JP5697497B2 - Radar receiver and pulse radar device - Google Patents

Description

  The present invention relates to a radar receiver and a pulse radar apparatus having a function of identifying deceptive interference waves as an ECCM (Electronic Counter Counter Measurements) function of a pulse radar.

  For example, the following Patent Document 1 discloses a pulse radar device. The pulse radar device radiates a pulse transmission wave to space, and the pulse transmission wave is reflected by a target and returned. It is a device that measures the distance and azimuth to the target by receiving a pulse reception wave that is a wave.

FIG. 10 is a block diagram showing a radar receiver mounted on a conventional pulse radar apparatus.
In the conventional pulse radar apparatus, when the transmitter 101 outputs a pulse transmission wave, the pulse transmission wave is output to the antenna 103 via the transmission / reception switch 102, and the pulse transmission wave is radiated from the antenna 103 to the space.
For example, when a target such as an airplane exists, the pulse transmission wave radiated to the space is reflected by the target and returns to the pulse radar device.
The antenna 103 receives a pulse reception wave that is a reflected wave that has been reflected back by the target, and outputs the pulse reception wave to the transmission / reception switch 102.
The transmission / reception switch 102 outputs the pulse reception wave received by the antenna 103 to the IF converter 104.

When receiving a pulse reception wave from the transmission / reception switch 102, the IF converter 104 converts the frequency of the pulse reception wave from a high frequency band to an intermediate frequency band, and an IF modulated wave (intermediate frequency band of the intermediate frequency band) as a signal after frequency conversion. Signal) to the intermediate frequency amplifier 105.
The intermediate frequency amplifier 105 has a function of a matched filter. When receiving the IF modulated wave from the IF converter 104, the intermediate frequency amplifier 105 maximizes the S / N ratio (signal-to-noise ratio) of the IF modulated wave, and the S / N The IF modulated wave having the maximum N ratio is output to the detector 106.
When receiving the IF modulated wave having the maximum S / N ratio from the intermediate frequency amplifier 105, the detector 106 detects the envelope of the IF modulated wave.

The pulse compressor 107 compresses the pulse waveform indicated by the envelope detected by the detector 106 to increase the pulse amplitude, and outputs the pulse waveform after amplitude amplification to the A / D converter 108.
The A / D converter 108 converts the pulse waveform output from the pulse compressor 107 from an analog signal to a digital signal, and outputs the digital signal to the signal processor 109.
Upon receiving the digital pulse waveform from the A / D converter 108, the signal processor 109 performs signal processing such as removing unnecessary components such as clutter contained in the pulse waveform, The pulse waveform is output to a target measurement processor (not shown) mounted on the pulse radar device.

Thereby, a measurement processor (not shown) can measure the distance and direction from the pulse waveform after signal processing to the target.
However, if the pulse received wave received by the antenna 103 is not a reflected wave of the pulse transmission wave that is reflected back to the target but a fake pulse wave emitted by the deception disturbing device, the target is Since it is determined that the target exists at a position different from the place where it originally exists, the radar function cannot be performed.

Japanese Patent No. 3427777 (FIG. 1)

  Since the conventional pulse radar device is configured as described above, when a false pulse wave is radiated from the deception jamming device, the target exists at a position different from the place where the target originally exists. Therefore, it is necessary to remove deceptive interference waves. However, the fraudulent interference wave for the side lobe of the pulse radar can be removed by SLC (Sidelobe Cancer), but the fraud disturbance wave for the main lobe of the pulse radar captures the rising edge of the nearest target echo. There is only a measure of leading edge tracking, and if the deception disturbing device emits a pulse wave at a timing earlier than the pulse of the radar, there is a problem that the deceptive disturbing wave cannot be removed.

Leading edge tracking is a function of tracking radar, and search radar does not have a function of leading edge tracking, and there is no coping method for removing deceptive interference waves.
Further, since the intermediate frequency amplifier 105 maximizes the S / N ratio of the IF modulated wave and does not have the ability to analyze the fraud interference waveform, it is difficult to detect the fraud interference wave in the radar receiver.

The present invention has been made to solve the above-described problems, and provides a radar receiver that can accurately identify whether a pulse reception wave is a reflected wave of a target or a deception interference wave. For the purpose.
The present invention also provides a pulse radar device capable of accurately identifying whether a received pulse wave is a reflected wave of a target object or a deceiving interference wave and measuring the distance and direction to the true target object. The purpose is to obtain.

