RU2459219C1 - System for built-in control and calibration of monopulse radar station - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: during control, a portion of probing signal power, which is fed to a circuit signal simulator and through a circulator to an adder with a heterodyne simulator signal, is output from a monopulse radar station; the resultant signal is fed to a mixer, conveyed at an intermediate frequency and is fed to a recirculation circuit, which is built on series-connected second adder and delay line, where the damped batch of delayed pulses returns to the mixer, where it is conveyed at carrier frequency using the heterodyne signal, passes through the circulator to series-connected valve, test antenna and radio communication channel to the antenna of the monopulse radar station. The processor of the monopulse radar station controls the process of built-in control in signal search, capture and tracking modes; measurement of bearing characteristics takes place based on target search results with scanning of the antenna system; capturing and tracking results are used to determine coordinates of the simulated target, controlled parameters of the transmitter, the receiver and signal of the detector; by comparing the controlled parameters with rated values, the processor determines accuracy of the monopulse radar station and deviation of calibration, which it then stores and takes into account when measuring coordinates of targets during combat.

EFFECT: controlling units of a monopulse radar station during operation, verifying calibration, which enables to take into consideration deviation thereof before combat.

2 cl, 2 dwg

Description

The invention relates to radar, in particular to systems for integrated monitoring of an onboard monopulse radar.

To check the serviceability of airborne radars throughout the entire life cycle interval, control is widely used, which allows the carrier to identify inoperative radars in a timely manner, to determine and compensate for calibration departures during combat work. The reliability of the control depends on the degree of control coverage of the radar systems, including the antenna system, and is largely determined by the target signal simulator used in the control.

In the integrated calibration monitoring system of a monopulse radar [1], an internal test signal is simulated, which is input through a directional coupler installed between one of the four inputs / outputs of the monopulse antenna and the corresponding input-output of the sum-difference converter. The internal test signal is simulated both when checking radars on Earth and when calibrating the radar before combat work, and depends on the level of external interference. The analysis of the interference level is performed by the received signal by the signal processor of the receiver. If the interference level is higher than the threshold, then calibration is not performed and during combat work, passport correction coefficients obtained using the external test signal emitted by the test antenna in the far zone in the laboratory are used. If the interference is less than the threshold, the internal test signal is turned on, according to the measurement results of which the signal processor determines the difference between the measured bearing and the certified one in the laboratory. If the relative error is greater than the threshold, passport correction data obtained from an external test signal in laboratory conditions is used in combat work; otherwise, the found ratio is used to scale the passport correction coefficients corresponding to work according to the internal test signal.

The advantage of the scheme is the ability to take into account changes in the calibration of angular measurements associated with temperature drifts and aging, causing an imbalance in the receiving channels of a monopulse radar in gain and phase.

The disadvantage of the circuit is that in the calibration control system, the result does not depend on the orientation of the antenna, because the test signal is introduced between the antenna and the sum-difference converter; accordingly, only the receiver is covered by the calibration control and the radar antenna is not covered. In addition, the simulation of the internal test signal is not related to the operation of the transmitter, is not synchronized with the moment of formation of the transmitter pulse, its carrier frequency and phase; therefore, calibration of coherent radars in which coherent signal accumulation is an integral part of the processing of the reflected signal in the radar receiver is not possible measuring bearing.

Built-in calibration verification system [2], operating in the near zone of the radar antenna, incl. during the flight, it is based on the reception of the signal emitted by the radar antenna, an external simulator of the target signal, forming a packet of damped delayed signals on the carrier frequency, and its re-emission towards the radar antenna. When checking the radar, it measures the coordinates of the simulated targets in a given delay corridor. By comparing the measured coordinates with the passport data, errors are determined that are taken into account during combat work.

The device of the target simulator consists of an antenna, the output of which is connected via a matching impedance to a waveguide, the second end of which is connected to a load reflecting the signal. The waveguide (cable) is made in the form of a compactly folded spiral.

The advantage of the device is the simplicity of obtaining a coherent simulated target signal in the analyzed range range, which, in addition to calibration, allows controlling the operation of the main radar units, including the receiver, transmitter, antenna and signal processing device, which evaluates the measured coordinates. The target simulator is compact and works in the near zone of the antenna of the radar under test.

The disadvantage of this device is that the attenuation of the delayed signal at the carrier frequency, even at the minimum operating range of the radar, may be lower than the threshold sensitivity of the receiver.

