JP5160022B2 - Pulse radar equipment - Google Patents

Description

In the present invention, when the relative speed between the pulse radar device and the target is not 0, the relative speed measurement mode, the relative speed correction, and the composite band processing are performed only in the composite band mode without using the relative speed measurement mode. The present invention relates to a pulse radar device that performs high-resolution relative distance measurement with respect to a target.
In particular, it is necessary to improve the accuracy of relative speed correction and obtain a high-resolution relative distance from the target by one synthesis band processing by performing relative speed measurement and synthesis band processing using the same data. The present invention relates to a pulse radar device that can shorten the time for observing received signals.

  In the conventional pulse radar apparatus, when the relative speed between the pulse radar apparatus and the target is not 0, a relative speed measurement mode for performing relative speed measurement with the target and a synthetic band mode for performing synthetic band processing are provided. Relative speed correction is performed on the signal in the combined band mode using the relative speed with the target measured in the relative speed measurement mode (see, for example, Patent Document 1).

  Note that there is Non-Patent Document 1 as a prior art document relating to the synthesis band processing.

Japanese Patent Laid-Open No. 11-231047 “High-Resolution Radar” by Donald R. Wehner, Second Edition, Arttech House, Chapter 5, 197-237

  Synthetic band processing is described in the above-mentioned document, but will be briefly described here in order to clarify the problem to be solved by the invention.

In a pulse radar device that obtains a high-resolution relative distance by using synthetic band processing, as shown in FIG. 13, during transmission, the transmission frequency is changed from f ₀ to f _N−1 for each pulse with respect to N transmission pulses St. Until the frequency step interval Δf. The transmission signal S _n (t) at that time is expressed by Equation 1. However, here, each signal is expressed as a complex signal in order to simplify the expression by the mathematical expression.

Where A is the amplitude of the transmission signal, φ _n is the initial phase of each transmission frequency, T _p is the pulse width, and T _pri is the pulse repetition period. The transmission signal S _n (t) represented by Equation 1 is located at a distance R away from the pulse radar device, and is reflected by the target having a relative velocity of 0 between the pulse radar device and the target. When received, the received signal U _n (t) is expressed by Equation 2.

However, A 'represents the amplitude of the received signal, and c represents the speed of light. With respect to the received signal U _n (t) represented by Expression 2, the frequency is determined using the local transmission signal W _n (t) having the same frequency and the same initial phase as the transmission signal S _n (t) represented by Expression 3. A complex video signal V _n (t) generated by down-conversion is expressed by Equation 4. Here, B represents the amplitude of the locally transmitted signal, and A ″ represents the amplitude of the complex video signal.

  From Equation 4, the complex digital video signal V (n) for the n (n = 0, 1,... N−1) th transmission pulse sampled with the same range bin number is expressed by Equation 5. However, the quantization error is ignored.

When the inverse Fourier transform is performed on the complex digital video represented by Expression 5, the signal P _v (k) after the inverse Fourier transform is represented by Expression 6.

From Equation 6, it can be seen that the amplitude value (intensity) obtained as the absolute value of P _v (k) becomes the peak value when Equation 7 holds.

If P _v of k amplitude value reaches a peak value of (k) and _{k p,} determine the _{k p} by detecting the peak of the _P v (k), the equation 8 with _{k p} thus determined pulse radar The relative distance R between the device and the target can be determined.

  In addition, the distance resolution ΔR is expressed by Equation 9, and it can be seen that by increasing N or Δf, the distance resolution ΔR decreases and a high resolution relative distance can be obtained.

However, when the pulse radar apparatus is moving or the target is moving, a relative speed is generated between the pulse radar apparatus and the target, and the received signal is affected by the relative speed. For example, the rising time of the transmission pulse of frequency f ₀ is set as the reference time, the relative distance between the pulse radar device 40 and the target 10 at that time is set as R ₀ , the pulse radar device is stationary, the target is at a constant velocity v and the linear motion is constant. If the transmission signal S _n (t) represented by Equation 1 is reflected by the target and received by the pulse radar device, the received signal is U ′ _n (t). Is represented by Equation 10.

For the received signal U ′ _n (t) when the relative velocity between the pulse radar device represented by equation 10 and the target is v, the same frequency and the same initial phase as the transmission signal S _n (t) represented by equation 3 The complex video signal V ′ _n (t) when the relative velocity between the pulse radar device and the target generated by down-converting the frequency using the local transmission signal W _n (t) having the frequency v is expressed by Equation 11 Is done. However, the amplitude of the complex video signal is A ″ as in the case of Equation 4.

  From Equation 11, the complex digital video signal V when the relative velocity between the pulse radar device and the target for the n (n = 0, 1,... N−1) th transmission pulse sampled with the same range bin number is v. ′ (N) is represented by Expression 12. However, the quantization error is ignored.

Therefore, when the inverse Fourier transform is performed on the complex digital video signal V ′ (n) in the case where the relative velocity between the pulse radar device represented by Expression 12 and the target is v, the signal P after the inverse Fourier transform is obtained. _{V ′} (k) is expressed by Equation 13.

From Equation 13, it can be seen that the amplitude value obtained as the absolute value of P _{V ′} (k) becomes the peak value when Equation 14 holds.

However, unlike the equation 7, when the relative velocity v between the pulse radar device and the target is not 0, exp (j2π (k / N-Δf (2R ₀ / c) + f ₀ (2v / c) T _pri + Δf (2v / c) nT _pri ) n) where the amplitude value k takes the maximum value, and the relative distance between the pulse radar device at the reference time and the target as shown in Equation 15 It can be seen that the distance deviated from _R0 is the peak. However, k _p2 (n) is exp (j2π (k / N-Δf (2R ₀ / c) + f ₀ (2v / c) T _pri + Δf (2v / c) nT _pri )) for each n. The value of k where the amplitude value of n) takes the maximum value is shown.

That is, as shown in FIG. 14, when the relative velocity v between the pulse radar apparatus and the target is not 0, the relative distance between the pulse radar apparatus and the target obtained by the high-bandwidth resolution by the synthesis band processing is the reference distance. A distance different from the relative distance R ₀ between the pulse radar device at the time and the target is shown. In FIG. 14, Srp represents a reflected signal from the target 10 when the relative speed v with respect to the target is 0, and Srp ′ represents a reflected signal from the target 10 when the relative speed v with respect to the target is not 0.

In the complex digital video signal when the relative velocity between the pulse radar apparatus and the target shown in Equation 12 is v, the values of Δf, f ₀ , T _pri , and N are known because they are transmission parameters. Therefore, in order to obtain the relative distance R ₀ between the pulse radar device having the true reference time and the target by the synthesis band processing, the relative speed with the target is measured by some method, and the relative speed expressed by Expression 16 is used. The speed correction amount Z (n) is obtained, and the relative speed may be corrected for the complex digital video signal V ′ (n) when the relative speed with respect to the target is v as shown in Expression 17.

Here, v _cal represents the relative speed with the measured target, and V _c (n) represents the complex digital video signal after the relative speed correction.

