WO2011007828A1 - Fm-cw radar apparatus and doppler velocity measuring method - Google Patents

Fm-cw radar apparatus and doppler velocity measuring method Download PDF

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Publication number
WO2011007828A1
WO2011007828A1 PCT/JP2010/061970 JP2010061970W WO2011007828A1 WO 2011007828 A1 WO2011007828 A1 WO 2011007828A1 JP 2010061970 W JP2010061970 W JP 2010061970W WO 2011007828 A1 WO2011007828 A1 WO 2011007828A1
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Prior art keywords
wave
beat signal
transmission
doppler
frequency
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PCT/JP2010/061970
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French (fr)
Japanese (ja)
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敏明 鷹野
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国立大学法人 千葉大学
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Priority to JP2011522846A priority Critical patent/JPWO2011007828A1/en
Publication of WO2011007828A1 publication Critical patent/WO2011007828A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
    • G01S13/951—Radar or analogous systems specially adapted for specific applications for meteorological use ground based
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
    • G01S13/343—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal using sawtooth modulation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
    • G01S13/584—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets adapted for simultaneous range and velocity measurements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/354—Extracting wanted echo-signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/356—Receivers involving particularities of FFT processing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Definitions

  • the present invention relates to a technique for observing the Doppler velocity of an object.
  • the FM-CW (Frequency Modulated Continuous Wave) method uses a continuous wave that modulates the frequency to enable observation with higher sensitivity and lower power compared to the conventional pulse method. With the configuration, the distance and speed of the object can be observed.
  • a transmission wave whose frequency changes with a predetermined period and shape is transmitted from the transmission antenna.
  • the reflected wave reflected by the object is received as a received wave by the receiving antenna.
  • the received wave is a signal having a time delay corresponding to the distance to the object.
  • the frequency of the beat signal formed by combining the transmitted wave and the received wave with a mixer is a frequency proportional to the distance between the radar and the object (beat frequency) and a frequency proportional to the relative speed between the radar and the object. (Doppler frequency) is added. Therefore, it is theoretically possible to obtain the distance between the radar and the object and the relative velocity between the radar and the object by detecting each frequency of the beat signal.
  • the beat signal may be mixed with unwanted noise of direct current or low frequency such as noise generated from the mixer or noise caused by direct sneaking of radio waves from the transmission system to the reception system.
  • unwanted noise of direct current or low frequency such as noise generated from the mixer or noise caused by direct sneaking of radio waves from the transmission system to the reception system.
  • the beat signal is buried due to such noise, and it becomes impossible to detect the distance and the relative speed of the object.
  • a region that is in such a state is referred to as a non-detection region.
  • the non-detection area exists as an area having a certain width depending on the distance to the object and the relative speed.
  • Patent Document 1 proposes to reduce the non-detection area by using two types of transmission waves with different modulation periods and transmitting these two types of transmission waves alternately to obtain different beat signals.
  • the conventional FM-CW radar device is effective in an observation environment where the distance between the radar device and the object is relatively close (such as observation of the distance between vehicles), but it is several kilometers to several tens of kilometers from the ground.
  • the Doppler frequency is very small compared to the beat frequency, and the relative velocity with the object is measured. It has become extremely difficult.
  • an FM wave transmitting unit that transmits an FM wave that is swept repeatedly, a reflected wave receiving unit that receives a reflected wave, and beat signal synthesis that synthesizes a beat signal from the transmitted wave and the reflected wave FM-CW radar comprising: an initial phase acquisition unit that acquires an initial phase of a beat signal in a plurality of sweeps; and a Doppler velocity candidate acquisition unit that acquires a Doppler velocity candidate from a difference between two or more acquired initial phases Propose the device.
  • the FM wave transmission unit has a plurality of wave transmission means for transmitting two or more types of transmission waves, and the Doppler velocity candidate acquisition unit calculates the difference in the initial phase corresponding to each transmission wave.
  • the FM-CW radar apparatus according to claim 1, further comprising: a narrowing calculation means for performing narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by selecting a matching one on the speed axis.
  • an FM wave transmission step for transmitting an FM wave that is swept repeatedly, a reflected wave reception step for receiving a reflected wave, and a beat signal synthesis step for synthesizing a beat signal from the transmitted wave and the reflected wave, Proposing a Doppler velocity measurement method comprising an initial phase acquisition step for acquiring an initial phase of a beat signal in a plurality of sweeps, and a Doppler velocity candidate acquisition step for acquiring a Doppler velocity candidate from a difference between two or more acquired initial phases.
