RU2269142C2 - Method for detecting on basis of criterion of relation of trustworthiness of packet signal with contour curve of known shape and device for realization of said method - Google Patents

Abstract

FIELD: radio-location technologies, possible use for detecting fluctuating echo-signals from airborne objects.

SUBSTANCE: method includes using a computer unit with satisfactory speed of operation, and also a priori registration, before beginning of processing, of information about contouring curve of packet echo-signal, following analysis of input information and computation by computer for m signals - of m values of relation of trustworthiness and their results of multiplication for comparison to threshold value and for deciding, whether an airborne object is detected.

EFFECT: possible detection on basis of criterion of relation of trustworthiness of packet radio-location signals with known shape of contouring curve.

2 cl, 3 dwg

Description

The invention relates to the field of radar and can be used to detect fluctuating echo signals from airborne objects (BO) with characteristics that are provided by using the likelihood ratio criterion taking into account the difference in signal-to-noise ratios in each component of the burst signal.

A known method of using radar detectors / cm "Theoretical Foundations of Radar", edited by Ya. D. Shirman, M., Sov. Radio, 1970, p. 157 /, which consists in the fact that after detection, analog echo signals are received for further processing, in which accumulate the echo signals of the radar pack from each VO and form the resulting value, which is then compared with a certain value of the assigned threshold, above which the detection of VO is detected.

A device for implementing the above method / see “Radar Reference”, M. Skolnik, M., “Sov. Radio”, 1976, volume 1, p. 194 and 195 /, containing a series-connected high-frequency part of the radar receiver, detector, analog-to-digital converter (ADC) , an input storage device (memory), the issuing unit and the output of the device with an indicator on the output, as well as the threshold register associated with the comparator, the threshold exceeding output of which is connected to the output permission input of the issuing unit.

Another close in technical essence to the claimed method is the method / see “Radar Handbook”, M. Skolnik, M., “Sov. Radio”, 1976, volume 1, pp. 183-194 /, which consists in the fact that after detection, the analog echo signals are converted into digital form using ADC and register in the input memory for subsequent primary processing, including detecting the VO by obtaining the value of the resulting signal by accumulating the echo signals of the radar pack from each VO and then comparing the resulting signal with the threshold value, which is assigned depending on the specific noise and interference situation during operation, and when the threshold is exceeded, the VO detection is detected and displayed on indicators of individual and collective use.

A device is also known that is close in technical essence to the claimed device / see "Radar Reference", M. Skolnik, M. "Sov. Radio", 1976, volume 1, p. 191 /, containing a series-connected high-frequency part of the radar receiver, detector, ADC, input memory with write and read address counters , the output unit and the output of the device with an indicator on the output, as well as the azimuth generation unit, the input of which is connected to the antenna selsyn, and the output of which is connected to the second input of the output unit, and, in addition, the operator panel and the threshold register, the input of which is connected with the first the output of the operator panel and the output of which is connected to the first input to an omparator, the threshold exceeding output of which is connected to the input of the information output permission block.

A disadvantage of the known methods and devices is that in the main cases when the signal + noise mixture is characterized, for example, by the Rice distribution, they do not provide a strict implementation of detection by the likelihood ratio criterion, since accumulation of echo signals is carried out by simple summation, which is due to the insufficient speed of computers used during the development of these circuits and devices.

The closest in technical essence to the claimed method is the method / see RF patent No. 2210790 IPC 7 G 01 S 13/56 for 2003, Bull. No. 23 /, which consists in the fact that after detecting the detectors, the analog echo signals are digitalized using the ADC and recorded in the input memory for subsequent primary processing and detection of VO by obtaining the value of the resulting signal by accumulating the echo signals of the radar packet from each VO and the subsequent comparison of the resulting signal with the threshold value, which is assigned depending on the specific noise and interference situation during operation, and if conducted If the resultant signal exceeds the threshold value, then a decision is made to detect VO, which is displayed on the indicators of individual and collective use, and prior to processing this information a priori, the known likelihood ratio function for a unit is recorded using the input device into the reprogrammable read-only memory (EPROM) echo signal in the form of a table of correspondence of the echo signal and the value of the function itself, and then in the process of processing information for each single echo signal For the selected from the input memory, the likelihood ratio functions are determined, which are recorded in the memory of the likelihood ratio values and thus get all the values of the likelihood ratio function for each radar pack, then, using the calculator for these values, the likelihood ratio functions determine their product, and then geometric mean value of the likelihood ratio function, which is then used as the address of the access to the compliance ROM and the value is read from this ROM, equivalent to the radar burst of echoes as the first operand to the calculator, as the second operand, in which the value of the echo signals is likewise read from the same EPROM when the maximum value of the likelihood ratio function is used as the address of access to the EPROM, if it is not implemented when the argument value is zero, then in the calculator for the indicated two operands the absolute difference is determined, which is then used as the value of the resulting radar signal cells for comparison with the threshold value, moreover, when the threshold is exceeded, they decide to detect VO.

