RU2390946C2 - Broadband station of radio engineering survey with high sensitivity - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: station of radio engineering survey comprising antenna-feeder device, broadband radio receiving device (RRD), device of signals parametres definition (SPDD), device of information digital processing (IDPD), automated workplace of operator, equipment of data transmission and means of radio communication, and also electric drive of antenna and unit of azimuth detectors, additionally there are working frequencies synthesiser (WFS) connected with according links, as well as multi-channel narrowband RRD, each channel of which comprises serially connected converter of frequency, multi-channel, unit of commutators, frequency coupler and multi-channel logarithmic detector. SPDD also comprises serially connected converter of frequency, multi-channel, unit of commutators, multi-channel logarithmic detector and Fourier converter with multi-channel receiver connected to multi-channel converter of frequency via unit of commutators. IDPD is arranged in composition of primary processing device, device of interchannel processing, device of analysis and control and analyser of parametres with according links.

EFFECT: increased sensitivity, accuracy of direction finding, efficiency, noise immunity and expansion of functional capabilities.

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Description

The invention relates to the field of electronic reconnaissance (RTR) and can be used in electronic monitoring of radiation from electronic means (RES) of land, air and sea based, in electronic warfare as a source of information about the electronic situation in the observation area, as well as for monitoring and analysis of the parameters of the signals emitting RES and the dynamics of their changes.

A device for fast signal detection, direction finding and location determination (DE patent No. 3639444, G01S 5/04, published 05/05/1988), which is a 2-channel frequency search phase direction finder. The device is intended for use in search and direction finding stations. The probability of detecting an emitting RES is dependent on the length of time the signals are received at the appropriate frequency. The disadvantages of this device include low accuracy of direction finding, low probability of detection of short-term emitted signals and a relatively narrow band of operating frequencies.

Known phase direction finders (RF patents No. 1690471, G01S 3/02, 1996, No. 2165628, G01S 3/00, 2001, No. 2126978, G01S 3/54, 1999). These direction finders have low speed, since switching antennas eliminates the work on short-term emitted signals; insufficient noise immunity, since the phase difference of the signals received by the antenna is measured in the entire frequency range; low direction finding accuracy due to fluctuations in signal frequencies and directions of their arrival in the elevation plane.

A known direction finder (RF patent No. 2201599, G01S 13/14, 2003) that implements a correlation-interferometric direction finding method.

The following disadvantages are inherent in this direction finder: a limited range of operating frequencies, a narrow band of simultaneous reconnaissance, and a low probability of detecting short-term emitted signals.

The closest to the proposed technical solution is the "Radio intelligence station" (RF patent No. 2136110 dated 04/23/1987, H04K 3/00, H04B 15/06, published on 08/27/1999).

The RTR station consists of an input path, a multi-channel frequency-selective splitter, each channel of which contains a first mixer with a filter, a second mixer, a third mixer with a filter, a first local oscillator and a second local oscillator, as well as a multi-channel adder, receiver, analyzer, and memory device and information processing. In this RTR station, an increase in the dynamic range is achieved due to the introduction of devices (mixers, filters, local oscillators) that provide an additional second frequency conversion of the input signal.

Known RTR station has the following disadvantages:

- low noise immunity, since all channels of the frequency splitter are added up and when signals are superimposed in time, these signals are not separated;

- low sensitivity, since all channels of the frequency splitter are constantly open and the noise of all channels are summed on the adder;

- the impossibility of reconnaissance of any kind of signals, since if there is a continuous signal at the input of the RTR station, for example, reconnaissance of pulse signals is impossible.

The objective of the present invention is to increase the sensitivity, direction finding accuracy, speed, noise immunity and expand the functionality of the broadband automatic station RTR emitting RES in terms of providing automatic reconnaissance of any kind of signals.