The radar receiver according to the present invention receives the pulse transmission wave in the space, and receives the pulse reception wave by the pulse wave transmission / reception means that receives the pulse reception wave that is the reflected wave reflected by the target and returning. The received pulse wave is sampled using an analog / digital converter whose sampling rate is higher than the pulse frequency of the pulse transmission wave radiated into the space from the pulse wave transmitting / receiving means, and the pulse waveform of the pulse received wave is detected. A pulse waveform detecting means, and the received wave identifying means specifies the rise time of the pulse received wave from the pulse waveform detected by the pulse waveform detecting means , and the rising portion, falling portion and overshoot portion of the pulse waveform. The droop of the pulse reception wave, which is the rate of decrease in amplitude from the maximum amplitude in the part excluding Constant and, when the rise time of the pulse received wave is longer than the rise time of the pulse transmitting wave, the pulse received wave is identified as a reflected wave of the target, rise rise time of a pulse transmission wave of the pulse received wave If it is not longer than the time, if the droop of the pulse reception wave is larger than the droop of the pulse transmission wave, the pulse reception wave is identified as a deception jamming wave .

According to the present invention, the pulse received by the pulse wave transmitting / receiving means that radiates the pulse transmission wave to the space and receives the pulse reception wave that is the reflected wave reflected by the target and returning. Pulse waveform detection that samples the received wave using an analog / digital converter whose sampling rate is higher than the pulse frequency of the pulse transmission wave radiated from the pulse wave transmission / reception means and detects the pulse waveform of the pulse reception wave And the received wave identifying means identifies the rising time of the pulse received wave from the pulse waveform detected by the pulse waveform detecting means, and excludes the rising portion, falling portion and overshoot portion of the pulse waveform. identify amplitude pulse of the received wave loop is a reduction ratio of the maximum amplitude in the portion, that If the rise time of the pulse received wave is longer than the rise time of the pulse transmitting wave, the pulse received wave is identified as a reflected wave of the target, the rise time of the pulse received wave is not longer than the rise time of the pulse transmitting wave In this case, if the droop of the pulse reception wave is larger than the droop of the pulse transmission wave, the pulse reception wave is configured to be identified as a fraud interference wave. There is an effect that it is possible to accurately identify whether it is a reflected wave of an object or a deceptive disturbance wave .

It is a block diagram which shows the pulse radar apparatus by Embodiment 1 of this invention. It is a flowchart which shows the processing content of the pulse radar apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows a mode that the pulse transmission wave is irradiated to the aircraft (target) located in the diagonal direction with respect to a pulse radar apparatus. It is explanatory drawing which shows a mode that the pulse transmission wave is irradiated with respect to the pulse radar apparatus to the aircraft (target object) in which the fuselage is positioned vertically. It is explanatory drawing which shows an example of the pulse waveform of the pulse transmission wave radiated | emitted from a pulse radar apparatus. It is explanatory drawing which shows the reflected wave and synthetic wave which are reflected on each surface. It is explanatory drawing which shows the reflected wave and synthetic wave which are reflected on each surface. It is explanatory drawing which shows an example of the pulse waveform of the fraud jamming wave transmitted from a fraud jamming device. It is explanatory drawing which shows the rise time and droop of a pulse received wave. It is a block diagram which shows the radar receiver mounted in the conventional pulse radar apparatus.

Embodiment 1 FIG.
1 is a block diagram showing a pulse radar apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a transmitter 1 is a device that transmits a pulse transmission wave that is a modulated wave in a high frequency band, for example.
The transmission / reception switch 2 is a device that outputs a pulse transmission wave transmitted from the transmitter 1 to the antenna 3 and outputs a pulse reception wave received by the antenna 3 to the IF converter 5.
The antenna 3 is a device that radiates the pulse transmission wave output from the transmission / reception switching device 2 to the space and receives the pulse reception wave that is a reflected wave that is reflected by the target and returned.

In the example of FIG. 1, the transmitter 1, the transmission / reception switch 2, and the antenna 3 are provided outside the radar receiver 4, but may be provided inside the radar receiver 4.
The IF converter 5 converts the frequency of the pulse reception wave output from the transmission / reception switch 2 from the high frequency band to the intermediate frequency band, and detects the IF modulated wave (intermediate frequency band signal) that is the frequency converted signal as a received signal. Processing to be output to the units 6 and 11 is performed.
The transmitter 1, the transmission / reception switch 2, the antenna 3 and the IF converter 5 constitute a pulse wave transmission / reception means.

