RU170728U1 - RADAR STATION FOR SELF-PROPELLED FIRE INSTALLATION - Google Patents

Abstract

The radar station for self-propelled firing installation contains an antenna, receiver, transmitter, synchronizer, workstation, digital computer system. The radar has introduced digital devices for generating a microwave linearly frequency modulated signal (LFM), a quasi-continuous radiation signal (THI) of the excitation of the transmitter, and processing received echo signals, which improve the quality of the processing of the LFM and THF signals and the reliability of the radar station. 2 ill.

Description

The utility model relates to the field of radar and can be used to detect, identify, capture, track aerial targets and provide radar information to anti-aircraft missiles of a self-propelled fire installation, on which a radar station is located, as well as to other launchers of an anti-aircraft missile complex.

Known closest to the claimed radar station (radar) as part of a self-propelled fire system (SOU) 9A317 [Self-propelled anti-aircraft missile system "BUK". Equipment and weapons yesterday, today, tomorrow. No. 6, 2003, pp. 26, 27, 28], [“Radar equipment, technical description, part 1, GS1.071.008 TO”].

The radar contains an antenna device, a receiver, a transmitter, a driver trigger pulse generator, a reference voltage generator (GON), a microwave driver of the transmitter excitation signals, a synchronizer, an automated workstation (AWS). All radar devices are connected to the digital computing system (DAC) of the SDA.

The radar can operate with a high repetition frequency of the probe pulses (low duty cycle), which corresponds to quasi-continuous radiation (SIR) of the probe signals. The SOI mode is used in the presence of powerful reflections from the underlying surface and meteorological conditions.

The radar can also work with a large duty cycle of the probing signals (low repetition rate); In this mode, probing microwave pulses with linear frequency modulation (LFM) are used, which improves the resolution of the station and its noise immunity. The LFM signal is first generated using a dispersive ultrasonic delay line (DLS) at its excitation frequency (10 MHz), then it is converted into a LFM microwave pulse, amplified in the transmitter and emitted by the antenna into space. Echoes reflected from aircraft are received by the antenna, amplified and converted into intermediate frequency pulses in the receiver. LFM intermediate frequency echoes are amplified, converted to 10MHz LFM, compression operations are performed in the optimal filter, which uses a similar DULZ.

In the SOI mode, a multichannel analog filter is used to determine the Doppler frequency offset of the received echo signals.

Station operation modes are set in the CVC: SOI or LFM, carrier frequency, repetition period of probing pulses.

An excitation voltage of DULZ 10 MHz is generated in the GON, which is also used in the phase detectors of the receiver. In the transmitter of the microwave excitation signals of the transmitter, the 10MHz chirp pulse is transferred to the carrier frequency of the station.

On the AWP screen, the air situation is formed in the radar coverage area, and with the help of the AWP control bodies, in conjunction with the DAC, the radar operating modes are set.

The disadvantage of this device is that the use of dispersive ultrasonic delay lines and analog filters does not allow to achieve high quality processing of LFM and SOI signals.

The proposed utility model solves the problem of improving the quality of processing of LFM and SOI signals.

To achieve this technical result, a radar station for the JMA containing an antenna, a receiver, the first input of which is connected to the antenna output, a transmitter, the output of which is connected to the antenna input, a shaper of the microwave excitation pulse of the transmitter, the first output of which is connected to the input of the transmitter, and the second output connected to the second input of the receiver, synchronizer, workstation, digital computing system, the first output of which is connected to the input of the synchronizer, the second output connected to the input of the workstation, the output of which is connected to the first input of the DAC, introduced a digital synthesizer of intermediate frequency signals (IF), an electronic computer for digital signal processing (DSP), a processor for digital decomposition of the signal into quadrature components (PCRC), the output of which is connected to the first DSP computer input, and the input is connected to the receiver output, the first synchronizer output is connected to the first input of the digital IF signal synthesizer, the second input of which is connected to the third DAC output, the second synchronizer output is connected ene PTSRK to second inputs of the computer and the DSP, whose output is connected to the second input of DDS, a fourth output is connected to the third input computer DSP output digital synthesizer coupled to the inverter input of the RF excitation pulse transmitter.