The closest in technical essence to the claimed device is a device / see RF patent No. 2210790 IPC 7 G 01 S 13/56 for 2003, Bull. No. 23 /, containing the high-frequency part of the radar receiver with an antenna, a detector, an ADC, an input memory with counters for write and read addresses, a unit for issuing information on detected VOs and an output of the device, which are connected in series with each other in the indicated order from the antenna input to the output devices, and besides the indicated elements, the device contains an antenna synchro coupled to an azimuth generating unit, which in turn is connected to an information output unit, an indicator, a calculator, a memory of values of the likelihood ratio function beater, first and second address counters, a comparator, an entire device operation control unit and an operator panel from which information is entered into the threshold register, and a correspondence table of values of the likelihood ratio function and its argument is entered into the reprogrammable read-only memory through the input device. Using a calculator and a comparator, the value of the resulting signal is calculated, when the threshold value is exceeded, the detection of VO is detected. As a result, VO detection with characteristics corresponding to the detection characteristics by the likelihood ratio criterion for a burst echo with a rectangular envelope is provided.

The disadvantage of this method and device for its implementation is that when the envelope of the burst echo is characterized by an arbitrary but known shape, the detection characteristics implemented by the application of the likelihood ratio criterion are not provided due to the fact that the method and device are designed to detect the burst echo with a rectangular envelope.

The aim of the claimed invention is to provide detection by criterion of the likelihood ratio of burst radar signals in the case when their envelope differs in shape from a rectangular one by using, on the one hand, a computer with sufficient speed, and on the other hand, by a priori registration of information about the envelope of the burst echo, as well as ensuring the detection of slowly fluctuating burst echoes with losses determined only by the uncertainty of the exact values th signal-to-noise ratios for the constituents of such burst signals.

This goal is achieved by the fact that the detection method according to the likelihood ratio of the burst signals with the envelope of a known shape, which consists in the fact that the detectors after linear detection of the analog echo signals are converted into digital form using the ADC and recorded in the input memory for subsequent primary processing and detecting the VO by obtaining the magnitude of the likelihood ratio function for the entire radar burst signal from each VO when the extremum of the likelihood ratio function for each component of the burst signal is realized with an argument equal to zero, for example, in the case when the signal + noise mixture is determined by the Rice distribution, followed by comparing the obtained value with the threshold value, which is assigned depending on the specific noise and interference situation during operation, if the likelihood ratio function for the entire burst signal does not exceed the threshold value, it is decided that the analyzed signal packet is false, and if it exceeds, it is accepted I’m the decision to detect VO, which is displayed on indicators of individual and collective use, while prior to processing this information a priori, the known signal-to-noise ratio by voltage for each unit signal of the radar packet is recorded using the input register in the calculator, and then during processing information for each single signal selected from the input memory, using a calculator, the values of the likelihood ratio functions and their product for each Locating burst signal, which is compared with a threshold value.

This goal is achieved by the fact that the detection device according to the likelihood ratio of the burst signal with the envelope of a known shape, containing a series-connected output of the high-frequency part of the radar receiver, a linear detector, an analog-to-digital converter (ADC), an input storage device (memory) with recording address counters and readings, an information output unit and a device output with an indicator on the output, as well as an azimuth generation unit, the input of which is connected to the antenna selsyn, and the output of which is connected to the second the progress of the information output unit, and, in addition, the operator panel, the first output of which is connected to the input of the threshold register, the output of which is connected to the first input of the comparator, the threshold exceeding output of which is connected to the input of the information output permission block, also contains a register of weight coefficients, the input of which connected to the second output of the operator console, and the output of the register of weight coefficients is connected to the first input of the calculator, and its second input is connected to the output of the input memory, the output of the calculator is connected to the second input of the comparator, while the output rows of the control unit are connected to the inputs of the calculator, the ADC registers the weight coefficients, a threshold register, the input memory, the read and write counters unit generate data comparator and indicator.