The first received signal detector 6 includes an intermediate frequency amplifier 7, a detector 8, a pulse compressor 9 and an A / D converter 10, detects the IF modulated wave output from the IF converter 5, Processing is performed to compress the pulse waveform indicated by the detection result to increase the pulse amplitude and output the pulse waveform after amplitude amplification. The first reception signal detector 6 constitutes a pulse reception wave detection means.
The intermediate frequency amplifier 7 has a function of a matched filter, and maximizes the S / N ratio (signal-to-noise ratio) of the IF modulated wave output from the IF converter 5 to maximize the S / N ratio. A process of outputting the modulated wave to the detector 8 is performed.

The detector 8 is a device that detects the envelope of the IF modulated wave output from the intermediate frequency amplifier 7.
The pulse compressor 9 compresses the pulse waveform indicated by the envelope detected by the detector 8 to increase the pulse amplitude, and outputs the pulse waveform after amplitude amplification to the A / D converter 10.
The A / D converter 10 converts the pulse waveform output from the pulse compressor 9 from an analog signal to a digital signal, and outputs the digital signal to the first reflected wave extractor 14.

The second received signal detection unit 11 includes a high-speed A / D converter (analog / digital converter) 12 and a memory 13, and the sampling rate is determined by the pulse frequency of the pulse transmission wave radiated from the antenna 3 to the space. The high-speed A / D converter 12 is used to sample the IF modulated wave output from the IF converter 5 and to detect the pulse waveform of the pulse received wave received by the antenna 3. The second received signal detector 11 constitutes a pulse waveform detector.
The high-speed A / D converter 12 samples the IF modulated wave output from the IF converter 5 at a sampling rate that is, for example, twice or more the pulse frequency of the pulse transmission wave, and converts the IF modulated wave that is an analog signal into a digital signal. By converting to, waveform data indicating the pulse waveform of the IF modulated wave is recorded in the memory 13.
The memory 13 is a recording medium for recording waveform data.

The reflected wave extractors 14 and 15 specify the rise time and droop of the pulse reception wave received by the antenna 3 from the waveform data recorded in the memory 13 of the second reception signal detection unit 11, and the pulse reception wave By comparing the rise time and droop of the pulse transmission wave with the rise time and droop of the pulse transmission wave, a process of identifying whether the pulse reception wave is a reflected wave of the target or a deception jamming wave is performed.
That is, when the rise time of the pulse reception wave is longer than the rise time of the pulse transmission wave, the first reflected wave extractor 14 identifies that the pulse reception wave is a reflection wave of the target and detects the first reception signal. Processing for outputting the pulse waveform output from the unit 6 to the signal processor 16 is performed.

The first reflected wave extractor 14 detects a pulse waveform when a plurality of overshoots occur within the rising time in the pulse reception wave or when the first reception signal detector 6 detects the pulse waveform. When the pulse waveform is not detected by the second received signal detector 11, the pulse received wave is identified as a reflected wave of the target, and the pulse waveform output from the first received signal detector 6 is determined. Processing to be output to the signal processor 16 is performed.
In addition, the first reflected wave extractor 14 has a pulse reception wave whose rise time is as short as that of the pulse transmission wave and the droop of the pulse reception wave is larger than the droop of the pulse transmission wave. A process of identifying that the received wave is a fraud jamming wave is performed.

When the rise time of the pulse reception wave is as short as the rise time of the pulse transmission wave and the droop of the pulse reception wave is smaller than the droop of the pulse transmission wave, the second reflected wave extractor 15 Performing the cross-correlation process of the rising part in the pulse transmission wave and determining the similarity, and if the rising part is recognized to be similar, the received pulse wave is identified as the reflected wave of the target, A process of outputting the pulse waveform output from the first received signal detector 6 to the signal processor 16 is performed. On the other hand, if it is not recognized that the rising portions are similar, a process of identifying that the pulse reception wave is a deception jamming wave is performed.
The reflected wave extractors 14 and 15 constitute received wave identification means.