  • the FM wave transmission step includes a plurality of wave transmission sub-steps for transmitting two or more types of transmission waves
  • the Doppler velocity candidate acquisition step includes a difference in the initial phase corresponding to each transmission wave.
  • the Doppler speed measurement method according to claim 3 further comprising a narrowing calculation sub-step for performing narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by comparing the speed axes and selecting a matching one on the speed axis. .
  • the present invention it becomes possible to measure the distance and relative velocity of an observation object that exists at a long distance such as a cloud, and it is possible to observe a more detailed weather condition.
  • FIG. 1 is a functional block diagram of an FM-CW radar apparatus according to Embodiment 1.
  • FIG. An example of the circuit configuration of the FM-CW radar apparatus of this embodiment Principle of measuring object distance and Doppler velocity by FM-CW method Doppler frequency spectrum
  • FIG. 3 is an example of a process flow of the Doppler velocity measurement method according to the first embodiment.
  • Example of functional block of FM-CW radar apparatus according to embodiment 2 Distribution of phase change rate of beat signal at a certain time
  • Embodiment 1 will mainly describe claims 1 and 3.
  • an FM-CW radar apparatus and a Doppler velocity measurement method are characterized in that initial phases of beat signals in a plurality of sweeps are obtained, and Doppler velocity candidates are obtained from a difference between two or more obtained initial phases.
  • FIG. 1 is a diagram for illustrating an example of functional blocks of the FM-CW radar apparatus according to the present embodiment.
  • the “FM-CW radar device” (0100) includes an “FM wave transmission unit” (0101), a “reflected wave reception unit” (0102), a “beat signal synthesis unit” (0103), and an “initial phase acquisition unit”. "(0104)” and "Doppler speed candidate acquisition unit” (0105).
  • FIG. 2 is a diagram illustrating an example of a circuit configuration of the FM-CW radar apparatus according to the present embodiment.
  • the “FM wave transmitter” (0101) has a function of transmitting FM waves that are swept repeatedly.
  • the repeated frequency sweep means that the frequency is repeatedly modulated in a predetermined frequency range.
  • the frequency range, the number of repetitions, etc. are appropriately changed according to the observation target and the observation environment.
  • frequencies of C band (5 GHz) and X band (10 GHz) are often used, but it is desirable to use a higher frequency when observing clouds or the like.
  • the water and ice particles that make up the clouds are approximately several ⁇ m to several tens of ⁇ m in size, so millimeter waves are used as transmitted waves in order to obtain sensitivity that enables observation of thin clouds without accompanying rain. It is desirable to use (30 GHz to 300 GHz).
  • An FM wave is a wave that undergoes frequency modulation with a constant amplitude.
  • the FM wave transmission unit includes a divider (0203, 0204), a splitter (0224, 0225), a mixer (0205, 0206), a band pass filter (0210, 0211). ), An amplifier (0215, 0216), a phase lock oscillator (0222, 0223), and a multiplier (0227).
  • the “reflected wave receiver” (0102) has a function of receiving a reflected wave.
  • a receiving antenna (0221) is provided separately from the transmitting antenna. This antenna is not limited as long as it can receive reflected waves. It can be implemented by conventional techniques depending on the frequency of the FM wave used.
  • the reflected wave receiving unit includes a mixer (0207, 0208), a bandpass filter (0212, 0213, 0214), and an amplifier (0217, 0218, 0219) in addition to the above-described receiving antenna.
  • the “beat signal synthesis unit” (0103) has a function of synthesizing a beat signal from a transmission wave and a reflected wave.
  • the beat signal is a signal having a phase that is a phase difference between the transmission signal and the reception signal.
  • E t A t cos (2 ⁇ f t + ⁇ t )
  • E r A r cos (2 ⁇ f r + ⁇ r )
  • I b 2A t a r cos ⁇ 2 ⁇ (f r -f t) t + ( ⁇ r - ⁇ t) ⁇ .
  • the reflected wave received by the receiving antenna (0221) passes through the low noise amplifier (0219) and the band pass filter (0212), is down-converted at the local oscillation frequency, and then mixed with the signal of the signal generator A. To generate a beat signal.
  • the “initial phase acquisition unit” (0104) has a function of acquiring initial phases of beat signals in a plurality of sweeps.
