RU63941U1 - PASSIVE RADAR STATION - Google Patents

Abstract

The utility model relates to radio direction finding and passive radar and can be used in the construction of devices for detection, direction finding, recognition and tracking, for example, air targets based on the signals of their radio systems, as well as in radio silence mode. The objective of the utility model is to enable tracking of air targets when they overcome the air defense system in radio silence mode. A passive radar station containing a first direction-finding antenna and a receiver operating in the frequency range (0.2 ... 18) GHz, a second direction-finding antenna and a radiometer operating in the MM range, an electric tracking drive, with which a circular antenna is provided for the antenna system , sector search or target tracking, low-frequency and high-frequency rotating joints, control device, signal processing device. The combination in one system of a recognizing direction finder and a thermal locator improves the tactical and technical characteristics of the device. IL

Description

The utility model relates to radio direction finding and passive radar and can be used in the construction of devices for detection, direction finding, recognition and tracking, for example, air targets based on the signals of their radio systems, as well as in radio silence mode.

Known passive radar station (radar) [L1], containing directional antennas, a drive, a receiving device, a terminal device, a rotating low-frequency transition, for example a contact, the input of which is connected to the output of the receiving device located together with the antenna in the rotating part, and the output is connected to the terminal device.

The disadvantage of this device is that only detected signals are transmitted to the signal processing terminal device, that is, high-frequency information is not analyzed.

Known closest to the proposed radio intelligence station [L2], comprising an antenna with a rotation drive and an azimuth sensor, a receiver, a low-frequency rotating contact device, a high-frequency rotating transition, a signal processing device, a control device, a terminal device, the antenna output being connected to the first input of the receiver the second input of which is connected through a low-frequency rotating contact device to the first output of the control device, the second output of which is connected to by the rotation drive, the output of the receiver through a high-frequency rotating transition is connected to the first input of the signal processing device, the second input of which is connected to the output of the azimuth sensor, and the output is connected to the input of the terminal device.

A well-known radio intelligence station detects, detects and tracks aerial targets that emit microwave radio or radar signals.

On combat aircraft, radio transmitters can be turned off to overcome air defense. Exercise control over aerial targets detected and identified using a direction finder

the characteristics of microwave radiation on-board radio systems, when these targets retain the radio silence mode, a known station is impossible.

To detect air targets in the radio silence mode, a radio thermal channel is used. The operation of the radio thermal channel is that a noise-like radio thermal signal received against a background of radio thermal radiation of a day or night sky is compared with a noise background, i.e. by thermal radiation of that part of the sky in which there are obviously no radiating objects.

For passive radiothermal locators (RTLs) operating in the detection mode, background characteristics are unknown, since those parts of the sky where there are no air targets are unknown.

This circumstance forces the use of complex adaptive antennas, with the help of which a cumbersome algorithm for generating a compensation channel (that is, a channel in which a useful signal is suppressed) is implemented [L3, Fig. 3.2].

In addition, the sensitivity of the RTL is proportional to the antenna gain and the effective duration of the received thermal signal. For example, if the signal duration increases n times, then the detection range of the RTL increases by times [L4, p. 171]. That is, the RTL antenna should be sharply directional, and the speed of viewing the space is small.

For example, to review a sector of space with a solid angle Ω sect = 0.1 at a distance of R = 20 km, a modern RTL with a single-beam antenna requires time tobz = 5 s [L5, p. 404].

For the needs of air defense - this is a lot.

As an alternative to single-beam RTL, multi-beam antennas with a matrix receiver are considered. A grid of fixed radiometric rays is formed, which are crossed by a moving target [L5, p. 404]. The direction to the target is determined by the direction of the beam in which the signal power exceeds the power of the thermal thermal background received by the remaining rays.

For mobile radars, this is difficult.

The objective of the utility model is to enable tracking of air targets when they overcome the air defense system in radio silence mode.