The signal processor 16 performs signal processing such as removing unnecessary components such as clutter included in the pulse waveform output from the first reflected wave extractor 14 or the second reflected wave extractor 15.
The measurement processor 17 performs a process of measuring the distance to the target and the direction of the target based on the pulse waveform after the signal processing by the signal processor 16. The measurement processor 17 constitutes a measurement means.
FIG. 2 is a flowchart showing the processing contents of the pulse radar device according to the first embodiment of the present invention.

Next, the operation will be described.
First, the transmitter 1 transmits a pulse transmission wave that is a modulated wave in a high frequency band, for example.
When the transmitter 1 transmits a pulse transmission wave, the transmission / reception switch 2 outputs the pulse transmission wave to the antenna 3.
As a result, when a pulse transmission wave is radiated from the antenna 3 to the space and the target is present in the space, the pulse transmission wave is reflected by the target and the reflected wave returns to the pulse radar device. .

FIG. 3 is an explanatory view showing a state in which a pulse transmission wave is irradiated to an aircraft (target) located in an oblique direction with respect to the pulse radar device, and FIG. 4 shows a fuselage with respect to the pulse radar device. It is explanatory drawing which shows a mode that the pulse transmission wave is irradiated to the aircraft (target object) located vertically.
Here, for convenience of explanation, it is assumed that the pulse transmission wave radiated from the pulse radar apparatus has a pulse waveform as shown in FIG.
In order to make it difficult to reproduce the pulse transmission wave in the deception disturbing device, the rising portion of the pulse transmission wave shown in FIG. 5 is formed into a complex pulse waveform.

When the aircraft (target) is positioned obliquely with respect to the pulse radar device, as shown in FIG. 3, the reflected wave A reflected by the aircraft nose, the reflected wave B reflected by both wings of the aircraft, A plurality of reflected waves reflected from different surfaces of the aircraft, such as the reflected wave C reflected from the tail of the aircraft, are combined and returned to the pulse radar device, but each surface of the aircraft has a different distance from the pulse radar device. The reflected waves reflected from the respective surfaces are shifted in time, and a composite wave of a plurality of identical pulses returns to the pulse radar device.
FIG. 6 is an explanatory diagram showing a reflected wave and a composite wave reflected on each surface.

Here, an example in which the target is an aircraft is shown, but the target is not limited to an aircraft. For example, the target may be a ship, but the shape of a ship is also three-dimensional like an aircraft. As seen from the antenna 3 of the pulse radar device, there is a difference in distance to each surface of the target.
Therefore, the pulse waveform of the composite wave (pulse reception wave) of the reflected waves that return to the pulse radar device after being reflected by the target is not the same shape as the pulse transmission wave radiated from the pulse radar device. A pulse waveform is formed by overlapping a plurality of reflected waves that are shifted in time by the length in the range direction of the object.
When attention is paid to the rising portion of the pulse reception wave, the rise time of the pulse reception wave is longer than that of the pulse transmission wave, and the pulse reception wave becomes gentle.
For example, in the case of a target having a length of 30 m in the range direction of the pulse radar device, a pulse delay of about 0.2 μsec occurs.

When the aircraft (target) fuselage is positioned vertically with respect to the pulse radar device, as shown in FIG. 4, the reflected wave E reflected by the aircraft fuselage and the reflection reflected by both wings of the aircraft are shown. There are waves D, F, etc., but the reflected waves D, F reflected by both wings of the aircraft are much smaller than the reflected waves E reflected by the fuselage, so they are reflected by the target and returned to the pulse radar device. The combined wave of the plurality of reflected waves has a pulse waveform similar to the pulse transmission wave radiated from the pulse radar device.
FIG. 7 is an explanatory diagram showing reflected waves and synthesized waves reflected on each surface.

On the other hand, a fraud jamming device normally receives a pulse transmission wave radiated from a pulse radar device by a receiver, amplifies the reception wave of the receiver, performs processing such as delay and modulation, and then receives the received signal. The deceiving interference wave having the same pulse waveform as the wave is transmitted to the pulse radar device.
FIG. 8 is an explanatory diagram showing an example of a pulse waveform of a fraud interference wave transmitted from a fraud jamming apparatus, and the pulse waveform of the fraud jamming wave has a shape similar to that of the pulse transmission wave shown in FIG.

