RU2814430C1 - Method of target location - Google Patents

Abstract

FIELD: location equipment.

SUBSTANCE: invention relates to location equipment, namely to methods for location detection of targets in a wide area of space and can be used in locators. In the target location method, the receiver and the transmitter of a single-position radar station (RS) for detecting targets are placed at the same position, base line for forward-scattering detecting targets is created by using location reflectors, which are placed on the boundary of the target detection zone around the single-position target detection RS, wherein the probing signal RS is emitted in the direction of the location reflectors reflecting the radiation of the single-position RS transmitter back towards the single-position target detection RS device, targets are detected by received signal "beats" caused by interference in space of direct signal and re-reflected signal from target, when signals propagate to the location reflector and back, signals from different targets are selected based on the time delay of the received signals relative to the time of emission of the probing signal.

EFFECT: possibility of detecting small-size targets with a single-position radar by forward-scattering location method in a circular or sector detection zone with simultaneous increase in the probability of detecting targets.

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Description

Description of the invention

The technical field to which the invention relates.

The invention relates to the field of location technology, namely to methods for location detection of targets in a wide area of space and can find application in locators.

State of the art

There are known methods and devices for target location intended for use in target detection radars:

1. Handbook of radio-electronic systems. In 2 volumes. Ed. B.H. Krivitsky. - M.: Energy, 1979.

2. D. Barton, G. Ward. Handbook of Radar Measurements. Per. from English, ed. MM. Weisbein. - M.: Soviet radio, 1976.

3. D. Barton. Radar systems. Per. from English, ed. K.N. Trofimova. - M.: Military Publishing House. 1967.

The main property of targets that determines the possibility of their location detection is the ability of targets to re-reflect radiation, which is usually characterized by their effective reflective surface (ERS).

Recently, to reduce the capabilities of locators to detect targets, the “Stealth” technology has been actively used, which significantly reduces the RCS of targets and limits the capabilities of target detection systems.

Thanks to the development of modern components and structural materials, remotely piloted and unmanned aerial vehicles (RPA and UAV) with minimal ESR values have become widespread.

Therefore, the problem of detecting such small targets, especially those made using Stealth technology, UAVs and UAVs, continues to be extremely relevant today.

As one of the ways to solve the problem of detecting small-sized targets, the so-called “transmission” location is considered, which makes it possible to use the effect of a significant increase in the ESR of targets at small angles of incidence and reflection of waves (electromagnetic, acoustic, etc.) from the target (Cheremisov A .K. Statistical characteristics of the effective scattering area of a body in bistatic radar // Radio engineering and electronics. - 1987. - vol. 32, no. 12).

Initially, experiments on radar detection of objects using radio waves began with a “transmission” observation scheme, which was a transmitter and a receiver remote from it. An object is registered when it crosses the line between the transmitter and receiver. Such a scheme was considered already in the first experiments of Heinrich Hertz on the emission and reception of electromagnetic waves, as well as in the experiments of A. Popov - G. Marconi on radio communications (Bogomolov, A.F. Radiolocation // Great Soviet Encyclopedia, 30 vols. 21. - M.: Soviet Encyclopedia, 1975. Lobanov M.M., Development of Soviet radar technology. - M.: Voenizdat, 1982).

Radar systems (radars) of the “transmission” type also include the first mass-produced domestic ground-based radar with continuous radiation RUS-1 and the American radar AN/FPS-23 (“Fluttar”) (Lobanov M.M. The beginning of Soviet radar. - M.: Soviet Radio, 1975. Chapursky V.V. Synthesized shadow radio holography in bistatic radar // Radio engineering. - 2009. - No. 3).

However, the subsequent development of radar followed the path of creating and improving combined (single-position) radars, which today are considered more advanced in relation to the “transmission” radars of the first generation.

In connection with the advent of stealth aircraft “Stealth”, small-sized RPVs and UAVs, interest in “transmission” radars has revived (Blyakhman A.B., Runova I.A. Bistatic effective dispersion area and object detection during transmission radar. Radio engineering and electronics. - 2001. - v. 46, No. 4. Ufimtsev P.Ya., Black bodies and shadow radiation. Radio engineering and electronics. - 1989. - No. 12).