The ground control system [3], adopted as a prototype, contains a target simulator connected to a tester antenna connected via a radio channel to the antenna of the tested radar sight, in particular it is a monopulse radar. The test antenna is installed at the time of monitoring on the seats of the antenna of the sight in its near zone. A heterodyne signal is sent to the target simulator from the sight. Imitation of the target is as follows. The signal received by the tester antenna is fed through the circulator to the first mixer, where it is mixed with the local oscillator signal, then amplified in the first intermediate frequency amplifier (IFA), delayed by the delay line, amplified by the second IFA, transferred to the carrier using the second mixer and the local oscillator signal received The signal delayed at the carrier frequency through the circulator enters the tester antenna and is re-emitted via the radio channel towards the antenna of the radar sighting device. In the radar sight, the coordinates of the simulated target are measured with the delivery of their values to the control system, which compares the received information with threshold values and concludes that the sight is working.

The advantage of the control scheme is the control coverage of all systems, including the transmitter, receiver, range and angle measuring system, and the antenna system. In addition, the target simulator allows you to check the operation of the radar sighting device using coherent signal processing.

The disadvantage of the system is that the target simulator together with the tester antenna cannot be used in the built-in monitoring system, due to the large signal loss in the radio line with acceptable small antenna sizes that do not obscure the target antenna, at which the simulated signal must be higher than the receiver threshold sensitivity. That is why the first UPCH is used in front of the delay line, and the operation of the sight is checked only on one relatively small delay of the signal of the working range, accordingly, the calibration of the sight and accounting for its departure during the flight before combat operation is not possible.

The aim of the invention is the creation of a built-in monitoring and calibration system that provides both high completeness of control of monopulse radar units during operation and calibration verification, including during carrier flight, allowing to take into account its departures before performing combat work.

The goal is realized by the fact that from the monopulse radar (radar sighting device) under test, part of the power of the probing signal is transmitted to the simulator of the target signal, where it passes through the circulator to the adder with the heterodyne signal of the simulator, the total signal is sent to the mixer, where the input signal is transferred at an intermediate frequency and fed to a recirculation circuit built on a second adder connected in series and a delay line covered by a feedback circuit in the form of an amplifier la, delayed decaying packet pulses returned to the mixer, where by means of the LO signal is transferred to a carrier frequency, it passes through the circulator in series connected valve testernuyu antenna and a radio communication antenna for monopulse radar.

To achieve this goal, a control system [3], containing a monopulse radar, the first output of which is connected to the input of the target signal simulator, in which a test antenna is installed, which is the output of the target simulator, connected by a radio channel to the monopulse radar antenna, the delay line and the amplifier are connected in series, the first a circulator and a mixer, in a monopulse radar from the first to the fourth inputs and outputs of the antenna system are connected to the inputs and outputs of the same-difference converter, the fifth input-output to which through the second circulator is connected to the first input of the monopulse receiver, the first and second outputs of the sum-difference converter are connected to the third and second inputs of the monopulse receiver, respectively, the first, second and third outputs of the monopulse receiver are connected to the same inputs of the processor, the fourth input-output of which is connected to transmitter input-output, fourth mono-pulse receiver input-output, fifth antenna system input-output, the processor controls the transmitter signal parameters and the angular position of the antenna system, tuning the monopulse receiver, digitizes and digitally processes the signal at the output of the monopulse receiver with detection, capture by tracking, measuring and outputting the coordinates of the targets to the consumer, the sixth input-output of the processor is the second input-output of the monopulse radar, characterized in that a second valve and a second adder are introduced into the target simulator, a local oscillator, a first gate and a first adder are connected in series, and connected in series to a monopulse radar second directional coupler, detector and switch, serially connected first directional coupler and key, while in the target simulator, the first input-output of the first adder is connected in series through the first circulator and the second valve to the input of the tester antenna, the first input-output of the mixer is connected to the third the input-output of the first adder, the second input-output of the mixer is connected to the first input-output of the second adder, the output of which is connected to the input of the delay line, the output of the amplifier is connected to the second the input of the second adder, in a monopulse radar, the first output of the transmitter through the second and first directional couplers connected in series is connected to the third input of the second circulator, the second output of the transmitter is connected to the input of the switch of the same name, the output of which is connected to the fifth input of the processor, the fourth output of the monopulse receiver is connected to the first input switch, the fourth input-output of the switch is connected to the second input-output of the key and the fourth input-output of the processor controlling the process control in the search, capture and tracking modes of the signal, according to the results of the target search with the scanning of the antenna system that determines the radar direction-finding characteristic, according to the results of capture and tracking of the error determining coordinates of the simulated target, the controlled parameters of the transmitter, receiver and detector signal comparing the values of the controlled parameters with passport data, which determines, according to the results of comparison, the radar serviceability and calibration drifts, which are stored and taken into account during measurements oordinat purposes in the battle, the key output is the first output of monopulse radar testernaya antenna located in the near field and the longitudinal axis of the monopulse radar antenna system.

