RU73108U1 - PASSIVE DETECTION OF OBJECTIVES - Google Patents

Abstract

The utility model relates to the field of passive location and can be used to detect real-time aircraft, calculate their coordinates and flight paths, followed by information transfer to the control center. A device for passive target detection, containing M receiving antennas, the first and second analog-to-digital converter (ADC), a special computer and the necessary peripherals to ensure its operation, characterized in that it additionally includes a low noise amplifier (LNA), the M inputs of which are connected to M receiving antennas, the first and second multichannel radio receivers (RPUs), the inputs of which are connected respectively to the first and second outputs of a low-noise amplifier, and the outputs are connected to the inputs of the first and second analog-to-digital pre verters, the first and second information processing channels whose inputs are connected to outputs of the first and second analog-to-digital converters, and the outputs are connected to spetcvychislitelej whose output is the output of the apparatus; a control controller connected at the input to the special computer, the first output to the second input of the first multichannel radio receiver and the first information processing channel, and the second output to the second input of the second multichannel radio receiver and the second information processing channel.

Description

The utility model relates to the field of passive location and can be used to detect real-time aircraft, calculate their coordinates and flight paths, followed by information transfer to the control center.

With the advent of anti-radar missiles and high-precision weapons at the theater of operations, the use of Stealth technology, hypersonic air attack means and the massive use of interference, the survivability of active radar stations has significantly decreased. This led weapons developers to look for new ways and means to increase the effectiveness of air defense.

Modern systems on the battlefield are complemented by reconnaissance and fire weapons on unmanned aerial vehicles (UAVs). They allow the enemy to obtain real-time reconnaissance information and reset it to control points via SHF (3 ... 18 GHz) radio channels. The tactical necessity of using UAVs makes it necessary to use onboard signal sources with a circular radiation pattern of the signal, which is an essential reconnaissance sign of UAVs.

On-board radio equipment of aircraft and helicopters, when performing tasks, create active electromagnetic fields of artificial origin in the frequency range from 1 MHz to 40 GHz. In addition to active fields, aircraft create their own electromagnetic radiation. This emission spectrum can be used to solve the problem of detecting, direction finding and determining the coordinates of an aircraft.

The target designation system based on the principles of passive direction finding (passive radar) becomes very attractive because it removes the main unmasking sign of active radar operation.

When constructing a multi-position passive radar, the difference-ranging method is used, based on measuring the difference in the signal path from the target to the receiving antennas of the radar. This method allows you to work on pulsed and continuous signals, including noise and noise-like.

The principal features of the method are the synchronous method of receiving signals from a radiating source on spaced antennas. High accuracy in determining the coordinates of targets is ensured by correlation signal processing, in which the form of the received signal does not matter. The coordinates of the source are determined by the difference in the arrival of signals at each position, and the difference in the arrival of the signal at one position relative to another is determined from the position of the maximum cross-correlation function of the signals from these positions.

The closest technical solution that meets the requirements of passive detection and control is the device described in the article “One-step estimation of the location of a radio emission source by a passive system consisting of narrow-base subsystems” (Radio Engineering and Electronics, Volume 49, No. 2, 2004, p. .156-170) is a prototype.

This device contains M receiving antennas, the first and second analog-to-digital converter (ADC), a special computer and the necessary peripherals to ensure its operation.

The purpose of the utility model is to increase the accuracy of determining the coordinates of the aircraft.

This goal is achieved by the fact that in the device containing M receiving antennas, the first and second analog-to-digital converter (ADC), a special computer and the necessary peripherals to ensure its operation, a low-noise amplifier (LNA) is additionally introduced, M inputs of which are connected to M receiving antennas, the first and second multichannel radio receivers (RPUs), the inputs of which are connected respectively to the first and second outputs of a low-noise amplifier, and the outputs are connected to the inputs of the first and second analog-to-digital converters, first the second and second channels of information processing, the inputs of which are connected to the first and second outputs of analog-to-digital converters, and the outputs are connected to a special computer, the output of which is the output of the device; a control controller connected at the input to the special computer, the first output to the second input of the first multichannel radio receiver and the first information processing channel, and the second output to the second input of the second multichannel radio receiver and the second information processing channel.

Comparison with the prototype shows that the inventive device is characterized by the presence of new units and their connections between them. Thus, the claimed device meets the criterion of "novelty."

A comparison of the proposed solutions with other technical solutions shows that the listed elements used in the blocks are known, however, their introduction in this connection with other elements leads to the expansion of the functionality of the device.

This confirms the conformity of the technical solution to the criterion of "significant differences".

Figure 1 presents a block diagram of the proposed device, figure 2 - disclosed a channel for processing information.

The device includes: receiving antennas 1, low noise amplifier (LNA) 2, multi-channel radio receiving device (RPU) 3, 4; analog-to-digital converter (ADC) 5, 6; control controller 9, special computer 10, information processing channel 7, 8, including filters 11, detector 12, direction finder 13, output driver 14.

The device operates as follows.

The purpose of the operation of the device is to determine the coordinates of the aircraft (sources of radio emission).

