RU149404U1 - RADAR SURVEILLANCE STATION WITH MULTIFREQUENCY SENSING SIGNAL - Google Patents

Abstract

A tracking radar with a multi-frequency sounding signal, containing the main (OA) and compensation (KA) antennas, a transmitting device (PDU), the output of which is connected to the OA input, a complex signal conditioner (FSS), receivers of the main (PRO) and compensation (PRK) channels , the first inputs of which are connected respectively to the outputs of OA and KA, the primary processing device (UPR) as part of a series-connected auto-compensator (AK), the first and second inputs of which are connected respectively to the outputs of the ABM and PRK, sequentially connected to protection against non-synchronous impulse noise (RFI) and the optimal filter (OF), as well as series-connected threshold device (PU), a device for suppressing signals received by the side lobes of the radiation pattern OA (PBL), and a coordinate measuring device (PEC), the output of which connected to the input of the secondary processing device (SVR), the output of which is the output of the radar, characterized in that it includes a heterodyne signal driver (FGS), a mixer (SM) and a control circuit (SU), and the distribution device includes a distribution device signal (URS), N coherent drives at a frequency of FN (KHFN), a power estimation device (UOM) and an incoherent drive (LV), the FSS output being connected through the first input and the SM output to the remote control input, and the FGS output is connected to the second inputs SM, PRO and PRK, the OF output is connected to the first input of the URS, the N outputs of which are connected via N KHF to the N inputs of the LV, the output of which is connected to the input of the control unit, and the UOM, the output of which is connected to the first input of the control unit connected to the first output with the input of the FGS, the second - with the second input of the URS, and the second input - with the source of the target designation signal (CC).

Description

The utility model relates to radar and can be used in pulsed radar stations (radar) tracking with a multi-frequency sounding signal.

One of the most effective means of obtaining radar information at present is multifunctional radar (MRS) with active phased antenna arrays with two-dimensional electronic scanning, which can simultaneously solve the problem of finding targets and carry out their tracking with high-precision coordinate measurement.

One of the most important characteristics of a radar tracking system is its performance, defined as the number of targets followed in a single review. In turn, the performance is determined by the time spent by the radar tracking for one target. In practice, a number of factors influence the performance of radar systems, one of which is fluctuations in the effective scattering area (EPR) of the objects being tracked, which lead to an increase in the average time required to detect a target and, accordingly, to a decrease in the number of tracking targets in one survey.

To reduce the time losses during target detection caused by EPR fluctuations, as a rule, multi-frequency sounding methods are used [1], due to which the amplitude of the reflected signal is averaged, which leads to a decrease in the target irradiation time and, accordingly, to an increase in the tracking radar performance.

Radars are known [2, 3,4] using a multi-frequency sounding signal.

The closest analogue (prototype) to the proposed solution for technical performance is "Mobile ground-based two-coordinate radar circular survey meter range" [4]. This radar contains the main and compensation antennas, a shaper of probing signals, a transmitter, receivers of the main and compensation channels, two auto-compensators, two primary processing devices, a device for combining and identifying information, and a secondary processing device. The sounding of space is carried out at two carrier frequencies, varying from measure to measure. The receivers of the main and compensation channels are direct amplification receivers, where the echo signals are selected by frequency, amplified and converted into a digital code using a high-speed analog-to-digital converter (ADC).

The primary processing devices detect, measure the coordinates and radial velocity of airborne objects (each in the band of its carrier frequency), and also measure the amplitude of the signals, accumulate, suppress the signals received by the side lobes of the radiation pattern of the main antenna. In this case, the accumulation and detection of the echo signal in the primary processing devices occurs at each operating frequency independently. After that, the coordinates of the detected object are selected in the device for combining and identifying information at the frequency of the radar, at which the amplitude of the detected signal is greater, and then the measured coordinates and radial velocities of the object are sent for subsequent processing.

This method of irradiation and signal processing can be used in radar tracking with a multi-frequency signal. However, the prototype has a number of disadvantages.

Firstly, as a result of irradiating the target at two frequencies, a signal accumulated coherently at one frequency is used for detection, i.e. only half the packet of impulses reflected from the target. This leads to energy losses and, consequently, to a decrease in the detection range of the target. It would be more rational to use incoherent addition of signals accumulated coherently at each of the two frequencies, followed by the use of the total signal to detect the target.

Secondly, the use of only two frequencies for irradiation is insufficient from the point of view of compensating for fluctuations in the EPR of targets [1].

These disadvantages can be eliminated by using the adaptive algorithm for irradiating the target with a multi-frequency signal, in which at the initial stage a small number of pulses are emitted at several frequencies (more than two) and the frequency is determined at which the power of the reflected signal is maximum. Further irradiation of the target is carried out at the selected frequency, which is considered the best from the point of view of maximum EPR, with subsequent coherent accumulation of signals reflected at this frequency.

The technical result of the proposed utility model is to increase the performance of radar tracking by reducing time losses caused by both the EPR fluctuations of the tracked object and the method of processing the reflected signal.