In Expression 17, if the relative speed v with the true target is equal to the relative speed V _cal with the measured target, the complex digital video signal V _c (n) after the relative speed correction expressed by Expression 17 is expressed by Expression 5. This is the same as the complex digital video V (n) when the relative speed to the target shown is zero. Therefore, by performing inverse Fourier transform on the complex digital video signal V _c (n) after the relative speed correction, the relative distance R ₀ between the pulse radar device at the reference time and the target can be obtained as described above. .

In the conventional pulse radar apparatus, a relative speed measurement mode and a composite band mode are provided, and the relative speed with respect to the target measured in the relative speed measurement mode is set as v _cal , and the relative speed correction amount Z (n ), A complex digital video signal V _c (n) after relative velocity correction is obtained, and a pulse radar device at a reference time is obtained by performing inverse Fourier transform on the obtained complex digital video signal V _c (n) after relative velocity correction. And a relative distance R ₀ between the target and the target.

In the conventional pulse radar apparatus, when the relative speed between the pulse radar apparatus and the target is not 0, the relative speed with the target and the high resolution relative distance measurement result when the high resolution relative distance is obtained by the synthesis band processing is obtained. The obtained timing is shown in FIG. In addition, a transmission pulse St and a reception pulse Sr at that time are also shown. In addition, since the pulse repetition period and the pulse width are not necessarily the same in the relative speed measurement mode and the composite band mode, the pulse repetition period and the pulse width in the relative speed measurement mode are set to T _pri1 , T _p1 , and the composite band mode. _These pulse repetition periods and pulse widths are T _pri2 and T _p2 .

In the conventional pulse radar device, first, as a relative velocity measurement mode, transmission is performed with respect to M pulses at the same transmission frequency for each pulse, for example, f ₀ , and then, as a synthesis band mode, a transmission frequency is set for each pulse. N pulses that change by a frequency interval Δf from f ₀ to f _N−1 are transmitted. Thereafter, the set of (M + N) pulses is repeatedly transmitted.

For the relative speed measurement with the target, the received signal of the same range bin number for the transmission pulse of M frequencies f ₀ in the relative speed measurement mode obtained every time of the pulse repetition period T _pri1 , the range bin number 3 in the example of FIG. The relative speed with respect to the target is measured by performing frequency analysis using.

On the other hand, in the synthesis band processing, the same range bin number for the N transmission pulses of the frequencies f ₀ , f ₁ ,..., F _N−1 in the synthesis band mode obtained every time of the pulse repetition period T _pri2 , In the example of 12, the received signal of the range bin number 3 is subjected to the relative speed correction using the relative speed with the latest target measured in the relative speed measurement mode, and then the phase synthesis process is performed to obtain a high resolution up to the target. Get the relative distance measurement result.

The principle of measuring the relative speed with the target in the conventional pulse radar apparatus will be described below. In conventional pulse radar apparatus, to measure the relative velocity of the target, as shown in FIG. 15 at the time of transmission, to the M transmit pulse St, the same transmission frequency from pulse to pulse, for example, the f ₀ is used. The transmission signal S ″ _n (t) at that time is expressed by Expression 18. However, in order to simplify the expression by the mathematical expression, each signal is expressed by a complex signal as in Expression 1. Further, the pulse repetition period and the pulse width are represented by T _pri and T _p with 1 omitted.

However, the amplitude of the transmission signal is A as in Equation 1. Φ ″ _m represents the initial phase of each transmission frequency.

The transmission signal S ″ _n (t) expressed by Equation 18 is reflected from the pulse radar device to a target that is moving at a constant linear velocity with a relative distance R ₀ at a relative distance R _{0 at the} reference time, and is transmitted to the pulse radar device. When received, the received signal U ″ _m (t) is expressed by Equation 19.

For the received signal U ″ _m (t) represented by Expression 19, a local transmission signal W ″ _m (t) having the same frequency and the same initial phase as the transmission signal S ″ _m (t) represented by Expression 20 is used. The complex video signal V ″ _m (t) generated by down-converting the frequency is expressed by Equation 21.

  However, as in Equations 3 and 4, B indicates the amplitude of the local transmission signal, and A ″ indicates the amplitude of the complex video signal. From Equation 21, m (m = 0, 1,...) Sampled with the same range bin number. The complex digital video signal V ″ (m) for the M−1) th transmission pulse is expressed by Equation 22. However, the quantization error is ignored.

Therefore, when the Fourier transform is performed on the complex digital video signal V ″ (m) represented by Expression 22, the signal P _{V ″} (k) after the Fourier transform is represented by Expression 23.

From Equation 23, it can be seen that the amplitude value of P _{V ″} (k) becomes the peak value when Equation 24 holds.

The P V _"k amplitude value reaches a peak value of _(k) When k _p3, from the formula 25 using k _p3, it is possible to obtain the relative velocity v of the pulse radar apparatus and the target.

Therefore, in the conventional pulse radar device, as shown in FIG. 12, first, as a relative speed measurement mode, M pulses are transmitted at the same transmission frequency, for example, f ₀ for each pulse, and then synthesized. As a band mode, N pulses whose transmission frequency changes by a frequency interval Δf from f ₀ to f _N−1 are transmitted for each pulse. Thereafter, the set of (M + N) pulses is repeatedly transmitted.

For the relative speed measurement with the target, the received signal of the same range bin number for the transmission pulse of M frequencies f ₀ in the relative speed measurement mode obtained every time of the pulse repetition period T _pri1 , the range bin number 3 in the example of FIG. Find using.

On the other hand, in the synthesis band processing, the same range bin number for the N transmission pulses of the frequencies f ₀ , f ₁ ,..., F _N−1 in the synthesis band mode obtained every time of the pulse repetition period T _pri2 , In the example of 12, the received signal of range bin number 3 is used. In order to obtain a true high-resolution relative distance, after performing relative speed correction using the relative speed with the latest target obtained in the relative speed measurement mode, synthetic band processing is performed.

Therefore, in order to obtain one high-resolution relative distance measurement result, a signal transmission time of at least M times the pulse repetition period T _{pri1 in} the relative velocity measurement mode and N times the pulse repetition period T _{pri2 in} the combined band mode is set. There was a problem of need.

  Furthermore, since the received signal used for the relative speed measurement with the target and the combined band process are different, there is a problem that the accuracy of the relative speed correction deteriorates for the target having a large relative speed change.

  The present invention has been made to solve the above-described problems, and its purpose is to obtain a single high-resolution relative distance measurement result when the relative speed is not zero between the pulse radar device and the target. It is possible to obtain a pulse radar device that can shorten the signal transmission time interval necessary for obtaining the signal and can increase the accuracy of relative speed correction even for a target having a large relative speed change.

