RU2285939C1 - Method for controlling airspace, irradiated by external radiation sources, and radiolocation station for realization of said method - Google Patents

Abstract

FIELD: radiolocation, possible use for controlling space, irradiated by external radio radiation sources.

SUBSTANCE: control of airspace irradiated by external radiation source is performed by observing the space by active channel of radiolocation station only in directions of observation zone in which ratio of energy of external radio-electronic means reflected by object to noise is greater than threshold value, while energy of external radio-electronic means reflected by object is received preliminarily, while time of waiting for irradiation by aforementioned device of observed direction is the least and does not exceed allowed value.

EFFECT: decreased time of operation of radiolocation station in active mode due to increased time of its operation in passive mode.

2 cl, 2 dwg

Description

The invention relates to the field of radar and can be used to control the space irradiated by external sources of radio emission.

A known method of active radar objects, which consists in the emission of sounding signals, receiving reflected signals, measuring the delay time of signals and the angular coordinates of objects, calculating the distance to objects (Theoretical basis of radar, edited by Ya.D.Shirman, M., "Sov. Radio ", 1970, pp. 9-11).

A known radar station that implements a known method comprising an antenna, an antenna switch, a transmitter, a receiver, an indicator device, a synchronizer, the signal input / output of the antenna is connected to an antenna switch, the input of which is connected to the output of the transmitter, and the output to the input receiver, the output of the receiver, in turn, is connected to the input of the indicator device, two synchronizer outputs are connected to the input of the transmitter and the second input of the indicator device, respectively, the coordinate output enny connected to the third input of the indicator device (Theoretical bases radar, ed. Ya.D.Shirmana, M., "Sov. Radio", 1970, str.221).

The disadvantage of this method and its implementing device is that the radiation of radar signals is carried out in each direction of the controlled area. This method makes the radar extremely vulnerable to anti-radar equipment, since with the continuous operation of the radar there is a high probability of detecting its signals, determining the direction of the radar and hitting it with anti-radar equipment. In addition, the possibility of energy concentration in any areas of the monitored zone to ensure the detection of unobtrusive targets or to detect targets under the influence of active interference is very limited. It can be carried out only by reducing the energy emitted in other directions of the zone.

It is known that as sources of radiation can be used sources that are not part of the radar. Such radiation sources are usually called "external" (Gladkov V.E., Knyazev I.N. Detection of air targets in the electromagnetic field of external radiation sources. "Radio engineering", issue 69, pp. 70-77). External sources of radio emission can be radars of neighboring states and other radio-electronic means (RES).

The closest way to control the space irradiated by external radiation sources includes a space survey using radar, additional reception of the energy of the external RES, reflected by the object, determining the boundaries of the zone in which the ratio of the reflected energy of the RES to the noise Q is greater than the threshold value Q _pores , and energy radiation is only those areas of the zone in which the reflected energy of RES is detected (RF Patent No. 2215303, 09/28/2001).

The device closest to the claimed one is a radar station (Fig. 1) containing a passive and active channels, a coordinate calculation unit, the passive channel including a series-connected receiving antenna and a receiver, the active channel including a series-connected antenna, an antenna switch, a receiver and a range calculating device, as well as a synchronizer and a transmitter, the output of which is connected to the input of the antenna switch, the first and second outputs of the synchronizer being connected respectively to the input of the transmitter and the second input of the distance calculating device (RF patent №2226701, 13.03.2001 g).

The essence of the known method is as follows.

For the used RES, the ratio of the energy reflected by the object to noise (i.e., the signal-to-noise ratio) at the receiving point is calculated according to the formula (Blyakhman AB, Runova IA The bistatic effective area of scattering and detection of objects during radar transmission to the light. "Radio engineering and electronics", 2001. vol. 46, No. 4, formula (1) on p. 425):

where Q = P _c / P _W - signal to noise ratio;

P _T is the average power of the transmitting device;

G _T , G _R - gain of the transmitting antenna of the RES and the receiving antenna of the radar, respectively;

λ is the wavelength;

η - generalized losses;

σ (α _B , α _G ) is the EPR of the object for the on-off system as a function of the vertical and horizontal diffraction angles α _B and α _G, respectively; the diffraction angle is understood to mean the angle between the direction of irradiation and the line connecting the object and the observation point;

F _T (β, θ), F _R (β, θ) are the radiation patterns of the transmitting antenna of the RES and the receiving antenna of the radar, respectively;

R _W - the average noise power in the band of the receiving device;

R _T , R _R - the distance, respectively, from the RES and the receiving device to the object.