для обеспечения обнаружения пачечного эхо-сигнала с вероятностью Р_с=0,5 при вероятности ложных тревог F=10^-1; 10^-2;...;10^-6 и разных значениях коэффициента γ, на фиг.3 - та же зависимость для Р_с=0,9. Определение коэффициента γ приводится далее.The drawings show: in Fig. 1 is a block diagram of a device that implements a method for detecting by criterion the ratio of likelihood of a burst signal with an envelope of known shape, in Fig. 2 - dependence on m of the required value

to ensure the detection of burst echo with a probability of P _with = 0.5 with the probability of false alarms F = 10 ^-1 ; 10 ^-2 ; ...; 10 ^-6 and different values of the coefficient γ, Fig. 3 shows the same dependence for P _c = 0.9. The determination of the coefficient γ is given below.

The device comprises a high-frequency part 1 of the radar receiver with antenna device 1.1, a linear detector 2, ADC 3, input memory 4 with counters 5 and 6 of the write and read addresses, respectively, antenna sync 7 connected to the antenna device, azimuth generating unit 8, output unit 9 , indicator 10, operator console 11, threshold register 12, comparator 13, weight coefficient register 14, calculator 15, control unit 16 and device output 17.

The elements 1, 2, 3, 4, 9 and 17 are connected in series with each other in the indicated order from the antenna input 1.1 to the output 17 of the device. The first output of the operator console 11 is connected to the input of the threshold register 12, the output of which is connected to the first input of the comparator 13, the threshold exceeding output of which is connected to the resolution input of the information output unit 9, the second output of the operator console 11 is connected to the input of the weight coefficient register 14, the output of which is connected with the first input of the calculator 15, its second input is connected to the output of the input memory 4, and the output of the calculator 15 is connected to the second input of the comparator 13, the outputs of the write counters 5 and read 6 are connected respectively to the second and third inputs of the input a memory 4, an antenna synchro 7 is mechanically connected to the antenna device 1.1, and the output unit 8 forming the azimuth associated with the second input unit 9 issued. The outputs of control unit 16 are connected to the corresponding inputs of calculator 15, ADC 3, memory 4, registers 12 and 14, output unit 9, counters 5 and 6, comparator 13 and indicator 10. The dotted line shows the mechanical connection of antenna syncron 7 with antenna device 1.1.

The technical result of the invention is the provision of detection with characteristics provided by the use of the likelihood ratio criterion for burst radar signals with an arbitrary but known envelope shape. These characteristics are calculated using a computer for various coefficients that determine the fragmentation of the energy of the burst signal by its components. Another result is that, compared with the case of using an optimized binary detector / cm. “Radar Handbook”, M. Skolnik, M., “Sov. Radio”, 1976, volume 1, p. 191, 193 /, for example, with the probability of false alarms 10 ^-4 , the probability of detection of VO equal to 0, 5, and the number of pulses making up the burst signal 5 ÷ 20, a gain of 1 ÷ 1.3 dB is ensured, and with a detection probability of 0.9 - 1.6 ÷ 1.9 dB. In the case of slowly fluctuating echoes, the detection of burst echoes with losses determined only by the uncertainty of the exact signal-to-noise ratios for each component of such burst echoes is realized. These losses are determined by relatively small quantities, which, as shown below, can be neglected.

In more detail, the essence of this invention is as follows.

First, we consider the case when the bursts of a burst echo signal are characterized by known signal-to-noise ratios.

The likelihood ratio of independent sample samples is written as

λ = f ₁ (x ₁ , Q ₁ ) f ₁ (x ₂ , Q ₂ ) ... f ₁ (x _m , Q _m ) / f ₀ (x ₁ ) f ₀ (x ₂ ) ... f ₀ (x _m ).

where f ₁ (x, Q) and f ₀ (x) are the probability densities of the random variable X, respectively, for a mixture of useful and interfering signals and some interfering noise signals; x - sample sample, the information of which is fed to the input of the detector; 1, 2, ..., m - serial number (i) of the sample sample; Q = [E ₁ (x ² ) / E ₀ (x ² )] - 1; E ₁ (x ² ), E ₀ (x ² ) - the second moments of the value of X for a mixture of signal and noise and for one noise, respectively.