The specified technical result is achieved by the fact that in the known radar containing the main (OA) and compensation (KA) antennas, a transmitting device (PDU), the output of which is connected to the OA input, a complex signal conditioner (FSS), receivers of the main (PRO) and compensation (PRK) channels, the first inputs of which are connected, respectively, with the outputs of OA and KA, the primary processing device (UPR) as part of a series-connected auto-compensator (AK), the first and second inputs of which are connected, respectively, with the outputs of the PRO and PRK, protection devices s from non-synchronous impulse noise (RFI) and the optimal filter (OF), as well as connected in series, a threshold device (PU), a device for suppressing signals received by the side lobes of the radiation pattern OA (PBL), and a coordinate measuring device (PEC), the output of which connected to the input of the secondary processing device (SVR), the output of which is the output of the radar, a heterodyne signal driver (FGS), a mixer (SM) and a control circuit (SU) are introduced, and a signal distribution device (URS), N coherent storage devices are included in the UPR frequency F _N (KHF _N ), power estimation device (PTO) and incoherent drive (LV), the FSS output being connected through the first input and the SM output to the remote control input, and the FGS output to the second SM, PRO and PRK inputs, the OF output is connected to the first input of the URS, the N outputs of which through N KHF _{N are} connected to the N inputs of the LV, the output of which is connected to the input of the control unit, and the OOM, the output of which is connected to the first input of the control unit connected to the first output with the input of the FSW, the second to the second the input of the URS, and the second input with the source of target designation (TSU).

The figure shows the structural diagram of the proposed utility model, where indicated:

1 - mixer (SM);

2 - shaper complex signal (FSS);

3 - control circuit (SU);

4 - signal distribution device (URS);

5 - secondary processing device (SVR);

6 - transmitting device (remote control);

7 - driver of heterodyne signals (FGS);

8 - optimal filter (OF);

9 - coherent storage frequency F ₁ (KHF ₁ );

10 - coherent storage frequency F _N (KHF _N );

11 - device for measuring coordinates (PEC);

12 - main antenna (OA);

13 - receiver of the main channel (PRO);

14 - a device for protection against non-synchronous impulse noise (RFI);

15 - power rating device (UOM);

16 is a device for suppressing signals received by the side lobes of the OA radiation pattern (PBL);

17 - compensation antenna (KA);

18 - receiver compensation channel (GTRK);

19 - auto-compensator (AK);

20 - primary processing device (UPR);

21 - incoherent drive (NN);

22 - threshold device (PU).

The figure does not show radar synchronization signals for simplicity.

As can be seen from the structural diagram, the device consists of the main and compensation antennas OA 12 and KA 17, respectively, a PDU 6 transmitting device, the output of which is connected to the OA 12 input, CM 1 mixer, FSS 2 complex signal shaper, FGS 7 heterodyne signal shaper, receivers of the main channel ABM 13 and the compensation channel GTRK 18, control circuits SU 3, primary processing devices UPR 20 and secondary processing devices UVO 5.

The UPR 20 includes an AK 19 auto-compensator, an anti-asynchronous impulse noise protection device ZNP 14, an optimal filter OF 8, a signal distribution device URS 4, N coherent drives at frequencies F ₁ ... F _N -KHF ₁ 9 ... KHF _N 10, an evaluation device power of UOM 15, incoherent drive HH 21, threshold device PU 22, a device for suppressing signals received by the side lobes of the radiation pattern OA PBL 16 and a device for measuring coordinates of PEC 11. At the same time, the output of FSS 2 through SM 1 is connected to the input of remote control 6, the output of FGS 7 connected to the second inputs of CM 1, RO 13 and GTRK 18, the first inputs of the PRO 13 and GTRK 18 are connected, respectively, with the outputs OA 12 and KA 17, and the outputs are connected to the first and second inputs of the AK 19, the output of which through ZNP 14 and OF 8 is connected to the first input of the URS 4 ; N outputs of URS 4 through N KHFN are connected to N inputs of UOM 15 and NN 21, the output of which is connected in series with PU 22, PBL 16, PEC 11 and UVO 5, the output of which is the output of the radar, the first input of SU 3 is connected to the output of UOM 15, the first output is with the input of FGS 7, the second is with the second input of the URS 4, and the second input is with the signal source of the control unit.

Unlike the prototype, the formation of a complex signal (linearly-frequency-modulated, phase-shifted, etc.) in FSS 2 is carried out at an intermediate frequency, and the receiving and transmitting paths are made according to a superheterodyne circuit using FGS 7 with a tunable frequency, SM 1 and mixers available in the ABM 13 and PPH 18 not shown in the figure.

The proposed radar tracking with a patented device operates as follows.

According to the target designation from the source of the control unit, the tracking radar beam is set in a given angular direction to the selected target. In this direction, a packet of pulses is emitted at N frequencies with M pulses at each frequency (N> 2, M≥1).