When the transmission / reception switch 2 receives a pulse reception wave that is a composite wave that is reflected back from the target by the antenna 3 (the pulse reception wave may be a fraudulent interference wave), The data is output to the IF converter 5 (step ST1 in FIG. 2).
When receiving a pulse reception wave from the transmission / reception switch 2, the IF converter 5 converts the frequency of the pulse reception wave from a high frequency band to an intermediate frequency band, and an IF modulated wave (intermediate frequency band of the intermediate frequency band) as a signal after frequency conversion Signal) is output to the received signal detectors 6 and 11 (step ST2).

When receiving the IF modulated wave from the IF converter 5, the first received signal detector 6 detects the envelope of the IF modulated wave, compresses the pulse waveform indicated by the envelope, and increases the pulse amplitude. The pulse waveform after amplitude amplification is output to the first reflected wave extractor 14 (step ST3).
That is, the intermediate frequency amplifier 7 of the first received signal detector 6 has a function of a matched filter. When receiving the IF modulated wave from the IF converter 5, the S / N ratio of the IF modulated wave is maximized. Then, the IF modulated wave having the maximum S / N ratio is output to the detector 8.

When receiving the IF modulated wave having the maximum S / N ratio from the intermediate frequency amplifier 7, the detector 8 detects the envelope of the IF modulated wave.
The pulse compressor 9 increases the pulse amplitude by compressing the pulse waveform indicated by the envelope in order to enable detection of a target even when the antenna 3 receives a weak received pulse. The pulse waveform after amplitude amplification is output to the A / D converter 10.
Upon receiving the pulse waveform from the pulse compressor 9, the A / D converter 10 converts the pulse waveform from an analog signal to a digital signal, and outputs the digital signal to the first reflected wave extractor 14.

When receiving the IF modulated wave from the IF converter 5, the second received signal detection unit 11 uses the high-speed A / D converter 12 to sample the IF modulated wave and receive the pulse received by the antenna 3. The pulse waveform of the wave is detected (step ST4).
That is, the high-speed A / D converter 12 of the second received signal detection unit 11 samples the IF modulated wave output from the IF converter 5 at intervals that can faithfully reproduce the pulse waveform of the pulse received wave. (For example, the IF modulated wave output from the IF converter 5 is sampled at a sampling rate twice or more the pulse frequency of the pulse transmission wave), and by converting the IF modulated wave that is an analog signal into a digital signal, Waveform data indicating the pulse waveform of the IF modulated wave is recorded in the memory 13.

The first reflected wave extractor 14 refers to the waveform data recorded in the memory 13 of the second received signal detector 11 and determines the rise time T1 and the droop dr1 of the pulse received wave received by the antenna 3. Specify (step ST5).
Here, FIG. 9 is an explanatory diagram showing the rise time and droop of the received pulse wave.
The “rise time” of the pulse reception wave is the time required for the pulse reception wave to rise.

In the pulse reception wave, an overshoot occurs after rising, and the output power cannot be maintained thereafter, so that a droop phenomenon in which the output power decreases occurs.
The “droop” indicates a rate of power reduction that occurs because the transmitter 1 cannot maintain power when outputting a pulse transmission wave.
The first reflected wave extractor 14 excludes the first 25% and the last 25% of the pulse reception wave in order to avoid being affected by overshoot distortion when specifying the droop of the pulse reception wave, Try to identify the droop.
That is, the remaining 50% portion is linearly approximated by, for example, the least square method, and the droop is specified by measuring the rate of decrease from the maximum amplitude in the droop measurement portion.

When the first reflected wave extractor 14 specifies the rise time T1 of the pulse reception wave received by the antenna 3 and the droop dr1, the first reflection wave extractor 14 compares the rise time T1 of the pulse reception wave with the rise time T2 of the pulse transmission wave.
Here, it is assumed that the rise time T2 and the droop dr2 of the pulse transmission wave are known, but when the transmitter 1 transmits the pulse transmission wave, the pulse is transmitted using, for example, a directional coupler. A part of the transmission wave is given to the second received signal detector 11, and the first reflected wave extractor 14 refers to the waveform data recorded in the memory 13 of the second received signal detector 11, The rise time T2 and the droop dr2 of the pulse transmission wave may be specified.