To achieve this technical result, a passive radar station containing a first direction-finding antenna with a rotation drive and an azimuth sensor, a receiver, a low-frequency rotating contact device, a high-frequency rotating transition, a signal processing device, a control device, an end device, while the output of the first antenna is connected to the first the input of the receiver, the second input of which is connected to the first output of the device through the first input of the low-frequency rotating contact device a control, and the output through a high-frequency rotating transition is connected to the first input of the signal processing device, the second input of which is connected to the output of the azimuthal sensor, and the output is connected to the first input of the terminal device, the second output of the control device is connected to the input of the rotation drive, the second direction finding antenna is introduced and radiometer, the output of which is connected through the second input of the low-frequency rotating contact device with the second input of the terminal device, the input is connected with the output of the second direction finding antenna.

The drawing shows a structural diagram of the proposed device.

Passive radar contains the first 1 and second 2 direction-finding antennas with a rotation drive 3 and an azimuth sensor 4, a receiver 5, a radiometer 6, a low-frequency rotating contact device (VKU) 7, a control device 8, a high-frequency rotating transition (VP) 9, a signal processing device 10 terminal device 11.

The output of the first 1 antenna is connected to the first input of the receiver 5, the second input of which through the first input of the VCU 7 is connected to the first output of the control device 8, and the output through (VP) 9 is connected to the first input of the signal processing device 10, the second input of which is connected to the azimuthal output sensor 4, and the output is connected to the first input of the terminal device 11, the second output of the control device is connected to the input of the rotation drive. The output of the radiometer 6 is connected through the second input of the VKU 7 to the second input of the terminal device 11, and the input is connected to the output of the second direction-finding antenna 2.

Antennas 1, 2, radiometer 6, receiver 5 are located on the rotating part of the rotation drive 2.

Passive radar consists of two radio channels.

The first channel is a radio direction finder, including the first antenna 1, receiver 5, VKU 7, VP 9, control device 8, signal processing device 10, terminal device 11. The radio direction finder is designed to detect, direction-finding and recognition of radio and microwave radar signals that emit working radio systems located on aircraft.

The second channel is radio thermal. It contains a second antenna 2 and a radiometer (receiver of noise radio emissions) 6. The radio thermal channel is designed to detect noise-like radio thermal signals emitted by powerful gas turbine engines and aircraft hulls heated by friction against air against the background of noise-like radio thermal radiation from day or night sky .

The device operates as follows.

First, the all-round view mode is activated. Microwave signals are received by the first antenna 1, amplified in the receiver 5, and are also subjected to heterodyning in it. From the output of the receiver 5, the high-frequency signals of the intermediate frequency through the high-frequency rotating junction 9 are transmitted via flexible coaxial cables to the signal processing device 10. Here, the azimuthal directions from which the microwave signals were received are determined and their parameters are measured: carrier frequency, pulse duration, repetition period , type of intrapulse modulation and others.

The measured parameters are compared with those stored in the catalog of the signal processing device 10, while the types of working radio systems are recognized.

If air targets are identified as dangerous, then the radar can go into sector search mode.

Further events are determined by the tactics of the attacking attack aircraft.

It is very likely that for some time to overcome air defense on combat aircraft, the transmitters of radio devices will be turned off.

The use of a passive radar thermal channel makes it possible to prevent the premature inclusion of “high” on active air defense radar transmitters.

In the proposed passive radar, the method of “two horns” is used [L4, p. 177]. Two identical horns are installed in the focus of the SLR antenna 2. With a relatively small distance between these horns, a significant angular separation of the rays is provided, which allows you to compare signals from two discrete sections of the sky.

Due to the relatively closely spaced identical beams in the absence of a source of thermal radiation, the two signals are well balanced. The operation of the antenna is almost not affected by the movement of the antenna, as well as cloudiness and atmospheric changes.

In radiometer 6, the thermal signal received in the first ray is compared with the signal received in the second ray directed “to the sky” (see, for example, the block diagram [L4, p. 5.26]).