The angular boundaries of the zone are calculated vertically and horizontally, in which the signal-to-noise ratio Q is not less than the threshold Q _POR . The value of the threshold Q _POR is selected based on the required reliability of detection of the energy of the RES reflected by the object.

Within the limits calculated in this way, the zone is inspected in a passive mode (in the frequency range of the selected RES). Active mode is not used. If in some direction of the inspected part of the zone the measured energy of the RES has a level not less than threshold, then this direction is examined in the active mode. In this case, a probe signal is emitted, an object is detected and its coordinates are measured. Then continue the inspection in passive mode.

Thus, the number of areas of the zone inspected in active mode is reduced. Due to this, in some directions of the zone, the concentration of radar radiated energy can be increased, which increases the reliability of object detection.

A disadvantage of the known technical solutions is as follows.

As you know, external sources of radiation, such as radars located on the territory of neighboring states, are characterized for an external observer by the randomness of radiation over time. Therefore, the use of such sources, irradiating the inspected section of the zone with a sufficient power level, as a rule, requires a long waiting time for exposure.

It can be shown that when using an external radar as an external 1st source, including one located on the territory of a neighboring state, the exposure time t _{i of the} inspected direction will be determined by the expression:

where Δα _i , Δβ _i is the angular size of the set of parts of the bottom beam of the i-th external radar, the radiation level of which provides Q≥Q _POR ;

ΔA _i ; ΔB _i - the angular size of the field of view of the external radar;

T _i - the period of the review of the space of the i-th external radar.

For the case when the fulfillment of the condition Q≥Q _{POR is} provided only by the main beam of the bottom of the i-th external radar (which takes place in the prototype), i.e. Δα _i Δβ _i = Δα _i0 Δβ _i0 , where Δα _i0 Δβ _i0 are the angular dimensions of the main beam of the bottom beam of the i-th external radar, given that the angular dimensions of the field of view of the external radar (ΔA _i , ΔB _i ) are significant, it is true:

и t_i→T_i.

and t _i → T _i .

It follows that since for modern surveillance radars the review period is T _i = 5 ÷ 15 s and is strictly limited, their use as external radars with a single-channel survey method is practically excluded, since the survey of a space consisting of tens of thousands of directions at a cost for inspection of each direction 5 ÷ 15 s is unacceptable.

In addition, modern radars operate in a wide range of frequencies, have a large number of signal types, the parameters of which, although they are known, require a larger number of channels for reception.

Modern radars are required to provide an overview of the space sequentially in time without additional beam stop, i.e. "on the aisle." Due to the fact that the moments of irradiation of the zone with the main beam of an external radar and the moments of reception of radiation by a radar station in the same directions rarely coincide, the achieved time of operation of the radar in the passive mode as a whole over the viewing area is small. Accordingly, the time of its operation in the active mode is significant. In the closest technical solutions when using external radars as radiation sources, the overwhelming majority of the time the radar operates on radiation practically in the entire field of view, which, as noted, increases its vulnerability to enemy anti-radar equipment and limits the possibility of energy concentration. This is a disadvantage of the closest technical solutions.

Thus, the solved problem (technical result) of the claimed technical solutions is to reduce the radar operating time in the active mode by increasing the time of its operation in the passive mode.

The problem is solved in that in the method of controlling the air space irradiated by external radiation sources, consisting in a survey of space by a radar station, in the additional reception of the energy of an external electronic means (RES) reflected by the object, in determining the boundaries of the zone within which the ratio of the reflected the object of the energy of the RES to the noise is greater than the threshold value, and in the radiation of the radar signals only in those directions of the zone in which the reflected energy of the RES is detected, according to the invention estvlyayut reception energy of the external REF, the waiting time of irradiation that view the directions and do not exceed the lowest allowable value.

The problem is also solved by the fact that:

- as external RES, choose ground-based radars, including radars of neighboring states, determine their parameters and coordinates;

наибольшее, где Д_MAKCi - максимальная дальность действия i-й внешней РЛС, Д_ФАКТi - расстояние от i-й внешней РЛС до просматриваемого участка зоны;- to view the area of the zone, select those external radars for which, ceteris paribus, the ratio

the largest, where D _MAKCi is the maximum range of the i-th external radar, D _FACTi is the distance from the i-th external radar to the area being viewed;

- to view the area of the zone, select those external radars for which, ceteris paribus, the diffraction angles are the smallest;

- to view the area of the zone choose external radar with a wide bottom in the elevation plane;

и углы дифракции и составляют карту соответствия участков контролируемой зоны параметрам внешних радиолокационных станций, подлежащим использованию при контроле этих участков.- based on the stored angular coordinates β _i , ε _i , and the range D _FACTi for i = 1, ..., n external radars calculate the values

and diffraction angles, and make a map of the correspondence of the areas of the controlled zone to the parameters of external radar stations to be used in monitoring these areas.

