JPS63180875A - Radar signal processor - Google Patents

Abstract

PURPOSE:To achieve a suppression of the rate of erroneous target detection and an upgrading of the rate of target detection in an area where clutters exist, by subdividing the unit of a threshold control region in an area relatively difficult in the detection of a target. CONSTITUTION:When a small area is subdivided into more than one part and when there is a large threshold difference between subdivided regions, the difference is detected with a small region division/expansion judging circuit 2 and a representative threshold in a small region is stored with a memory control circuit 5 into a threshold memory 3 and threshold in the remaining region of the small area is stored temporarily into an auxiliary memory 4. When radar signal level is uniform among continuous small areas, the continuous small areas are determined with the circuit 2 to be the same in threshold. The memory 3 records the threshold thus determined for use in the subsequent radar rotation cycle together with an indicator identifying the threshold as such in a subdivided region or in continuous same areas. The auxiliary memory 4 records the subdivided regions provisionally. Thus, the rate of target detection can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a target detection device for a radar signal processing device.
In particular, the present invention relates to a target detection device that detects a target by dividing a radar coverage area into small areas and performing threshold control in units of small areas.

[Conventional technology]

Conventionally, in radar signal processing for this type of target detection,
The size of the small area, which is a processing unit, is divided into the same unit in the distance direction and azimuth direction over the entire radar coverage area,
A threshold storage circuit for threshold control in units of small areas is provided for the entire radar coverage area, and the units for control remain constant.

[Problem that the invention seeks to solve]

The target detection device of the conventional radar signal processing device described above is
Since the threshold for target detection is the same value within a small area, an aircraft as a target and other objects such as ground clutter, weather clutter, chaff, etc. exist simultaneously within the small area. In this case, depending on the amplitude of the radar reflection signal from each, if threshold control is performed to detect the target as much as possible, other clutter will also be detected as false targets and the necessary false target alarm rate may not be obtained. On the other hand, if threshold control is performed to suppress the detection of erroneous targets as much as possible, there is a drawback that the target cannot be detected and the target detection rate deteriorates. In order to overcome this drawback, there is a method of reducing the unit of the small area, but this method has the drawback that the storage circuit for storing the threshold value becomes proportionally large in scale.

[Means for solving problems]

In determining the threshold value for target detection, the radar signal processing device of the present invention further subdivides the small area, which is the basic processing unit, so that the radar signal level is not uniform within the small area. In this case, there is a circuit that determines the threshold value in units of this subdivided region, and a circuit that determines the threshold value for these consecutive small regions as the same threshold when the radar signal level is uniform between consecutive small regions. , recording the determined threshold for use in the next radar rotation cycle;
In addition to the threshold value, it has a storage memory that also records an index indicating whether it is a threshold value for a subdivision area or a threshold value for the same continuous area, and an auxiliary memory that temporarily records the subdivision area. .

