JPS6019469B2 - Angle information detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an angle information detection device for detecting angle information of a target such as a flying object.

Radar devices are used to measure the azimuth, elevation, distance, etc. of flying steel objects such as aircraft.

Radar devices also have functions for searching for and tracking targets such as aircraft, or guiding them to air routes, etc., in accordance with their respective purposes.

Generally, in order to scan a space and search for a distant target, the position of the target is detected by rotating a directional beam and receiving pulse reflected waves from the target. Due to spatial noise, intersecting radio wave propagation routes, etc., a target echo that should be received may not be received, or a pseudo echo may appear at a position deviated from the true position. When automatically detecting a target using radar, etc., the direction or distance of the target can be determined using the so-called sliding window method, which uses the so-called sliding window method to detect the target position from the group of reflected echoes by emitting repeated transmission pulses while scanning the antenna beam. It is done.

By the way, the detection accuracy of a target position in a radar device depends on the beam width of the cedar beam.

The narrower the beam width of the radar beam, the higher the target detection accuracy, but the narrower the beam width, the longer the scanning time for overturning, and the lower the data rate. Therefore, search radars are generally designed to improve search capabilities by increasing the beam width and increasing the data rate at the expense of target detection accuracy.

However, recent target detection devices for aircraft and the like are required to detect target positions with high precision in response to an increase in the number of targets to be searched. In particular, air traffic control radars, etc., require accurate detection of target positions when monitoring and guiding aircraft. The occurrence of echoes is a major hindrance to improving the reader function. Therefore, the present invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to provide an angle information detection device that prevents data rate from decreasing, improves the target search function, and makes it possible to accurately capture the target position. be.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. That is, FIG. 1 is a block diagram showing one embodiment of the angle information detection device according to the present invention.

In FIG. 1, a monopulse antenna for receiving pulse waves from space has a structure similar to that of an antenna used in a so-called known monopulse radar.

The monopulse antenna 1 is normally used for transmitting and receiving radar waves in a monopulse radar.
In the present invention, it is of course possible to use the device for both transmission and reception, but the embodiment shown in FIG. 1 shows an example in which it functions only for reception.
The monopulse antenna 1 includes a pair of receiving antennas 101 and 102, and receives reflected received waves from a reflector 103. Received signals from receiving antennas 101 and 102 are respectively supplied to hybrid circuit 2, which derives received pulse signals corresponding to the sum and difference patterns of both receiving antennas 101 and 102.

The sum and difference patterns are fed to a sum channel detection circuit 3 and a difference channel detection circuit 4, respectively. That is, in the monopulse antenna 1, antenna patterns A and B are obtained by the two receiving antennas 101 and lo2 that are close to each other as shown in FIG. Waveforms as shown in C and D in Figure b are obtained.

Therefore, the sum channel detection circuit 3 and the difference channel detection circuit 4 are configured to mix the sum signal and the difference signal with the receiving station oscillation signal, respectively, and convert it into an intermediate frequency.

Sum channel detection circuit 3 and difference channel detection circuit 4
The target signal is supplied to the angle signal detection circuit 5.

The angle signal detection circuit 5 can be composed of, for example, a phase detector, and in this case, the reception gains of the sum channel and the difference channel are adjusted by, for example, an automatic gain control circuit, and the signals from the sum channel detection circuit 3 and the difference channel detection circuit 4 are adjusted. By making sure that the amplitude does not change due to changes in reception strength, the monopulse antenna 1
The angular error information from the center direction of the sum pattern, that is, from the pointing direction of the monopulse antenna 1, can be extracted as an analog voltage signal corresponding to the angular error together with the identification of the error direction.

This kind of configuration is seen in the so-called monopulse radar system, and the one shown in Figure 1 shows, for example, the horizontal configuration, but if error detection in the vertical direction is also performed, a further configuration is required. Prepare one monopulse antenna. Furthermore, as a monopulse antenna, in addition to the use of a parabolic antenna shown in FIG. 1 in which a reflector is added to a so-called primary hose antenna, it is also possible to use a so-called electronic scanning antenna by arranging a large number of antenna elements.

