JPH0216480A - Tracked signal deciding circuit for radar countermeasuring equipment - Google Patents

Abstract

PURPOSE:To correctly decide whether a signal is tracked or not even with respect to a signal whose input level is high by controlling the input data by amplitude. CONSTITUTION:When pulse data having data of pulse width and pulse amplitude is inputted from an input terminal, an input controller 2 allows only a pulse having pulse amplitude exceeding a threshold level to pass through, and eliminated a pulse being under the threshold level. A signal detecting circuit 3 detects a pulse train radiated from the same radar, as a signal by a frequency, a pulse arrival time and pulse width data with regard to the pulse passing through the input controller 2. A continuous input deciding circuit 4 measures the frequency of a signal, decides whether the signal is a continuous input or not, and controls a threshold level of the input controller 2 in accordance with its result. A deciding circuit 5 outputs whether the signal is tracked or not a in accordance with whether the threshold level for controlling the input controller 2 is the upper limit value or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the field of radio wave detection, and particularly to an improvement of a tracked determination circuit of a radar reverse detection device.

[Conventional technology]

A tracking determination circuit of a conventional radar reverse detection device is configured as shown in FIG. In the figure, 1 is an input end, 3 is a signal detection circuit, 4 is a continuous input determination circuit, and 6 is an output end for outputting determination results.

Next, the operation will be explained. frequency, pulse arrival time,
When pulse data with pulse width and pulse amplitude data is input from the input terminal 1, the signal detection circuit 3 detects the pulse train emitted from the same radar as a signal based on the frequency, pulse arrival time, and pulse width data. do. The continuous input determination circuit 4 measures the frequency of signal detection, determines whether the signals are input continuously over time, and if the signals are input continuously for a long time, outputs a message indicating that the signal is being tracked from the output terminal 6. do.

[Problem to be solved by the invention]

The tracking determination circuit of the conventional radar reverse detection device is configured as described above, so if the radar that is attempting reverse detection is nearby, its side lobe will be received, so it will not be possible to detect the tracked state. At the very least, there is a problem in that the input signal becomes continuous as shown in FIG. 2, and it is erroneously determined that the object is being tracked.

This invention was made in order to solve the problems of the conventional ones as described above, and it is possible to accurately determine whether or not the radar is being tracked even when the radar is in close proximity. The purpose is to obtain a judgment circuit.

[Means to solve the problem]

The tracked determination circuit of the radar reverse detection device according to the present invention includes:
A pulse input controller is added to the tracked target determination circuit, the input pulse is controlled by the pulse amplitude, and whether or not the tracked target is determined is determined based on the threshold level.

[Effect]

The tracked determination circuit in this invention determines whether the input signal is continuous or intermittent, controls the threshold level of the input signal according to the result, and compares the threshold level with (maximum amplitude of input signal - specified value). By doing this, it is determined whether the vehicle is being tracked, so even if a radar signal that is not in the tracked state is constantly input at a high level, it can be correctly determined that the vehicle is not in the tracked state.

〔Example〕

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

FIG. 1 shows a tracking determination circuit of a radar reverse detection device according to an embodiment of the present invention, and in the figure, the same reference numerals as in FIG. 5 indicate the same parts. 1 is the input terminal of the pulse radar,
Reference numeral 2 represents an input controller that controls the input of data input from the input terminal 1 according to the amplitude, and 5 represents a determination circuit. Also, 3,4
．． Reference numerals 6 denote a signal detection circuit, a continuous input determination circuit, and an output terminal, respectively, which are similar to the conventional ones.

Next, the operation will be explained. frequency, pulse arrival time,
When pulse data having pulse width and pulse amplitude data is input from input terminal 1, input IJ? B12 allows only pulses with pulse amplitudes above the threshold level to pass through, and removes pulses below the threshold level. The signal detection circuit 3 detects a pulse train emitted from the same radar as a signal based on the frequency, pulse arrival time, and pulse width data of the pulses that have passed through the input controller 2. The continuous input determination circuit 4 measures the frequency of signal detection, determines whether the signal is a continuous input, and controls the threshold level of the input controller 2 according to the result.

That is, while the determination circuit 4 determines that the input is continuous,
The input controller 2 increases the threshold level by a specified level at specified time intervals, and decreases the threshold level by a specified level while determining that the input is not continuous. However, the upper limit of the threshold level is set to a value obtained by subtracting a certain specified value from the maximum amplitude value of the signal detected by the signal detection circuit. In the determination circuit 5, when the threshold level for controlling the input controller 2 is the upper limit value, it outputs to the output end 6 that the object is being tracked, and when it is not the upper limit value, it outputs that the object is not being tracked.

A detailed explanation will be given below using FIG. 3. Figure (a) shows an input signal from a nearby radar that is not being tracked. In this case, since the initial threshold level is the lower limit value, it is determined to be a continuous input, and as a result, the threshold level gradually increases. , and eventually reaches an equilibrium point, but since it is not the threshold level - the upper limit value, a message indicating that it is not being tracked is output. In addition, the input signal from the radar being tracked is shown in FIG. Outputs tracking information.

Note that when not being tracked, the threshold level for controlling the input controller 2 is equal to the average sidelobe input level, so by adding a distance calculation circuit 7 as shown in FIG. 4, the distance to the radar can be calculated. It can be calculated.

The calculation formula at that time is shown below. However, it is assumed that the radar effective radiation power, sidelobe level ratio, and radar wave wavelength are preset.

Distance = (λ/4π)・ (ERP -5L/PA)”
” (1/L) However, ERP: Radar effective radiation power SL: Sidelobe level ratio λ: Radar wave wavelength PA: Average sidelobe input level L: Receiving system loss (constant) [Effects of the invention] As described above, According to the tracked target determination circuit of the radar reverse detection device according to the present invention, since the input data is controlled by the amplitude, it is possible to correctly determine whether or not the tracked target is being tracked even for a signal with a high input level. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a tracking determination circuit of a radar reverse detection device according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of inputting a proximity radar signal, and FIG. 3 is a correspondence between signal input and threshold level. FIG. 4 is a diagram showing another embodiment of the present invention, and FIG. 5 is a configuration diagram of a tracked determination circuit of a conventional radar reverse detection device. In the figure, 1 is an input end, 2 is an input controller, 3 is a signal detection circuit, 4 is a continuous input determination circuit, 5 is a determination circuit, and 6 is an output end.

Claims (1)

[Claims] (1) A circuit that is installed in a radar reverse detection device that receives radar signals, performs recognition processing, and outputs them, and that determines whether or not the radar being detected is tracking the radar signal. a continuous input determination circuit that determines whether or not an input has been input; an input limiter that limits the input radar signal by changing a threshold according to the determination result of the continuous input determination circuit; and the threshold and the maximum amplitude of the input radar signal. What is claimed is: 1. A tracking determination circuit for a radar reverse detection device, comprising: a determination circuit for determining whether or not a target is being tracked depending on whether or not a value corresponding to .