In 1998, the country created a “transmission” radar 52E6 - “Struna-1”, which successfully passed State tests and by 2006 had undergone 2 modernizations (52E6M and 52E6MU - “Barrier-E”):

1. Weapons and technologies of Russia. Encyclopedia. XXI Century. Volume 9. Air and missile defense. M. 2004.

2. History of domestic radar. Ed. S.V. Khokhlova, M. 2015.

3. Gao Charlie. How Russia Is Trying to Make America's F22 and F35 as Obsolete as Battleships. "The National Interest", 10/14/2017.

Transmission acoustic location systems are actively used to detect underwater objects:

1. V.A. Zverev. Two phenomena in experiments on location in light. Acoustic Journal, No. 4, v. 64, 2018.

2. V.A. Zverev. A method of transmissive location without false alarms and missing a signal for the passage of a location object. Acoustic Journal, No. 6, vol. 64, 2018.

3. V.E. Turov et al. Experimental studies of identifying moving target signals using the background location method. Bulletin of SibGUTI. No. 3. 2016.

The general disadvantages of the above analogues of the invention are:

- the need to use at least two location posts: transmitting and receiving, located at a considerable distance (base) from each other;

- detection of targets occurs in a narrow spatial sector between the receiving and transmitting posts due to the “beats” of the carrier frequency caused by the interference of two beams of wave propagation - direct and reflected by the target (Fig. 1).

Building a target detection barrier “on the fly” around a defended object, by analogy with known perimeter security systems, is possible by surrounding the defended object with a sufficient number of receiving and transmitting posts (Fig. 2). In fact, such a “bistatic” locator only gives a signal about crossing a protected perimeter (barrier) (RLK 52E6 “Struna-1”. Multi-link radar barrier. “Military Review. Air Defense”, April 21, 2020).

The narrowness of the spatial width of the realized barrier for detecting targets of a “clearance” radar is determined by the limited angular conditions for the implementation of increased values of the EPR of targets (Kovalev F.N. Methods, models and algorithms of forward location. Dissertation for the degree of Doctor of Technical Sciences. Federal State Budgetary Institution of Higher Professional Education "NSTU im. R E. Alekseeva". 2015).

According to the results of State tests of the 52E6MU “transmission” radar, the transverse size of the barrier zone 50 km long lies in the range of 3.3...12.8 km, depending on the type of target (RPA, cruise missile, fighter, bomber): http://www.433175 .ru/; Weapons and technologies of Russia. Encyclopedia. XXI Century. Volume 9. Air and missile defense. M. 2004; Armament of Russian air defense and distribution systems. M. 2011; History of domestic radar. Ed. S.V. Khokhlova, M. 2015).

Information processing methods in the 52E6(M, MU) radar are protected by Russian patents:

Patent No. RU 2124220, priority dated October 29, 1997.

Patent No. RU 2154840, priority dated September 23, 1999.

Patent No. RU 2195683, priority dated December 28, 2000.

As a close analogue of the invention (prototype), the domestic radar of the "Resonance-N" type can be considered (Advertising brochure "RTI SYSTEMS" (http://roe.ru), Armament of Air Defense and Distribution Zones of Russia. M.: Publishing house: NO "Association "League for Assistance to Defense Enterprises", 2011). The model of the station was presented at the MAKS-2005 exhibition in Zhukovsky and at the Army-2020 forum (International Military-Technical Forum Army-2020, “http://bastion-opk.ru “Weapons of the Fatherland” . Information resource on weapons and military equipment").

Each of the four modules of the station is equipped with a transmitter operating on a separate transmitting antenna with a wide radiation pattern, which irradiates all targets in a 90° working sector; response signals from targets are received by a receiving antenna based on a digital phased array antenna (DFAR), forming a multi-lobe radiation pattern in the entire spatial sector irradiated by the transmitting antenna. This makes it possible to ensure the detection of all targets simultaneously in the entire sector of responsibility of each locator module and to use a long signal accumulation time for processing.

The disadvantage of the prototype of the invention is that the target is detected only by the perpendicular reflection of radio waves from the target surface, just like in other single-position locators.