By the way, in the apparatus of the present invention, the signal from the angle signal detection circuit 5 is stored in the arithmetic circuit 6 for each received pulse.

Further, the arithmetic circuit 6 is supplied with antenna direction angle information from an antenna angle detection circuit 7 that detects the antenna pointing direction of the monopulse antenna 1 with respect to a predetermined reference direction.

When the monopulse antenna 1 is configured with a parabolic antenna, etc., the antenna direction angle information can be obtained by simply obtaining the mechanical rotation angle information of the antenna such as a shaft encoder, or in the case of an electronic scanning antenna, it is sufficient to obtain the mechanical rotation angle information of the antenna such as a shaft encoder. The control signal from the unit is used. Now, the calculation circuit 6 introduces the angle information of the target from the angle signal detection circuit 5 over a plurality of received pulses, and converts the angle information of each received pulse into the antenna direction angle information from the antenna angle detection circuit 7. The angular position of the same target is statistically determined from the correspondence relationship between the two objects. Arithmetic circuit 6 is angle detection circuit 6
1, a gate circuit 62 and a correlation calculation circuit 63.

The angle detection circuit 61 detects the target direction angle for each received pulse based on the monopulse antenna angle and the received target angle signal. That is, the operation of the angle detection circuit 61 will be explained with reference to FIG.

In Fig. 3, if we assume that the sum pattern of the antennas in the azimuth direction moves sequentially as P,, P2, P3 for each received pulse, then the angle information from each beam center to the target object is t,, t2, are obtained from the angle signal detection circuit 5.

In other words, the beam center azimuth angle is 95 degrees and 1
Suppose that the temperature changes in three stages such as 00 degrees and 109 degrees.

When the azimuth is 95 degrees, the target image has a difference of 4 degrees to the right (t, = 14
degree), 1 degree difference to the left when the azimuth is 100 degrees (t2 = -1
degree), 6 degrees difference to the left when the azimuth is 105 degrees (t3 = -6
degree). Therefore, in the angle detection circuit 61, the antenna direction is 95 degrees and 100 degrees, respectively.
The direction is 9 degrees and 105 degrees.
This indicates that information indicating that the target existed at 9 degrees was obtained.

In the example shown in Figure 3, the angle step in the beam direction is also large;
Also, the angular difference accuracy is in units of 1 degree, but this is just an example for explanation, and in actual operational examples, angular accuracy of several millimeters to about 0.1 mil (1 mil = 0.056 degrees) is required. There are cases.

The apparatus of the present invention derives a target position each time a plurality of pulse waves are received by a monopulse attenuator, and calculates accurate position information of the target by processing the plurality of target position information.

That is, the example shown in FIG. 3 will be expanded and a more specific example will be explained with reference to FIG. 4.

FIG. 4 is a diagram showing the correspondence between the antenna angle and the angle error signal obtained for each pulse reception signal.

As is clear from FIG. 4, when the antenna angle and the received pulse correspond, the angular differences between the center of each antenna beam and the target signal are 15 degrees, 12 degrees, and 10 degrees, respectively. Nephew degree, 10. The case where the technique is 11 degrees, 12 degrees, and 0 degrees is shown. Therefore, the antenna angles are 97 degrees, 99 degrees, and 99 degrees, respectively.
degrees, 100 degrees, 101 degrees, 102 degrees, and 103 degrees, the true target position information, that is, the absolute angle, is the antenna angle plus the deviation angle: 102 degrees, 100 degrees, 99.5 degrees,
Obtained as 100.5 degrees, 100 degrees, 100 degrees, and 103 degrees.

Among these values, as a condition for statistical processing, for example, exclude angle information 102 degrees and 103 degrees with large deviations, and calculate a value close to the true target angle as a target angle of 100 degrees from the average of the remaining five information. Obtainable. In addition, the method for determining the angle is not just an average, but a calculation process that weights each angle information using the correlation between the output signal of the target detection circuit and the output signal of the antenna angle detection circuit, and then calculates the target angle. You can also decide.