  The pulse radar device according to the present invention repeatedly transmits a plurality of pulses whose transmission frequency changes by a predetermined frequency interval for each pulse in a target direction, receives a reflection signal obtained at each pulse repetition period, and receives an I component, And a pulse radar apparatus for generating a Q component video signal, a complex video signal having an I component video signal of the same range bin number obtained from a received signal with respect to a transmission pulse as a real part and a Q component video signal as an imaginary part, and A complex conjugate video signal is generated by inverting the sign of the imaginary part of the complex video signal, and the complex video signal and the complex conjugate video signal are shifted by an optimum shift amount and multiplied to generate a complex signal for relative speed measurement. Complex conjugate multiplying means, frequency spectrum analyzing means for obtaining a frequency spectrum of the complex signal for relative velocity measurement, and the frequency spectrum. Is provided with a relative velocity measurement means for determining the relative velocity of the target from the vector.

  The pulse radar apparatus according to the present invention can shorten the signal transmission time interval necessary for obtaining a single high-resolution relative distance measurement result, and can perform relative speed correction even for a target having a large relative speed change. There is an effect that the accuracy can be increased.

Embodiment 1 FIG.
A pulse radar apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing a configuration of a pulse radar apparatus according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.

  In FIG. 1, the pulse radar device according to the first embodiment includes a timing generator 1, a frequency synthesizer 2, distributors 3a and 3b, a reference intermediate frequency signal generator 4, and frequency converters 5a and 5b. A pulse modulator 6, a power amplifier 7, a transmission / reception switch 8, and an antenna 9 are provided.

  Further, the intermediate frequency amplifier 11, the 90-degree hybrid 12, the phase detectors 13a and 13b, the A / D converters 14a and 14b, the video signal storage memory 15, and the shift complex conjugate multiplier (complex conjugate multiplication). Means) 16, a frequency spectrum analyzer (frequency spectrum analyzing means) 17, a relative speed measuring instrument (relative speed measuring means) 18, a relative speed corrector (relative speed correcting means) 19, and a composite bander (synthetic band). Means) 20, an envelope detector 21 and a display 22 are provided.

  Next, the operation of the pulse radar device according to the first embodiment will be described with reference to the drawings.

The timing generator 1 outputs a frequency switching signal to the frequency synthesizer 2, a pulse modulation signal to the pulse modulator 6, and a transmission / reception switching signal to the transmission / reception switching device 8 at intervals of the pulse repetition period T _pri . In the frequency synthesizer 2, one of the N types of signals whose frequency and initial phase are determined in advance in ascending order from the lowest frequency or in descending order from the highest frequency by the frequency switching signal from the timing generator 1. It generates every pulse repetition period T _pri and outputs it to the distributor 3a.

In the distributor 3a, the input signal from the frequency synthesizer 2 is divided into two, one is used as a local oscillation signal of the frequency converter 5a for transmission signal generation, and the other is converted to the frequency converter 5a, and the other is converted to frequency conversion for intermediate frequency signal generation. It outputs to the frequency converter 5b as a local oscillation signal of the converter 5b. The frequency converter 5a generates a transmission carrier signal having a frequency that is the sum of the frequency of the local oscillation signal from the distributor 3a and the frequency of the reference intermediate frequency signal generated by the reference intermediate frequency signal generator 4, and a pulse modulator. 6 is output. The pulse modulator 6 performs pulse modulation with a predetermined pulse width T _p for each pulse repetition period T _{pri on} the input signal from the frequency converter 5 a by the pulse modulation signal from the timing generator 1.

The output signal of the pulse modulator 6 is input to the power amplifier 7, the power is amplified, and is output to the transmission / reception switch 8. The transmission / reception switch 8 outputs an input signal from the power amplifier 7 at a predetermined time interval to the antenna 9 for each pulse repetition period T _pri by the transmission / reception switching signal from the timing generator 1. The antenna 9 radiates the input signal from the transmission / reception switch 8 to space as a transmission signal.

The transmission signal is reflected on the target 10 and the background, is received by the antenna 9 as a reflected signal, and is output to the transmission / reception switch 8. The transmission / reception switch 8 outputs an input signal from the antenna 9 at a predetermined time interval to the frequency converter 5b for each pulse repetition period T _pri by the transmission / reception switching signal from the timing generator 1.

  Further, a local oscillation signal is also input from the distributor 3a to the frequency converter 5b. In the frequency converter 5 b, an intermediate frequency signal having a difference between the frequency of the received signal and the local oscillation signal is generated and output to the intermediate frequency amplifier 11. The intermediate frequency amplifier 11 amplifies the power of the intermediate frequency signal and outputs the result to the distributor 3b. The distributor 3b divides the input signal from the intermediate frequency amplifier 11 into two and outputs them to the phase detectors 13a and 13b.

On the other hand, the reference intermediate frequency signal generated by the reference intermediate frequency signal generator 4 is separated into two signals having a phase difference of 90 degrees by the 90 degree hybrid unit 12, and is output to the phase detectors 13a and 13b. The phase detectors 13a and 13b have a frequency that is the difference between the frequency of the intermediate frequency signal and the reference intermediate frequency signal from the input signal from the distributor 3b and the input signal from the 90-degree hybrid 12, and are 90 degrees from each other. A video signal of I component and Q component having a phase difference is generated. The generated I and Q video signals are input to A / D converters 14a and 14b having a sampling frequency of 1 / T _p and converted into digital I and Q video signals for each range bin having the same interval as the pulse width T _p. And output to the video signal storage memory 15.

The video signal storage memory 15 stores the digital I and Q video signals of all the range bin numbers in a time interval N times the pulse repetition period T _pri .

  The shift complex conjugate multiplier 16 takes out digital I and Q video signals of the same range bin number obtained from the received signals corresponding to N transmission pulses having different frequencies from the video signal storage memory 15, and converts the digital I video signal into a real part. A complex digital video signal in which the digital Q video signal is an imaginary part and a complex conjugate digital video signal in which the sign of the imaginary part of the generated complex digital video signal is inverted is generated, and the complex digital video signal and the complex conjugate digital video are generated. The signal is shifted by an integer amount α having a value of 1 or more and less than N, and multiplication is performed to generate N-α sets of digital I and Q signals for relative speed measurement. The generated N-α sets of complex digital signals for measuring relative velocity are output to the frequency spectrum analyzer 17.

FIG. 2 shows the processing contents in the shift complex conjugate multiplier 16 when α is 1. In FIG. 2, V ′ (n) (n = 0, 1,..., N−1) is a complex digital video signal, and V ′ ^* (n) (n = 0, 1,..., N−1) is , X (n ′) (n ′ = 0, 1,..., N−2) represents a complex digital signal for relative speed measurement.

  When the processing shown in FIG. 2 is performed on the complex digital video signal V ′ (n) when the relative velocity between the pulse radar device and the target shown in Equation 12 is v, the output signal is a relative velocity measurement signal. The complex digital signal X (n ′) is expressed by Equation 26.

  However, * shows a complex conjugate. Further, since the number N ′ of the complex digital signal X (n ′) for relative speed measurement is shifted by α, the following equation is obtained.