〔Example〕 Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

Threshold determination circuit l and small area division/enlargement determination circuit 2r
i. Threshold memory, which is a circuit for detecting and determining the threshold; 3. Auxiliary memory 4 and memory control 5
The amplitude comparison circuit 6 is a circuit that compares the radar signal 6 and the threshold value 7 to determine the presence or absence of a target. Based on the amplitude value of the input radar signal 7 and the radar target signal 9, the threshold value determination circuit 1 determines and determines the value of the threshold value for the next radar rotation period in units of small areas. Normally, the threshold determined for each small area is stored in the threshold storage memory 3 and used for the next rotation cycle, but in the threshold judgment circuit, the small area is further subdivided into two or more. If the difference in threshold values between the sub-division areas is large, the small-area division/enlargement determination circuit 2 detects this, and the memory control circuit 5 stores the typical threshold value of the sub-area in the conventional threshold value memory. The threshold values for the remaining areas of the small area are recorded once in the auxiliary memory 4. After that, in the small area in the same direction, the threshold determined by the threshold determination circuit 1 is
When the small area division/enlargement determination circuit 2 determines whether the threshold value is the same not only for the particular small area but also for two neighboring small areas, the memory control circuit 5 determines whether the threshold value is the same for the two neighboring small areas. The threshold φ value is the threshold value memory memo IJ −
3K is not recorded, and only the index indicating that the threshold value was the same is added to the threshold value of the small area preceding the two consecutive small areas that have the same threshold value, and is stored in the threshold storage memory 3. The address of the threshold storage memory 3 where the threshold value of the subsequent small area should originally be recorded becomes empty. This empty space is filled with the threshold value determination result for the next small area, thereby creating an empty space in the threshold storage memory 3 in the small area in the same direction for the number of times that the same threshold value has been determined consecutively for the small area. When the threshold judgment for all small areas in the same direction is completed, the memory control circuit 5II'i stores the sub-division thresholds in the small areas as many times as there is free space in the threshold storage memory 3. Threshold data is read from the memory 4, inserted and recorded at the address following the address of the threshold storage memory 3 where the representative threshold value of the subdivided small area is recorded, and the data of the subsequent small area is recorded. The threshold data is shifted by one address in the threshold storage memory 3. The number of consecutive small areas with the same threshold in the same direction and the number of threshold values in the auxiliary memory 4 recorded because the thresholds differ due to subdivision of the small area, if the former is large, all If there are few subdivision thresholds, the thresholds that have been subdivided and recorded in the auxiliary memory 4 will only be the first recorded representative threshold because there is no space in the threshold storage memory 3. is used,
As a result, it is not subdivided and is treated as a normal small area.

FIG. 2 is a conceptual diagram of the above operation. Ari shows small areas #1 to #10 in the same direction separated by distance and direction as an example of dividing a small area, and Bri shows an example of a threshold value for these small areas. 8 has a subdivision threshold, and small regions #4 and #6 are small regions having the same continuous threshold. C indicates the memory contents of the threshold value storage memory 3, and T Hz a
THs a d small area #2. Indicates that the representative threshold value of #8 is recorded, ■ indicates a subdivision small area, and e indicates a continuous same threshold small area. I)
THxb, T Hsb with the contents of ri auxiliary memory 4
This indicates that the threshold values for the remaining areas of the subdivision areas of ri small areas #2 and #8 are stored. C' indicates the final recorded contents of the threshold value storage memory 3, and indicates that "THzb and THsb of the auxiliary memory 4 are searched after the representative threshold values T H2m and T H2b of the relevant small area." .

〔Effect of the invention〕

As explained above, in the present invention, the level of the radar signal is relatively uniform in an area where there is no reflection from clutter, etc., so the unit of the area for threshold control is expanded, and there are many causes of erroneous targets due to clutter etc. In areas where target detection is relatively difficult, by subdividing the unit of threshold control area, the radar can be Enables threshold control for target detection that matches signal conditions,
This has the effect of suppressing the false target detection rate in areas with clutter and improving the target detection rate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a radar signal processing device of the present invention, and FIG. 2 is a conceptual diagram showing the operation contents of FIG. 1. 1...Threshold judgment circuit, 2...Small area division/enlargement judgment circuit, 3...Threshold memory memory, 4...Auxiliary memory , 5...
Memory control circuit, 6... Amplitude comparison circuit, 7...
...Radar signal, 8...Threshold value, 9...
...Radar target signal, A...Example of small area division, B...Example of determined threshold value, C...
...Contents of threshold memory memorization.

Claims (1)

[Claims] In the target detection control method of radar target detection equipment for aircraft, etc., the radar coverage area is divided into a plurality of two-dimensional or three-dimensional small areas, and these small areas are used as processing units for target estimating, and the detection from the target is A radar signal characterized by including a function of performing threshold control for target detection on an amplitude value of a reflected signal in small area units and determining that an amplitude value of a target signal exceeding this threshold value is a target. Processing equipment.