On the other hand, the intermediate frequency amplified signal from the sum channel detection circuit 3 is detected by a detector 8, and one is supplied to an indicator 9,
The signal is displayed on a PI display or the like, and the other is supplied to a target detection circuit such as a sliding window to confirm the presence or absence of a target.

The target signal from the target detection circuit 10 is supplied to the gate circuit 62 in the calculation circuit 6, and the gate circuit is configured such that the output of the angle detection circuit 61 is supplied to the correlation calculation circuit 63 only when the target is confirmed. 62. Target detection circuit 1
The output signal from 0 is further supplied to the distance detection circuit 11, and is supplied to the correlation calculation circuit 63 as distance information of the object target.

The correlation calculation circuit 63 performs calculation for each distance range bin to determine the target angle, and outputs the target angle information together with the target distance information from the distance detection circuit 11.

As described above, the device of the present invention uses a monopulse antenna and multiple angle information obtained from multiple continuous received pulses from one target object, and calculates the true value by processing these multiple angle information. It detects the target position.
Such a configuration is a new configuration that has not been seen before.

That is, devices using conventional monopulse antennas drive and control the so-called antenna itself to track the target.
At the center position angle of the antenna pattern, that is, the null point (
(The voltage signal level shown in FIG. 2C becomes zero) to improve the angular accuracy by chasing the target, or
Since the target angle is detected and determined using a single received pulse, only a low cutting angle accuracy can be obtained. In contrast, the device of the present invention does not use a monopulse antenna for tracking, nor does it detect and determine the target angle using a single received pulse. It is configured to detect and determine a target angle by processing a plurality of angle information obtained from a plurality of reflection echo groups, and can accurately detect the target angle information. Furthermore, as described above, the device of the present invention accurately detects the target position using a plurality of received pulses obtained from the target. or may receive target return signals from other radar transmitters.

When used as an own radar device, for example, in FIG. 1, a duplexer is connected between the hybrid circuit 2 and the sum channel detection circuit 3, and transmission pulses from other transmitters are sent out through this duplexer. It can be configured as follows. Furthermore, the device of the present invention is suitable for use in air traffic control radars. In particular, when the antenna system of the secondary surveillance radar is configured with a monopulse antenna and the device of the present invention is applied, the position and angle of the target can be accurately captured. This has great practical effects.

[BRIEF DESCRIPTION OF THE DRAWINGS] A schematic diagram showing the configuration of an embodiment of the angle information detection device according to the present invention; FIG. 2 is a waveform diagram illustrating the operation of the monopulse antenna of the device shown in FIG. 1; , FIGS. 3 and 4 are explanatory diagrams illustrating the operation of the apparatus shown in FIG. 1. 1... Monopulse antenna, 3... Sum channel detection circuit, 4... Difference channel detection circuit, 5... Angular signal detection circuit, 6...・・・
・Arithmetic circuit, 7...Antenna angle detection circuit, 10・
...Target detection circuit. 2 figures, 3 figures, 4 figures

Claims (1)

[Claims] 1. A monopulse antenna that receives pulse waves from space, a sum channel detection circuit that detects a signal with a sum pattern of the signals received by this monopulse antenna, and a signal with a difference pattern of the signals received by the monopulse antenna. a difference channel detection circuit connected to the difference channel detection circuit and the sum channel detection circuit, and outputting a first angle signal representing the arrival direction angle of the received pulse with respect to the pointing direction of the monopulse antenna for each received pulse. an antenna angle detection circuit that outputs an antenna angle signal representing the pointing direction of the monopulse antenna with respect to a predetermined reference direction; and a target that detects a target using the signal from the sum channel detection circuit. a detection circuit, a first angle signal connected to the angle signal detection circuit and the antenna angle detection circuit, which adds the first angle signal and the antenna angle signal for each received pulse to represent the arrival direction angle of the received pulse with respect to the reference direction; 2
an output circuit that outputs an angle signal for each received pulse, and a plurality of angle signals that are connected to this output circuit and the target detection circuit and output from the output circuit in response to a plurality of received pulses when a target is detected. and an arithmetic circuit that averages or weights the angle signals of 2 for each distance range bin, averages them, and outputs a target angle signal representing a target angle with respect to the reference direction.