The invention is illustrated by further description with reference to the following drawings.

Figure 1 presents the structural diagram of the system.

In Fig.2 presents the algorithm of the integrated monitoring and calibration of monopulse radar.

In figure 1, the following notation:

1 - Target Simulator (IC);

2 - Monopulse radar (MRLS);

3 - The first circulator;

4 - The first adder (SUM 1);

5 - The first valve (B 1);

6 - heterodyne (Get);

7 - The second valve (B 2);

8 - Mixer (CM);

9 - The second adder (SUM 2);

10 - Delay line (LZ);

11 - Test antenna (A);

12 - Amplifier (CSS);

13 - Antenna System (AC);

14 - The second circulator;

15 - Sum-difference Converter (PSA);

16 - Key (KL);

17 - The first directional coupler (BUT 1);

18 - The second directional coupler (HO 2);

19 - Monopulse receiver (PFP);

20 - Switch (COM);

21 - Detector (D);

22 - Transmitter (PRD);

23 - Processor (PRC).

In figure 1, the local oscillator 6 through series-connected first valve 5, the first adder 4, the first circulator 3 and the second valve 7 is connected to the input of the test antenna 11, the third input-output of the first adder 4 is connected to the first input-output of the mixer 8, the second input - the output of which is connected to the first input-output of the second adder 9, the output of the delay line 10 through a series-connected amplifier 12, the second adder 9, is connected to the input of the delay line 10, the output of the test antenna through a radio link is connected to the monopulse radar antenna system, the first the output of the transmitter 22 through a series-connected second directional coupler 18, the first directional coupler 17 and the key 16 is connected to the first input of the first circulator 3, the third output of the second directional coupler 18 through the detector 21 is connected to the third input of the switch 20, the fourth output of the monopulse receiver 19 is connected to the first input of the switch 20, the output of which is connected to the fifth input of the processor 23, the second output of the transmitter 22 is connected to the same input of the switch, the fifth input-output of the total-differential conversion The index 15 through the second circulator 14 is connected to the first input of the monopulse receiver 19, the first, second and third outputs of which are connected to the same inputs of the processor 23, the first, second, third and fourth inputs and outputs of the antenna system 13 are connected to the same inputs and outputs of the total-difference a converter 15, the first and second outputs of which are connected to the third and second input of the monopulse receiver 19, respectively, the fourth input-output of the processor 23 is connected to the fourth input-output of the monopulse receiver 19, the transmit-output of the transmitter 22, the second input-output of the key 16, the fourth input-output of the switch 20 and the fifth input-output of the antenna system 13, the sixth input-output of the processor 23 is the second input-output of the monopulse radar 2.

Elements included in the target simulator and monopulse radar are widely used in radar and do not require explanation for implementation.

The first adder 4 can be made on the basis of two loop directional coupler [4, Fig.4.37, p.194]. The second adder 9 can be made on the basis of an annular power divider [4, Fig.4.36, p.193]. The test antenna can be made in the form of a half-wave vibrator.

The operation of a single-pulse radar 2 in combat mode does not require special explanation. Moreover, the test antenna 11 of the target signal simulator 1 is located at the top of the fairing of the antenna system 13, has a sufficiently small size that does not deform the direction-finding characteristic of the antenna system 13 and does not significantly reduce its gain. The processor 23 controls the parameters of the signal of the transmitter 22, the settings of the monopulse receiver 19 and the angular position of the antenna system 13. The signal of the transmitter 22 through the directional couplers 18 and 17, the circulator 14, the sum-difference converter 15 and the antenna system 13 is radiated in a given direction. The current position of the axis of the antenna system 13 is controlled by the processor 23 at the fifth input-output of the antenna system 13 and is taken into account when searching, processing and tracking the reflected signal. The reflected signal received by the antenna system 13, through the sum-difference converter 15 and the circulator 14, enters the monopulse receiver 19, then to the processor 23, where the target signals are digitized, detected, selected, target selected, tracking, measurement of its coordinates taking into account calibration data , sewn into memory, and issuing them to the consumer.

