JPH04143687A - Radar signal processor - Google Patents

Abstract

PURPOSE:To make possible the automatic detection of disturbance signals, disturbance arrival bearing and run length by automatically generating the threshold in a specified azimuth region on the basis of the maximal value in average amplitude value of one scan part and its azimuth angle. CONSTITUTION:A maximal value extractor 6 eliminates smaller average amplitude value than detection limit threshold 104 from input average amplitude values to compare with its relative size in order of azimuth direction on the residue to extract the largest of the most average amplitude values as the maximal value so as to transmit into a threshold generator 7 as maximal value data 101 along with its azimuth angle. In the generator 7, a threshold-set constant 10 is multiplied by the maximal value to show as lower value than it so as to output the value in which a specified azimuth range part that threshold azimuth width 106 designates is maintained as a detection threshold value 108. A disturbance detector 8 compares the average amplitude value 103 of next scan determining the threshold 108 with the threshold 108, a disturbance detection hit 109 is output whenever it exceeds the threshold 108 and a disturbance data extractor 9 extracts run length along with central azimuth to match with a disturbance level so as to output a disturbance signal message 110.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a radar signal processing device that processes radar reception signals acquired by a pulse radar device, and particularly relates to a technique for detecting interference signals contained in radar reception signals. .

(Prior Art) The interference signal detection method in a conventional radar signal processing device is a semi-automatic detection method. That is, in the conventional radar signal processing device, the average amplitude value for each sweep is obtained for the logarithmic video obtained by logarithmically amplifying and detecting the radar reception signal using a logarithmic amplifier with a wide dynamic range, and this is inputted to one side of the interference detector. AV that is proportional to the strength of the interfering signal by converting its average amplitude value to the display distance on the PPI display
A (amplitude versus azimuth) video is formed while the manually set threshold is the other input of the disturbance detector and the threshold is converted to a display distance on a PPI display to form a threshold video. and convert AVA video and threshold video to PPI
They are simultaneously displayed on the display, and the operator variably adjusts the threshold level while viewing the display. As a result, the jamming detector detects a jamming signal in the direction with an average amplitude of 11 (AVA video) exceeding the threshold, and the subsequent jamming data extractor forms and outputs a jamming signal message including the direction of arrival and run length. It has become.

Note that before the logarithmic video is subjected to the average value extraction process,
The removal of clutter components using automatically detected or manually set clutter area signals and the removal of receiver noise areas are now performed (for example, in Japanese Patent Laid-Open No. 195471-1983).
(see publication).

(Problem M to be Solved by the Invention) In the conventional radar signal processing device described above, the operator manually controls the threshold according to the intensity of the interference signal while visually observing the intensity. There was a problem in that it was difficult to set an appropriate threshold when different interference signals were received at the same time, or when interference signals with large fluctuations in strength were received, and the interference signals could not be detected sufficiently6. The present invention was made in view of such problems, and an object thereof is to provide a radar signal processing device that enables automatic detection of interference signals.

(Means for Solving the Problems) In order to achieve the above object, a radar signal processing device of the present invention has the following configuration.

That is, the radar signal processing device of the present invention calculates an average amplitude value for each sweep of the radar from a logarithmic video obtained by logarithmically amplifying and detecting a received signal of a pulse radar, and detects interference when the average amplitude value exceeds a threshold level. In a radar signal processing device configured to detect signals; a memory for storing the average amplitude values for one scan; and a memory for storing the average amplitude values for one scan; a maximum value extractor that extracts a local maximum value and the azimuth of the sweep that gives the local maximum value; receiving the extracted local maximum value and the azimuth of the sweep that gives the local maximum value, and extracting the local maximum value by a preset percentage from the local maximum value; a threshold generator that outputs a lowered value that is maintained over a preset azimuth range centered on the azimuth angle as the threshold for one scan;
It is characterized by having the following.

(Function) Next, the function of the radar signal processing device of the present invention configured as described above will be explained.

In the present invention, the average amplitude value for one scan is stored in a memory, the maximum value and its azimuth are detected within the average amplitude value for one scan, and based on the maximum value and azimuth, Automatically generate thresholds. When there are multiple local maximum values, thresholds are automatically set accordingly.

In this way, the interference signal can be automatically detected, and as a result, the direction of arrival and run length can also be automatically extracted.

Therefore, according to the present invention, even when interference signals with different intensities are received from a plurality of directions at the same time, or when interference signals with large fluctuations in intensity are received, it is possible to reliably detect the interference signals.

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

FIG. 1 shows a radar signal processing device according to an embodiment of the present invention. In FIG. 1, the signal processing device according to the present embodiment includes a logarithmic amplifier 1, an A/D converter 2, receiver noise, and clutter removal. In addition to the conventional configuration of a detector 3, an average amplitude extractor 4, a disturbance detector 8, and a disturbance data extractor 9, a scan memory 5, a maximum value extractor 6, and a threshold generator 7 are provided. The explanation will be given below with reference to FIG. 1, although it partially overlaps with the explanation of the conventional example.