When the aircraft (target) is located in an oblique direction with respect to the pulse radar device, as described above, there is a difference in distance to each surface of the target when viewed from the antenna 3 of the pulse radar device. In addition, the rise time of the pulse reception wave is longer than the rise time of the pulse transmission wave. Since the fraudulent interference wave is a signal that receives a pulse transmission wave and amplifies and transmits the reception wave as it is, the rise time is short like the pulse transmission wave.
Therefore, when the rise time T1 of the pulse reception wave is longer than the rise time T2 of the pulse transmission wave (step ST6; YES), the first reflected wave extractor 14 determines that the pulse reception wave is a reflected wave of the target object. The pulse waveform output from the first received signal detector 6 is identified and output to the signal processor 16 (step ST7).

When the rise time T1 of the pulse reception wave is approximately the same as the rise time T2 of the pulse transmission wave and is short (step ST6; NO), the first reflected wave extractor 14 determines the droop dr1 of the pulse reception wave and the pulse transmission wave. The droop dr2 is compared.
When the droop dr1 of the pulse reception wave is larger than the droop dr2 of the pulse transmission wave (step ST8; NO), the first reflected wave extractor 14 is a pulse wave transmitted from a transmitter different from the transmitter 1. Therefore, it is identified that the received pulse wave is a deception jamming wave (step ST9).
In this case, the pulse waveform output from the first received signal detector 6 is not used for detecting the target.

When the droop dr1 of the pulse reception wave is smaller than the droop dr2 of the pulse transmission wave (step ST8; YES), the first reflected wave extractor 14 may be the reflected wave of the target. Therefore, the second received wave extractor 15 is left to identify the received pulse wave without identifying that the received pulse wave is a deceiving interference wave.
When the pulse reception wave is a reflected wave of the target, the droop dr1 of the pulse reception wave may be smaller than the droop dr2 of the pulse transmission wave because the latter half of the pulse reception wave overlaps due to multipath.

However, the first reflected wave extractor 14 may be a combined wave of the reflected waves reflected on the respective surfaces of the target object when a plurality of overshoots occur within the rise time in the received pulse wave. Therefore, the pulse reception wave is identified as a reflected wave of the target, and the pulse waveform output from the first reception signal detector 6 is output to the signal processor 16.
Further, the first reflected wave extractor 14 has a pulse waveform detected by the first received signal detector 6, but even when the second received signal detector 11 does not detect the pulse waveform, The pulse reception wave is identified as a reflected wave of the target, and the pulse waveform output from the first reception signal detector 6 is output to the signal processor 16.

Since the first received signal detector 6 performs pulse compression, the pulse received wave at a level that can finally be detected does not have an amplitude enough to confirm the pulse shape before compression, and therefore the second received signal detector 11 cannot detect a pulse waveform.
However, in actual operation, it is considered that the deceiving jammer transmits a fraud jamming wave with a strength that can be reliably received by the pulse radar device, and transmits a fraud jamming wave that requires pulse compression. There is almost no operation.
Even if a fraudulent interference wave that requires pulse compression is transmitted, if it is an interference from a long distance, the risk is small, so it can be handled as a reflected wave of the target.

When the second reflected wave extractor 15 is entrusted with the identification of the pulse reception wave from the first reflected wave extractor 14, that is, the rise time T1 of the pulse reception wave is approximately the same as the rise time T2 of the pulse transmission wave. And the droop dr1 of the pulse reception wave is smaller than the droop dr2 of the pulse transmission wave, the cross-correlation processing of the rising portions of the pulse reception wave and the pulse transmission wave is performed to determine the similarity. In consideration of waveform collapse due to multipath, the falling portion is not included in the cross-correlation processing.
The cross-correlation processing of the rising part of the pulse reception wave and the pulse transmission wave is not particularly limited as long as the similarity of the rising part can be determined, but for example, the rising part of the pulse reception wave and the pulse By performing FFT processing on the rising portion of the transmission wave and comparing the FFT result of the rising portion of the pulse reception wave with the FFT result of the rising portion of the pulse transmission wave, the similarity of the rising portion can be determined.