The problem is also solved by the fact that in a radar station containing a passive channel including a serially connected receiving antenna and a receiver, and an active channel including a serially connected antenna, an antenna switch, a receiver and a range calculator, as well as a synchronizer and transmitter, the output of which is connected with the input of the antenna switch, and the first and second outputs of the synchronizer are connected respectively to the input of the transmitter and the second input of the range calculator , according to the invention, a second input of the receiver, a synchronizer input and a channel control unit containing a memory, and a calculator connected to its output, the output of which is connected to the second input of the receiver, and its second input is connected to the third output of the synchronizer, as well as a second calculator, input and the output of which is connected respectively to the output of the receiver and the input of the synchronizer.

The essence of the claimed technical solutions is as follows.

To solve this problem, information is required on the parameters of external radar systems that irradiate the radar's viewing area, which comes from electronic reconnaissance equipment, is stored and regularly updated, i.e. a map of RES is compiled and maintained. Such information contains data on the location of the RES, the time intervals of the operation of the RES on the radiation, the wavelengths of the emitted signals, the radiation power and its change depending on the angles at which the analyzed sections of the viewing area are irradiated.

The prior information on all (n) radioelectronic stations that irradiate the zone is analyzed and passively inspected for each direction of the radar's viewing area, it is analyzed and an external radio electronic station is selected that is best suited for use at the current radar operation step.

An external RES (k-e from i = 1, ..., n) is selected, having:

- the shortest waiting time for irradiation of the analyzed section of the zone, not exceeding the permissible t _ADD , which is determined on the basis of the permissible time to increase the review period:

- the largest value of the ratio of the maximum range of the RES to the distance of the RES to the area being viewed:

- smallest diffraction angles:

- the widest beam (Δθi) in the elevation plane:

Moreover, criterion (3) is the most important and, therefore, mandatory. For its implementation, it is necessary to bring as close as possible the moment of inspection of the radar direction in the passive mode to the moment of irradiation of this direction by external RES, i.e. to reduce the waiting time for irradiation by an external RES of the radar being inspected. To reduce this waiting time to the greatest extent in the claimed invention uses a phased antenna array (PAR). The HEADLIGHT makes it possible to change the position of the beam in the sector of electronic scanning in random order. This ability of the PARS allows at any time from the many directions in the electronic scanning sector to select for inspection in the passive mode the direction whose waiting time for irradiation with any external RES is the smallest. The use of an arbitrary order of choosing the direction for inspection in the passive mode instead of a sequential transition from direction to direction can significantly reduce the waiting time for irradiation of the direction. Obviously, the best effect is achieved when using two-dimensional PAR.

The receiving position, which is a passive radar with a phased array, has a frequency-tunable equipment for receiving and processing signals from external RESs, in particular external active radars, including those located in neighboring countries. According to the results of the selection of an external RES, the receiving channel equipment is tuned.

After selecting the RES, the signal is received by the passive channel. If at the same time a reflected signal of an external RES is detected during an acceptable waiting time, i.e. conditions are met:

this means that an object is present in this direction. To detect an object and measure its coordinates in this direction, an active channel emits a signal.

If, during the acceptable waiting time by the passive channel, the level of the received radiation of the RES did not exceed the threshold value, i.e. (7) is not satisfied, this means that in this direction the object is absent. The probe signal in this direction is not emitted. The antenna beam of the passive channel moves to the next, not previously seen, direction of the controlled zone, and the process repeats.

For the case of using active radars as external radars, including those located in the territory of neighboring countries, the criterion for choosing an external radar is the total angular size of the main beam and side lobes, at which the level of received radiation has a signal-to-noise ratio Q not less than the threshold Q _POR . Such radars include, first of all, radars, the remoteness of which from the area being viewed (D _FACT ) is substantially less than the maximum radar range (D _MAX ).

