RU2540982C1 - Method of determining coordinates of targets (versions) and system therefor (versions) - Google Patents

Abstract

FIELD: physics, navigation.SUBSTANCE: inventions relate to radar. In the first version of the method of determining coordinates of targets, based on determining angular coordinates of a target from radio-frequency radiation reflected from said target using a passive radar station, according to the invention, the radio-frequency radiation source used is an external radar station located on the line of visibility of the passive radar station and having known coordinates and irradiating the scanned area; the method comprises receiving and measuring the time of receiving a probing signal reflected from a target and angular coordinates thereof, and receiving a forward probing signal of the external radar station and calculating the emission time thereof, and the range to the target is determined from the measured time of receiving the probing signal reflected by the target and the calculated time of emission thereof. Said technical result according to the second version is achieved due to that the method of determining coordinates of a target, based on determining angular coordinates of the target from the radio-frequency radiation reflected by the target using a passive radar station, according to the invention, the radio-frequency radiation source used is an external radar station with known coordinates and irradiating the scanned area; using an on-board radar station placed in line-of-sight range of the external radar station, receiving therefrom a forward probing signal, calculating the emission time thereof and the calculated value is transmitted at a universal time to n?1 passive radar stations, which are used to receive and measure the time of receiving probing signals reflected by targets and angular coordinates thereof, and the range to targets is determined from the measured time of receiving the probing signal reflected by targets and the time of emission thereof received from the on-board radar station. Said technical result is achieved due to that the system for determining coordinates of targets according to the first version is a passive radar station, comprising two receiving channels and a coordinate calculating unit, each channel having an antenna and a receiver; the passive radar station also comprises a probe emission time calculating unit, a target tracking unit and a universal time sensor. The listed components are interconnected in a certain manner. Said technical result is achieved due to that the system for determining coordinates of targets according to the second version is a passive radar station, comprising two receiving channels and a coordinate calculating unit, each channel having an antenna and a receiver; the system also includes n>1 passive radar stations and an on-board radar station, and the passive radar station also includes a delay calculating unit, a target tracking unit and a universal time sensor. All listed components are interconnected in a certain manner, wherein the on-board radar station includes a unit for calculating the time when the probe is emitted by the external radar station.EFFECT: measuring range to a detected remote target while maintaining stealthiness of operation and without power consumption on emission.4 cl, 6 dwg

Description

The invention relates to the field of radar and can be used in airborne passive radar stations (PRLS) located on aircraft, satellites, aerostats and other objects that are in direct line of sight of an external radar station with known coordinates and parameters of sounding signals irradiating controlled zone in which the detection and determination of the angular coordinates of targets reflecting radio emission located at long ranges, secretly and with minimal energy energy costs.

The prior art method (patent RU No. 2233456 IPC 7 G01S 13/00) for radar detection of objects based on the reception of radiation from controlled directions, measurement of radiation parameters and the decision to detect a target (object), while searching for radiation sources, accept radiation of these radiation sources, measure the correlation of received radiation with radiation from controlled directions, and this measured parameter is compared with a threshold, space inspection is carried out using a repeater, Assumption line of sight of the radiation source and passive radar (CLDP).

The prior art complex is known (patent RU No. 2233456 IPC 7 G01S 13/00) (Fig. 1), including a radar and relay, a radar contains two antennas and receivers of the first and second channels, a computer (correlator) and a threshold device. The outputs of the antennas are connected to the corresponding inputs of the receivers of the first and second PRLS channels, and their outputs are connected to the first and second inputs of the computer, the output of the computer is connected to the input of the threshold device. The repeater is removed from the PRLS within line of sight.

The complex operates as follows: the signal reflected from the target irradiated by an external radiation source is received by the first antenna and fed to the receiver input of the first PRLS channel, the signal from the radiation source re-emitted by the relay located in the line of sight of the radiation source and the PRLS is received by the second antenna and served at the input of the receiver of the second channel of the PRLS. The signals from the outputs of the first and second channels of the PRLS are fed to the first and second inputs of the calculator, which generates a signal proportional to the level of correlation of the signals at its input, and serves it to a threshold device. Exceeding the threshold is recorded as target detection in a controlled direction.

The advantage of the method and the complex is that it provides the secrecy of its work and the ability to detect targets illuminated by an external radiation source, i.e. without the cost of their own energy for irradiation of space.

The disadvantage of this method and complex is that by providing detection of a target in a controlled direction, it does not allow measuring the distance to this target.