In the second reflected wave extractor 15, the rising portion is correlated (for example, when the correlation indicating the processing result of the cross-correlation processing is larger than a predetermined threshold value), and it is recognized that the rising portions are similar. If this is the case (step ST10; YES), the received pulse wave is identified as a reflected wave of the target, and the pulse waveform output from the first received signal detector 6 is output to the signal processor 16 (step ST7). ).
On the other hand, if it is not recognized that the rising portions are similar (step ST10; NO), a process of identifying that the pulse reception wave is a deception jamming wave is performed (step ST9).
In this case, the pulse waveform output from the first received signal detector 6 is not used for detecting the target.
Note that transmitters such as TWT and klystron include characteristics unique to the transmitter such as rising, falling, and droop that are not intended by the transmitter. It is possible to identify whether it is a reflected wave of the pulse transmission wave transmitted from the radar device or a deception jamming wave transmitted from the deception jamming device.

The signal processor 16 is identified by the first reflected wave extractor 14 or the second reflected wave extractor 15 that the pulse received wave is a reflected wave of the target, and is output from the first received signal detector 6. When the received pulse waveform is received, signal processing such as removal of unnecessary components such as clutter contained in the pulse waveform is performed. Since this signal processing itself is a known technique, a detailed description thereof will be omitted.
The measurement processor 17 measures the distance to the target and the direction of the target based on the pulse waveform after the signal processing by the signal processor 16. Since the measurement process itself is a known technique, a detailed description thereof will be omitted.

  As is apparent from the above, according to the first embodiment, reception is performed by the antenna 3 using the high-speed A / D converter 12 having a sampling rate higher than the pulse frequency of the pulse transmission wave radiated from the antenna 3 to the space. The second received signal detector 11 for sampling the received pulse received wave and detecting the pulse waveform of the received pulse is provided, and the reflected wave extractors 14 and 15 are detected by the second received signal detector 11. The pulse reception wave rise time T1 and the droop dr1 are identified from the pulse waveform thus generated, and the pulse reception wave rise time T1 and the droop dr1 are compared with the pulse transmission wave rise time T2 and the droop dr2 to receive the pulse. Since it is configured to identify whether the wave is a reflected wave of a target object or a deceiving disturbance wave, it is received by the antenna 3. Have been or pulses received wave that is reflected wave of the target, an effect that can accurately identify whether a fraud disturbance.

Embodiment 2. FIG.
In Embodiment 1 described above, when the first reflected wave extractor 14 or the second reflected wave extractor 15 identifies that the pulse reception wave is a fraudulent interference wave, it is output from the first reception signal detector 6. Although it has been shown that the generated pulse waveform is not used for detecting the target object, the fraud jamming device that transmits the fraud jamming wave may be specified.

In this case, the characteristics of the deceptive jamming wave transmitted by a known fraud jamming device are identified (for example, characteristics unique to the transmitter such as rising, falling, and droop of the fraud jamming wave), and feature data indicating the characteristics and the fraud Prepare a database that records the correspondence of jamming devices.
When the first reflected wave extractor 14 or the second reflected wave extractor 15 identifies that the received pulse wave is a fraudulent interference wave, an interference device search means (not shown) is characterized by the received pulse wave. And the feature data indicating the characteristics of the received pulse wave are collated with the feature data recorded in the database.
If the feature data recorded in the database includes feature data that matches the feature data indicating the feature of the received pulse wave, the jamming device search means selects the deceptive jammer that corresponds to the feature data. Identifies the source of fraud interference.
According to the second embodiment, in addition to the same effects as those of the first embodiment, there is an effect that the transmission source of the fraud interference wave can be specified.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 Transmitter (pulse wave transmission / reception means), 2 Transmission / reception switcher (pulse wave transmission / reception means), 3 Antenna (pulse wave transmission / reception means), 4 Radar receiver, 5 IF converter (pulse wave transmission / reception means), 6 1st Received signal detector (pulse received wave detecting means), 7 intermediate frequency amplifier, 8 detector, 9 pulse compressor, 10 A / D converter, 11 second received signal detector (pulse waveform detecting means), 12 high speed A / D converter (analog / digital converter), 13 memory, 14 first reflected wave extractor (received wave identifying means), 15 second reflected wave extractor (received wave identifying means), 16 signal processor , 17 Measurement processor (measuring means), 101 transmitter, 102 transmission / reception switch, 103 antenna, 104 IF converter, 105 intermediate frequency amplifier, 106 detector, 107 pulse compressor, 108 A D converter, 109 a signal processor.