Disclosure of the invention

The essence of the proposed method of target location is based on the implementation in a single-position locator of the principle of detecting targets “through the light” through the use of radar (acoustic, etc.) reflectors as remote transmitters of a “bistatic” locator, placed in a circle around the single-position locator on the border of the target detection zone and re-reflecting the radiation of the single-position locator transmitter back in the direction of the locator. By analogy with a “bistatic” “transmission” locator, target detection is carried out by “beats” of the received signal caused by interference in space of the direct “locator-reflector” signal and the signal re-reflected at a small angle from the target.

An analysis of the size of the target detection ellipse obtained from tests of the “bistatic” radar 52E6MU (Fig. 1) shows that for effective radar detection of small targets “through the air”, reflectors must be placed around a circle with a radius of up to 50 km in increments of up to 7.5° in azimuth, and each of the receiving beams of the radar with digital phase array must be directed to the corresponding radar reflector (Fig. 3).

The technical result of the proposed technical solution is to ensure the possibility of detecting small targets by a single-position locator under conditions that maximize the effective scattering surface of targets, characteristic of a "transmission" location. An additional result of the proposed technical solution is an increase in the probability of target detection by receiving two responses from the target in one sounding:

- the first time - when radio waves propagate from the locator transmitter to the locator reflector;

- the second time - during the reverse propagation of waves from the location reflector to the locator receiver.

Due to the fact that the interference of the direct signal and the signal reflected from the target (the so-called “beat”) has a harmonic sinusoidal structure, mutual compensation of the signals is possible (the “beat” sinusoid hits “zero”). Reverse propagation of the signal (from the reflector to the radar receiver) also causes interference, the phase of which will be random relative to the interference of the direct signal, therefore the probability of the results of both interferences falling into the “zero” of the sinusoid practically approaches zero.

Brief description of drawings

In fig. 1 numbers indicate:

1. Transmitting station

2. Receiving station

3. Radiation from the transmitting station

4. Direct path of radio waves

5. Reflected (refracted) path of radio waves

6. Bistatic radar processing station, highlighting signal beats caused by the interference of direct and reflected signals

7. Purpose

8. Ellipse of the realization of a large EPR value of the target

In fig. 2 numbers indicate:

1. Transmitting station

2. Receiving station

3. Radiation from the transmitting station

6. Bistatic radar processing station

In fig. 3 numbers indicate:

4. Direct path of radio waves to the reflector

5. Reflected (refracted) path of radio waves to the reflector

7. Purpose

8. Ellipse of large target ESR value

9. Single-position radar with CFAA

10. Radar reflectors

11. Direct path of radio wave propagation from the reflector to the radar receiver

12. The path of radio waves reflected (refracted) from the target from the reflector to the radar receiver

Carrying out the invention

The implementation of the invention is illustrated in Fig. 3.

An example of a target detection method is based on the operation of a single-position radar 9 with a multi-lobe radiation pattern. Each of the lobes of the radiation pattern is directed to the radar reflector 10, which are located radially around (or in the sector of responsibility) the single-position radar 9.

The radar sounding signal 4 is emitted in the direction of the radar reflectors. When a target is in the lobe of the radar pattern, a direct signal from radar 4 and a re-reflected signal from target 5 arrive at the radar reflector. As a result of the difference in the signal propagation path, they interfere, which causes amplitude modulation (beating) of the signal arriving at the reflector. The total signal (4+5) received by the reflector is reflected in the opposite direction and, like the direct signal from the radar, passes back to the radar in two ways: a direct signal from the reflector to radar 11 and a re-reflected signal from target 12, which also interfere at the receiving end (11+12) and cause additional signal beats in the receiver of a single-position radar. Signal beats in the receiver of a single-position radar, caused by the interference of direct and reflected signals, are used in processing to detect a target and determine the parameters of its movement.

Selection of signals from different targets is carried out based on the time delay of the received signals relative to the time of emission of the probing signal.

Claims (1)

A method for locating targets, in which the receiver and transmitter of a single-position radar for target detection are placed at one position, a base line for detecting targets “through the air” is created by using location reflectors, which are placed on the border of the target detection zone around the single-position radar for target detection, in this case, the radar probing signal is emitted in the direction of location reflectors that reflect the radiation of the single-position radar transmitter back in the direction of the single-position target detection radar device, targets are detected by the “beats” of the received signal caused by interference in space of the direct signal and the re-reflected signal from the target during propagation signals to the location reflector and back, the selection of signals from different targets is carried out by the time delay of the received signals relative to the moment of emission of the probing signal.