JPH01178880A - Detecting circuit of radar target - Google Patents

Abstract

PURPOSE:To select an optimum video or blank even when hits of a false target are increased due to noise, by a method wherein the state of detection of the hits is monitored regularly and video selection is executed in accordance with an increase or decrease in the number of hits. CONSTITUTION:Selection of a normal hit a' or an MTI hit c' is conducted by an automatic control circuit 5 for N/M selection. The level of a normal video (a) is monitored regularly by the automatic control circuit 5 for N/M selection, and when it rises above a reference value, the MTI hit c' is selected. Next, selection of a hit (i) selected by an automatic control circuit 6 for NM/L selection or a LOG hit b' is conducted in such a manner that: the state of detection of the N/M hit (i) is monitored regularly by the automatic control circuit 6 for NM/L selection, and when the number of hits increases above a reference value, the LOG hit b' is selected. As for selection of an NM/L hit (j) or a blank (h), the NM/L hit (j) is monitored regularly by an automatic control circuit 7 for NML/B selection, and when the number of hits increases above a reference value, the blank (h) is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] 7 The present invention relates to a target detection circuit in a radar device.

[Conventional technology]

FIG. 3 is a system diagram showing a conventional radar target detection circuit, in which l is a CFAR quantization circuit and 2 is an N/L
3 is a selection circuit that performs selection based on a selection signal from a manual/automatic selection control circuit; 4 is a selection manual control circuit; .

Next, the operation will be explained. Based on the control signal from the selection manual control circuit 4, the selection circuit 3a selects normal video a or LOG video b.

The selected video (hereinafter referred to as rN/L video) d is input to the CFAR-quantization circuit 1, and the N/L video is detected. Furthermore, the MTI video C is also input to the CFAR quantization circuit 1, and the MTI hiso l-f is detected. N/
The level of L video d is constantly monitored by the NL/M selection automatic control circuit 2, and when it rises above the reference value, the M
The TI hit selection signal is output to the selection circuit 3b, and the MTI
Hit f is selected. The selection circuit 30'T: selects whether to output the selected hit (NL/M hit) g or blank (not output a hit) h based on the control signal from the selection manual control circuit 4. .

[Problem to be solved by the invention]

Since the conventional radar target detection circuit is configured as described above, even when there is a lot of noise and it becomes necessary to select LOG video b or blank h, the selection must be made manually, making it difficult to make detailed video selections. The problem was that I couldn't do it.

The present invention has been made in view of these points, and an object of the present invention is to provide a radar target detection circuit that can automatically control video selection.

[Means to solve the problem]

In order to achieve such an object, the radar target detection circuit according to the present invention includes an automatic N/M selection control circuit that automatically controls whether to select a normal hit or an MTI hit based on the level of normal video; An NM/L selection automatic control circuit that automatically controls which of the selection result, N/M hit or LOG hit, is selected based on the N/M hit, and which of the selection result, NM/L hit or blank, is selected. An automatic NML/B selection control circuit is provided to automatically control whether to select the NM/B selection based on the NM/L hit.

Another invention is an N/M selection automatic control circuit that automatically controls whether to select a normal hit or an MTI hit based on the level of normal video, and a selection of N/M hit, LOG hit, and blank. NM/L controlled collectively based on N/M hit and LOG hit
/B selection automatic control circuit.

[Effect]

In the radar target detection circuit according to the present invention, the hit detection status is constantly monitored and video selection is performed depending on the increase or decrease in the number of hits. Therefore, even if the number of false target hits increases due to noise, the optimal video or blank is selected.

〔Example〕

FIG. 1 is a system diagram showing an embodiment of a radar target detection circuit according to the present invention. In the same figure, 5 is normal
Normal hit a'', which is the CFARI quantized output of video a, and M, which is the CFARI quantized output of MTI video C.
N/M selection automatic control circuit automatically controls which of TI Hiso h C' l is selected based on the level of normal video a; N that automatically controls which one of N/M hits i to select based on N/M hits i.
M/L selection automatic control circuit, 7 is NM/I-
NM/L to select either hit i or blank h
Automatic control based on human i! ■N M L /
B is an automatic selection control circuit, and the same or equivalent parts in FIG. 1 as in FIG. 3 are given the same reference numerals.

In the radar target detection circuit configured as described above, first, a normal hit a' and an MTI hit c' are selected. Normal video a level is always N/M
It is monitored by the selection automatic control circuit 5, and when it rises above the reference value, MT■Hit C° is selected. next,
Selected hit (hereinafter referred to as rN/MN/top) i and LOG hit b' are selected, but this is because the detection status of N/M hit i is always automatically controlled to select NM/L? I+1 circuit 6 monitors it, and when the number of hits increases above the reference value, it is controlled to select LOG hit b°? This is done by dialing 111. Also, regarding the selection of N M/L hit j and blank h, NM/L hit j is constantly monitored by the NML/B selection automatic control circuit 7, and when the number of hits increases beyond a reference value, blank h is selected. This is done by controlling the selection.

In the above embodiment, the selection of the N/M hit i and the LOG hit b'' and the selection of the NM/L hit j and blank h are controlled in separate circuits. A similar effect can be expected even if the selection of hit i, LOG hit b°, and blank h are controlled all at once.

FIG. 2 is a system diagram showing the case of the above-mentioned collective control as a second embodiment, in which the N/M hit i and the LOG hit b°
is constantly monitored by the NM/L/B selection automatic control circuit 8, and if the number of hits for each becomes larger than the reference value, N
/M hit i −+ L OG hit b° − blank h
The selection will be controlled in this order. In FIG. 2, the same or equivalent parts as in FIG. 1 are given the same reference numerals.

〔Effect of the invention〕

As explained above, the present invention has the advantage that by automatically controlling all video selections, fine-grained selection control can be performed and the probability of false target detection can be kept below a certain level.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the radar target detection circuit according to the present invention, FIG. 2 is a system diagram showing a second embodiment of the radar target detection circuit according to the present invention, and FIG. FIG. 2 is a system diagram showing a radar target detection circuit. 1 ・CF A R quantization circuit, 3 a, 3 b,
3 c... selection circuit, 5... N/M selection automatic control circuit, 6... NM/L selection automatic control circuit, 7...
NML/B selection automatic control circuit, 8... NM/L/B selection automatic control circuit.

Claims (2)

[Claims] (1) N/M that automatically controls whether to select normal hit or MTI hit, which is the CFAR quantized output of normal video, based on the level of normal video.
An automatic selection control circuit, an automatic NM/L selection control circuit that automatically controls which of the selection results, N/M hits and LOG hits, is selected based on the N/M hits, and NM/L selection results, which are the selection results. NML that automatically controls whether to select L hit or blank based on NM/L hit
/B selection automatic control circuit. (2) N/M that automatically controls whether to select normal hit or MTI hit, which is the CFAR quantized output of normal video, based on the level of normal video.
The present invention is characterized by comprising an automatic selection control circuit and an automatic NM/L/B selection control circuit that collectively controls the selection of N/M hits, LOG hits, and blanks based on the N/M hits and LOG hits. Radar target detection circuit.