The formation of signals at each operating frequency is as follows. The signals at the intermediate frequency with FSS 2 are fed to the input of SM 1, where, together with the heterodyne signal from FGS 7, they are converted to a high (working) frequency and fed to the remote control 6, which amplifies, filters and transmits them through an antenna switch (not shown in the figure) on OA 12, from where the generated probe signal is radiated into space. The choice of the operating frequency is carried out using the control signal generated from the output 1 of the control circuit of the control system.

The echo signals reflected from the target at each of the N frequencies through the main OA 12 and compensating KA 17 antennas are received in the receivers of the main and compensation channels PRO 13 and PRK 18, the second inputs of which are supplied with a heterodyne signal generated in FGS 7. In the receivers of the main and compensation channels PRO 13 and PRK 18 the reflected echo signals are transferred to the intermediate frequency, amplified, selected in frequency and converted into a digital code, and then fed to the input of the primary information processing device

In each sounding cycle, regardless of the frequency of the emitted signal, the UPR 20 implements intra-period processing, which includes protection against active noise interference, protection against non-synchronous impulse noise, and optimal echo filtering. Then, at each frequency, coherent accumulation of the signals reflected from the target in coherent drives KHF ₁ 9 ... KHF _N 10 is performed. The number of coherent drives is determined by the number of frequencies used to irradiate the target. The distribution of received signals according to KHF ₁ 9 ... .KHF _N 10 depending on the operating frequency is carried out in URS 4.

The signal from the output of the coherent drives KHF ₁ 9 ... KHF _N 10 is fed to the UOM 15 device, which estimates the power of the signal reflected from the target at each of N frequencies. The obtained capacity estimates are sent to the first input of the control circuit of control system 3, to the second input of which a target designation containing information about the coordinates of the tracked object is supplied. In the control circuit SU 3 is the choice of the radar frequency corresponding to the maximum power of the reflected signal. Further irradiation of the target is carried out at the selected optimal frequency, for which purpose corresponding control signals are generated in the control system 3 and fed to the inputs of the FSW 7 and URS 4. The URS 4 signal distribution device connects a coherent drive tuned to the optimal operating frequency, and further accumulation of reflected signals occurs in selected KN.

Moreover, to reduce the time required to detect the target, the signals accumulated in N coherent drives at the stage of searching for the optimal frequency are summed in the incoherent drive HH 21 with the reflected signals accumulated coherently at the optimal frequency. The resulting signal from the output of the incoherent drive is used to detect the target. For this, the signal is fed to the threshold device PU 22, the device PBL 16 and PEC 11, in which, respectively, the comparison with the detection threshold (measurement), the suppression of signals received from the side lobes of the radiation pattern and the measurement of the coordinates of the tracked object are implemented. Further, information about the measured target parameters goes to UVO 5, where the secondary processing of information issued to the end user is carried out.

Thus, the introduction of a prototype containing OA, KA, PDU, FSS, PRO, PRK, UPR and UVO, additionally FGS, SM and SU, and in UPR-URS, N KHF _N , NN, and UOM with corresponding connections, allowed us to create a device, the use of which in radar tracking with a multi-frequency probing signal allows to increase its performance, which is achieved by reducing time losses caused by both fluctuations of the EPR of the target and the method of signal accumulation.

Bibliography:

1. G.M. Cherries. Multi-frequency radar. M .: Military Publishing, 1973.

2. A method of constructing a two-dimensional radar image of an air target, RF patent No. 2234110, publ. 08/10/2004.

3. A device for recognizing air targets in a two-frequency way, RF patent No. 2407033, publ. 12/20/2010.

4. Mobile ground-based two-coordinate radar circular survey meter range (prototype), RF patent No. 2341813, publ. 12/20/2008.

Claims (1)

A tracking radar with a multi-frequency sounding signal, containing the main (OA) and compensation (KA) antennas, a transmitting device (PDU), the output of which is connected to the OA input, a complex signal conditioner (FSS), receivers of the main (PRO) and compensation (PRK) channels , the first inputs of which are connected respectively to the outputs of OA and KA, the primary processing device (UPR) as part of a series-connected auto-compensator (AK), the first and second inputs of which are connected respectively to the outputs of the ABM and PRK, sequentially connected to protection against non-synchronous impulse noise (RFI) and the optimal filter (OF), as well as series-connected threshold device (PU), a device for suppressing signals received by the side lobes of the radiation pattern OA (PBL), and a coordinate measuring device (PEC), the output of which connected to the input of the secondary processing device (SVR), the output of which is the output of the radar, characterized in that it includes a heterodyne signal driver (FGS), a mixer (SM) and a control circuit (SU), and the distribution device includes a distribution device signal (URS), N coherent drives at a frequency of FN (KHFN), a power estimation device (UOM) and an incoherent drive (LV), the FSS output being connected through the first input and the SM output to the remote control input, and the FGS output is connected to the second inputs SM, PRO and PRK, the output of the OF is connected to the first input of the URS, the N outputs of which through N KHF _{N are} connected to the N inputs of the LV, the output of which is connected to the input of the PU, and the UOM, the output of which is connected to the first input of the control panel connected to the first output with the input FGS, the second - with the second input of the URS, and the second input - with the source of the target designation signal (CC).

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