The task is achieved by the fact that in the RTR station containing the antenna-feeder device (AFU), the outputs of which are connected to a broadband radio receiving device (RPU), a device for determining signal parameters (OOPS) connected to a broadband RPU through a switch, a digital information processing device ( UCOI), one of the inputs of which is connected to the block of azimuth sensors mechanically connected to the AFU, the operator's automated workstation (AWP) connected to the electric drive and data transmission equipment (ADF) and radio communications equipment, while the electric drive is mechanically connected to the AFU, an additional working frequency synthesizer (MFR) connected to the input of the broadband RPU and multi-channel RPU narrowband, the inputs of which are connected to the outputs of the RPU broadband, are additionally included. Each channel of a multi-channel narrow-band RPG contains a multi-channel frequency converter (RPC), a switch block, a frequency splitter and a multi-channel logarithmic detector in series. OOPS also contains a multichannel frequency converter, a switch unit and a logarithmic multichannel detector, the construction of which is similar to the corresponding narrow-band RPU devices in series. In addition, the UOPS includes a Fourier converter and a multi-channel receiver connected to a multi-channel frequency converter through a block of switches. The UCOI contains a primary processing device (UPR) connected to the outputs of the RPU broadband and narrowband, an interchannel processing device (UMO) connected to the outputs of the logarithmic UOPS detector, and a parameter analyzer whose inputs are connected to the Fourier converter and multichannel receiver, as well as an analysis and control (UAU), the information inputs of which are connected to the block of azimuth sensors, ULV, the analyzer of parameters and UPR, the control outputs are connected to the RMS, electric drive and switch blocks UOPS and RPU narrowband, and information output - to the operator's workstation.

A comparative analysis of the proposed technical solution and prototype shows that the proposed technical solution introduced new devices (narrow-band receiver, operating frequency synthesizer), and a number of devices whose functions are similar to the functions of the prototype (device for determining signal parameters, digital information processing device) are based on known devices, but the connections between them and the operation algorithms differ from the prototype, which allows to obtain new properties: increased sensitivity, speed , bandwidth and providing intelligence capabilities of any kind of signals.

The specified set of distinctive features, according to the authors, is new, because in known sources of information was not given.

The invention is industrially applicable, as it can be used in those areas of the country’s economy where electronic means of monitoring emitting means are used (tracking of ground, air and sea-based emitting means, electronic surveillance and control).

The drawing shows a structural diagram of a broadband automatic station RTR emitting RES.

The AFU includes a direction finding antenna and reception compensation antennas along the side lobes.

The direction-finding antenna is a mirror antenna and an n-channel irradiator and has a narrow directivity pattern in azimuth (1-3 °) and multi-beam in elevation. The number of rays in elevation (N) is determined by the requirements for the viewing sector in elevation and direction finding accuracy.

Side lobe compensation antennas are biconical and horn antennas. The gain of these antennas is 2-3 dB higher than the gain in the direction of the side lobes of the direction-finding antenna in the entire working area in azimuth and elevation, thereby compensating reception on the side lobes of the direction-finding antenna.

The antenna rotates uniformly in azimuth using an electric drive at a speed of 6 or 12 revolutions per minute (the speed is set with the operator's workstation). The speed value is selected based on the required viewing period of the observation zone in azimuth.

The azimuth sensor block provides information on the current position of the main beam of the direction-finding antenna in azimuth with high accuracy (1-2 angular minutes). The reading is relative to the direction to the North.

The broadband RPU is a multi-channel broadband microwave receiver with direct amplification, and its working frequency range is equal to the working frequency range of the station. The number of channels m is equal to the number of outputs of the AFU, including direction finding and compensation channels.

To expand the dynamic range of the received signals, each channel contains a detector receiver and a receiver with a microwave amplifier. Each channel of a multichannel broadband RPU also contains a detector and a logarithmic video amplifier. Broadband RPU provides reception of signals in the entire operating frequency range of the RTR station.