In FIG. 1 shows an electrical structural diagram of the proposed device.

In FIG. 2 shows an electric structural diagram of a digital IF signal synthesizer.

The radar station for the JMA contains (Fig. 1) an antenna 1, a receiver 2, a transmitter 3, a digital IF synthesizer 4, a driver 5 of a microwave excitation pulse of a transmitter 3, PCRK 6, a computer DSP 7, a synchronizer 8, AWP 9, DAC 10. Output the transmitter 3 is connected to the input of the antenna 1. The output of the antenna 1 is connected to the first input of the receiver 2. The first output of the transmitter 5 of the microwave excitation pulse of the transmitter is connected to the input of the transmitter 3, and the second output is connected to the second input of the receiver 2, the output of which is connected to the first input of the PCRC 6 whose output is connected to ne the first input of the computer DSP 7, the output of which is connected to the second input of the DAC 10, the first input of which is connected to the output of the AWP 9, the input of which is connected to the second output of the DAC 10. The first output of the synchronizer 8 is connected to the first input of the digital signal synthesizer IF 4, the output of which is connected with the input of the transmitter 5 of the microwave excitation pulse of the transmitter, the second input of the synthesizer 4 is connected to the third output of the DAC 10, the first output of which is connected to the input of the synchronizer 8. The second output of the synchronizer 8 is connected to the second inputs of the PCRK 6 and the computer of the DSP 7. The fourth output DDS 10 is connected to the third input of DSP computer.

The digital signal synthesizer of the inverter 4 contains (Fig. 2) a phase 11 increment register, a phase 12 accumulator, a phase to amplitude 13 converter, a digital-to-analog converter (DAC) 14. The input 16 is connected to the phase 11 increment register, the input 17 is connected to the second inputs of the phase 12 drive and the DAC 14, from the output of the synthesizer 18, a LFM or SOI pulse is removed at an intermediate frequency.

The digital IF signal synthesizer is designed to generate THD or LF pulses at the intermediate frequency of the receiver. Here, the principle of direct digital synthesis (DDS) of a pure sinusoidal signal or a linearly modulated frequency of a sinusoidal signal is implemented. The conversion of the frequency of clock pulses (TI) to the intermediate frequency is used. TI enter the phase 12 drive at input 17 (Fig. 2). Let, for example, the capacity of a phase storage device be 14 bits. The maximum binary number (units in all 14 bits) of the phase accumulator corresponds to a phase angle of 360 °. The phase increment in drive 12 with each TI will be 360 °: 2 ¹⁴ = 1.32 arc minutes. In other words, the entire trigonometric circle is divided by a phase 12 accumulator into 16384 points. Each point (each phase angle) of the trigonometric circle corresponds to a binary number that varies with each TI from 00000000000000 to 1111111111111111. These 14 bit binary numbers are the addresses that enter the phase converter in amplitude 13. There is a read-only memory (ROM) in which all sine wave amplitudes for one period are recorded. These amplitudes in numerical form are extracted from the ROM with each TI and transmitted to the DAC 14, where they are converted into an analog sinusoidal signal.

For the described device, there is a DDS adjustment equation

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, here

F _TI - frequency of clock pulses,

F _PR - the frequency at the output of the synthesizer,

n is the number of bits of the drive,

M is the tuning word.

The tuning word M arrives at the phase 12 storage device from the phase 11 increment register, which, in turn, is recorded at input 16 (Fig. 2) from the radar central control center. If the conversion time M is constant all the time, then at the output of the digital synthesizer 4 a pure sinusoidal signal is generated. Its frequency, for example, at M = 1 is equal to the ratio of F _TI to 2 ¹⁴ . With M = 2, the frequency doubles. The digital word M contained in the phase 11 increment register sets the “step size” for each update of the phase 12 drive. For example, for M = 2, the step size that the radius vector passes in the trigonometric circle for each TI will no longer be 1.36 ', as with M = 1, and 2.72', that is, two times more. The phase 12 accumulator, in fact, is a counter modulo M, which increments its contents with each TI. The increment value is determined by the binary word M, which in turn corresponds to the frequency deviation. The magnitude and frequency of the output of the number M in the phase increment register for the LFM signal is calculated in the DDS of the radar. For SOI, the signal M does not change during the entire synthesis time. As a digital signal synthesizer, the IF LFM and IF THD can be used, for example, a 1367MN15 programmable chip, which is produced commercially. In this chip, the resolution for setting the phase is 14 bits, the DAC resolution is 12 bits.