In addition, because of the unknown parameters of the signals from external sources of radiation, it is impossible to provide a quasi-consistent reception, which reduces the detection range of the target, and due to the unpredictable operation of a random source of radiation, the use of the passive mode for detecting targets from reflections from targets of signals emitted by the source can only be episodic .

The closest method to the proposed methods for determining the coordinates of targets irradiated by an external source of radio emissions is known, based on the determination of the angular coordinates and the distance to the targets from the reflected radio emissions using passive radar stations (PRLS), which are receiving channels (PC) located in spaced in space reception points. (Theoretical Foundations of Radar. Edited by Y.D. Shirman. M., Sov. Radio, 1970, p. 494- 495). In this method, "due to the lack of information about the radiation period ..." to determine all the coordinates of the target requires a complex of two or more spaced apart in the radar space with a consistent overview of the space.

Known closest to the proposed options complex, which is a two-position radar station (Theoretical fundamentals of radar. Edited by Y.D. Shirman. M., Sov. Radio, 1970, p. 500), implementing the closest known method (Figure 2 ), containing PC 1 and PC 2 spaced in space, each of which includes an antenna 1 and a receiver 2, and also contains a block - a multi-channel correlator (MK) 3 and a block for calculating target coordinates (VK) 4. The outputs of antennas 1 are connected to the inputs of the receivers 2, and their outputs are connected to the first and second the moves of the MK 3 unit, respectively, its output is connected to the first input of the VK 4 unit, and the coordinate outputs of the antennas 1 of PC 1 and PC 2 are connected to the second and third inputs of the VK 4 unit, respectively.

The complex works as follows: the signal reflected from the target irradiated by an external radiation source 5 is received by antennas 1 and fed to the inputs of receivers 2 of PC 1 and PC 2, respectively, and from their outputs the signals are sent to the corresponding inputs of MK 3, in which the target is identified by the presence of correlation of signals received from it by both PCs. At the same time, signals from the coordinate outputs of antennas 1 of PC 1 and PC 2 and a signal from the output of MK 3 to the first input of VK 4 are received at the second and third inputs of the VK 4 block, by which the coordinates of a specific target are determined in VK 4.

The advantage of these known methods and complex is the determination of angular coordinates and range with the secrecy of its work and the simplicity of its implementation in the presence in the area irradiated by an external source of radiation, one goal.

The disadvantage of the closest method and complex is a significant complication of the implementation of the method with an increase in the number of targets (radiation sources or reflection sources) (ibid., P. 495, last paragraph). At the same time, in addition to the need to increase the number of PCs spaced in space, the time required to determine the coordinates of the targets will increase during sequential coordinated inspection of the angular directions simultaneously by several PCs, and this, when using an external radiation source, creates an instability of the method and the ability to skip targets.

In addition, the disadvantage lies in the fact that due to the unknown parameters of the signals of the radiation sources, it is impossible to provide a quasi-consistent reception, which reduces the detection range of the target, and due to the unpredictable operation of a random radiation source, the use of the passive mode for detecting targets from reflections from signal targets, emitted by the source can only be episodic.

Thus, the problem to be solved (technical result) is the measurement of the distance to the detected target, located at a great distance while maintaining the secrecy of work and without the cost of energy for radiation.

The problem (technical result) is solved by the fact that in the first version of the method for determining the coordinates of targets irradiated by an external source of radio emission, based on the determination of the angular coordinates of the target from the reflected radio emission using a passive radar station, according to the invention, a line of sight is selected as the source of radio emission PRLS external radar station with its known coordinates and irradiating the viewing area, receive and measure the moment of reception reflected For the purpose of the probing signal and its angular coordinates, they also take the direct radar sensing signal and calculate the moment of its emission, based on the measured time of reception of the probing signal reflected by the target and the calculated moment of its radiation, calculate the distance to the target.

The problem (technical result) in the second embodiment is solved by the fact that in the method for determining the coordinates of targets irradiated by an external source of radio emission, based on determining the angular coordinates of the target from the reflected radio emission using a passive radar station, according to the invention, an external radar station is selected as the source of radio emission with its known coordinates and the irradiated viewing area, using an airborne radar station (radar), located in the direct zone the visibility of the radar, take its direct sounding signal, calculate the moment of its radiation and transmit the calculated value in a single time to n≥1 radar, with which they also receive and measure at the same time the moments of reception of the probing signals reflected by the targets and their angular coordinates and based on the measured the moments of reception of the sounding signal reflected by the targets and the value of the moment of its radiation received from the radar, the range to the targets is calculated.