When the frequency spectrum analysis is performed on the video signal X (n ′) for relative velocity measurement represented by Expression 26, the first term exp (−j2πf ₀ (2v / c) αT _pri ) and the second term exp (-j2παΔf (-2R ₀ / c)) and the third term exp (-j2πα ² Δf (2v / c) T _pri ) are terms that are not related to the variable n ′. It does not affect. On the other hand, the fourth term exp (−j2π2αΔf (2v / c) n′T _pri ) represents a Doppler frequency for a signal having a transmission carrier frequency of 2αΔf.

When inverse Fourier transform is used as the frequency spectrum analysis method, a signal obtained by inverse Fourier transform at the N ′ point with respect to the video signal X (n ′) for relative velocity measurement represented by Equation 26, that is, a complex digital for relative velocity measurement. The frequency spectrum P _X (k ′) of the signal is expressed by Equation 28.

  In the frequency spectrum analyzer 17, the frequency spectrum of the complex digital signal for relative speed measurement from the shift complex conjugate multiplier 16 is obtained using the inverse Fourier transform as described above, and the result is output to the relative speed meter 18. To do.

From Equation 28, it can be seen that the amplitude value (intensity) obtained as the absolute value of P _X (k ′) becomes the peak value when Equation 29 holds.

If the value of k ′ at which the amplitude value of P _X (k ′) takes the maximum value is k _p4 , the relative velocity v between the pulse radar device and the target can be obtained from Equation 30 by obtaining k _p4. .

  In the relative velocity measuring instrument 18, as described above, the relative velocity with respect to the target is obtained by detecting the peak signal of the amplitude value of the frequency spectrum of the complex digital signal for measuring the relative velocity from the frequency spectrum analyzer 17, and the result thereof. Is output to the relative speed corrector 19.

The relative speed corrector 19 _{obtains the} relative speed correction amount Z (n) expressed by Expression 16 using the relative speed with the target obtained by the relative speed measuring instrument 18 as v _cal , and measures the relative speed with the target. The digital I and Q video signals having the same range bin number obtained from the received signals for the same N sets of different transmission pulses used in the shift complex conjugate multiplier 16 are extracted from the video signal storage memory 15 and the digital I video signal is obtained. For the complex digital video signal having the real part and the digital Q video signal as the imaginary part, the relative speed correction shown in Expression 17 is performed to obtain the complex digital video signal after the relative speed correction, The digital video signal is output to the synthesis bander 20.

In the combining zone 20, by inverse Fourier transform of the relative velocity corrected complex digital video signal inputted from the relative velocity corrector 19 performs synthesis of band complex signal having a pulse width T _p following distance resolution ΔR And outputs the result to the envelope detector 21. The envelope detector 21 obtains the amplitude values of all complex signals input from the synthesis bander 20 and outputs them to the display unit 22 as a result of high distance resolution relative distance measurement by synthesis band processing. The display 22 displays the input signal from the envelope detector 21.

  FIG. 3 shows the relative speed and the high resolution with respect to the target when a high resolution relative distance is obtained by the synthesis band processing when there is a relative speed between the target and the radar apparatus in the pulse radar device according to the first embodiment. The timing at which the relative distance measurement result is obtained is shown. In addition, a transmission pulse St and a reception pulse Sr at that time are also shown.

As shown in FIG. 3, the pulse radar device according to the first embodiment repeatedly transmits N pulses whose transmission frequency changes by a frequency interval Δf from f ₀ to f _{N−1 for} each pulse.

In the relative velocity measurement process, the same range bin number for N transmission pulses of the frequencies f ₀ , f ₁ ,..., F _N−1 in the composite band mode obtained every time of the pulse repetition period T _pri , FIG. In the example, the received signal of range bin number 3 is used. Also, in the synthesis band process, the same received signal used for the relative speed measurement with the target is subjected to the relative speed correction using the relative speed with the target obtained in the relative speed measurement process, and then the synthesis band process is performed. Do.

In other words, the pulse radar device according to the first embodiment repeatedly transmits N (an integer greater than or equal to 2) pulses having a transmission frequency of f ₀ to f _N−1 by a frequency interval Δf for each pulse in the target direction. An integer value having a value of 1 or more and less than N for a complex video signal having the same range bin number and its complex conjugate signal for f ₀ to f _N−1 transmission pulses obtained at each pulse repetition period. Shift complex conjugate multiplier 16 that performs multiplication by shifting by α, frequency spectrum analyzer 17 that obtains the frequency spectrum of the signal obtained by complex conjugate multiplication, and relative velocity that obtains the relative velocity with respect to the target from the obtained frequency spectrum. Using the relative speed between the measuring instrument 18 and the obtained target, the relative speed correction is performed on the same video signal used for the relative speed measurement with the target. And the Hare relative velocity corrector 19, those having a composite band 20 or the like for combining band processing to the video signal subjected to the relative velocity correction.

Therefore, the relative speed with respect to the target can be obtained every time interval N times the pulse repetition period T _pri without providing the relative speed measurement mode shown in the conventional pulse radar device for _obtaining the relative speed with the target. By performing the relative band correction on the same received signal used for the relative speed measurement with the target using the relative speed with the obtained target, and performing the composite band process, N of the pulse repetition period T _pri One high-resolution relative distance measurement result can be obtained with double signal transmission time.

Embodiment 2. FIG.
A pulse radar apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a diagram showing a configuration of the pulse radar apparatus according to Embodiment 2 of the present invention.

  4, the pulse radar apparatus according to the second embodiment includes a multiple shift complex conjugate multiplier (complex conjugate multiplication means) 23, a multiple frequency spectrum analyzer (frequency spectrum analysis means) 24, and a plurality of relative velocity measuring instruments. A (relative speed measuring means) 25 and a relative speed averager (relative speed average means) 26 are provided. Others are the same as those in the first embodiment.

  Next, the operation of the pulse radar device according to the second embodiment will be described with reference to the drawings.

  In FIG. 4, the operations up to the video signal storage memory 15 are the same as those in the first embodiment.

  The multi-shift complex conjugate multiplier 23 extracts the digital I and Q video signals having the same range bin number obtained from the received signals for the N transmission pulses having different frequencies from the video signal storage memory 15 and executes the digital I video signals. A complex digital video signal in which the digital Q video signal is an imaginary part and a complex conjugate digital video signal in which the sign of the imaginary part of the generated complex digital video signal is inverted is generated, and the complex digital video signal and the complex conjugate digital are generated. The video signal is shifted by a plurality of different integer values α having a value of 1 or more and less than N, and multiplication is performed to generate a plurality of N-α sets of digital I and Q signals for relative speed measurement. The generated plurality of N-α sets of complex digital signals for measuring relative velocity are output to the multi-frequency spectrum analyzer 24.

  In the multiple frequency spectrum analyzer 24, the frequency of the plurality of relative velocity measurement complex digital signals is obtained by performing inverse Fourier transform on each of the plurality of N−α sets of complex velocity measurement complex digital signals from the multiple shift complex conjugate multiplier 23. The spectrum is obtained and the result is output to the multiple relative velocity measuring device 25.