Antenna 1 is designed to broadcast microwave sounding pulses and receive reflected echo signals. As an antenna, you can use, for example, a phased antenna array [patent RU 91226 U1 10/14/2010], which is used in the radar of the anti-aircraft missile system of the Buk M2 anti-aircraft missile system. The headlamp contains a radiating and distribution system of microwave signals, ferrite phase shifters with magnetic memory, and a phase distribution control device. The electronic scanning of the antenna pattern in the form of a narrow beam is carried out in the vertical plane and the horizontal plane in a given sector.

The transmitter 3 is designed to amplify the LFM of the microwave excitation pulse, first in the pre-amplifier, for example, on the KU-171 klystron, then in the terminal power amplifier, for example, on the KIU-217 klystron.

The receiver 2 is intended for amplification and conversion of echo signals. Contains low-noise microwave amplifier, converter, intermediate frequency pre-amplifier. The received microwave signals are first amplified in a preliminary low-noise amplifier, then converted into intermediate frequency signals using the voltage Fg = Fnes-Fpr. The output bandpass filter of the converter is tuned to the frequency Fpr. The local oscillator frequency, equal to the difference between the carrier and the intermediate frequency, enters the receiver from the shaper 5. Then, the IF signals are amplified in the intermediate frequency pre-amplifier (IF). As the receiver, you can use, for example, the mass-produced product R-7M2.

PCRK 6 (Fig. 1) is designed to amplify the intermediate frequency signals from the output of the receiver, convert analog signals to IF in digital form and digitally decompose these signals into quadrature components. That is, when sampling the radar signal at each reference point, two samples are taken for the in-phase and quadrature components, which represent the complex envelope of the received signal. The PCRK includes an analogue IF amplifier with a bandpass filter. The filter is tuned to Rpr. = 28 MHz, the filter bandwidth is 3 MHz. After amplification, the received signal with the help of phase detectors and analog-to-digital converters (ADCs) is decomposed into quadrature components and converted to digital form. Sampling frequency 112MHz, ADC resolution 14 bits. In PCRK digital low-pass filters are formed with decimation in the sampling frequency of each quadrature component. PTsRK is a part of the RZU device which is produced in series.

In the computer DSP 7 (Fig. 1), the quadrature components obtained in the PCRK are subjected to further processing. For example, the LFM signal is first compressed in an optimal digital filter. Then one of the programs for its further processing is implemented depending on the radar operating modes. For example, for chirp signals, the functional software of the SOC computer provides the following processing modes:

- signal processing in the chirp mode "Overview";

- signal processing in the chirp mode "Capture";

- signal processing in the chirp mode "Maintenance";

- signal processing in chirp mode "AGC".

For example, the processing of radar signals in the chirp mode "Overview" is as follows.

From the output of PCRK 6 (Fig. 1), the signal arrives at a sampling frequency of 7 MHz. In the DSP computer, samples are decimated with a decrease in frequency to 1 MHz. Further, in the optimal digital filter, the LFM signal is compressed in the frequency domain.

In the radar amplitude mode of operation, the signal amplitude module calculation procedure, the incoherent accumulation procedure, and the target signal detection procedure are performed.

In the mode of selection of moving targets by means of double periodical compensation, the SEC procedure is performed, then the procedures for calculating the signal amplitude module, incoherent accumulation and target signal detection are performed. After the detection procedure, information is generated about the detected targets for the DAC (10) and the AWP indicator 9 (Fig. 1). As a DSP computer, it is possible to use, for example, the SOLO 317 electronic computer, which is mass-produced.

The device operates as follows.

First, for example, an LFM pulse is generated at an intermediate frequency in a digital IF 4 signal synthesizer (Fig. 1). The duration of the LFM pulse and the frequency of the TI are issued from the synchronizer 8, the code of the frequency deviation from the DAC 10.