Narrow-band RPU is also multi-channel; the number of channels is the same as in broadband RPU. Each channel of a narrow-band RPU contains a multi-channel frequency converter (PFR), a block of switches, a frequency splitter and a multi-channel logarithmic detector. The RFI multi-channel contains a frequency splitter, which provides the separation of the entire operating frequency range into k channels and the conversion of the microwave signal in each channel into an intermediate frequency and amplification of the intermediate frequency signals. The frequency band of each of the k channels is selected on the basis of ensuring the required sensitivity, noise immunity, and types of signals being scanned. For example, when reconnaissance of onboard RES in the centimeter wavelength range, the frequency band can range from 300 to 1000 MHz.

Each of k channels is connected to a frequency splitter on s channels through a switch. Each of the s channels of the frequency splitter is connected to a specific channel of a multi-channel logarithmic detector. The frequency band of the frequency splitter is selected based on the frequency band of the signals being scanned. For example, with a pulse duration of 0.025 μs, the band of each of the S channels should be at least 50 MHz. Thus, the operating frequency band of the narrow-band RPU at the input can vary from the bandwidth of one of the k channels to the magnitude of the frequency range of the station, and the output is equal to the frequency band of one of the s channels of the frequency splitter, which allows for high sensitivity and selectivity of the narrow-band RPU.

The narrow-band RPU in the RTR station is used to select frequency signals in a difficult jamming environment and to increase the sensitivity of the station along the direction-finding channel if the sensitivity of the broadband RPU is insufficient to detect the RES signal.

The N × 1 switch provides the microwave signal connection of one of the direction-finding channels of the broadband RPU to the OOPS, which provides the determination of the carrier frequency, pulse duration and amplitude, type of modulation, and signal spectrum width.

OOPS contains three receivers operating in parallel.

One receiver is constructed similarly to a narrow-band RPU and contains a multi-channel frequency converter, a block of switches, and a logarithmic detector. This receiver is actually the first stage of the frequency determination device and is designed to divide the entire frequency range into k frequency channels and determine the duration and amplitude of the signals. Each of the k channels of this receiver through a switch is connected in parallel to a Fourier converter, which provides reconnaissance of extended signals (more than 3 μs) and a multichannel receiver (MP), designed for reconnaissance of short signals (less than 3 μs), which includes a frequency splitter, to the outputs whose logarithmic detectors are connected. The Fourier converter cycle time is about 1 μs, which provides a high signal throughput. The Fourier converter and the MP are the second stage of the device for determining the frequency.

The UCOI is a high-speed processor and matching devices and contains a UPR that provides processing of RPU signals of narrow-band and broadband, an inter-channel processing device for signals of the first stage of the OOPS, a parameter analyzer for processing the signals of the Fourier converter and a multi-channel receiver, and an analysis and control device for generating a complete form of signal parameters and angular coordinates of the radiation source, as well as control of the operating modes of the RTR station as a whole.

The RFS is a signal generator and is designed to calibrate the paths of both RPU and UOPS, as well as to monitor the operability of the RTR station as a whole. The RFS provides the formation of any kind of signals: pulsed, continuous, interfering, quasi-continuous, frequency-modulated (FM) and phase-shift keying (FCM), which are used both to configure the RTR station and to monitor its operability.

The operator’s workstation contains a computer, a video monitor, a keyboard and a graphic manipulator. With the AWP, the operating modes of the RTR station are controlled, the display shows the reconnoitered information. The workstation also provides the formation of output information, which is transmitted to the consumer through the ADF and radio communications.

RTR station provides the following main technical characteristics:

automatic reconnaissance and delivery to the consumer in real time of information about the parameters and angular coordinates of the radio electronic equipment emitting any kind of signals:

- simple impulse signals;

- complex pulse signals with intrapulse modulation (FCM and FM);

- continuous and quasi-continuous signals;

- interference signals;

- signals with pulse-wise tuning of the operating frequency;

- short pulse signals (up to 0.025 μs).

Recognition of a class (type) of RES.