A radar reception signal 101 acquired by a pulse radar device (not shown) is input to a logarithmic amplifier 1. Logarithmic amplifier 1 logarithmically amplifies and detects radar reception signal 101 with a high dynamic range and outputs logarithmic video signal 102. This logarithmic bidet 10th
2 is the receiver noise that is digitized by the A/D converter 2,
Input to clutter remover 3.

The receiver noise and clutter remover 3 removes the receiver noise component only region and the signal in the clutter region from the input digitized logarithmic video for each sweep, and sends the remaining digitized logarithmic video to the average amplitude extractor 4. Output. In addition,
The method for removing only the receiver noise component is the same as the conventional method. Further, the removal of clutter components is performed based on a clutter area signal 112 applied from the outside. This clutter area signal 112 is also automatically detected or manually set as in the conventional case.

The average amplitude extractor 4 receives an angle signal 113 from the outside as a control signal, extracts azimuth data for each sweep including azimuth data of the current sweep, and calculates an average amplitude value 103 for each sweep. , and outputs it to the interference detector 8 and scan memory 5. Note that the average amplitude value is calculated by integrating the output of the receiver noise and clutter remover 3 and dividing it by the remaining range bin from which the receiver noise and clutter have been removed.

In the scan memory 5, the average amplitude value 1 for each sweep
03 for one scan and outputting the stored average amplitude value to the maximum value extractor 6 are performed simultaneously.

The local maximum value extractor 6 first compares the magnitude relationship between the input average amplitude value and an externally set detection limit threshold 104, and deletes the average amplitude value smaller than the intraocular pressure limit threshold 104. , Compare the magnitude relationship between the remaining average amplitude values in the order of azimuth, and extract the one with the largest average amplitude value among the predetermined connected multiple sweeps as the local maximum value,
The azimuth that gives the maximum value is extracted, and maximum value data 105 consisting of both is output to the threshold generator 7. When there are multiple local maximum values, local maximum value data 105 is formed for each.

In the threshold generator 7, a threshold azimuth width 106 and a threshold level setting constant 107 are externally given as control signals, and the maximum value data 1
The "local maximum value" in 05 is multiplied by the threshold level setting constant 107 to set it as a value at a level lower than the local maximum value, and the threshold azimuth width 106 is defined around the "azimuth" in the local maximum value data 105. The detection threshold 108 is maintained for a predetermined azimuth range.
It is output to the interference detector 8 as

The disturbance detector 8 compares the magnitude relationship between the average amplitude value 103 in the next scan after determining the detection threshold 108 and the detection threshold 108, and each time the average amplitude value 103 exceeds the detection threshold 108. The interference detection hit 109 is sent to the interference data extractor 9.
Output to.

The interference data extractor 9 receives the interference detection hit 109 and performs, for example, sliding window processing to extract the center direction, extracts the run length, and edits and outputs the interference signal message 110 along with the interference signal level. .

(Effects of the Invention) As explained above, according to the radar signal processing device of the present invention, it is possible to automatically generate a threshold, automatically detect the interference signal received by the pulse radar device, and determine the direction of arrival of the interference and the direction of interference. Since the length can be automatically detected, even if interference signals of different intensities are received from multiple directions at the same time, or if interference signals with large fluctuations in intensity are received, the effect can be reliably detected.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a radar signal processing device according to an embodiment of the present invention. 1... Logarithmic amplifier, 2... A/D converter, 3... Receiver noise, clutter remover,
4... Average amplitude extractor, 5... Scan memory, 6... Maximum value extractor, 7...
...Threshold generator, 8...
Disturbance detector, 9... Disturbance data extractor, 1
01... Radar reception signal, 102...
Logarithmic video, 103...Average amplitude value, 104
...Detection limit threshold, 105...
...Local maximum value data, 106...Threshold azimuth width, 107...Threshold level setting constant, 108...Detection thread 7 shhold, 109... .....interference detection hint, 110.....interference signal message,
112...Clutter area signal.

Claims (1)

[Claims] Radar signal processing that calculates the average amplitude value for each sweep of the radar from the logarithmic video obtained by logarithmically amplifying and detecting the received signal of the pulse radar, and detects a disturbance signal when the average amplitude value exceeds a threshold level. In the device; a memory for storing the average amplitude values for one scan; and a maximum value among the average amplitude values that exceed a preset value among the average amplitude values stored in the memory, and a direction of a sweep giving the maximum value. a local maximum extractor for extracting corners;
In response to the extracted maximum value and the azimuth of the sweep that gave the maximum value, a value that is lowered by a preset percentage from the maximum value and maintained over a preset azimuth range centered on the azimuth. a threshold generator that outputs the threshold value for one scan as the threshold value for one scan.