Next, the LFM pulse of the intermediate frequency from the output of the digital synthesizer 4 is fed to the input of the mixer, which is part of the transmitter 5 of the microwave excitation signal of the transmitter. The output filter of the mixer is tuned to the frequency Fnes equal to the sum of the frequencies Fpr and Fg. The frequency Fg is generated in the multiplier, the output filter of which is tuned to one of the higher harmonics of the frequency of the master oscillator, which is part of the former 5. The generated LFM pulse at the carrier frequency is amplified in the transmitter and emitted into space. The received echo signal at the carrier frequency after amplification in the microwave amplifier of the receiver is subjected to inverse transformation, that is, it is transferred to the intermediate frequency. This operation is performed in the converter, which is part of the receiver 2. The output filter of the converter of the receiver 2 is tuned to the frequency difference Fnes and Fг, that is, to the intermediate frequency.

The LFM echo of the intermediate frequency from the output of receiver 2 is fed to PCRK 6. Here, the echoes of the intermediate frequency are decomposed into two quadrature components, discretized, and converted to digital form. In digital low-pass filters that are formed in the PCRC, thinning occurs in frequency of each quadrature component.

Then, in DSP 7 computer, decimation of samples is carried out by summing samples from PCRK 6 with decreasing frequency to 1 MHz and the LFM signal is compressed in an optimal digital filter in the frequency domain. Using the functional software stored in DSP computers, the following signal processing procedures take place depending on the selected mode, for example, “Overview”, “Capture”, “Track” and others. Modes of operation of the radar are set in the AWP 9 and through the DAC 10 in the form of binary codes are transmitted to the DSP computer. PCRK and DSP computers operate under the control of clock pulses, which are generated in the synchronizer 8. Information from the DSP computer is transmitted to the DAC and used in radar devices, for example, in the form of marks and inscriptions is displayed on the AWP screens 9.

Similarly, the device operates in SOI mode.

For SOI signals, the DSP computer software provides the following operating modes:

- signal processing in SOI “Overview" mode;

- signal processing in the SOI mode “Ambiguity solution”;

- signal processing in the SOI “Capture” mode;

- signal processing in the SOI “Maintenance” mode;

- signal processing in the SOI "AGC" mode.

For example, in the SOI “Review” mode, digital information is distributed after the PCRK for periods and the mathematical arrangement of digital gates within each period. Next, digital information is matched with the strobe duration, weighted by the Hann function, obtaining the signal spectrum in each strobe using the fast Fourier transform operation, calculating the signal modulus in each strobe, and choosing the maximum signal amplitude in each strobe. After the procedure for detecting and selecting the maximum amplitude, the input information for the DAC of the AWP indicator is generated.

Thus, the replacement of dispersive ultrasonic delay lines and analog filters by digital devices for generating and processing LFM and SOI pulses ensures the operation of the radar with high quality and reliability.

Claims (1)

A radar for a self-propelled firing system, comprising an antenna, a receiver, the first input of which is connected to the output of the antenna, a transmitter, the output of which is connected to the input of the antenna, a shaper of the microwave excitation pulse of the transmitter, the first output of which is connected to the input of the transmitter, and the second output is connected to the second input receiver, synchronizer, workstation, digital computer system, the first output of which is connected to the input of the synchronizer, the second output is connected to the input of av an automated workstation, the output of which is connected to the first input of a digital computer system, characterized in that a digital synthesizer of intermediate frequency signals, an electronic computer for digital signal processing, a processor for digital decomposition of the signal into quadrature components, the output of which is connected to the first input of the electronic computer, are introduced into it digital signal processing machines, and the first input is connected to the output of the receiver, the first synchronizer output is connected to the first input of the digital an intermediate frequency signal integrator, the second input of which is connected to the third output of the digital computer system, the second synchronizer output is connected to the second inputs of the digital signal decomposition processor and the digital signal processing electronic computer, the output of which is connected to the second input of the digital computer system, the fourth output which is connected to the third input of an electronic computer for digital signal processing, the output of a digital signal synthesizer in the intermediate frequency is connected to the input of the microwave excitation of the transmitter pulse.

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