RU2573822C2 - Method of protecting surveillance radar station with phased antenna array from interference - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method of protecting a surveillance radar station with a phased antenna array from interference during surveillance of a scanning area in a given part thereof comprises, in each beam position, establishing one of pre-calculated current amplitude and/or phase distributions on elements of the phased antenna array, wherein the beam position corresponds to the current scanning direction, and the positions of beam pattern "zeros" correspond to directions of interference sources.

EFFECT: improved protection of mobile surveillance radar stations with a phased antenna array from interference.

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Description

The invention relates to the field of radar, in particular to the protection of mobile surveillance radar stations (radar) with a phased array (PAR) from active and passive interference.

As you know, there are always interference in the radar’s viewing area: active interference — in the form of radio emissions from various electronic devices, passive interference — in the form of radar signals reflected from the earth’s surface, local objects, meteorological conditions (Theoretical fundamentals of radar. Edited by B.E. Dulevich. - M .: Sov. Radio, 1978, p. 415-416). In combat conditions, radars are also affected by specially organized active and passive interference. Interference makes it difficult to detect targets, leading to an overload of the radar information processing system (RLI).

A well-known way to protect radars with headlamps from interference (active and passive) is to reduce the level of all side lobes of the antenna pattern (BOTTOM) (Radar Reference. Edited by M. Skolnik, vol. 1. - M .: Sov. Radio, 1976 , pp. 91-94). However, since the level of the DND side lobes is related to the width of its main lobe (beam), and the antenna directivity coefficient (LPC), an arbitrary decrease in the level of all DND side lobes is impossible. With a decrease in the level of the side lobes, the main lobe of the BOTTOM expands, the directivity of the antenna decreases, which results in a deterioration of such technical characteristics of the radar as the accuracy of measuring the angular coordinates, the resolution by angular coordinates, and the detection range, which is usually unacceptable.

The closest way to protect the surveillance radar with headlamp from interference includes the formation of a beam with the position of the beam in the current direction of the field of view and the positions of the "zeros" of the beam in the directions to the sources of interference by sequential adaptation of the headlamp to interference (Monzingo R.A., Miller T.U. Adaptive Antenna Arrays. Introduction to Theory. - M.: Radio and Communications, 1986, pp. 45-60).

"Zero" DNA - a specially created area of the DNA with a relatively low level.

The mentioned adaptation is carried out in the form of multiple cyclic changes in the parameters of the PAR (amplitudes and / or phases of the currents in the elements depending on the type of PAR) according to a predetermined algorithm with analysis of the signals at its output. At the end of the adaptation process, the distribution of amplitudes and / or phases of the currents over its elements is established in the PAR, ensuring the formation of a beam with the beam position in the current direction of the field of view and with narrow "zeros" in the directions to the sources of interference.

Since the process of adaptation of the PARS takes much longer than can be allocated for this in mobile surveillance radars, the suppression of interference in such radars is not sufficiently provided.

The problem being solved (technical result) is to increase the immunity of mobile surveillance radars with headlamps from interference.

The technical result is achieved in that in a method for protecting a surveillance radar with a HEADLIGHT from interference, including the formation of a beam with the position of the beam in the current direction of the field of view and with the positions of the "zeros" of the beam in the directions to the interference sources based on the established distribution of amplitudes and / or phases of currents over elements of the PAR, according to the invention, in a given part of the viewing area determine the direction to the sources of interference, during the inspection of the viewing area for the current direction in a given part of it from pre-calculated distributions of amplitudes and / or phases then s on the elements of phased array are selected and set in the PAR distribution in which the position of the beam corresponds to the current direction of the field of view, and the provisions of "zeros" DNA - the directions on the sources of interference.

The essence of the proposed method is as follows.

In the inventive method, the formation of the DND is carried out in accordance with the distribution of amplitudes and / or phases of the currents along the PAR elements selected from the set of pre-calculated distributions for a given part of the viewing area, in which the main petal of the DND (PAR beam) occupies all possible positions in accordance with the review program , and the "zeros" of the DND cover all possible directions to sources of interference.

For the operation of the proposed method requires a preliminary determination of directions to interference sources (angular coordinates of interference sources). This operation can be carried out both by means of a radar operating in a passive mode, and attached by means of a passive location. To determine the position of the sources of passive interference, various known methods for isolating clusters of sources of reflected signals can be used.

The part of the viewing area in which it is necessary to provide protection from interference is set in the vicinity of the main lobe of the bottom and can be installed, for example, 30-40 ° on each side of the main lobe of the bottom (Fig. 1).

The calculated distributions of the amplitudes and / or phases of the currents over the PAR elements are stored in the memory of the computer, the on-board electronic computer (COMPUTER).

These calculations can be carried out at the stage of radar design, entered into the memory of the on-board computer at the stage of radar manufacture, and periodically updated during its operation.

Since the search time for a distribution from pre-calculated distributions cannot exceed the value specified in the radar, the number of pre-calculated distributions is limited, it is determined by the performance of the on-board computer and the size of a given part of the field of view. Based on these restrictions, it is advisable to set the angular dimensions of the “zeros” of the DND within 5-30 ° for each angular coordinate.

Since the distributions are calculated in advance, they are not time limited and can be carried out quite accurately, providing the required sufficiently low levels of "zero" DND, and hence the corresponding interference suppression.

Thus, the claimed technical result is achieved.

The invention is illustrated by the following drawings.

FIG. 1 - BOTTOM in elevation with "zero" in the direction of active interference.

FIG. 2 is a functional diagram of a radar that implements the inventive method.

