RU2226701C2 - Method for determination of co-ordinates of objects and radar for its realization - Google Patents

Abstract

FIELD: radio detection and ranging, applicable in radars. SUBSTANCE: the aim is to determine the co-ordinates of objects reflecting the radio emissions of external sources at a single-position construction of the system. The raised problem is solved due to a combined use of the methods of passive and active radio detection and ranging. In the method for determination of co-ordinates of objects illuminated by an external source of radio emissions, the radio emissions of the mentioned sources reflected by the objects are received, the time shifts between the direct and reflected radio emissions from the external source and the angular co-ordinates of the objects are measured, the range to one of the objects is measured by the method of active radio detection and ranging, which is then used for computation of ranges to the other objects. The device for realization of the given method has a passive detection channel including an antenna and a receiver, an active detection channel including an antenna, antenna selector switch, transmitter, receiver, device for range computation and a synchronizer. The device has also a co-ordinate computation unit including a device for measurement the time shift of the received signals and a device for co-ordinate computation. EFFECT: facilitated procedure. 2 cl, 4 dwg

Description

The proposed technical solutions relate to the field of radar and can be used in surveillance radar stations.

A known method of active radar objects, which consists in the emission of sounding signals, receiving reflected signals, measuring the delay time of the signals and the angular coordinates of the objects, calculating the distance to the objects (Theoretical basis of radar. / Ed. Ya. D. Shirman. - M .: Sov. Radio, 1970, pp. 9-11).

A known radar station that implements the known method (Theoretical Foundations of Radar. / Ed. Ya. D. Shirman. - M .: Sov. Radio, 1970, p. 221), comprising an antenna, antenna switch, transmitter, receiver, indicator device, synchronizer, moreover, the signal input / output of the antenna is connected to the antenna switch, the input of which is connected to the output of the transmitter, and the output is connected to the input of the receiver, the output of the receiver, in turn, is connected to the input of the indicator device, two synchronizer outputs are connected to the input of the transmitter and second input of the display device, respectively, the coordinate output antenna coupled to the third input of the display device.

A disadvantage of the known solutions is the need to irradiate the entire area of responsibility of the radar, which requires significant energy costs. In addition, the constant radar radiation reduces the secrecy of its work.

Closest to the proposed one is a method for determining the coordinates of objects irradiated by a source of radio emissions, based on the reception at separated points of space of the reflected radio emissions, measuring the time shift between radio emissions and the angular coordinates of objects, calculating the distances to objects (Theoretical basis of radar / Ed. I. D. Shirman. - M .: Sov. Radio, 1970, p. 497).

Known (Theoretical Foundations of Radar. / Ed. By Ya. D. Shirman. M .: Sov. Radio, 1970, p. 500) a two-position passive radar station (Fig. 1), which implements a known method containing spatially spaced passive detection channels 1 and 2, each including a series-connected antenna 3 and a receiver 4, as well as a coordinate calculation unit 5, comprising a series-connected device for measuring the shift of the received signals in time 6 and a device for calculating the coordinates 7, the input of the device for measuring the shift being received of the received signals in time 6 and the input of the coordinate calculation device 7 are the first and second inputs of the coordinate calculation unit 5, respectively, the second inputs of each of these devices are the third and fourth inputs of this block, the outputs of the receivers 4 of the passive detection channels are connected to the first and third inputs of the calculation unit 5 coordinates, and the coordinate outputs of the antennas 3 of both detection channels are connected to the second and fourth inputs of this block.

The indicated technical solutions can use radio emissions of various sources, for example, such as broadcast television or radio transmitting stations, radar stations, atmospheric interference, etc. (Radar Reference. / Ed. M. Skolnik. T. 4. - M .: Sov Radio, 1978, pp. 213-214).

The disadvantage of the closest technical solutions is the need to have spaced receiving positions.

The invention is aimed at eliminating this drawback.

The problem to be solved is the determination of the coordinates of objects reflecting the radio emissions of sources, with a one-position system construction.

The problem is solved through the joint use of passive and active radar methods.

The specified technical result is achieved by the fact that in the method for determining the coordinates of objects irradiated by a source of radio emissions, based on the reception of reflected radio emissions, measuring the time shift between radio emissions and the angular coordinates of objects, calculating the distances to objects, according to the invention, additionally take direct radio emission of the source, measure it angular coordinates, time shifts between direct and reflected radio emissions, the method of active radar measure the range to one of the objects.