  • the initial phase acquisition unit acquires the initial phase by performing the following arithmetic processing using a computer such as a personal computer (0226) based on the beat signal generated by the beat signal synthesis unit.
  • FIG. 3 is a diagram illustrating the principle of measuring the distance and Doppler velocity of an object by the FM-CW method.
  • the transmission signal is indicated by a solid line and modulated in a sawtooth shape. This modulation is modulated from the center frequency f 0 at a frequency width of F. Period of the sweep is T m.
  • the signal of the received wave reflected by the object is indicated by a broken line in FIG.
  • the received signal is a signal having a time delay ⁇ corresponding to the distance to the object.
  • the beat signal can be approximated as a wave having a frequency (beat frequency) proportional to the time delay (distance), so the distance to the object is detected by detecting the frequency of the beat signal.
  • the actual beat signal is composed of reflection signals from a plurality of objects at different distances, but the beat signal is subjected to FFT (Fast Fourier Transform) processing to obtain a frequency spectrum, so that a plurality of objects can be obtained. It becomes possible to obtain the distance.
  • FFT Fast Fourier Transform
  • ⁇ t (0) is the initial phase of the transmission wave.
  • ⁇ is a phase change when reflected by the object.
  • the phase ⁇ b (t) of the beat signal is the difference between the phases of the transmission signal and the reception signal, and can be expressed by Equations 3 and 4.
  • the number 3 the frequency of the beat signal, it can be seen that determined the beat frequency f b, the value of the Doppler frequency f d.
  • the beat frequency f b dependent on the distance to the object the Doppler frequency f d is seen to be dependent on the relative velocity of the object.
  • f b >> f d (f b to f b + f d )
  • the distance to the object is calculated from the frequency of the beat signal using Equation 5.
  • the initial phase is the sum of the second term and the third term on the right side of Equation 3.
  • the “Doppler speed candidate acquisition unit” (0105) has a function of acquiring a Doppler speed candidate from the difference between two or more acquired initial phases.
  • the “Doppler speed” is a relative speed of the object with respect to the radar apparatus. When the Doppler speed is positive, the object has a relative speed away from the radar apparatus. Conversely, if it is negative, the object will have a relative velocity approaching the radar device. In principle, it is possible to obtain the relative speed with the object using the Doppler frequency from Equation 4. However, as described above, it is often difficult to detect the Doppler frequency smaller than the beat frequency. Therefore, as shown below, the Doppler frequency is detected from the difference between two or more initial phases.
  • phase change on reflection of the third term can be regarded as constant for a short T m, considering the difference [Delta] [theta] b of the initial phase of the beat signal for each sweep, represented by the number 7.
  • the number 7 shows that the initial phase of the beat signal is rotating at a Doppler frequency f d. Therefore, the Doppler velocity can be obtained by measuring the change in the initial phase.
  • a process for acquiring a Doppler velocity candidate from the difference between the initial phases of two or more acquired beat signals will be specifically described below.
  • a plurality of frequency components are detected from data of one sweep time of the beat signal.
  • Data acquisition M points sampled during one sweep time T m M / 2 pieces of frequency components are obtained by the FFT (Fast Fourier Transform) processing thereto.
  • Each frequency component obtained here corresponds to a reflected signal from the distance related in Equation 5. Therefore, it can be said that M / 2 pieces of data are acquired in the distance direction by one sweep.
  • the sweep argument is N times
  • N pieces of data are obtained in the time direction.
  • the phase data is as shown in Equation 8.
  • Expression 9 is obtained by arranging the phase data of the mth row in a certain distance direction in the time direction.
  • FIG. 4 shows the spectrum of the Doppler frequency in such a case.
  • the spectrum indicated by A represents the true Doppler velocity
  • aliasing occurs, so that a plurality of Doppler velocity candidates appear periodically as indicated by B.
  • the sampling frequency should be set as high as possible, the observation parameters should be adjusted, and the physical properties of the object such as rain and clouds should be taken into account. It is possible to determine the true Doppler speed.
  • FIG. 5 is a flowchart showing an example of the processing procedure of the present embodiment.
  • the FM wave transmission step step S0501
  • an FM wave that is repeatedly swept in frequency is transmitted.
  • the reflected wave receiving step step S0502
  • the reflected wave is received.
  • the beat signal synthesis step step S0503
  • a beat signal is synthesized from the transmitted wave and the reflected wave.