The task (technical result) is solved in that the complex for determining the coordinates of targets according to the first embodiment, which is a radar system containing two PCs and a VC unit, each channel contains an antenna and a receiver, the antenna outputs are connected to the corresponding inputs of the receivers of the first and second channels, coordinate the outputs of the antennas are connected to the third and fifth inputs of the VK unit, respectively, according to the invention, a radar moment calculation unit (IMWM), a target tracking unit (SC), and a single-time sensor ( DEV), the output of the receiver of the second PC is connected to the first input of the VMIZ unit, the output of the receiver of the first PC is connected to the first input of the VK unit, the output of the VMIZ unit is connected to the second input of the VK unit, its output is connected to the first input of the SC block, the outputs of the DEV are connected to the fourth input VK block, the second input of the VMIZ block and the second input of the SC block.

The task (technical result) is solved by the fact that the complex for determining the coordinates of targets according to the second option, containing the radar, radar, includes two PCs and a VC unit, each channel contains an antenna and a receiver, the antenna outputs are connected to the corresponding inputs of the receivers of the first and second PC, coordinate the antenna output of the second PC is connected to the third input of the VK unit, according to the invention, n> 1 radar and airborne radar station (radar) are introduced into the complex, and the delay calculation unit (OT), the center block and the sensor are entered into the radar At the same time, DEV, the outputs of which are connected to the third input of the OT unit, to the second input of the VK unit and to the second input of the SC unit, the output of the receiver of the second PC is connected to the first input of the OT unit, the output of the receiver of the first PC is connected to the second input of the OT unit, and its output connected to the first input of the VK unit, the output of which is connected to the first input of the SC unit, the radar includes a unit for calculating the radiation moment of the radar probe.

The essence of the claimed method according to the first embodiment, (Figure 3), is that as an external source of radiation choose a radar, which is in direct visibility of the radar, located on a hill (on a tower, mountain, airship, airplane, satellite, etc. .). The coordinates of the radar are precisely known and the signal parameters are predefined. The choice as an external source of radiation radar provides the following advantages:

- easy to open the signal structure and provide quasi-consistent reception;

- quasi-consistent reception of radar signals allows you to increase the detection range and determine the coordinates of the target with the required accuracy and resolution;

- ensures the stability of the operation, since the tasks of the radar are constant monitoring of space;

- jamming from the opposing side is unlikely, as the interference will affect the radar;

- The ESR of the target increases significantly if it is near the line connecting the radar and radar, and this allows to increase the detection range (Reference radar. Edited by M. Skolnik, t.4, p. 209);

- the radiation power is sufficient to detect small targets, for example, when choosing a missile defense station as a radar station located in Europe.

To determine the distance to the target, the direction to the target is determined, the moment of radar signal emission is determined from the known distance to it and the moment of direct reception of its probe, the distance to it is calculated by formula (3), the conclusion of which is given below:

1. At a certain angle α between the direction to the target (Figure 3) and the direction to the radar, direct delay ΔT of the signal emitted by the radar and received by PC 2 and calculated from the known range d, the determined delay τ of the signal reflected from the target relative to the direct delay ΔT of the signal radiated radar, calculate the range using the VK unit to this target in polar coordinates according to the following formulas:

$$r_{\mathrm{Ts}}=\sqrt{r_{\mathrm{BUT}}^2-2C\times \Delta T_{\mathrm{BUT}}\times r_{\mathrm{BUT}}\times Cos\alpha +{\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">C</figure-callout>}}^2\times \mathrm{<figure-callout\; id="2"\; label="\Delta \; T\; A"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}}{T}_A^{}{}_2^{},\left(\mathrm{one}\right)$$

; a - угол между направлениями на РЛС и на цель;where C is the speed of light; $$\Delta T_{\mathrm{BUT}}=\frac{d}{C}$$

; a is the angle between the directions to the radar and to the target;

r _C is the distance from the radar to the target;

a = arcos Cosβ × Cosε.

2. According to the known at a single time the time of reception t _CR and the calculated value of ΔT determine the moment of radiation of the probe t _s according to the formula:

$${\text{t}}_{\text{s}}=t_{PR}-\left({\tau }_{\mathrm{BUT}}+{\tau }_{\mathrm{Ts}}\right),\left(2\right)$$

; $${\tau }_{Ц}=r_{Ц}\times \frac{1}{C}$$

.where (τ _A + τ _C ) is the total propagation time of the radar probe to the target and from it to the radar; $${\tau }_{\mathrm{BUT}}=r_{\mathrm{BUT}}\times \frac{\mathrm{one}}{C}$$

; $${\tau }_{\mathrm{Ts}}=r_{\mathrm{Ts}}\times \frac{\mathrm{one}}{C}$$

.