, то уровень энергии внешней РЛС, падающей на осматриваемый участок зоны, будет достаточным для обнаружения объекта не только в области главного лепестка, но и боковых (уровень которых в данном случае составляет -13 дБ при равномерном амплитудном распределении поля по полотну антенны), а при дальнейшем возрастании указанного отношения - и в области фона, т.е. при этом

и t_i→0.So, for example, if the ratio

, then the energy level of the external radar incident on the area being examined will be sufficient to detect an object not only in the main lobe region, but also side ones (the level of which in this case is -13 dB with a uniform amplitude field distribution over the antenna sheet), and when a further increase in this ratio - and in the background, i.e. wherein

and t _i → 0.

. К тому же современные аэродромные РЛС имеют широкие диаграммы направленности в угломестной плоскости, что обеспечивает облучение ими одновременно большого участка зоны.The specified criterion will also be satisfied for those used as external airfield and track radars, the density of which, as a rule, is quite high and therefore the probability of fulfilling the condition is high

. In addition, modern airfield radars have wide radiation patterns in the elevation plane, which ensures that they simultaneously irradiate a large portion of the zone.

Favorable conditions for external radars are also achieved when the external radar irradiates the analyzed part of the zone with small diffraction angles. So at a diffraction angle of not more than ± 10 °, the ESR of an object increases by tens and hundreds of times (Blyakhman AB, Runova IA Bistatic effective area of scattering and detection of objects during radar transmission to the light. "Radio engineering and electronics", 2001, volume 46, No. 4, p. 424-432), which leads to a decrease in the exposure time t _i , since the detection of the object becomes possible when it is irradiated with its side lobes and the background of the radar bottom.

The choice of an external radar is based on a priori, regularly updated data on the parameters and location of the radar. These data make it possible to compile a digital map of the correspondence of the areas of the controlled space to the radar stations to be used as external ones for the control of these areas. The specified map makes it possible to provide automatic tuning of the parameters of the receiving channel for the review of areas of the zone in the passive mode.

Thus, a reduction in the waiting time for exposure to an external RES of the inspected direction in the field of view is achieved and a solution to the problem is provided — an increase in the radar operating time in the passive mode.

The invention is illustrated by the following drawings.

Figure 1 - block diagram of the closest radar;

Figure 2 - block diagram of the inventive radar.

The inventive radar station (figure 2) contains a passive channel 1, an active channel 2 and a channel control unit 3, while the passive channel 1 includes a series-connected receiving antenna 4 and receiver 5, the active channel 2 includes a series-connected antenna 6, antenna switch 7, a receiver 8 and a range calculator 9, as well as a synchronizer 10 and a transmitter 11, the output of which is connected to the input of the antenna switch 7, and the first and second outputs of the synchronizer 10 are connected respectively to the input of the transmitter 11 and the second input of the range calculator 9, the channel control unit 3 includes a memory unit 12 and a calculator 13 connected to its output, the output of which is connected to the second input of the receiver 5, and its second input is connected to the third output of the synchronizer 10, as well as the calculator 14, input and the output of which is connected respectively to the output of the receiver 5 and the input of the synchronizer 10.

The inventive radar station can be performed using the following functional elements.

Receiving antenna 4 and antenna 6 - HEADLAND with electronic scanning in azimuth and elevation and with circular mechanical rotation in azimuth (Radar Handbook, edited by M. Skolnik, vol. 2, M., Sov. Radio, 1977, pg. 132-138).

Receivers 5 and 8 are of a superheterodyne type (Handbook of the basics of radar technology. M., 1967, pp. 343-344).

Antenna switch 7 - balanced antenna switch based on a circulator (A.M. Pedak et al. Guide to the basics of radar technology. Edited by V.V. Druzhinin. Military publishing house, 1967, pp. 166-168).

The range calculator 9 is a digital computer that implements the calculation of the distance to the object by the magnitude of the delay of the reflected signal (Theoretical Foundations of Radar. / Ed. By Ya. D. Shirman, M., Sov. Radio, 1970, p. 211).

Synchronizer 10 - Radar devices (theory and principles of construction). Ed. V.V. Grigorina-Ryabova, pp. 602-603.

The transmitter 11 is a multi-stage pulse transmitter on the klystron (A.M. Pedak et al. Guide to the basics of radar technology. Edited by V.V. Druzhinin. Military publishing house, 1967, pp. 277-278).

ZU 12 - a storage device (Integrated circuits. Handbook edited by T.V. Tarabrina, - M .: "Radio and communications", 1984).

Calculator 13 - a digital computer that implements the choice of RES in accordance with the criteria (3) - (6).

Calculator 14 is a digital computer that implements active channel control in accordance with the criteria (7).

The inventive radar operates as follows.