  The plurality of relative velocity measuring devices 25 obtains a plurality of relative velocities with respect to the target by detecting the peak signals of the amplitude values of the frequency spectra of the plurality of complex digital signals for measuring the relative velocity, and the results are used as the relative velocity averager 26. Output to. In the relative speed averager 26, the average of a plurality of relative speeds with the target input from the plurality of relative speed measuring devices 25 is obtained and the result is output to the relative speed corrector 19.

  The operations after the relative speed corrector 19 are the same as those in the first embodiment.

That is, the pulse radar device according to the second embodiment repeatedly transmits N (integer greater than or equal to 2) pulses whose transmission frequency changes by a frequency interval Δf from f ₀ to f _{N−1 for} each pulse in the target direction. A pulse radar apparatus that performs a complex video signal having the same range bin number and a complex conjugate signal with respect to a transmission pulse of f ₀ to f _N−1 obtained at each pulse repetition period with a plurality of different values of 1 or more and less than N. A multi-shift complex conjugate multiplier 23 that performs multiplication by shifting the integer value α; a multi-frequency spectrum analyzer 24 that obtains each frequency spectrum of a signal obtained by complex conjugate multiplication of a plurality of N-α sets; A plurality of relative speed measuring devices 25 for obtaining a plurality of relative speeds with a target from a plurality of frequency spectra, and a relative speed for averaging the plurality of relative speeds with the obtained target. A relative speed corrector 19 that performs relative speed correction on the same video signal used for measuring the relative speed with respect to the target using the average relative speed between the degree averager 26 and the obtained target, and relative speed correction are performed. And a synthesis bander 20 for performing synthesis band processing on the video signal.

Therefore, the relative speed with respect to the target can be obtained every time interval N times the pulse repetition period T _pri without providing the relative speed measurement mode shown in the conventional pulse radar device for _obtaining the relative speed with the target. By performing the relative band correction on the same received signal used for the relative speed measurement with the target using the relative speed with the obtained target, and performing the composite band process, N of the pulse repetition period T _pri A single high-resolution relative distance measurement result can be obtained in double signal transmission time, and relative speed measurement with a target with high measurement accuracy can be performed.

Embodiment 3 FIG.
A pulse radar apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing the configuration of the pulse radar apparatus according to Embodiment 3 of the present invention.

  In FIG. 5, the pulse radar device according to the third embodiment is provided with a frequency spectrum adder (frequency spectrum adding means) 27. Others are the same as in the first or second embodiment.

  Next, the operation of the pulse radar device according to the third embodiment will be described with reference to the drawings.

  In FIG. 5, the operations up to the multiple frequency spectrum analyzer 24 are the same as those in the second embodiment.

  The frequency spectrum adder 27 adds the frequency spectra of the plurality of relative velocity measurement complex digital signals from the plurality of frequency spectrum analyzers 24 for the same frequency bin, and outputs the result to the relative velocity measurement device 18.

  The operations after the relative velocity measuring instrument 18 are the same as those in the first embodiment.

That is, the pulse radar device according to the third embodiment repeatedly transmits N (an integer of 2 or more) pulses whose transmission frequency changes by a frequency interval Δf from f ₀ to f _{N−1 for} each pulse in the target direction. A pulse radar apparatus that performs a complex video signal having the same range bin number and a complex conjugate signal with respect to a transmission pulse of f ₀ to f _N−1 obtained at each pulse repetition period with a plurality of different values of 1 or more and less than N. A multi-shift complex conjugate multiplier 23 that performs multiplication by shifting the integer value α; a multi-frequency spectrum analyzer 24 that obtains each frequency spectrum of a signal obtained by complex conjugate multiplication of a plurality of N-α sets; A frequency spectrum adder 27 that adds a plurality of frequency spectra for each frequency bin, and adds the obtained frequency spectra for each frequency bin. Based on the obtained frequency spectrum, the relative velocity measuring device 18 for obtaining the relative velocity with respect to the target and the relative velocity with respect to the obtained target are used to perform relative velocity correction on the same video signal used for measuring the relative velocity with respect to the target. A relative speed corrector 19 and a composite bander 20 for performing a composite band process on the video signal subjected to the relative speed correction are provided.

Therefore, the relative speed with respect to the target can be obtained every time interval N times the pulse repetition period T _pri without providing the relative speed measurement mode shown in the conventional pulse radar device for _obtaining the relative speed with the target. By performing the relative band correction on the same received signal used for the relative speed measurement with the target using the relative speed with the obtained target, and performing the composite band process, N of the pulse repetition period T _pri A single high-resolution relative distance measurement result can be obtained in double signal transmission time, and the target reflected signal-to-noise power ratio at the time of measuring the relative speed with the target can be increased equivalently. In addition, although the case where it applied to the said Embodiment 1 was demonstrated, it is applicable also to the said Embodiment 2. FIG. That is, in FIG. 4, a frequency spectrum adder 27 is provided after the multiple frequency spectrum analyzer 24.

Embodiment 4 FIG.
A pulse radar apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing the configuration of the pulse radar apparatus according to Embodiment 4 of the present invention.

  In FIG. 6, the pulse radar device according to the fourth embodiment is provided with an optimum shift amount selector (optimum shift amount selection means) 28. Others are the same as those in the first embodiment.

  Next, the operation of the pulse radar device according to the fourth embodiment will be described with reference to the drawings.

  In FIG. 6, the operations up to the video signal storage memory 15 are the same as those in the first embodiment.

  The shift complex conjugate multiplier 16 takes out digital I and Q video signals of the same range bin number obtained from the received signals corresponding to N transmission pulses having different frequencies from the video signal storage memory 15, and converts the digital I video signal into a real part. A complex digital video signal in which the digital Q video signal is an imaginary part and a complex conjugate digital video signal in which the sign of the imaginary part of the generated complex digital video signal is inverted is generated, and the complex digital video signal and the complex conjugate digital video are generated. The signal is shifted by an integer amount α having a value of 1 or more and less than N, and multiplication is performed to generate N-α sets of digital I and Q signals for relative speed measurement. The generated N-α sets of complex digital signals for measuring relative velocity are output to the frequency spectrum analyzer 17.

  The frequency spectrum analyzer 17 obtains the frequency spectrum of the complex digital signal for relative velocity measurement from the shift complex conjugate multiplier 16 using inverse Fourier transform, and outputs the result to the relative velocity meter 18. In the relative velocity measuring device 18, the relative velocity with respect to the target is obtained by detecting the peak signal of the amplitude value of the frequency spectrum of the complex digital signal for measuring the relative velocity from the frequency spectrum analyzer 17, and the result is obtained as a relative velocity corrector. 19 and output to the optimum shift amount selector 28.

  The optimum shift amount selector 28 selects a small shift amount α when the relative speed with respect to the target is fast, and conversely selects a large shift amount α when the relative speed with respect to the target is slow, and selects the selected shift amount. α is output to the shift complex conjugate multiplier 16. The shift complex conjugate multiplier 16 performs the above-described processing using the latest shift amount α input from the optimum shift amount selector 28, obtains a complex digital signal for relative speed measurement, and obtains the result as a frequency spectrum analyzer 17. Output to. Thereafter, this operation is repeated.