The specified technical result is also achieved by the fact that in a radar station containing a passive detection channel, including a series-connected antenna and a receiver, as well as a coordinate calculation unit containing a series-connected device for measuring the shift of the received signals in time and a device for calculating the coordinates, the input of the device for measuring the shift the received signals in time and the input of the coordinate calculation device are the first and second inputs of the coordinate calculation unit, respectively Of course, the second inputs of each of these devices are the third and fourth inputs of this block, while the output of the receiver of the passive detection channel is connected to the first, and the coordinate output of the antenna is connected to the second input of the coordinate calculation unit, according to the invention, the active detection channel and the fifth input of the block are introduced coordinate calculation, and the active detection channel includes an antenna, an antenna switch, a transmitter, a receiver, a range calculator and a synchronizer, the signal input / output of the antenna is connected to the antenna a switch whose input is connected to the output of the transmitter, and the output to the input of the receiver, the output of the receiver is connected to the input of the range calculator and to the third input of the coordinate calculation unit, the antenna output of the antenna and the output of the range calculation device are connected to the fourth and fifth inputs of the coordinate calculation unit, respectively , the synchronizer outputs are connected to the synchro inputs of the coordinate calculator, transmitter, and range calculator.

The essence of the proposed technical solutions is as follows. To determine the coordinates of objects in the zone of responsibility of the radar, use a passive detection channel 1 and an active detection channel 8. The entire system is located at one position (figure 2).

The angular coordinates of the i-th and j-th objects (elevation angles ε _i , ε _j , azimuths β _i , β _j ) reflecting the radio emissions of the source are measured by the angular position of the antenna of the detection channel 8 operating in the passive mode. The antenna of the passive detection channel 1 is directed to the source and receives its direct radio emission. It can be shown (Fig. 3) that the range R _i to the i-th object with the known coordinates of the j-th object (ε _j , β _j , R _j , j ≠ i) irradiated by the same source, and measured relative to the direct radiation of the source time shifts Δt _i , Δt _{j of} radiation reflected from objects, is determined by the expression:

Δε _k = ε _k -ε _AND ; Δβ _k = β _k -β _AND ; k = i, j;

Δt _i >0; Δt _j >0;

c is the speed of light.

Measurements of the time shifts Δt _i , Δt _{j of the} received radio emissions relative to the direct radiation of the source are made by the position of the maxima of their mutual correlation functions.

The invention is illustrated by the following drawings.

Figure 1 - functional diagram of a known technical solution when determining the coordinates of objects using a passive radar;

Figure 2 is a diagram explaining the proposed method for determining the coordinates of objects;

Figure 3 is a geometric explanation of the calculation of the coordinates of the object.

Figure 4 - block diagram of a radar that implements the proposed method.

The proposed radar (figure 4) contains a passive detection channel 1, including a series-connected antenna 3 and a receiver 4, as well as a coordinate calculation unit 5, comprising a series-connected device for measuring the shift of the received signals in time 6 and a device for calculating the coordinates 7, and the input of the measurement device the shift of the received signals in time 6 and the input of the coordinate calculation device 7 are the first and second inputs of the coordinate calculation unit 5, respectively, the second inputs of each of these devices are the fourth and fourth inputs of this block, while the output of the receiver 4 of the passive detection channel 1 is connected to the first, and the coordinate output of the antenna 3 is connected to the second input of the coordinate calculation unit 5, respectively, the active detection channel 8 and the fifth input of the coordinate calculation unit 5, the active channel Detection 8 includes an antenna 9, an antenna switch 10, a transmitter 11, a receiver 12, a range calculator 13 and a synchronizer 14, the signal input / output of the antenna 9 is connected to an antenna switch 10, the input of which is connected to the output the transmitter 11, and the output is with the input of the receiver 12, the output of the receiver 12 is connected to the third input of the coordinate calculation unit 5 and with the input of the range calculator 13, the coordinate output of the antenna 9 and the output of the range calculation device 13 are connected to the fourth and fifth inputs of the coordinate calculation unit 5, respectively , the three outputs of the synchronizer 14 are connected to the synchro inputs of the coordinate calculation device 7, the transmitter 11 and the range calculation device 13.

The proposed radar station can be performed using the following functional elements.

Antennas 3 and 4 - PAR with electronic scanning in azimuth and elevation and with circular mechanical rotation in azimuth (Reference radar. / Under the editorship of M. Skolnik. T.2. - M .: Sov. Radio, 1977, p. 132-138).