Maintenance of distribution zones for their entire period of work with assignment of a conditional number.

Exclusion of interfering signals.

Display as a complete radio environment, and the form of specific signals.

Monitoring the health of the equipment.

Training of operators.

Reproduction of the RES reconnaissance process for a certain period of time.

The RTR station provides operation in several modes:

- “Input of initial data”;

- "Work";

- "The control";

- "Training";

- "Technological";

- “Playback”.

In the "Input data" mode with the operator's workstation, the input data necessary for the organization of the "Work" mode can be entered:

- period of rotation of the antenna;

- numbers and priorities of frequency channels;

- forbidden and priority frequencies;

- priorities by type of signals (“short” - “long”, “weak” - “powerful”);

- priority directions in azimuth and RES classes;

- information on parameters and RES for the image bank;

- an option of a raid of RES for the "Training" mode.

Information is entered only if it is changed in comparison with the previous stage of work.

In the "Work" mode, the radiating RESs are prospected and information is provided to the consumer. Intelligence is carried out automatically without operator intervention. The operator can make adjustments to change the reconnaissance and prioritization modes for frequency channels and directions both in azimuth and elevation.

The work of the RTR station will be considered according to the structural diagram shown in the drawing.

Reconnaissance RES is carried out “in the passage” with uniform rotation of the antenna using an electric drive.

RES observation time is from 10 to 100 ms, depending on the power and frequency range of the signal. The signal from the AFU enters the RPU broadband, amplified and detected. Part of the microwave power from each channel of the broadband RPU is branched into the corresponding channel of the narrow-band RPU, and from direction finding channels to the N × 1 switch. The video signals from the broadband RPU output go to the UCO URO. In the UPR, the amplitudes of the signals are compared, only signals received by the main beam of the direction-finding antenna are received for processing, i.e. the signal amplitude in the direction-finding channel of which is greater than in the compensation channel. Signals received by the side lobes of the direction-finding antenna and the compensation channels are not accepted for processing. This ensures high selectivity of signal reception in the direction and increases the noise immunity of the RTR station.

If the signal is received by the direction finding channel, then the OOPS is connected to this channel of the broadband RPU via the N × 1 switch to determine the signal parameters. In the initial position, the OOPS is connected to the first (lower) beam of the AF AF. Since the sensitivity of the broadband RPU is lower than the OOPS, it may turn out that the signal is in the OOPS and not in the broadband RPU. In this case, according to the information about the carrier frequency received from the OOPS, the narrow-band RPU is tuned to the frequency of the signal received by the OOPS. Tuning is done by controlling narrowband RPU switches.

The narrowband RPU signals are processed similarly to the broadband RPU signals, i.e. Only signals received by direction finding channels are accepted for processing.

Since the construction of the UOPS and narrowband RPU is similar, their sensitivity is approximately the same, which ensures their joint work. However, when controlling the switches from the OOPS, it is impossible to reconnaissance of several signals simultaneously located in the direction finding antenna beam if their frequencies differ by an amount greater than the frequency band of the narrow-band RPU, as well as signals with pulse-frequency tuning of the operating frequency (PFRCH). To do this, it is possible to control the switches in both the UOPS and the RPU with a narrow-band incoming microwave signal, due to which, with a high sensitivity of the station, its throughput and signal reconnaissance with frequency hopping are increased.

The presence of two parallel-operating receivers in the OOPS: a Fourier converter, which provides high accuracy in determining the frequency and the ability to work over time-extended signals, and a multi-channel receiver, which provides reconnaissance of short signals (up to 25 ns), allows you to explore any kind of signal. The parameter analyzer provides an analysis of the information of the Fourier converter and the MP and the determination of the carrier frequency, the type of modulation and the width of the signal spectrum. First of all, the information of the Fourier transform is used, if there is no information in it, then the information of the magnetic field is used. The inter-channel processing device provides the determination of the number of the frequency channel in which the signal is received, the amplitude and duration of the pulse. Joint processing of the information of the ULV, the Fourier converter and the magnetic field provides an accurate determination of the frequency in the entire operating frequency range of the RTR station. In addition, the ULV provides the processing of signals at given priorities when they are superimposed over time (weak or strong, short or long), which ensures high noise immunity of the station in a complex electronic environment. Priorities are set by changing detection thresholds in ULV. In the RTR station, reconnaissance modes can also be adaptively changed according to the operator’s commands, while the “Work” mode does not stop. The operator can set the intelligence mode to “Searchless,” “Search,” or “Ultrafast search.”