  The operations after the relative speed corrector 19 are the same as those in the first embodiment.

  That is, the pulse radar device according to the fourth embodiment obtains the optimum shift amount α from the obtained relative speed with respect to the target, and reflects the result to the shift complex conjugate multiplier 16 and the multiple shift complex conjugate multiplier 23. An optimum shift amount selector 28 and the like are provided.

Therefore, even if the relative speed measurement mode shown in the conventional radar apparatus is not provided in order to obtain the relative speed with respect to the target, the relative speed with respect to the target can be obtained every time interval N times the pulse repetition period T _pri. And the composite band processing is performed after performing the relative speed correction on the same received signal used for the relative speed measurement with the target using the obtained relative speed with the target, so that N times the pulse repetition period T _pri A high-resolution relative distance measurement result can be obtained in one signal transmission time, and it is possible to measure relative speed with a target with high efficiency and accuracy according to the target relative speed. In addition, although the case where it applied to the said Embodiment 1 was demonstrated, it is applicable also to the said Embodiment 2 and 3.

Embodiment 5 FIG.
A pulse radar apparatus according to Embodiment 5 of the present invention will be described with reference to FIGS. FIG. 7 is a diagram showing a configuration of a pulse radar apparatus according to Embodiment 5 of the present invention.

  In FIG. 7, the pulse radar device according to the fifth embodiment is provided with a frequency selector (frequency selector) 29 and a target relative speed / distance correspondence device (target relative speed / distance correspondence means) 30. Others are the same as those in the first embodiment.

  Next, the operation of the pulse radar device according to the fifth embodiment will be described with reference to the drawings.

  8 and 9 are diagrams showing the operation of the frequency selector of the pulse radar device according to Embodiment 5 of the present invention. FIG. 10 is a diagram showing the operation of the target relative speed / distance correspondence device of the pulse radar apparatus according to Embodiment 5 of the present invention.

  In FIG. 7, the operation up to the frequency spectrum analyzer 17 is the same as that in the first embodiment.

  In the frequency selector 29, the amplitude value (intensity) of each frequency component of the frequency spectrum of the complex digital signal for relative velocity measurement from the frequency spectrum analyzer 17 is obtained, and when the amplitude value is larger than a predetermined threshold, or As shown in FIG. 8, when the amplitude value is larger than the predetermined threshold and the frequency is within the predetermined frequency gate range, or exceeds the predetermined threshold as shown in FIG. When the width of the continuous frequency having the amplitude value is smaller than the predetermined frequency width, or the width of the continuous frequency having the amplitude value exceeding the predetermined threshold is smaller than the predetermined frequency width, And when those frequencies are within the range of a predetermined frequency gate, those frequency components are set to a frequency spectrum in a range including the target frequency component, and all And it outputs the frequency spectrum in the range including the target frequency components to the relative velocity meter 18.

  An example of the operation of the frequency selector 29 will be described with reference to FIGS. FIG. 8 and FIG. 9 show the amplitude value of each frequency component of the frequency spectrum of the complex digital signal for relative velocity measurement from the frequency spectrum analyzer 17, respectively. In FIG. 8, the predetermined threshold is 0.04, and the predetermined frequency gate range is 0 to 5000 Hz. Therefore, among the three frequency components FA, FB, and FC exceeding the threshold value, FA and FB are selected as a frequency spectrum in a range including the target frequency component.

In FIG. 9, the predetermined threshold is 0.04, and the predetermined frequency width is 700 Hz. Since the frequency widths W _FA , W _FB , W _FC of the three frequency components FA, FB, FC exceeding the threshold are 564 Hz, 459 Hz, 1084 Hz, respectively, FA and FB smaller than the predetermined frequency width are the target A frequency spectrum including a frequency component is selected as a frequency spectrum.

  In the relative speed measuring device 18, the relative speed with respect to each target is obtained by detecting the peak signal of the frequency spectrum in the range including the frequency components of each target from the frequency selector 29, and the result is sent to the relative speed corrector 19. Output.

The relative speed corrector 19 sequentially selects a relative speed with one target from the relative speeds with all the targets obtained by the relative speed measuring device 18, and sets the relative speed with the target as v _cal, as shown in Expression 16 And the same obtained from the received signals for the same N sets of different transmission pulses of the frequency used in the shift complex conjugate multiplier 16 for measuring the relative speed with respect to the target. The digital I and Q video signals of the range bin number are taken out from the video signal storage memory 15, and the relative speed shown by the equation 17 is applied to the complex digital video signal having the digital I video signal as a real part and the digital Q video signal as an imaginary part. And the complex digital video signal after the relative speed correction is obtained, and the obtained complex digital video signal after the relative speed correction is outputted to the synthesis bander 20.

In the combining zone 20, by inverse Fourier transform of the relative velocity corrected complex digital video signal inputted from the relative velocity corrector 19 performs synthesis of band, synthetic band to obtain a pulse width T _p following distance resolution ΔR Processing is performed and the result is output to the envelope detector 21.
The envelope detector 21 obtains the amplitude values of all complex signals input from the synthesis bander 20 and outputs them to the target relative speed / distance correspondence unit 30 as a result of high distance resolution relative distance measurement by synthesis band processing.

  The target relative speed / distance correspondence device 30 compares the amplitude value of each relative distance with a predetermined threshold value from the high distance resolution relative distance measurement result by the synthetic band processing from the envelope detector 21, When the amplitude value is larger than a predetermined threshold value, or as shown in FIG. 10, when the width of a continuous distance having an amplitude value exceeding the predetermined threshold value is smaller than the predetermined distance width, or The amplitude value (intensity) of the frequency spectrum of the complex digital signal for measuring relative velocity when the amplitude value is larger than a predetermined threshold and the relative velocity measuring unit 18 obtains the relative velocity with the target used by the relative velocity correcting unit 19. ), Or when the relative distance is the closest to the converted value, the relative distance is set as the relative distance of the target of the relative speed used in the relative speed corrector 19, and the high distance by the synthetic band processing from the envelope detector 21. The ability relative distance measurement result, by adding the relative speed of the target used in the relative velocity corrector 19, the information of the relative distance of the target of the relative speed, and outputs to the display unit 22.

An example of the operation of the target relative speed / distance correspondence unit 30 will be described with reference to FIGS. FIG. 10 shows the results of high-range resolution ranging from the envelope detector 21 by the combined band processing. In FIG. 10, the predetermined threshold is 0.02, and the predetermined distance width is 3.0 m. Since the distance widths W _RA and W _RB of the two distance components RA and RB exceeding the threshold are 1.7 m and 3.9 m, respectively, an RA smaller than the predetermined distance width is detected by the relative speed corrector 19. It is selected as the target relative distance for the relative speed used.

  Also, for example, when the relative velocity with respect to the target used by the relative velocity corrector 19 is obtained by the relative velocity measuring device 18 and the amplitude value of the frequency component is FA in FIG. In FIG. 10, among the two distance components RA and RB exceeding the threshold value in FIG. 10, the RA whose amplitude value is closest to 0.129 is the relative distance of the target relative speed used by the relative speed corrector 19. Selected as.