If a detector is used according to the likelihood ratio criterion, the probability of detecting a burst signal

Pc = 1-Fc (Z _m ) | _{Zm = Zpore} , where

Z _m is the integration region in the m-dimensional space, the boundary of which is determined by the set of those values x ₁ , x ₂ , ..., x _m for which λ = С; C-constant, which changes with a change in the value of Z _m ; Z _then - the threshold value of Z _m ; a vertical line with equality for this line means a condition under which the expression itself is true.

The threshold value is selected from the condition for the execution of the set probability of false alarm (F). The value of F = 1-F _p (Z _m ) | _{Zm = Zpore} , where

a Z _m is the same integration region as in (1).

а отношение f₁(x,Q)/f₀(x)=f(x,Q) в области возможных значений Х характеризуется только одним экстремумом.Note that the functions f ₁ (x, Q) and f ₀ (x) have the following properties: f ₁ (x, Q) ≥0; f ₀ (x) ≥0;

and the ratio f ₁ (x, Q) / f ₀ (x) = f (x, Q) in the range of possible values of X is characterized by only one extremum.

The method for detecting a burst signal by the likelihood ratio criterion is simplified if it is determined by a function that depends on one variable (x ^* ) and which has the same value for x ^* as λ for x ₁ , x ₂ , ..., x _m . This condition is satisfied if

λ = f (x ₁ , Q ₁ ) f (x ₂ , Q ₂ ) ... f (x _m , Q _m ) = f (0, Q ₁ ) f (0, Q ₂ ) ... f (0 , Qm-1) f (x ^* , Q _m ),

where any of the values of Q _i can be selected as Q _m . From this equality it follows that

Equality (3) characterizes the boundary of the domain Z _m in m-dimensional space.

From (3) the quantity x ^* is determined, which is compared with the threshold V _pores . If x * ≥V _pore. , then the signal is considered detected, but if x ^* <V _{then it} is not. The implementation of this procedure is a method for detecting a burst signal by the likelihood ratio criterion for known values of Q _i .

In the most common case when the signal + noise mixture is characterized by the Rais distribution, the function

а

but

- модифицированная функция Бесселя первого рода нулевого порядка. Тогда (3) имеет вид0≤x _i ≤∞, where

- a modified Bessel function of the first kind of zero order. Then (3) has the form

При этом функция f(x,Q) характеризуется одним экстремумом в точке х=0.as

Moreover, the function f (x, Q) is characterized by one extremum at the point x = 0.

характеризуется нелинейной пропорциональной зависимостью. Тогда не величину х^*, а это произведение целесообразно сравнивать с его пороговым значением. Заметим, что на практике вместо расчета величин

можно, аналогично тому, как и в /3/, использовать таблицу значений

In the case under consideration, as with (3), the value of x ^{* is} compared with a threshold. The implementation of such a procedure with the modern development of the level of computer technology does not cause difficulties. But this procedure can also be simplified if we take into account that the dependence of the quantity x ^* and the value of the product of functions

characterized by a nonlinear proportional relationship. Then, not the x ^* value, but this product should be compared with its threshold value. Note that in practice, instead of calculating the quantities

you can, in the same way as in / 3 /, use the table of values

A method for detecting a burst signal by the likelihood ratio criterion can be obtained, as in / 3 /, in another way.

Тогда

Выбираем другую функцию

где

Let for the functions f (x _i , Q _i ) under consideration

Then

Choose another function

Where

имеют одинаковые значения при любых сочетаниях х_i, еслиThe functions λ and

have the same meaning for any combination of x _i if

а

but

получаем

Determining from (5) the value

we get

характеризуют различные точки границы одной и той же области Z_m. Поэтому применение (4) и (5) дает одинаковые конечные результаты.X ^* and

characterize different points of the boundary of the same region Z _m . Therefore, application of (4) and (5) gives the same final results.

Когда величины Q_i разные, тоA simplified method for detecting a burst signal with Q ₁ = Q ₂ = ... = Q _m is defined / 1 / as

When the quantities Q _{i are} different, then

где

- весовые коэффициенты.

Where

- weighting factors.

этой пары. В случае использования (4) или (5) граница области Z_m для тех же условий отличается по форме от прямой линии, чем обусловлены некоторые энергетические потери

при использовании (6).The boundary of the region Z _m for any pair of pulses of the burst signal when using the simplified detection method (6) is a straight line whose angle of inclination to the coordinate axes X _i and X _{i + 1} is determined by the ratio

of this pair. In the case of using (4) or (5), the boundary of the region Z _m for the same conditions differs in shape from a straight line, which causes some energy losses

when using (6).

