of the rate of change of the transformed coordinates in two samples to the mean square error of that estimate, the decision to detect a maneuver is made by comparing the obtained ratio of the absolute increment of the estimates of the rate of change of the converted coordinates to the standard error of this estimate in each new position of the “sliding window” with a threshold corresponding to a given probability of detecting the maneuver, characterized in that they measure the radial velocity of the ballistic targets, when converting the measured polar coordinates calculate the product of the measured range values by the measured values for At the same time, these products are converted to digital signals, in each new position of the “sliding window” two fixed samples of the obtained products are formed, one of the samples being a part of the other sample, and in each sample an estimate of the rate of change of the range product by the radial speed by the optimal weighted summation of the products of the measured range values by the measured values of the radial velocity, calculate the absolute increment of the obtained estimates, calculate the root mean square If the error of estimating the rate of change of the product of the range by the radial speed in a sample of a smaller volume, the ratio of the absolute increment of the estimates of the rate of change of the product of the range by the radial speed and the standard error of this estimate is calculated; in each new position of the “sliding window”, the ratio of the absolute increment of the estimates of speed to the standard error is compared of this estimate, the decision to detect a maneuver is made at a time when the value of the obtained absolute ratio is incremented I-range product the rate of change in radial velocity estimates for the mean square error of the estimation becomes larger than a predetermined threshold.

Images