Dangerous attacking air targets are accompanied in the sector mode by a direction finder. In this case, the direction in which the reception of radio signals ceases is determined instantly. In this direction, the search continues in sector mode for an antenna 2 of a thermal thermal locator. If one of the rays of the RTL 2 antenna is aimed at the target (the source of thermal radiation), then the other at that moment is directed to the part of the sky in which only the background thermal signal takes place, since the radiating object (attack aircraft) or a group of objects (link of bombers) localized in space and represent a point target.

The direction in which the power of the thermal signal in the first beam exceeds the power of the background radio thermal signal in the second beam is the direction to the target.

The radio thermal channel of the passive radar operates in the MM range on a wave of 3.3 or 8.6 mm. At these waves, the maximum radiothermal contrast of the radiating object is achieved, as well as the minimal influence of clouds and atmospheric changes on radiothermal contrast [L5, p. 445, Tables 12, 13].

A microwave radar detector of a passive radar operates in the range (0.2 ... 18) GHz (the operating range occupied by aircraft radio systems).

The frequency range (0.2 ... 18) GHz is divided into 36 frequency subbands with a band of 500 MHz each. The operating mode of the receiver 5 at each time

determined by the code of the frequency subband number. The binary parallel code coming from the control device 8 through VCU 7 to the second input of the receiver 5 determines the number of the frequency subband, the signals of which are currently being processed in the receiver 5.

Also through VCU 7 from the output of the radiometer 6, the video signals are supplied to the terminal device 11.

In the control device 8, in addition to the codes of the subband number, commands are also generated that specify the operation mode of the rotation drive 3: circular search, sector search, tracking of the selected target.

These modes are successfully implemented, for example, in a servo drive with an asynchronous electric motor, electromagnetic powder couplings and the corresponding electronic nodes for generating the error signal [L6, p. 32, 196].

In addition to the intermediate frequency voltages, the signal processing device 10 receives the antenna azimuth code from the output of the azimuth sensor 4. Here, the bearings of the received signals are determined and their parameters are measured.

The terminal device 9 registers the received information.

Thus, the combination in one system of a recognizing direction finder and a thermal locator allows tracking over detected air targets even in the period when they maintain the radio silence mode.

This is the technical result, which is achieved by the claimed device.

Literature

1. Central Research Institute "Rumb". Inventions on the subject of the industry. Series IV: Radar technology. Issue 6, 1984, p. 3. G01S 3/02, application 2269021, arch. No. - P21953 s.

2. RF patent №54211 for utility model "Radio intelligence station".

3. Karavaev VV, Sazonov VV "The statistical theory of passive location" - M .: Radio and communication, 1987.

4. Nikolaev A.G., Pertsov S.V. "Radiolocation (passive radar). Edited by Prof. A.A. Krasovsky. - M.: Soviet Radio, 1964.

5. Issues of prospective radar. Collective Monograph (Edited by A.V.Sokolov). - M.: Radio Engineering, 2003.

6. Smirnova V.I. and others. "Fundamentals of design and calculation of tracking systems." - M.: Mechanical Engineering, 1983.

Claims (1)

A passive radar station containing a first direction-finding antenna with a rotation drive and an azimuth sensor, a receiver, a low-frequency rotating contact device, a high-frequency rotating transition, a signal processing device, a control device, a terminal device, while the output of the first antenna is connected to the first input of the receiver, the second input of which through the first input of the low-frequency rotating contact device is connected to the first output of the control device, and the output through the high-frequency rotary The transition is connected to the first input of the signal processing device, the second input of which is connected to the output of the azimuth sensor, and the output is connected to the first input of the terminal device, the second output of the control device is connected to the input of the rotation drive, characterized in that a second direction-finding antenna and radiometer are introduced into it the output of which is connected through the second input of the low-frequency rotating contact device to the second input of the terminal device, the input is connected to the output of the second direction-finding antenna.