В случае, когда все Q_i равны, величина γ=1/m, а в случае, когда вся энергия пачечного сигнала сосредоточена в одном импульсе, величина γ=1. В других случаях 1/m<γ<1. Заметим, что формальное увеличение числа импульсов в пачечном сигнале, когда Q₁≠0, Q₂=Q₃=...Q_m=0, не изменяет значений функций F_c(Z_m) и F_п(Z_m) при использовании обнаружения по критерию отношения правдоподобия. Следовательно, величины вероятностей Р_с и F остаются такими же, как при m=1 для Q₁, a величина

уменьшается в m раз.The difference in Q _i in the burst signal will be estimated by the coefficient

In the case when all Q _i are equal, the quantity γ = 1 / m, and in the case when all the energy of the burst signal is concentrated in one pulse, the quantity γ = 1. In other cases, 1 / m <γ <1. Note that the formal increase in the number of pulses in a burst signal, when Q ₁ ≠ 0, Q ₂ = Q ₃ = ... Q _m = 0, does not change the values of the functions F _c (Z _m ) and F _p (Z _m ) when using detection by criterion of likelihood ratio. Consequently, the probabilities P _c and F remain the same as for m = 1 for Q ₁ , and the quantity

decreases m times.

A digital model was developed for calculating, according to (5), characteristics of the detection of a burst signal. Using a computer on this model, the results are obtained, which are in the form of graphs shown in figure 2 and 3. In these drawings, the following conventions: F ₁ = 10 ^-1 ; F ₂ = 10 ^-2 ; F ₃ = 10 ^-3 ; F ₄ = 10 ^-4 ; F ₅ = 10 ^-5 ; F ₆ = 10 ^-6 ; γ ₁ = 1 / m; γ ₂ = 0.7 / (m / 2); γ ₃ = 0.9 / (m / 2); γ ₄ = 1.

чем в случае обнаружения пачечного сигнала, характеризуемого коэффициентом γ=1/m. Уменьшение

составляет ≈0,7 дб при Р_с=0,5 и F=10^-1÷10^-6, а при Р_с=0,9 оно - ≈0,5÷0,6 дб. Это уменьшение незначительно возрастает при увеличении m.In accordance with the obtained characteristics, the detection of a burst signal characterized, for example, by the coefficient γ = 0.8 (2 / m), where m≥4, is provided with lower values

than in the case of detecting a burst signal characterized by a coefficient γ = 1 / m. Decrease

is ≈0.7 dB at R _c = 0.5 and F = 10 ^-1 ÷ 10 ^-6 , and at R _c = 0.9 it is ≈0.5 ÷ 0.6 dB. This decrease increases slightly with increasing m.

Next, we consider the case of detecting a fluctuating burst signal with a known envelope shape, i.e. the case when the relations of the quantities Q _{i are} known.

It is known that the amplitude of the signals when changing the viewing angle of the HE can fluctuate in the range of 20 ÷ 30 dB / cm. "Reception of signals in the presence of noise." Edited by L.S. Gutkin. M., ed. Foreign lit., 1960, p. 232 /.

обусловленные несовпадением применяемой и требуемой по критерию отношения правдоподобия формой границы области Z_m. Например, при n=±10 дб; m=8; F=10^-3 и

величина

а при m=2 - менее 0,01 дб. Если n=±5 дб, то при тех же условиях величина

и 0,003 дб соответственно для m=8 и 2. С учетом экспоненциального /см. "Прием сигналов при наличии шума". Под редакцией Л.С.Гуткина. М., изд. Иностр. лит., 1960 г., стр.232/ распределения величины сигнала в диапазоне 25 дб, когда она изменяется относительно

от -8,5 дб до +16,5 дб, средняя величина

т.е. не значительна и на практике ею можно пренебречь, а заявленный способ целесообразно использовать и для обнаружения флюктуирующих пачечных эхо-сигналов с известной формой огибающей.Using the mentioned digital model and computer, the detection characteristics are obtained for the case when the values of Q _i in the received burst signal differ n times from Q _i in (5). As a result, losses occur.

due to the mismatch between the applicable and required by the likelihood ratio criterion, the shape of the boundary of the region Z _m . For example, with n = ± 10 dB; m is 8; F = 10 ^-3 and

value

and with m = 2 - less than 0.01 dB. If n = ± 5 dB, then under the same conditions the quantity

and 0.003 dB, respectively, for m = 8 and 2. Taking into account exponential / cm. "Reception of signals in the presence of noise." Edited by L.S. Gutkin. M., ed. Foreign lit., 1960, p. 232 / distribution of the signal in the range of 25 dB, when it changes relative to

from -8.5 dB to +16.5 dB, average

those. it is not significant and in practice it can be neglected, and the claimed method is expedient to use to detect fluctuating burst echo signals with a known envelope shape.

