JP2611172B2 - Target identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target identifying device which can be used for identifying the type of a target detected by a radar device.

[0002]

2. Description of the Related Art As a conventional target identification device related to a radar device, there has been a simple device as shown in FIG. FIG.
In the figure, 1 is a radar device, 12 is a frequency component analyzer for obtaining a frequency component of a target signal, 13 is a display for displaying the frequency component obtained in 12, and 14 is a speaker for displaying the target signal as sound.

The operation of this device will be described. The frequency component of a target signal extracted by the radar device 1 is analyzed by a frequency component analyzer 12, and the analysis result is displayed on a display 13, and if necessary, the radar is used. The target signal extracted by the device 1 is displayed on the speaker 14 as sound.

[0004]

The conventional apparatus described above merely displays the frequency components of the target signal or the target signal converted into sound. For this reason, it is necessary for a human to identify the type of the target and the like based on past experience from the displayed frequency components and the like of the target signal. However, since the relationship between the displayed frequency components, etc. and the types of targets, etc., is not always clear, not only does it take a long time for humans engaged in the identification of the targets, but also the objectivity of the identification results is high. There was a problem of lack.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to analyze a target signal obtained by a radar device to obtain a characteristic value related to the type of the target and the like. I do.

[0006]

According to the present invention, there is provided a target identifying apparatus for detecting a frequency component of a target signal obtained by a radar apparatus.
Display that converts the fluctuation between signals into a time fluctuation of the signal level.
A criminator and a target signal obtained by the radar device.
A detector for determining a time variation of a signal level, and the disk
It is determined by one or both of the limiter and the detector.
Fundamental frequency analyzer for determining the fundamental wobble frequency of the time variation was
And a display for displaying the fundamental fluctuation frequency obtained by the fundamental frequency analyzer .

[0007]

In the target identification device according to the present invention, the radar
The target signal obtained by the device is relevant to the type of target, etc.
Frequency component of the target signal or
Signal level fluctuation over time, that is, time fluctuation
Calculated as the reciprocal of the fundamental cycle of this time variation.
Obtain the wave number and use the obtained fundamental fluctuation frequency as the target type, etc.
It is displayed as a characteristic value to be represented. For example, if the target detected by the radar device is a ship or a vehicle, the frequency component (Doppler frequency component) and the signal level of the target signal periodically fluctuate in relation to the fluctuation period such as rolling and pitching specific to the target. I do. If the targets are helicopters, they periodically fluctuate according to the rotation speed of the rotor specific to the target. As described above, generally, the frequency component and the signal level of the target signal fluctuate over time, that is,
It has time fluctuation, and the basic fluctuation period of this time fluctuation (base
Cycle) also depends on the mechanical properties of the target,
The time variation of the frequency and signal level of the target signal is obtained and the
If the basic fluctuation frequency is obtained as the reciprocal of the basic period of the time fluctuation, a characteristic value related to the type of the target can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a target identification apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a main configuration of a target identification device according to an embodiment of the present invention added to a radar device. In FIG. 1, 1 is a radar device, 2 is a signal switch, 3 is a discriminator that converts the time variation of the frequency component of the target signal into time variation of the signal level, and 4 is the time variation of the signal level of the target signal. Is a fundamental frequency analyzer for finding the fundamental fluctuation frequency of the signal found in 3 or 4, and 6 is a display.

Next, the operation of this device will be described.
The target signal extracted by the radar device 1 during the target tracking is supplied to the discriminator 3 through the signal switch 2. The discriminator 3 converts the time variation of the frequency component of the supplied target signal into a signal level, and supplies an output signal to the fundamental frequency analyzer 5. The fundamental frequency analyzer 5 obtains the fundamental fluctuation frequency of the supplied signal and supplies it to the display 6. The display 6 displays the supplied fundamental fluctuation frequency. Also, by switching the switch 2 as necessary,
The target signal is detected by the detector 4 to determine the time variation of the signal level, then the fundamental frequency analyzer 5 determines the fundamental variation frequency and displays it on the display 6.

In this embodiment, the basic fluctuation frequency relating to the time variation of the frequency component of the target signal is obtained. This is the basic fluctuation period of the Doppler frequency accompanying the speed change of the target which greatly affects the frequency component of the target signal. Corresponds to asking for Further, the basic fluctuation frequency relating to the time variation of the signal level of the target signal is obtained. This corresponds to obtaining the basic fluctuation period of a change such as the direction of the target which greatly affects the signal level of the target signal.

Therefore, since the basic fluctuation period that gives a time change such as the speed and direction of the target also depends on the mechanical characteristics inherent to the target, the basic fluctuation frequency displayed by the target identification device according to the present invention is It becomes a characteristic value indicating the type of the target and the like, and is effective for identifying the target.

In the above, the means for obtaining the basic variation frequency relating to the time change of the target speed and direction from the target signal obtained by the radar apparatus and the display of the acquired basic variation frequency have been described. However, the obtained basic fluctuation frequency can be used not only for displaying but also for automatically determining the type of the target by comparing with the basic fluctuation frequency acquired in the past for various targets. In addition, as an example of the fundamental frequency analyzer, there is one based on the Cebstrum method, but the present invention is not limited to the above method. Also,
In the embodiment shown in FIG. 1, the case where the target signal extracted by the radar device 1 passes through the discriminator 3 and the case where the target signal extracted by the signal switch 2 passes through the detector 4 is shown. Instead, it is also possible to simultaneously analyze both output signals with a plurality of fundamental frequency analyzers and take a correlation between the analysis results.

[0014]

According to the target identifying apparatus of the present invention, it is possible to obtain a characteristic value related to the type of the target from the target signal obtained by the radar, and to improve the accuracy of the target identification. In addition, it is possible to facilitate training of a person who is engaged in identifying the target.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of a target identification apparatus according to the present invention.

FIG. 2 is a block diagram showing a main configuration of a conventional target identification device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radar apparatus 2 Signal switch 3 Discriminator 4 Detector 5 Fundamental frequency analyzer 6 Display 12 Frequency component analyzer 13 Display 14 Speaker

Claims (1)

(57) [Claims] 1. A time variation of a frequency component of a target signal obtained by a radar device is converted into a time variation of a signal level.
Discriminator and the eye obtained by the radar device
A detector for determining the time variation of the signal level of the reference signal;
Discriminator and / or detector
Fundamental frequency for calculating the fundamental fluctuation frequency of the obtained time variation
A target identification apparatus comprising: a number analyzer; and a display for displaying a fundamental fluctuation frequency obtained by the fundamental frequency analyzer .