JPS58195172A - Radar device - Google Patents

Abstract

PURPOSE:To detect another target concealing in the range side lobe of a large target as well by estimating the time and amplitude of the side lobe from the peak time and amplitude of the signal after compression and detecting the signal exceeding the same. CONSTITUTION:The amplitude of the compression range pulse outputted by a pulse compression circuit 1 through a processing circuit 2 for various signals is stored in an amplitude storage circuit 4. On the other hand, the peak value of the range pluse and the output time thereof are detected in a detection circuit 5 for the position of peak time and the amplitude and time of the side lobe are estimated by a forming circuit 7 for a subtraction signal from such detected value and the corresponding side lobe pattern from a pattern storage circuit 6. The estimated value is applied to a subtraction circuit 8 by which the side lobe component is removed from the storage content of the circuit 4. The small target signal concealing in the side lobe of the large target is thus detected according to the output exceeding the detection level.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the removal of range side ropes in a pulse compression type radar device.An example of the configuration of a normal pulse compression type radar after pulse compression is shown in FIG. . In the figure, the 111th section pulse compression circuit, (2) various signal processing circuits (MTI, etc.), 1!
1 is a detection circuit.Next, the operation will be explained. l! 2. Figure 111 is a diagram showing the time and amplitude of the target signal (when three targets are approaching in the example in the figure). , as shown in Figure 2), a range sidelobe appears in the time direction.If this signal is detected by the detection circuit (3) shown in Figure 1 at a detection level of 1 or higher in Figure 2), As shown in Figure 2 (C), the target cannot be separated. Furthermore, when the detection level is set to H in FIG. 2(b) in order to branch the target, the detection signal a becomes impossible to detect a small target as shown in FIG. 2(d).

In this way, according to the conventional device, when a range sidelobe appears in the signal after pulse compression and the target is approaching, a small target signal is hidden in the sidelobe of the large @Vh target signal and cannot be detected. 0 This invention estimates the time and amplitude of the range side lobe from the peak time and amplitude of the signal after compression, and detects the signal that causes this as a separate target, thereby improving the range of a large target signal. The object of the present invention is to provide a radar device tube capable of detecting very small target signals hidden in side lobes and difficult to detect.

Hereinafter, one embodiment of the present invention will be described.
In Figure 3, the 111rX pulse compression circuit, (!l
iVarious signal processing circuits, +41F! An amplitude storage circuit that temporarily stores the amplitude of the signal, a beater time position detection circuit that detects the peak amplitude and time sound of the 61H signal, and (6) stores the pattern of the range side rope caused by pulse compression. sidelobe pattern memory circuit, (7
), the peak time detected by the peak time position detection 161,
A subtraction signal creation circuit (8) creates a subtraction signal from the side lobe pattern of the amplitude and site 0 lobe pattern storage circuit (6), and a subtraction signal creation circuit (7) creates a subtraction signal from the signal stored in the storage circuit (4). The subtraction circuit that subtracts the signal tube, and the detection circuit at t31 is the 0th order. Sakuga theory, oh. it
□ a + * memory time a 14, 4, bi ≠, 1:1 n e, □, (6
) to detect the peak time and amplitude of the output of the pulse compression circuit il+ in the subtraction circuit (8). The signal peak time and amplitude are detected in the zero peak time position detection circuit (6) that stores the amplitude of the signal. However, when digital signal processing 1 is performed, the signal peak , so in order to create a subtraction signal accurately, from the maximum value of the sampling signal and the signals with larger amplitudes before and after it,
As shown in FIG. 4(c), the time of the peak of the signal and the total amplitude of the signal are 1i1. -f^.

The time of the side rope is calculated from the side rope pattern stored in the subtraction signal generation circuit (7) e, side rope pattern storage circuit 18) and the signal peak time and amplitude calculated by the beater time position detection circuit (5). and estimate the amplitude,
m4 As shown in Figure (d), a zero eradication circuit f81 r'U, amplitude Recorded in the memory circuit (4) 1: From the stored signals, each subtraction number created by the subtraction signal creation circuit (7) is subtracted corresponding to time i, and the result is shown in FIG. 4(e).
Since the 0 detection circuit (3) which obtains the output indicated by 1 detects a signal higher than the detection level shown in Fig. 4(e), @Fig. 4(f)
), it is possible to detect all separations of approaching targets with different amplitudes.In addition, in the above embodiment, a configuration was shown in which the side rope signal is subtracted from the signal after pulse compression by the pulse compression circuit. , the same effect can be obtained even if the detection level of the detection circuit is changed at every time depending on the amplitude of the full range side rope.

Furthermore, the same effect can be obtained even when the signal t after subtraction is not automatically detected by the detection circuit and is displayed in analog form on the indicator.〇As described above, according to the present invention, the signal t generated by pulse compression The target can be completely separated and detected regardless of the presence of range side lobes.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the main configuration of a conventional pulse compression type radar, Figure 582 is an explanatory diagram of its operation a@8, and Figure 3 is a block diagram showing the configuration according to an embodiment of the present invention. FIG. 4 is a diagram illustrating the operation of the present invention. In the figure, Il+...pulse compression circuit, (2)...various signal processing circuits, (4)...amplitude storage circuit, (61...
・Peak time position detection circuit, (6)...Side rope pattern storage circuit, (7)...Subtraction signal creation circuit, (
8)...Subtraction circuit, (3)...Detection circuit〇In addition, the same reference numerals in the figures indicate the same or corresponding parts〇Representative Makoto Kuzuno- Fig. 1 Fig. 2

Claims (1)

[Claims] In a radar using a pulse compression method, a range side lobe pattern is determined by the compression method, circuit, etc. A radar device 0 characterized in that the amplitude of a range side lobe and a time tube are estimated, and a signal that generates this estimated value is detected as a target signal.