The angular coordinates of the aircraft in azimuth and elevation relative to the point of the center of mass of the carrier are determined by the phase-difference direction finder.

The range to the aircraft is determined by computational methods according to known bearings and the law of displacement of the center of mass in a relative coordinate system.

Functionally, the device consists of a direction finder 13 with a digital antenna array 1, a detector 12 of time-frequency characteristics of targets (target classifier), output shapers 14 of the target coordinate matrices and calculators 9, 10, in which the algorithms for extrapolating the aircraft trajectories, control device algorithms and network algorithms function data exchange and control from the radio complex.

The direction finder 13 with a digital antenna array 1 consists of a fixed antenna array (receiving antennas 20 ... 18000 MHz) located on a spatially separated reception point.

Each of the antennas is connected to the LNA 2 input (low-noise amplifier), which ensures the matching of the impedances of the antenna element and the connecting cable. Each LNA 2 output is connected to its receiving path, which is formed by one of the channels of a multi-channel radio receiving device (RPU) 3, 4 and an analog-to-digital converter (ADC) 5, 6. Thus, an individual digital channel of signal samples from one lattice element is formed.

The ADC 5, 6 of the signal simultaneously performs signal sampling on multiple channels. The size of this set is determined by the number of elements of the antenna array 1. For example, depending on the accuracy requirements for determining the coordinates, you can choose 16, 26 or 32 channels. So, for a lattice of 16 elements, the potential accuracy of the device is about 6 arc minutes. As the number of elements increases, accuracy increases.

Coherent signal processing is performed in the filters 11, the detector 12 and the direction finder 13 of the information processing channel 7, 8.

Due to the need to ensure the stability of the amplitude-frequency characteristics (AFC) of the direction-finding path, it provides measures for measuring the AFC before taking signal samples in the operating frequency band. The frequency response of the frequency response is associated with the stability of the electrical parameters of the channel and is controlled by the control algorithm of reference (known signal sources) during operation from the controller 9.

The direction finder 13 provides the determination of the angular coordinates of the aircraft (sources of radio emission - IRI) from the phase portrait of the incoming signal. The direction finder determines the angles of arrival of signals to the antenna array from different directions on the same frequency and frequency band. The number of directions is set by the required accuracy of determining the angular coordinates. For an accuracy of 6 minutes, the instantaneous matrix of angles has a dimension of 3600 elements. The time to obtain the bearing (the quantum of the time for solving the problem) depends on the speed of the computer on the signal processor 10.

With a step of a quantum of time, it is possible to give consumers the coordinates of targets in the observation frequency band. Direction finder 13 is constructed in two channel type, one channel (7) is panoramic, panoramic, which continuously provides bearings for received signals from the threshold level of the detector 12. The threshold of the detector 12 is selected for tactical reasons.

The second channel (8) of the direction finder 13 operates according to target designation, which ensures the continuity of the issuance of coordinates for speed targets. There can be several such channels, depending on the degree of responsibility of the device.

Information processing is carried out in the computing resources of the special computer 10.

The matrix (azimuth-elevation angle) is preliminarily filled in the frequency range, which is incomplete, without the range coordinate, which is obtained by the calculation method according to the trigonometric equations of aircraft flight. This coordinate is calculated and it complements the IRI coordinate base to a logical level.

Dynamics of work.

The multi-channel receiver 3, 4 switches to either panoramic mode or direction finding. In the panoramic mode, all receivers switch to adjacent frequencies, at which the simultaneous observation band of the RPU 3, 4 is expanded by the number of channels. The restructuring process can be controlled, i.e. RPU 3, 4 can observe the frequency band with predetermined gaps in the range.

In the case of direction finding mode, all receivers operate at the same frequency with one of the available bands.

The signals from the output of special computer 10 in digital form are sent for processing and issued in the information complex.

With a certain pace of adjustment of RPU 3, 4 over a range, IRI is observed (located) and their coordinates are automatically determined, with reference to the time of detection.

Time binding is performed for the differential-range measuring method for updating coordinates and solving special algorithms for the synthesis of space-time separation.

In case of receipt of the target designation command, in the second information processing channel 8, all its elements are transferred to the direction-finding mode at a given frequency and issue bearings in the complex to refine the coordinates of the PRI.

Thus, the considered device for passive detection of radio sources increases the accuracy of determining the coordinates of the aircraft.

Claims (1)

A device for passive target detection, containing M receiving antennas, the first and second analog-to-digital converter (ADC), a special computer and the necessary peripherals to ensure its operation, characterized in that it additionally includes a low noise amplifier (LNA), the M inputs of which are connected to M receiving antennas, the first and second multichannel radio receivers (RPUs), the inputs of which are connected respectively to the first and second outputs of a low-noise amplifier, and the outputs are connected to the inputs of the first and second analog-to-digital pre verters, the first and second information processing channels whose inputs are connected to outputs of the first and second analog-to-digital converters, and the outputs are connected to spetcvychislitelej whose output is the output of the apparatus; a control controller connected at the input to the special computer, the first output to the second input of the first multi-channel radio receiver and the first information processing channel, and the second output to the second input of the second multi-channel radio receiver and the second information processing channel.