Receivers 4 and 12 - superheterodyne type (Handbook on the basics of radar technology. M., 1967, S. 343-344).

A device for measuring the shift of received signals in time 6 - multichannel correlator (Theoretical foundations of radar. / Ed. Ya.D.Shirmana. - M .: Sov. Radio, 1970, p. 500).

Coordinate computing device 4 - a digital computer that implements calculations by the formula (1).

Antenna switch 10 is a balanced antenna switch based on a circulator (A.M. Pedak et al. Guide to the basics of radar technology. / Ed. By V.V. Druzhinin. Military Publishing House, 1967, p. 166-168).

Transmitter 11 - a multi-stage pulse transmitter on a klystron (A.M. Pedak et al. Guide to the basics of radar technology. / Ed. By V.V. Druzhinin. Military Publishing House, 1967, pp. 277-278).

The range calculator 13 is a digital computer that implements the calculation of the distance to the object by the magnitude of the delay of the reflected signal (Theoretical Foundations of Radar. / Ed. By Ya.D. Shirman. - M .: Sov. Radio, 1970, p. 221).

To explain the principle of operation of the proposed device (figure 4), the process of its operation can be divided into three stages: at the first stage, using the passive channel 1 in the process of reviewing the radar’s area of responsibility, a radio emission source is detected. In this case, the antenna 3 is displayed in its direction. The position of the antenna 3 determines the angular coordinates of the source (elevation angle ε _and , azimuth β _and ), which from the coordinate output of antenna 3 go to the second input of the coordinate calculation unit 5; at the second stage, the detection channel 8 operates in a passive mode, i.e. in the area of responsibility, the source’s radiation reflected from the i-th object is received, and the angular coordinates of the object (elevation angle ε _i , azimuth β _i ) are determined, which from the coordinate output of antenna 9 go to the fourth input of the coordinate calculation unit 5. Signals from the outputs of receiver 4 and the receiver 12 enters the device for measuring the shift of the received signals in time 6, where their time shifts Δt _i and Δt _j are measured relative to the direct radiation of the source; at the third stage, using the detection channel 8, operating in active mode, the range is measured to one of the objects in the zone of responsibility (j-th object in figure 4). In this case, the antenna 9 is installed in the direction with the coordinates ε _j , β _j and the probe signal generated in the transmitter 11 is emitted. The signal reflected from the object is received by the antenna 9, through the antenna switch enters the receiver 12 and then to the range calculator 13, where the distance R _j to the object is determined. The angular coordinates and the distance of the jth object measured in this way are supplied to the coordinate calculator 7, where, in accordance with formula (1), the distance R _i to the object detected by the detection channel 8 in the passive mode is calculated.

Claims (2)

1. The method of determining the coordinates of objects irradiated by an external source of radio emissions, based on the reception of reflected objects of radio emissions from external sources, measuring the time shift between these radio emissions and the angular coordinates of the objects, calculating the distances to the objects, characterized in that they additionally receive direct radio emission from an external source, measure it angular coordinates, time shifts between direct and reflected radio emissions of an external source, the method of active radar measurement the distance to one of the objects, which is used to calculate the distances to other objects. 2. A radar station containing a passive detection channel, including a series-connected antenna and a receiver, as well as a coordinate calculation unit comprising a series-connected device for measuring the shift of the received signals in time and a device for calculating the coordinates, the input of the device for measuring the shift of the received signals in time and the input of the device coordinate calculations are the first and second inputs of the coordinate calculation unit, respectively, the second inputs of each of these devices are three the fourth and fourth inputs of this block, while the output of the receiver of the passive detection channel is connected to the first, and the coordinate output of the antenna is connected to the second input of the coordinate calculation unit, characterized in that the active detection channel and the fifth input of the coordinate calculation unit are input, and the active detection channel includes antenna, antenna switch, transmitter, receiver, range calculator and synchronizer, the signal input / output of the antenna is connected to the antenna switch, the input of which is connected to the output of the transmitter ka, and the output is with the input of the receiver, the output of the receiver is connected to the third input of the coordinate calculation unit and the input of the range calculator, the antenna output and the output of the range calculation device are connected to the fourth and fifth inputs of the coordinate calculation unit, respectively, the three synchronizer outputs are connected to the sync inputs coordinate calculator, transmitter, and range calculator.

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