In conclusion, we will qualitatively, rather than quantitatively, evaluate the operation of the claimed method for detecting a rapidly fluctuating burst signal with known mean values of Q _i for each component of such a signal.

а для обнаружения сильных - линейный детектор, что соответствует использованию решающего правила

В первом случае, форма границы области Z_m, например, при m=2 соответствует дуге окружности, а во втором - прямой линии. Эти формы соответственно для достаточно слабых и достаточно сильных сигналов близки к форме, определяемой по критерию отношения правдоподобия.V / cm. "Reception of signals in the presence of noise." Edited by L.S. Gutkin. M., ed. Foreign lit., 1960, p. 231 / it is indicated that to detect weak fluctuating burst echoes it is advisable to use a quadratic detector, which corresponds to the application of the decision rule

and to detect strengths - a linear detector, which corresponds to the use of the decision rule

In the first case, the shape of the boundary of the region Z _m , for example, for m = 2 corresponds to an arc of a circle, and in the second to a straight line. These forms, respectively, for sufficiently weak and sufficiently strong signals are close to the form determined by the likelihood ratio criterion.

в случае реализации сильных, за счет флюктуации, сигналов характеризуется некоторыми, хоть и незначительными, энергетическими потерями.Using the decision rule

in the case of the implementation of strong, due to fluctuations, signals is characterized by some, albeit insignificant, energy losses.

в случае появления слабых сигналов. Это в данном случае определяется значительным несовпадением формы границы области Z_m для большей части спектра значений флюктуирующего сигнала в сравнении с формой, определяемой отношением правдоподобия. Такие потери уменьшаются, если пользоваться решающим правилом (5), т.к., в этом случае, указанное несовпадение в среднем уменьшается. Поэтому использование (5), по сравнению с указанными правилами, дает хоть и незначительно, но лучшие результаты обнаружения.Losses are observed when using the rule.

in case of weak signals. This in this case is determined by a significant discrepancy in the shape of the boundary of the region Z _m for most of the spectrum of fluctuating signal values in comparison with the shape determined by the likelihood ratio. Such losses are reduced if decisive rule (5) is used, because, in this case, the indicated mismatch decreases on average. Therefore, the use of (5), in comparison with the indicated rules, gives, albeit slightly, but better detection results.

The possibility of implementing the method will be considered through a description of the operation of the device.

The method is as follows.

Before starting work, more precisely in advance, outside the operating mode, using the operator panel, information on the shape of the envelope of the burst echo signal in the form of a series of voltage-to-noise ratios for each component of this signal, which we will call a series of weight coefficients, is entered into the register 14. In accordance with the instructions of the operator before work, he, using the remote control 11, writes to the register 12 the threshold value corresponding to the moment of operation of the noise and noise situation in a particular region. The threshold may change directly during operation.

During operation, the echo signals reflected from the VO are received through the antenna device 1.1 and amplified in the high-frequency part 1 of the radar receiver, and then they are detected using a linear detector 2 (the envelope of each signal is extracted) and converted using digital-to-analog converter 3. All further digital processing is carried out during hard timing using the control unit 16, which generates a sequence of control signals, the time intervals between which are determined by the duration of the operations of the controlled units. This duration is determined by the speed of the controlled units and is tested experimentally when setting up the control unit. The control unit 9 can be implemented, for example, using a cyclic control signal generator, in which time intervals between the output signals are formed by predetermined specific feedbacks of this generator and which can be quickly changed / cm. B.I. Kryzhanovsky "Electronic Wheel". Radio electronics and communication, "Knowledge". 1991, No. 5, p. 24 /.