Unlike combat work, where search, detection, capture, tracking of the target and measurement of its coordinates are performed, with the built-in control on the control sequence diagram, additionally, when scanning the antenna beam, the direction-finding characteristics of the antenna are measured in a narrow sector, the center of which corresponds to the direction of the simulated target, measurement currents and voltages of the transmitter 22, receiver 19, the amplitude and duration of the signals of the detector 21, reflecting the power and duration of the probe signal of the transmitter 22. As ontroliruemyh currents and voltages of the transmitter 22 and receiver 19 are controlled by the voltage at the points of nodes, power supply voltage, current consumption in the silent mode, and the radiation in the pauses between the probing pulses.

By comparing the results of measurements of the coordinates of the target being followed and all controlled voltages with tolerances, the radar serviceability, the possibility of its use in solving a combat mission are determined. By comparing the measured direction-finding characteristics with the passport, wired in memory, the radar calibration drift by angle is determined, which are taken into account during combat work.

The operation of the system in the built-in control and calibration mode is initiated by an external command coming to the sixth input-output of the processor 23, and is explained in FIG. According to the program embedded in the memory, the processor 23 through the fourth input-output controls both the operation of the radar nodes and the process of integrated monitoring by the cyclogram sewn into memory. The beginning of the built-in control is the issuance by the processor 23 of the initial settings to the transmitter 22, the monopulse receiver 19 and the antenna system 13, after which, through the key 16, the microwave pulses of the transmitter are switched on to the target simulator 1 (Fig. 2, pos. 26). Next, the transmitter 22 is turned on, the target is searched with the antenna system 13 scanned, the target signal is detected with the measurement and recording of the bearing at different positions of the antenna system (Fig. 2, item 27). In parallel, according to the time diagram of the built-in control, the processor 23, through the fourth input / output, controls the output of the controlled voltages by the transmitter 22, receiver 19 to the switch 20, from the output of which the controlled signals from the second output of the transmitter 22 come from the fourth output of the receiver 19 and from detector 21. All monitored voltages supplied to the fifth input of processor 23 are digitized and recorded at calculated time points.

According to the results of the assessment of the bearing of the simulated signal at different positions of the scanning antenna system 13, the processor 23 calculates the direction-finding characteristics of the antenna system 13 and determines its departures relative to the certified, wired in memory (Fig.2 pos.28). Next, the processor 23, after detection, captures and tracks the target, measures the coordinates, compares the measured coordinates with the tolerance (FIG. 2, pos. 29), compares the results of the recording of controlled voltages with the tolerance (FIG. 2, pos. 30). Based on the comparison of all parameters controlled with the built-in control with tolerances, the processor 23 decides on the health of the radar being checked. In addition, according to the results of the comparison of the direction-finding characteristic with the values recorded in the memory, the processor 23 determines the offset of the calibration of the measurements by the angle and refines the correction parameters of the signals of the single-pulse receiver and the results of measurements of the coordinates of the target during combat operation (Fig.2 pos.31). The results of the built-in control are displayed to the consumer through the sixth interface input-output of the processor 23.

Simulation of the target signal in the built-in control mode is as follows. The pulse microwave signal of the transmitter 22 through the second 18 and first 17 directional couplers and the public key 16 connected in series is output to the target simulator 1, the input of which is the first input of the circulator 3. In the target simulator 1, the microwave pulse signal through the first circulator 3 is fed to the first adder 4, where it is summed with the continuous signal of the local oscillator 6, which has passed the first valve 5. From the third input-output of the first adder 4, the resulting sum goes to mixer 8, where the input microwave signal is transferred to an intermediate frequency equal to th difference signal input carrier frequency and heterodyne. The intermediate frequency signal from the second input-output is fed to a recirculator consisting of a second adder 9, a delay line 10 and an amplifier 12. As a result of the recirculation at the first input-output of the second adder 9, a packet of damped pulses at an intermediate frequency is received, which arrives at the second input-output mixer 8. In mixer 8, delayed pulses are transferred to the carrier frequency equal to the sum of the intermediate frequency and the local oscillator. The delayed microwave pulses from the first input-output of the mixer 8 through the first adder 4, the circulator 3, the second valve 7 are fed to the test antenna 11 and are radiated towards the antenna system 13.