The radar that implements the inventive method (Fig. 2) contains an antenna 1, a beam control device 2, the output of which is connected to the control input of the antenna 1, serially connected transmitter 3, antenna switch 4, receiver 5 and calculator 6, as well as synchronizer 7, with this signal input / output of the antenna 1 is connected to the input / output of the antenna switch 4, and its coordinate output is connected to the second input of the calculator 6, the first output of the calculator 6 is the radar output, its second output is connected to the first input of the beam control device 2, the outputs first to fourth synchronizer 7 are connected respectively to the second input beam control device 2, transmitter 3, an input, the second input of the receiver 5 and the third input of the calculator 6.

Radar can be performed using the following functional elements.

Antenna 1 - PAR with electronic beam control in elevation and mechanical rotation in azimuth (Radar Reference. Edited by M. Skolnik, vol. 2. - M.: Sov. Radio, 1977, p. 138).

Beam control device 2 is a device for converting digital values of amplitudes and phases of currents along PAR elements into electrical signals that control the type of DND (Integrated Circuits. Handbook edited by B.V. Tarabrin. - M.: Radio and Communications, 1984).

Transmitter 3 - a multi-stage pulse transmitter on a klystron (A.M. Pedak et al. Guide to the basics of radar technology. Edited by V.V. Druzhinin. - M.: Military Publishing House MO, 1967, pp. 278-279, Fig. 7.2).

Antenna switch 4 - balanced antenna switch based on a circulator (A.M. Pedak et al. Guide to the basics of radar technology. Edited by VV Druzhinin. - M.: Military publishing house MO, 1967, S. 166-168).

Receiver 5 - superheterodyne receiver (A.M. Pedak et al. Guide to the basics of radar technology. Edited by V.V. Druzhinin. - M.: Military publishing house MO, 1967, pp. 343-344, Fig. 8.1).

Calculator 6 is a digital computer (computer) that performs the operations of determining the directions for interference, selecting a distribution in which the beam position corresponds to the current position of the beam, and the positions of the "zeros" of the bottom beam cover all possible positions of interference sources in a given part of the field of view (Integrated circuits. Reference Edited by B.V. Tarabrin. - M.: Radio and Communications, 1984).

Synchronizer 7 - is made on the basis of a master oscillator and a chain of frequency dividers connected in series (Radar devices (theory and construction principles). Edited by V.V. Grigorin-Ryabov. - M .: Sov. Radio, 1970, p. 602 -603).

Consider the work of the radar that implements the inventive method (Fig. 2).

The pre-calculated distributions of the amplitudes and / or phases of the currents over the PAR elements for all positions of the antenna beam and for all possible positions of the "zeros" of the bottom beam in a given part of the viewing area are stored in the memory of the calculator 6. Since the time available in the radar to select the desired distribution from the previously calculated distribution is limited, then these calculations are carried out for the angular dimensions of the "zeros" of the BOTTOM, established on the basis of the time available in the radar and the speed of the onboard computer (within 5-30 ° for each angular coordinate).

At the command of the synchronizer 7, the transmitter 3 generates a high-frequency sounding signal, which is transmitted through the antenna switch 4 to the antenna 1 and is radiated. The reflected signal received by the antenna 1, through the antenna switch 4 enters the receiver 5, is converted to the video frequency and fed to the first input of the calculator 6, where it is compared with the detection threshold, above which a decision is made to detect the target. The angular coordinates of the beam from the coordinate output of the antenna 1 go to the second input of the calculator 6.

Simultaneously with the radiation of the probe signal from the fourth output of the synchronizer 7, a signal is supplied to the third input of the calculator 6, from which the delay value of the probe signal reflected from the target is calculated, and according to well-known formulas (Theoretical fundamentals of radar. Edited by Y.D. Shirman. - M .: Sov. Radio, 1970, p. 221) determines the distance to the target. From the first output of the calculator 6 information about the goals is issued to the consumer.

Directions to sources of active interference (bearings) are determined in the passive mode of radar operation. Active interference radiation is received by the antenna 1, through the antenna switch 4 is fed to the input of the receiver 5, where it is compared with a threshold, above which a decision is made to detect interference. The signs of the presence of active interference and the angular coordinates of the sources of interference from the output of the receiver 5 and from the coordinate output of the antenna 1 are supplied respectively to the first and second inputs of the calculator 6, recorded in its memory and updated throughout the duration of the interference. By measuring the bearings in the calculator 6 calculates the direction of interference.

In the calculator 6, from the pre-calculated distributions of the amplitudes and / or phases for the PAR elements, a distribution is selected in which the beam position corresponds to the current direction of the field of view, and the position of the "zeros" of the bottom beam corresponds to the directions to the sources of interference.

The values of the amplitudes and / or phases of the currents of the PAR elements of the selected distribution are transmitted to the beam control device 2, where they are converted into electrical signals, which, upon command from the synchronizer 7, are transmitted to the antenna 1. As a result, a beam is formed, the beam of which is installed in the current direction of the radar field of view, "Zeros" of the DNA - in the direction of interference.

Thus, in the radar that implements the inventive method, the claimed technical result is achieved.

Claims (1)

A method for protecting a survey radar station with a phased array (PAR) from interference, including generating an antenna pattern (BOTTOM), the beam position of which coincides with the current direction of a given viewing area, and the position of "zeros" is with directions to interference sources, carried out on the basis of the distribution of amplitudes and / or phases of currents over the PAR elements, characterized in that in advance, before the mentioned formation of the BOTTOM, the distributions of amplitudes and / or phases of currents over the PAR elements are calculated and stored In order to examine all the possible positions of the beam and the sources of interference in a given viewing area, during the inspection of a given viewing area, determine the angular coordinates of the sources of interference, from which the distribution in which the beam position corresponds to the current direction of the viewing area and the position is selected from the stored amplitude and / or phase distributions “Zeros” of the DND — to directions to the sources of interference, and the DND is formed corresponding to the selected distribution.

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