Data on the location of the RES, the time intervals of the operation of the RES on the radiation, the wavelengths of the emitted RES signals, the radiation power and its change depending on the angles at which sections of the viewing area are irradiated, are received from electronic reconnaissance equipment and recorded in memory 12, where they are stored and regularly updated.

In the process of radar operation, the direction of the field of view is analyzed to determine the need for radiation from the probing signal of the active channel to measure the coordinates of the object. For each direction of the field of view, a RES is best suited for use. The choice of RES is carried out in the calculator 13 by checking the criteria (3) - (6) for all external RES, the parameters of which are recorded in the memory 12.

After the RES is selected, the receiver 5 is configured to receive signals of this RES. For this, from the output of the calculator 13, the signal parameters of the selected RES are fed to the receiver 5. Then, using the receiving antenna 4 and the receiver 5, the signal of the selected RES is received.

If, when receiving in the analyzed direction, a reflected signal of an external RES is found that satisfies the conditions (7), then to detect the object and measure its coordinates from the output of the calculator 14, a control signal is supplied to the input of the synchronizer 10, by which a high-frequency sounding signal is generated by the transmitter 11. From the output of the transmitter 11, the high-frequency signal through the antenna switch is supplied to the antenna 6 and emitted. The signal reflected from the object is received by the antenna 6 and fed through the antenna switch 7 to the receiver 8, where it is converted to an intermediate frequency, filtered, amplified and fed to the range calculator 9. In the range calculator 9, the distance to the object R is calculated from the delay time of the reflected signal ₀ . The azimuth and elevation angle of the object (ε ₀ and β _0, respectively) are determined by the position of the antenna beam 6.

If during the acceptable waiting time by the passive channel 1, the level of the received radiation of the RES did not exceed the threshold value, i.e. conditions (7) are not satisfied, the signal of the active channel 2 in this direction is not emitted. The beam of the receiving antenna 4 of the passive channel 1 moves to the next, not previously seen, direction of the controlled area, and the process repeats.

Claims (7)

1. The method of monitoring the air space irradiated by external sources of radiation, which consists in a passive mode of viewing the space of a radar station (radar), in receiving the reflected energy of an external electronic electronic means (RES), in determining the boundaries of the zone, within which the ratio of the reflected energy of the RES noise is greater than the threshold value, and in the radiation of radar signals in the active mode only in those directions of the zone in which the reflected energy of the RES is detected, characterized in that the energy of that external RES, the waiting time for the irradiation of which the inspected direction is the shortest and does not exceed the permissible, determined on the basis of the permissible time for increasing the radar survey period, while the information used on the time intervals of the work of the RES for radiation from electronic reconnaissance equipment is stored and regularly updated for each direction radar coverage areas. 2. The method according to claim 1, characterized in that the external radar stations are selected as ground radars, including radars of neighboring states, and their parameters are determined based on a priori information from electronic intelligence. 3. The method according to claim 2, characterized in that for viewing a section of the zone, those external radars are selected for which, other things being equal, the ratio

the greatest, where D _maxi is the maximum range of the i-th external radar, D _facti is the distance from the i-th external radar to the area being viewed. 4. The method according to claim 2, characterized in that for viewing a portion of the zone, those external radars are selected for which, other things being equal, the diffraction angles are the smallest. 5. The method according to claim 2, characterized in that for viewing a section of the zone, external radars with a wide BOTTOM in the elevation plane are selected. 6. The method according to claim 2, or 3, or 4, or 5, characterized in that on the basis of memorized and updated information from electronic intelligence on the location of the RES, the time intervals of the operation of the radiation, the wavelengths of the emitted signals, the radiation power and its changes depending on the angles at which the analyzed areas of the viewing area are irradiated, make a map of the correspondence of the areas of the controlled area to the parameters of external radar stations to be used in monitoring these areas. 7. A radar station containing a passive channel including a series-connected receiving antenna and a receiver, and an active channel including a series-connected antenna, an antenna switch, a receiver and a range calculator, as well as a synchronizer and transmitter, the output of which is connected to the input of the antenna switch, the first and second outputs of the synchronizer are connected respectively to the input of the transmitter and the second input of the range calculator, characterized in that in the passive channel given a channel control unit containing a memory device and connected to its output a computer that implements the choice of radar means, and also introduced a computer that controls the active channel, while the output of the computer that implements the choice of radio electronic equipment is connected to the second input of the passive channel receiver, and the second input of the computer that implements the choice of RES is connected to the third output of the synchronizer of the active channel, the input of the computer that implements the control of the active channel is connected to the output of the receiver of the passive channel, and the output connected to the input of the synchronizer of the active channel.

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