In the "Search-less" mode, all or several (more than 2) channels of multi-channel frequency converters of OOPS and RPU narrow-band are constantly open. At the same time, reconnaissance of any kind of signals is provided, but the sensitivity of the UOPS and narrowband RPU is lower than with an open single channel. Therefore, a mode is also provided in which all channels are closed, but are opened by an incoming signal. At the same time, the highest sensitivity and intelligence of any kind of signals is provided. The RTR station also provides for a “Search” mode.

In the "Search" mode, only one frequency channel is constantly open, which ensures the highest sensitivity and noise immunity of the station, but the band of reconnaissance frequencies narrows.

During the “Ultrafast search”, when the Fourier transducer cycle is changed (about 1 μs), the number of the open frequency channel in the OOPS periodically changes, while the entire operating frequency range is viewed, which makes it possible to detect weak signals, and then automatically switch to the “Search” mode and ensure its direction finding and measurement of parameters.

The combination of the above modes allows the operation of the RTR station in a complex jamming environment and provides reconnaissance of any kind of signals.

The RTR station also provides for the rejection of interfering signals by the carrier frequency, direction or by the totality of the parameters of the RES — the carrier frequency, duration and pulse repetition period (f, τ, T), which is carried out in UAU. UAU provides reception of information from RPU of broadband and narrowband, UOPS and a block of azimuth sensors and analysis of this information during the observation, as well as separation of signal sequences from various RES and determination of the parameters of signals and angular coordinates of the RES using a pulse packet received during the observation. The angular coordinates of the RES (azimuth and elevation angle) and the parameters of its signal are determined as the most probable during the observation using the formula:

where Xi is the angular coordinate (or parameter) determined by the i-th pulse;

Ui is the amplitude of the i-th pulse;

S is the number of pulses received during the observation time.

Since the direction finding antenna beam has a bell-shaped shape, the parameters and angular coordinates of the distribution elements determined at the moment when the direction finding antenna direction is accurately directed to the distribution lines have a larger weight than on the slopes of the direction finding antenna, which reduces errors due to omissions of pulses and asymmetry of the direction finding and improves accuracy direction finding and determination of RES parameters.

The elevation angle value for each i-th pulse is determined in the UPR either by the AFU channel number in the presence of a signal in only one direction-finding channel, or by a single-pulse amplitude method, in the presence of a signal in the adjacent two beams of the direction-finding antenna.

To improve the accuracy of direction finding by elevation and the accuracy of determining the frequency, periodically using the RF signals, the RPU paths of the broadband and narrowband, as well as the OPS are calibrated. Information about the multichannel (non-identical transmission coefficients of the channels of both RPUs and UOPS) is stored in the UCOI and is used to determine the elevation angle and number of the UOPS frequency channel. In addition, when calculating the elevation angle by the single-pulse method, it is taken into account at what frequency the signal is received, since the steepness of the direction-finding characteristic can vary in the operating frequency range. The initial data on the steepness of the direction-finding characteristic are recorded in the memory of the UCOI processor when setting up the RTR station.

The azimuth of the RES is read from the azimuth sensor at the time of receipt of each i-th pulse.

The remaining parameters of the RES signal for each i-th pulse are determined in the ULV and the parameter analyzer.