3. Calculate the distance r _Aj to the j-th target, for j = 2 ... n (Fig. 3, b), according to formula (3), derived by solving two equations obtained from the ACV triangle:

$$r_{\mathrm{BUT}j}=\frac{d^2-{\left(t_{PRj}-t_s\right)}^2\times {\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="00000010.png,00000011.png"\; state="\{\{state\}\}">C</figure-callout>}}^2}{2\left[d\times Cos{\alpha }_j-\left(t_{PRj}-t_s\right)\times C\right]},\left(3\right)$$

where t _prj - the moment of reception of the signal reflected from the j-th target in a single time.

The essence of the claimed method according to the second embodiment (Figure 4) is that as an external radiation source choose a radar in direct line of sight of the radar. Its coordinates are precisely known and the signal parameters are predetermined. With the known parameters of the radar signal, quasi-consistent reception is possible, which allows to increase the detection range of targets irradiated by this radar. To determine the range to the target, first determine the moment of radar signal emission from the known range from the radar to the radar and the moment of direct reception of its radar probe using its IMIZ unit, determine the direction to the target using the radar and calculate the distance to it using formula (3), similarly computing the first option. The difference is that:

; $$\Delta T=\frac{d}{C}$$

; $$d=2R\times Sin\frac{L}{2R}$$

, $$t_s=\frac{d_B}{C}$$

; $$\Delta T=\frac{d}{C}$$

; $$d=2R\times Sin\frac{L}{2R}$$

,

where R is the radius of the Earth; L is the length of the arc along the surface of the Earth from points A (RLS) to point B (RLS); d _B - the distance from the radar to radar.

The received information is transmitted to n≥1 PRLS.

The invention is illustrated by drawings:

figure 1 - PRLS that implements an analogue method;

figure 2 - complex that implements the prototype method;

figure 3 is a diagram illustrating the operation of the proposed method according to the first embodiment;

4 is a diagram illustrating the operation of the proposed method according to the second embodiment;

5 is a complex that implements the proposed method according to the first embodiment;

6 is a complex that implements the proposed method according to the second embodiment.

Let us consider in more detail the feasibility of the method and the complex according to the first and second options with specific examples.

The claimed complex that implements the claimed method for determining the coordinates of targets according to the first embodiment (Figure 5), including PRLS1, which contains two channels - PC1 and PC2 and a VK 4 unit, each channel contains antennas 1 and receivers 2, the outputs of each antenna 1 are connected to the corresponding the inputs of the receivers of the 2 channels PC 1 and PC 2, the coordinate outputs of these antennas are connected to the third and fifth inputs of the VK 4 unit, respectively, the VMIZ 6 unit, the SC 7 unit and the DEV 8 single time sensor are introduced into the PRLS1, the output of the PC2 channel 2 receiver is connected to the first input of the block VMIZ 6, the receiver stroke PK1 is connected to the first input of the VK 4 unit, the output of the VMIZ 6 unit is connected to the second inputs of the VK 4 unit, its output is connected to the input of the SC 7 unit, the DEV 8 outputs are connected to the fourth input of the VK 4 unit, the second input of the VMIZ 6 unit and the second the input of SC 7.

The complex works as follows. The relative location of the radar 1 and radar 5 is precisely known. The signal emitted by the radar 5 is received by the antenna 1 of the PC 2 channel and, after amplification in the receiver 2, the signal is fed to the first input of the VMIZ 6, where the radiation moment of the radar 5 probe is calculated. Using the PC1 channel , the directional antenna 1 of this channel and the moment of probe radiation calculated using the VMIZ 6 block in the VK 4 block, the range to the target is calculated by the formula (3).

The claimed complex, which implements the method for determining the coordinates of targets declared in the second embodiment (Fig. 6), contains n≥1 radar and airborne radar station 9, each radar includes two receiving channels PC 1 and PC 2, block VK 4, block VZ 6, SC 7 unit and DEV 8 single time sensor, each receiving channel contains an antenna 1 and a receiver 2, the outputs of the antennas 1 are connected to the corresponding inputs of the receivers 2 of PC 1 and PC 2, the outputs of DEV 8 are connected respectively to the third input of the VZ 6 unit, with the second input block VK 4 and with the second input of block SC 7, the output of the receiver 2 To 2 is connected to the first input of the VZ 6 unit, the output of the receiver 2 of PC 1 is connected to the second input of the VZ 6 unit, and its output is connected to the first input of the VK 4 unit, the output of which is connected to the first input of the SC 7 unit, the coordinate output of the antenna is 1 PC 2 connected to the third input of the VK unit 4, radar 9 includes a unit for calculating the moment of radiation of the probe (VMIZ) 10.