  The display 22 displays an output signal from the target relative speed / distance correspondence unit 30.

  When a frequency spectrum in a range including a plurality of target frequency components is selected by the frequency selector 29, the relative speed corrector 19 displays the frequency spectrum as many times as the relative speed with respect to the target obtained by the relative speed measuring device 18. The operation 22 is repeated, and the relative distances corresponding to the relative velocities with all the targets are obtained.

  That is, the pulse radar device according to the fifth embodiment includes a frequency selector 29 that selects a frequency spectrum in a range including a target frequency component from the frequency spectrum of the complex digital signal for relative speed measurement, and a relative speed with respect to the target. A target relative speed / distance correspondence device 30 or the like that performs relative distance correspondence is provided.

Accordingly, in order to obtain the relative speed with respect to the target, the relative speed with respect to the target is obtained every time interval N times the pulse repetition period T _pri without providing the relative speed measurement mode shown in the conventional pulse radar device. By performing the relative band correction on the same received signal used for the relative speed measurement with the target using the calculated relative speed with the target, and performing the synthesis band processing, the pulse repetition period T _pri A single high-resolution relative distance measurement result can be obtained in N times the signal transmission time, and it is possible to cope with a case where there are a plurality of targets. In addition, although the case where it applied to the said Embodiment 1 was demonstrated, it is applicable also to the said Embodiment 2, 3, 4.

Embodiment 6 FIG.
A pulse radar apparatus according to Embodiment 6 of the present invention will be described with reference to FIG. FIG. 11 is a diagram showing a configuration of a pulse radar apparatus according to Embodiment 6 of the present invention.

  In FIG. 11, the pulse radar apparatus according to the sixth embodiment is provided with a replica signal generator (replica signal generation means) 31, a subtracter (subtraction means) 32, and a post-subtraction video signal storage memory 33. ing. Others are the same as those of the fifth embodiment.

  Next, the operation of the pulse radar device according to the sixth embodiment will be described with reference to the drawings.

  In FIG. 11, the operations up to the target relative speed / distance correspondence device 30 are the same as those in the fifth embodiment.

  In the target relative speed / distance correspondence unit 30, the relative speed with respect to the target used in the relative speed corrector 19 and the target of the relative speed are added to the high distance resolution relative distance measurement result by the synthetic band processing from the envelope detector 21. Information on the relative speed of the target, the relative speed with respect to the target used in the relative speed corrector 19, information on the relative distance of the target of the relative speed, and the relative distance. The amplitude value of the high distance resolution relative distance measurement result by the synthetic band processing from the envelope detector 21 is output to the replica signal generator 31 as information on the target intensity of the relative speed used in the relative speed corrector 19.

  In the replica signal generator 31, the target relative speed / distance correspondence unit 30 obtains the target based on the information on the relative speed with the target used in the relative speed corrector 19 and the information on the relative distance and strength of the target of the relative speed. A replica signal of the reflected signal is generated, and the generated replica signal is output to the subtractor 32.

  In the subtracter 32, the same range bin number obtained from the received signals for the same N sets of different transmission pulses used in the shift complex conjugate multiplier 16 for measuring the relative speed with the target from the video signal storage memory 15 is used. The digital I and Q video signals are extracted, and the subtracted digital I and Q video signals are generated by subtracting the replica signal generated by the replica signal generator 31 from the extracted digital I and Q video signals. In addition to being output to the speed corrector 19, it is output to the video signal storage memory 33 after subtraction.

The relative speed corrector 19 _obtains a new relative speed correction amount Z (n) expressed by Expression 16 using the relative speed with another target obtained by the relative speed measuring device 18 as v _cal , and the subtracted digital I For the complex digital video signal after subtraction with the real part of the video signal and the digital Q video signal after subtraction as the imaginary part, the relative speed shown in Equation 17 is corrected, and a complex digital video signal after relative speed correction is newly obtained. The obtained complex digital video signal after the relative speed correction is output to the synthesis bander 20.

The operations from the synthesis bander 20 to the target relative speed / distance correspondence unit 30 are the same as those in the fifth embodiment.

  In the replica signal generator 31, the information on the relative speed with the target newly used in the relative speed corrector 19 from the target relative speed / distance correspondence unit 30 and the information on the relative distance and intensity of the target of the relative speed are used. Then, a new replica signal of the target reflection signal is generated, and the generated replica signal is output to the subtractor 32.

  In the subtracter 32, the digital I and Q video signals after the previous subtraction are taken out from the subtraction video signal storage memory 33, and are newly generated by the replica signal generator 31 from the taken out digital I and Q video signals after the subtraction. By subtracting the replica signal, new digital I and Q video signals after subtraction are generated, and the result is output to the relative speed corrector 19 and newly output to the video signal storage memory 33 after subtraction.

  The operations from the relative speed corrector 19 to the post-subtraction video signal storage memory 33 are repeated by the number of relative speeds with respect to the target detected by the relative speed measuring device 18.

  That is, in the pulse radar device according to the sixth embodiment, information on the relative speed with respect to the target used in the relative speed corrector 19 from the target relative speed / distance correspondence unit 30 and the relative distance of the target of the relative speed. From the information on the intensity and the replica signal generator 31 that generates a replica signal of the target reflected signal and the same video signal used for measuring the relative speed with the target, or after subtraction taken out from the video signal storage memory 33 after subtraction A subtracter 32 that subtracts a replica signal of the target reflection signal from the video signal, a post-subtraction video signal storage memory 33 that stores the subtraction video signal, and the like are provided.

Accordingly, in order to obtain the relative speed with respect to the target, the relative speed with respect to the target is obtained every time interval N times the pulse repetition period T _pri without providing the relative speed measurement mode shown in the conventional pulse radar device. By performing the relative band correction on the same received signal used for the relative speed measurement with the target using the calculated relative speed with the target, and performing the synthesis band processing, the pulse repetition period T _pri A single high-resolution relative distance measurement result can be obtained with a signal transmission time of N times, and even when there are multiple targets, it is possible to receive a small reception in a side lobe with a large received signal strength target. It can be avoided that the signal strength target is buried.

It is a figure which shows the structure of the pulse radar apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows operation | movement of the shift complex conjugate multiplier of the pulse radar apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows operation | movement of the pulse radar apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the pulse radar apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the pulse radar apparatus which concerns on Embodiment 3 of this invention. It is a figure which shows the structure of the pulse radar apparatus which concerns on Embodiment 4 of this invention. It is a figure which shows the structure of the pulse radar apparatus which concerns on Embodiment 5 of this invention. It is a figure which shows operation | movement of the frequency selector of the pulse radar apparatus which concerns on Embodiment 5 of this invention. It is a figure which shows operation | movement of the frequency selector of the pulse radar apparatus which concerns on Embodiment 5 of this invention. It is a figure which shows operation | movement of the target relative speed / distance correspondence device of the pulse radar apparatus which concerns on Embodiment 5 of this invention. It is a figure which shows the structure of the pulse radar apparatus concerning Embodiment 6 of this invention. It is a figure which shows operation | movement of the conventional pulse radar apparatus. It is a figure which shows operation | movement of the conventional pulse radar apparatus. It is a figure which shows operation | movement of the conventional pulse radar apparatus. It is a figure which shows operation | movement of the conventional pulse radar apparatus.