If there are continuous or long signals, they are quantized by the Fourier converter operation cycles (about 1 μs) and the parameters and angular coordinates are determined for each i-th cycle, which are then analyzed in UAU, where the signal type and its parameters are finally determined.

Thus, such a construction of the OPS, in which both the MP and the Fourier processor work simultaneously, allows you to explore any kind of signal: from the shortest (0.025 μs) to continuous and interfering.

Information on each signal is fed to the operator's computer. In the automated workplace, the REC class is recognized by comparing the parameters of the explored RES with the parameters of the RES in the image bank, tracking the RES from review to review with assigning a conditional number for the entire period of the RES, generating output information and displaying information on the monitor screen. At the request of the operator, information can be displayed in tabular form or against a background of real terrain. In addition, the operator can observe the situation in coordinates: azimuth-frequency, azimuth-power, frequency-power, and also observe the shape of individual signals. In this case, the operator does not participate in the formation of output information to the consumer, it is generated and transmitted automatically with a given intelligence cycle (5 or 10 s).

In the "Control" mode, the health of the equipment of the RTR station is monitored with accuracy to an interchangeable unit (module). For control, RF signals and special control tests are used.

The "Training" mode is used to train operators. In this mode, only the operator’s workstation is involved. The operator selects a variant of the electronic environment (raid) and can participate in the reconnaissance of radio electronic equipment: change reconnaissance modes, set priorities, observe the general electronic environment with various types of screen forms.

The “Technological” mode is used to configure the equipment of the RTR station. This mode is similar to the “Work” mode, but without rotation of the antenna, which is simulated in the UCOI. As the signal of the RES, either the RF signal or the signal of the external generator received by the AFU is used.

The “Playback” mode allows you to play on the AWP screen the process of reconnaissance of radio electronic equipment in the “Work” mode for a certain period of time. This is ensured due to the fact that all reconnoitered information is automatically documented in the computer memory. The “Playback” mode allows you to conduct a detailed analysis of the operation of the RTR station in the “Work” mode and evaluate the specific actions of the operator, thereby contributing to the improvement of their skills.

Thus, the use of the proposed technical solution allows you to create a broadband automatic RTR station with high technical characteristics: sensitivity, direction finding accuracy, noise immunity to bandwidth, and also provide reconnaissance of any kind of signals.

Claims (1)

Broadband radio intelligence station containing an antenna-feeder device (AFU), the outputs of which are connected to a broadband radio receiving device (RPU), a device for determining signal parameters (OOPS) connected to a broadband RPU through a switch, a digital information processing device (UCOI), designed to control modes of the radio intelligence station, one of the inputs of which is connected to the block of azimuth sensors, mechanically connected to the AFU, while the specified switch ensures the connection of one of the direction finding channels of the broadband RPU to the UOPS in accordance with the control of the station’s operating modes, which also contains the operator’s automated workstation connected to the electric drive and data transmission equipment and radio communications equipment, while the electric drive is mechanically connected to the AFU, characterized in that it additionally includes a working frequency synthesizer (MFR) connected to the input of the broadband RPU, and the narrow-band RPU, the inputs of which are connected to the outputs of the broadband RPU oh, and each channel of the narrow-band RPU contains a multi-channel frequency converter, a switch unit, a frequency splitter and a multi-channel logarithmic detector, the OOPS also contains a multi-channel frequency converter, a switch block and a multi-channel logarithmic detector, as well as a Fourier converter with a multi-channel receiver connected to multichannel frequency converter through the block of switches, UCOI as part of the primary device bots (UPR), connected to the outputs of the RPU broadband and narrowband, an interchannel processing device, connected to the outputs of a logarithmic UOPS detector, a parameter analyzer whose inputs are connected to a Fourier converter and a logarithmic multichannel detector, an analysis and control device, the information inputs of which are connected to interchannel processing device, parameter analyzer and UPR, and control outputs are connected to the RF system and switch blocks of the UOPS and RPU narrowband go, and the information output is to the operator's workstation.

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