The complex works as follows. The relative location of the radar 1, radar 5 and radar 9 is known exactly. The signal emitted by radar 5 receives the radar 9, using BVMIZ 10 calculates in a single time the moment of radiation of the radar 5 probe and transmits this information in the form of a radio signal to radar 1, in which the signal through the antenna 1 of the channel, PC 1 enters the receiver 2. Using the antenna 1 of the channel PC 2, the PRLS 1 receives the signal reflected from the target, and after amplification in the receiver 2 of this channel, the signal is fed to the first input of the OT 6 unit, to the second input of this block the signal from the output of the receiver 2 channel PC 1, respectively corresponding to the moment of radiation of the radar probe 5. In a single time, the delay of the signal reflected from the target relative to the moment of radiation of the radar probe 5 is determined. This information is sent to block B K 4, in which the coordinates of the target are calculated by formula (3). In the presence of several radar signals, the signal about the moment of radiation of the probe in a single time from radar 9 is transmitted to each radar.

Thus, the task is solved and the claimed technical result is achieved.

Claims (4)

1. A method for determining the coordinates of targets irradiated by an external source of radio emission, based on the determination of the angular coordinates of the target from the reflected radio emission using a passive radar station (RLS), characterized in that the external radar station located in the direct line of sight of the RLS is selected as a radiation source (RLS) ) with its known coordinates and the irradiated viewing zone, the moment of reception of the probing signal reflected by the target and its angular coordinates, as well as Niemann VRLS line probing signal and calculate the time of its radiation, based on the measured moment of receiving the reflected purpose probing signal and the calculated moment of its radiation range to the target is calculated. 2. A complex for determining the coordinates of targets, which is a passive radar station (PRLS) containing two receiving channels (PC) and a coordinate calculation unit (VK), each channel contains an antenna and a receiver, the antenna outputs are connected to the corresponding inputs of the receivers of the first and second channels , the coordinate outputs of the antennas are connected to the third and fifth inputs of the VK unit, respectively, characterized in that the radar moment calculation unit (IMWM), target tracking unit (SC) and a single time sensor (DE ), the output of the receiver of the second PC is connected to the first input of the VMIZ unit, the output of the receiver of the first PC is connected to the first input of the VK unit, the output of the VMIZ unit is connected to the second input of the VK unit, its output is connected to the first input of the SC block, the outputs of the DEV are connected to the fourth input of the block VK, the second input of the block IMIZ and the second input of the block SC. 3. A method for determining the coordinates of targets irradiated by an external source of radio emission, based on the determination of the angular coordinates of the target from the reflected radio emission using a passive radar station (RLS), characterized in that an external radar station with known coordinates is selected as the source of radio emission and irradiating the viewing area, using the airborne radar station (radar) located in the line of sight of the radar, take its direct sounding signal, calculate the moment t of its radiation, the calculated value in a single time is transmitted to n≥1 RLS, with which they receive and measure the moments of reception of the probing signals reflected by the targets in a single time and their angular coordinates, based on the measured moments of the reception of the probing signal reflected by the targets and the value received from the radar the moment of its radiation, the range to the targets is calculated. 4. A complex for determining the coordinates of targets, containing a passive radar station (RLS), the RLS includes two receiving channels (PC) and a coordinate calculation unit (VK), each channel contains an antenna and a receiver, the antenna outputs are connected to the corresponding inputs of the receivers of the first and second PC , the coordinate output of the antenna of the second PC is connected to the third input of the VK unit, characterized in that the complex includes n> 1 radar and airborne radar (radar), the radar has a delay calculation unit (OT), a target tracking unit (SC) and a single time sensor (DEV), the outputs of which are connected to the third input of the OT unit, to the second input of the VC unit and to the second input of the OTs unit, the output of the receiver of the second PC is connected to the first input of the OT unit, the output of the receiver of the first PC is connected to the second the input of the OT unit, and its output is connected to the first input of the VK unit, the output of which is connected to the first input of the SC unit, the radar includes a unit for calculating the radiation moment of the radar probe.

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