In this case, the obtained values of the values of the echo signals in the order of arrival with the help of SChAZ 5 are recorded in the input memory 4, arranged, for example, according to the ring addressing principle and having a capacity exceeding the required for detecting the maximum possible number of HE. In the input memory 4, for each detected HE, all (m) values of the values of the components of the burst signal are stored, and when a new value is received, the oldest is erased. As a result, a “moving window” of input information analysis is implemented. Using SCHA 6, values of m signals are read from memory 4 strictly in accordance with the order of their arrival from ADC 3 and transferred to the first input of calculator 15, and to the second input, a series of weight coefficients transmitted from register 14 in the same sequence as the values of the signals from the memory 4. In the calculator 15 m values of the likelihood ratio and their product are calculated, which is fed to the second input of the comparator 13 for comparison with the threshold value received through the first input of the comparator 13 from register 12. Moreover, if the value of the product m likelihood values relationship does not exceed the threshold value, it is decided that the analyzed packet signals intended for the VO is false. This VO is not displayed on the indicator 10 and is not issued to the output 17 of the device for further processing. Otherwise, when the threshold value is exceeded, a decision is made to detect the VO, which is displayed on the indicator 10 and the information on this VO is sent to the output 17 of the device for further processing through the information output unit 9, which is a register on which the moving window range information is recorded "analysis, as well as the azimuth and magnitude of the analyzed components of the burst signal, followed by their issuance, provided that the threshold value is exceeded by the likelihood ratio for the entire burst signal.

Similarly, for other signal packs, other VOs are detected in this radar survey. At the next reviews, the radars also process new packets of echo signals of each VO, confirming or refuting the correctness of their detection.

Information sources

1. M. Skolnik. Handbook of Radar, Volume 1. Owls. radio, 1976

2. Theoretical foundations of radar. Edited by Y.D.Shirman. M., Sov. radio, 1970

3. S.K. Tyulpanov. Patent No. 2210790 of the Russian Federation for 2003, Bull. No. 23.

4. Reception of signals in the presence of noise. Edited by L.S. Gutkin. M., Publishing house of foreign countries. lit., 1960

5. D. Middleton. Introduction to statistical communication theory. Translation from English edited by B.R.Levin. M., Sov. Radio, Volume 1, 1961 and Volume 2, 1962

6. B.R. Levin. Theoretical foundations of statistical radio engineering. M., Radio and Communications, 1989

Claims (2)

1. A method for detecting by the criterion of the likelihood ratio of a radar burst signal with an envelope of a known shape, which consists in the fact that after receiving and linear detection, the analog echo signals are converted into digital form and recorded in a storage device for subsequent primary processing and decision-making on the detection of airborne objects by obtaining the value of the likelihood ratio function for the entire radar burst signal from each air object, for the case when the mixture with the noise + noise is characterized by a rice distribution, followed by comparing the obtained value of the likelihood ratio function for the entire radar burst signal with a threshold value, which is assigned from the condition for the execution of the set probability of false alarms, characterized in that a priori, before the initial processing, using the register of weight coefficients - signal-to-noise ratios by voltage for all components of the analyzed packet, record the values of these coefficients, and then transmit them together with the magnitude the signals themselves from the storage device to the calculator, where they calculate the likelihood ratio function for each component of the analyzed signal packet, and then calculate their product and thus obtain the likelihood ratio function for the entire radar burst signal, if, when comparing with the threshold the magnitude of the product of the likelihood ratio values does not exceed it, then decide that the analyzed signal packet for a given estimated ear object is false, otherwise make a decision about finding an air object. 2. A detection device based on the likelihood ratio of a radar burst signal with an envelope of a known shape, comprising a radar antenna, a high-frequency part of the radar receiver, a linear detector, an analog-to-digital converter (ADC), an input storage device (memory) with write and read address counters , an information output unit, a device output with an output indicator, and an azimuth generation unit, the input of which is connected to an antenna selsyn, which, in turn, is connected to a radar antenna, and the output for which it is connected to the second input of the information output unit and, in addition, an operator panel, the first output of which is connected to the input of the threshold register, the output of which is connected to the first input of the comparator, the threshold exceeding output of which is connected to the resolution input of the information output unit, and also containing the unit control, the outputs of which are connected to the control inputs of the ADC, threshold register, input memory, write and read counters, information output unit, comparator and indicator, characterized in that the device comprises a calculator and a register for weight coefficients, the input of which is connected to the second output of the operator panel, and the output of the register of weight coefficients is connected to the first input of the calculator, and its second input is connected to the output of the storage device, the output of the calculator is connected to the second input of the comparator, while the control inputs of the calculator and register of weight coefficients connected to the outputs of the control unit.

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