JPS6093976A - Automatic detector of radar target - Google Patents

Abstract

PURPOSE:To maintain the definite number of occurring false targets even in the drift of the intensity of clutter, by providing a target detection level comparator with a plurality of detection level comparators detecting false target and a level comparator detecting a target. CONSTITUTION:An automatic apparatus for detecting a radar target is provided with two systems of controlling a false target, which comprise false target number control level comparators 1 and 3 and counters 2 and 4 respectively, and with one system of detecting a target, which comprises a target detection level comparator 5 and a counter 6. Outputs of these systems are delivered to a target detection level determinator 8, and the levels of the false target number control level comparators 1 and 3 are controlled so that the number of occurring target detections is maintained at a definite value.

Description

[Detailed description of the invention] The present invention relates to an automatic detection device for primary radar targets.

Conventionally, this type of automatic target detection method for primary V-da has a target detection slope liJ! a small cell (e.g. 1 x 1 square mile)
and set the detection level (for example, to' to 1) for each cell.
0') t- was set, the number of signals exceeding the detection novel was always counted, the detection level was changed according to the counted value, and the number of false targets was maintained at a constant value. In addition, this detection level follows the fluctuations in the signal strength of clutter, so if a false target is not detected for a certain period of time, automatic target detection will detect the target while keeping the number of false targets at a constant value by lowering the detection novel etc. It was a method. Therefore, depending on the characteristics of the clutter, there is a drawback that when the detection level is lowered, a large number of erroneous targets occur and a constant value cannot be maintained due to a delay in tracking the clutter intensity.

The purpose of the present invention is to solve such drawbacks by controlling the number of false targets at all levels including the false target number control level and the IfJ4M@output level, and to control the number of false targets to a constant value using the false target number control level, and to improve target detection. Detect multiple targets at level 2
- An object of the present invention is to provide an automatic radar target detection device that can always keep the number of erroneous targets constant even with fluctuations in J-force intensity.

The radar target automatic detection device of the present invention compares an input signal for each predetermined target detection area with a plurality of false target detection levels having different detection levels, and outputs a signal higher than these detection levels. a comparison means, a plurality of false target counting means for respectively counting the outputs of these false target novel comparison means, and comparing the input signal for each target detection area with a predetermined target detection level, and detecting a signal exceeding this detection level. A target level comparing means for outputting as a target, a target counting means for counting the output of this target level detecting means, and an input of the output of this target counting means and the output of each of the false target counting means to calculate each false target detection level. and a detected novel determining means for setting each of the target detection levels and controlling the number of false target occurrences to be constant.

In general, the clutter signal strength in the radar received signal fluctuates over time, so a multistage pilot detection level (erroneous target number control level) is set, and the strength of p clutter is determined based on the counting status of each detection stage. Since it is possible to estimate the number of false targets from these multistage bimit detection levels, the target detection level can be determined, and even with fluctuations in clutter intensity, false targets can be detected. It is possible to ensure that the number of occurrences always remains constant. Therefore, in the present invention, by providing a multi-stage pilot detection level and a target detection level for the target detection level and processing them simultaneously, it is possible to maintain the number of false targets constant.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the invention.

In this embodiment, the erroneous target number control level comparator 1. 3 and counter 2.4, and a target detection level ratio V unit 5 and counter 6.
It has a system. That is, the erroneous target number control level comparator 1. Counter 2.3 and target detection level comparator 5 each count the number of false targets. 4. According to the 6% threshold fist level is given as shown in Figure 2.

The video signal from input terminal 9 received by the radar receiver is passed to a false target number control level comparator l.

3, the number of video signals exceeding a predetermined amplitude level is counted by a counter 2.4, and the result of these counts is ? It is output to the target detection level determiner 8. In this target detection level determiner 8.

A target detection level is determined from these counting results, and the detection level is output to the target detection level comparator 5. This target detection level comparator 5 compares the input video signal with the video signals from all radar receivers and forwards the nine signals that exceed its target detection level to the target format converter 7, so that the target is detected and the intersection distance is determined. Extract the direction and create target data.

On the other hand, eye 5 - the output of the image detection level comparator 5 is input to the counter 6 to count the target number, and is output to the target detection level determiner 8 to maintain the target number of occurrences at a constant value. Erroneous target number control level comparator 1.3 controls the novel.

The target detection level of the target detection level determiner 8 is, for example, 10' to 10-7 per small cell of 1×1 square mile.
Since it is necessary to set the false target number control level comparator 1. 3 control level will be set to a small number of 1 to 2 per small cell, but since these radar data are determined empirically, each control level and detection level will be set based on these empirical values. settings can be made.

Note that if there are two or more erroneous target number control level comparators, the target detection level can be set.

As described above, the present invention includes a plurality of detection level comparators for detecting the number of false targets in the target detection level comparator.
Target detection using level comparators in parallel has the effect of keeping the number of false targets constant even when the clutter intensity fluctuates.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a waveform diagram explaining the detection level ft in FIG. 1. In the figure, 1, 3... Erroneous target number control level comparator, 2
．． 4゜6...Counter, 5...Target detection level comparator, 7...Target 7 automatic converter, 8...Target detection level determiner , 9...
...Input terminal, 10... Output terminal. 7- Exposure to

Claims (1)

[Claims] A plurality of false target level comparing means for comparing an input signal for each predetermined target detection area with a plurality of false target detection levels having different detection levels and outputting a signal that is higher than these detection levels, and these false target level comparing means. a plurality of erroneous target counting means for counting the outputs of each target detection area; and target level comparison means for comparing the input signal with a predetermined target detection level for each target detection area and outputting a signal equal to or higher than the detection level as a target; A target counting means for calculating the output of the target level detecting means by llf, and inputting the output of this target counting means and the output of each of the false target counting means to respectively set the false target detection level and the target detection level. and detection level determining means for controlling the number of occurrences of false targets to be constant.