The high completeness of the built-in control is provided by the on-board simulator of target 1, which allows on the ground and during the flight to control the entire radar 2, including antenna 13, transmitter 22, receiver 19 and processor 23. In the prototype, the required control completeness is provided by an external control device including a simulator of target, only in ground conditions.

The results of the built-in control before and during the flight allow you to automatically determine the serviceability of the radar, departures of the direction-finding characteristic and take them into account during combat work, which increases the likelihood of completing a combat mission.

The use of a radio line only for transmitting a simulated target signal to a radar makes it possible to reduce the size of the test antenna to sizes that do not reduce the gain of the antenna system and do not distort its direction-finding characteristics at different scanning angles.

The manufacture and testing of the built-in monitoring and calibration system confirmed its effectiveness, the ability to determine and account for departures of the direction-finding characteristics of a single-pulse radar during combat work.

Using the information presented in the application materials, the device can be manufactured according to the existing technology known in the radio industry, based on well-known components and used in monopulse pulse-Doppler radars for navigating aircraft.

LITERATURE

1. US patent No. 5808578 from 09/15/98. "Guided missile calibration method".

2. US patent No. 7719462 from 05/18/10. "Time of light radar calibration system".

3. Patent of Russia No. 2205441 dated 05/27/03. "A complex for testing on-board systems of an unmanned aerial vehicle."

4. L.G. Maloratsky, L.R. Yavich. "Design and calculation of microwave elements on strip lines." - M .: Soviet Radio, 1972.

Claims (2)

1. The built-in monitoring and calibration system containing a monopulse radar, the first output of which is the output of a pulsed microwave signal from the transmitter, is connected to the input of the target signal simulator, in which a test antenna is installed, which is the output of the target simulator, connected by a radio channel to the monopulse radar antenna, and a line is connected in series delays and amplifier, the first circulator, which is the input of the target simulator, and the mixer, in the monopulse radar from the first to the fourth inputs and outputs of the antenna system connected to the same inputs and outputs of the total-differential converter, the fifth input-output of which through the second circulator is connected to the first input of the monopulse receiver, the first and second outputs of the total-differential converter are connected to the third and second inputs of the monopulse receiver, respectively, the first, second and third outputs monopulse receiver connected to the same inputs of the processor, the fourth input-output of which is connected to the input-output of the transmitter, the fourth input-output of monopulse p the receiver, the fifth input-output of the antenna system, the processor controls the parameters of the transmitter signal and the angular position of the antenna system, tunes the monopulse receiver, digitizes and digitally processes the signal at the output of the monopulse receiver with the detection, capture, tracking, measurement and output of target coordinates to the consumer, sixth input -processor output is the second interface input-output of a monopulse radar, through which control commands are entered, the initial data for conducting the built-in role and the consumer displays the results of combat work and control, characterized in that a second gate and a second adder are introduced into the target simulator, a local oscillator, a first gate and a first adder are connected in series, a second directional coupler, a detector and a switch connected in series are connected in series, connected in series the first directional coupler and the key, while in the target simulator, the first input-output of the first adder through the first circulator and the second valve connected in series n with the input of the test antenna, the first input-output of the mixer is connected to the third input-output of the first adder, the second input-output of the mixer is connected to the first input-output of the second adder, the output of which is connected to the input of the delay line, the output of the amplifier is connected to the second input of the second adder , in a monopulse radar, the first output of the transmitter is connected to the third input of the second circulator through the second and first directional couplers connected in series, the second output of the transmitter is connected to the switch input of the same name, the output One of which is connected to the fifth input of the processor, the fourth output of the monopulse receiver is connected to the first input of the switch, the fourth input-output of the switch is connected to the second input-output of the key and the fourth input-output of the processor that controls the process of built-in control in the search, capture and signal tracking modes, according to the results of the target search with scanning of the antenna system that determines the radar direction-finding characteristic, according to the results of capture and tracking, which determines the coordinates measurement errors, we simulate target, controlled parameters of the transmitter, receiver and detector signal, comparing the values of the controlled parameters with tolerances, recorded in the memory, which determines the radar serviceability and calibration deviations, which are remembered and taken into account when measuring the coordinates of targets during combat operation, the key output is the first output monopulse radar. 2. The built-in monitoring and calibration system according to claim 1, characterized in that the test antenna is located in the near field and on the longitudinal axis of the monopulse radar antenna system.

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