Claims (7)

While the pulse transmission wave is radiated to the space, the pulse reception wave received by the pulse wave transmission / reception means for receiving the pulse reception wave, which is a reflected wave reflected by the target and returning, Sampling using an analog / digital converter whose sampling rate is higher than the pulse frequency of the pulse transmission wave radiated into the space from the pulse wave transmission / reception means, and detecting the pulse waveform of the pulse reception wave; and The rise rate of the pulse reception wave is specified from the pulse waveform detected by the pulse waveform detection means, and the rate of decrease in amplitude from the maximum amplitude in a portion excluding the rising portion, falling portion and overshoot portion of the pulse waveform identify droop of the pulse received wave is, rising of the pulse received wave If the time is longer than the rise time of the pulse transmitting wave, the pulse receiving wave is identified as a reflected wave of the target, when the rise time of the pulse receiving wave is not longer than the rise time of the pulse transmission wave, A radar receiver comprising: received wave identifying means for identifying that the pulse received wave is a fraudulent interference wave if the pulse received wave droop is larger than the pulse transmitted wave droop . The received wave identification means, when the rise time of the pulse reception wave is not longer than the rise time of the pulse transmission wave, and if the droop of the pulse reception wave is smaller than the droop of the pulse transmission wave, When the cross-correlation processing of the rising portion in the pulse transmission wave is performed and the correlation indicating the processing result of the cross-correlation processing is greater than a preset threshold, the pulse reception wave is a reflected wave of the target identifying, if the correlation degree is smaller than the threshold, the radar receiver according to claim 1, wherein said pulse receiving wave is identified as the deception disturbance. Detecting a pulse reception wave received by the pulse wave transmission / reception means, compressing a pulse waveform indicated by the detection result to increase a pulse amplitude, and providing a pulse reception wave detection means for outputting a pulse waveform after amplitude amplification;
The received wave identifying means outputs the pulse waveform output from the pulse received wave detecting means to the target measuring means in the pulse radar device when the pulse received wave is identified as a reflected wave of the target. The radar receiver according to claim 1 or 2, wherein The received wave identifying means identifies the received pulse wave as a reflected wave of the target when a plurality of overshoots occur within the rise time in the received pulse wave. The radar receiver according to any one of claims 1 to 3 . The received wave identifying means outputs the pulse waveform after amplitude amplification from the pulse received wave detecting means, but when the pulse waveform is not detected by the pulse waveform detecting means, the received pulse wave is detected as the target object. The radar receiver according to claim 3 , wherein the radar receiver is identified as a reflected wave. When there is a database that records the correspondence between the characteristic data indicating the rise, fall, or droop of deceptive jamming waves transmitted by a known jamming device and the jamming device,
Extract feature data indicating rising, falling, or droop of a pulse reception wave identified as a fraudulent interference wave by the reception wave identification means, and search the database for a disturbance device corresponding to the feature data of the pulse reception wave. radar receiver according to claim 1, characterized in that a jamming device search means for. A pulse wave transmission / reception unit that radiates a pulse transmission wave to space and receives a pulse reception wave that is a reflected wave reflected back from a target and received by the pulse wave transmission / reception unit Pulse reception wave detection means that detects the pulse reception wave, compresses the pulse waveform indicated by the detection result to increase the pulse amplitude, and outputs the pulse waveform after amplitude amplification, and is emitted from the pulse wave transmission / reception means to the space. A pulse waveform for detecting a pulse waveform of the pulse reception wave by sampling the pulse reception wave received by the pulse wave transmitting / receiving means using an analog / digital converter having a sampling rate higher than the pulse frequency of the pulse transmission wave. specific detection means, the rise time from the detected pulse waveform of the pulse received wave by the pulse waveform detecting means Rutotomoni, rising portion of the pulse waveform, to identify the pulse of the received wave loop is a reduction ratio of the amplitude of the maximum amplitude in the portion excluding the falling portion and overshoot, rise time of the pulse received wave When the pulse transmission wave is longer than the rise time of the pulse transmission wave, the pulse reception wave is identified as a reflected wave of the target, and when the pulse reception wave rise time is not longer than the rise time of the pulse transmission wave, the pulse If the droop of the received wave is larger than the droop of the pulse transmitted wave, the received wave identifying means for identifying that the pulse received wave is a fraudulent interference wave, and the received wave identifying means reflects the pulse received wave on the target object. If it is identified as a wave, the pulse received wave detection means based on the pulse waveform output from the pulse wave detection means Pulse radar apparatus provided with a measuring means for measuring the azimuth of the distance and the target to target material.

Images