Explanation of symbols

  1 timing generator, 2 frequency synthesizer, 3a, 3b distributor, 4 reference intermediate frequency signal generator, 5a, 5b frequency converter, 6 pulse modulator, 7 power amplifier, 8 duplexer, 9 antenna, 10 target, 11 intermediate frequency amplifier, 12 90 degree hybrid, 13a, 13b phase detector, 14a, 14b A / D converter, 15 video signal storage memory, 16 shift complex conjugate multiplier, 17 frequency spectrum analyzer, 18 relative speed Measuring instrument, 19 Relative velocity corrector, 20 Synthetic band detector, 21 Envelope detector, 22 Display, 23 Multiple shift complex conjugate multiplier, 24 Multiple frequency spectrum analyzer, 25 Multiple relative velocity measuring instrument, 26 Relative velocity average 27 frequency spectrum adder 28 optimum shift amount selector 29 frequency selector 30 Target relative speed / distance correspondence unit, 31 replica signal generator, 32 subtractor, 33 memory for storing video signal after subtraction.

Claims (12)

A pulse that repeatedly transmits a plurality of pulses whose transmission frequency changes by a predetermined frequency interval for each pulse in a target direction, receives a reflection signal obtained at each pulse repetition period, and generates an I component and a Q component video signal A radar device,
A complex video signal in which the I component video signal of the same range bin number obtained from the received signal with respect to the transmission pulse is a real part, a Q component video signal is an imaginary part, and a complex conjugate video in which the sign of the imaginary part of the complex video signal is inverted Complex conjugate multiplication means for generating a signal, shifting the complex video signal and the complex conjugate video signal by an optimum shift amount and performing multiplication to generate a complex signal for relative speed measurement;
A frequency spectrum analyzing means for obtaining a frequency spectrum of the complex signal for relative velocity measurement;
A pulse radar apparatus comprising: a relative speed measuring means for obtaining a relative speed with respect to a target from the frequency spectrum. Relative speed correction means for correcting the relative speed for the I component video signal and Q component video signal of the same range bin number used for the complex conjugate multiplication, using the obtained relative speed with the target;
2. A synthesis band means for synthesizing a band using the I component video signal and the Q component video signal after the relative velocity correction, and obtaining a relative distance from the target with a predetermined resolution. The pulse radar device described. The complex conjugate multiplication means includes a complex video signal having a real part of an I component video signal having the same range bin number obtained from a received signal with respect to a transmission pulse, an imaginary part of the Q component video signal, and an imaginary part of the complex video signal. Generating a complex conjugate video signal with an inverted sign, shifting the complex video signal and the complex conjugate video signal by an optimum shift amount, and performing multiplication to generate a plurality of complex signals for measuring relative speed;
The frequency spectrum analyzing means generates a frequency spectrum of the plurality of relative velocity measurement complex signals,
The relative speed measuring means obtains a plurality of relative speeds with a target from a frequency spectrum of the plurality of relative speed measuring complex signals,
The pulse radar apparatus according to claim 2, further comprising: a relative speed averaging unit that averages the plurality of obtained relative speeds and outputs the average to the relative speed correction unit. The complex conjugate multiplication means includes a complex video signal having a real part of an I component video signal having the same range bin number obtained from a received signal with respect to a transmission pulse, an imaginary part of the Q component video signal, and an imaginary part of the complex video signal. Generating a complex conjugate video signal with an inverted sign, shifting the complex video signal and the complex conjugate video signal by an optimum shift amount, and performing multiplication to generate a plurality of complex signals for measuring relative speed;
The frequency spectrum analyzing means generates a frequency spectrum of the plurality of relative velocity measurement complex signals,
4. The pulse radar device according to claim 2, further comprising: a frequency spectrum adding unit that adds frequency spectra of the plurality of complex signals for measuring the relative velocity for each same frequency bin. An optimum shift amount selecting means for selecting an optimum shift amount based on the obtained relative speed with respect to the target or an average of a plurality of relative speeds with the obtained target and outputting the selected shift amount to the complex conjugate multiplying means; The pulse radar device according to any one of claims 1 to 4, wherein: A frequency selecting means for selecting a frequency spectrum in a range including a target frequency component from the frequency spectrum of the complex signal for relative velocity measurement;
A target relative speed / distance correspondence means for performing correspondence between a relative speed with the target and a relative distance with the target;
The relative velocity measuring means obtains a relative velocity with respect to a target with respect to a frequency spectrum in a range including all the selected frequency components of the target,
5. The pulse radar device according to claim 2, wherein the relative speed correcting unit corrects the relative speed by sequentially using the relative speed with respect to the target one by one. The frequency selection means selects a frequency component that exceeds a predetermined threshold from a frequency spectrum of the complex signal for relative velocity measurement as a frequency spectrum in a range including a target frequency component. The pulse radar device described. The frequency selection means is a frequency spectrum of a range including a target frequency component when a width of a frequency component exceeding a predetermined threshold is within a predetermined range of the frequency spectrum of the complex signal for relative speed measurement. The pulse radar device according to claim 6, wherein the pulse radar device is selected. The frequency selection means, as a frequency spectrum of a range including a target frequency component when a frequency of a frequency component exceeding a predetermined threshold is within a predetermined range of the frequency spectrum of the complex signal for relative speed measurement The pulse radar device according to claim 6, wherein the pulse radar device is selected. The target relative speed / distance correspondence means determines the distance of the signal when the width of the signal exceeding a predetermined threshold is within a predetermined range among the results after the synthesis band processing. The pulse radar device according to any one of claims 6 to 9, wherein the relative distance of the target of the relative speed used in the step is used. The target relative speed / distance correspondence means measures the relative speed of the relative speed with respect to the target used by the relative speed correction means when the intensity of the signal that exceeds a predetermined threshold among the results after the synthesis band processing. The distance of the signal is the relative distance of the target of the relative speed used in the relative speed correction means when the intensity of the frequency spectrum of the complex signal is closest to the intensity of the complex signal or a converted value thereof. The pulse radar device according to any one of claims 6 to 9. Using the target relative speed / distance correspondence means, information on the relative speed with the target used in the relative speed correction means, and information on the relative distance and intensity of the target of the relative speed, the reflected signal from the target Replica signal generation means for generating a replica signal;
A replica signal of the reflected signal from the target is subtracted from the I component video signal and Q component video signal of the same range bin number used for the complex conjugate multiplication to generate a subtracted video signal, or from the subtracted video signal, the target The pulse radar device according to any one of claims 6 to 11, further comprising: subtracting means for subtracting a replica signal of the reflected signal from the signal to generate a new post-subtraction video signal.

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