  • the initial phase acquisition step step S0504
  • initial phases of beat signals in a plurality of sweeps are acquired.
  • a Doppler speed candidate acquisition step step S0505
  • a Doppler speed candidate is acquired from the difference between two or more acquired initial phases.
  • the FM-CW radar apparatus and the Doppler velocity measurement method of the present embodiment can obtain the Doppler velocity candidates for determining the Doppler velocity, even when indefiniteness due to the aliasing occurs. Relative velocity can be observed.
  • the optimal Doppler is selected from among a plurality of Doppler speed candidates even if a return occurs by transmitting two or more types of transmission waves.
  • An FM-CW radar device and a Doppler velocity measurement method capable of obtaining velocity will be described.
  • FIG. 6 is a diagram for illustrating an example of functional blocks of the FM-CW radar apparatus according to the present embodiment.
  • the “FM-CW radar device” (0600) includes an “FM wave transmission unit” (0601), a “reflected wave reception unit” (0602), a “beat signal synthesis unit” (0603), and an “initial phase acquisition unit”. ”(0604) and“ Doppler velocity candidate acquisition unit ”(0605), the FM wave transmission unit further includes“ multi-wave transmission means ”(0606), and the Doppler velocity candidate acquisition unit further includes“ “Refinement calculation means” (0607). Since the components other than the “multiple transmission unit” and the “squeezing calculation unit” are the same as those in the first embodiment, the description thereof is omitted.
  • the “multiple wave transmission means” (0606) has a function of transmitting two or more types of transmission waves.
  • the transmission wave transmitted here is an FM wave that repeats frequency modulation at a predetermined period as described in the first embodiment.
  • the multiple wave transmission means transmits two or more types of transmission waves having different modulation periods in this way. Each modulation period in two or more types of transmission waves can be arbitrarily determined. Since this point is also related to the narrowing down calculation means, it will be described later.
  • the “squeezing calculation means” (0607) compares the differences of the initial phases corresponding to the respective transmission waves, and selects the ones that match on the speed axis, thereby narrowing down to obtain the optimum Doppler speed from a plurality of Doppler speed candidates. It has a function to perform. “Choose one that matches on the speed axis” means to select one that matches among the observation data obtained based on a plurality of transmission waves at a certain time. The processing in the narrowing down calculation means will be specifically described below.
  • FIG. 7A shows observation data when a cloud is observed by transmitting an FM wave having a modulation frequency of 4 kHz as one transmission wave in the vertical direction from the ground.
  • the distribution of the phase change rate of the beat signal at a certain time is obtained by FFT, with the vertical axis representing altitude and the horizontal axis representing phase difference and velocity.
  • FFT FFT
  • each observation data is displayed with the same speed (m / s) scale and with the position of zero phase difference aligned.
  • the phase difference corresponding to the speed is different.
  • FIG. 7A the velocity range where the phase change rate distribution is generated with a high frequency exists for each period (2 ⁇ ) (0701, 0702, 0703).
  • FIG. 7B a velocity region in which the phase change rate distribution occurs at a high frequency exists for each period (2 ⁇ ) (0711, 0712, 0713).
  • the ones that coincide in the speed are about +2.4 (m / s) to +2.9 (m / S) is limited to the speed range (0701, 0711) and does not match in other speed ranges. Anything that doesn't match and appears elsewhere only appears by wrapping, with no substance. Therefore, the actual Doppler velocity of the cloud can be specified to be about +2.4 (m / s) to +2.9 (m / s) which coincides in both observation data. Therefore, it can be observed that the clouds are rising at this speed.
  • a matching speed range appears in addition to the above-described speed range of about +2.4 (m / s) to +2.9 (m / s).
  • the speed ranges in the ⁇ 3 period when the modulation frequency is 4 kHz and the ⁇ 4 period when the modulation frequency is 3 kHz are the same.
  • a speed range of about +21.4 (m / s) to +21.9 (m / s) and a speed of about -16.6 (m / s) to -16.1 (m / s) It matches in the area.
  • the speed of the clouds is about 10 m / s at the fastest, it can be seen that these speeds are not realistic. In this way, the specific Doppler speed can be narrowed down from the Doppler speed candidates generated by the folding.
  • 3 kHz and 4 kHz are selected as the modulation frequencies.
  • a combination having a large common multiple such as 3 kHz and 7 kHz can be selected to widen the interval on the speed axis. This makes it possible to detect the Doppler speed in a wide speed range. It is also possible to use three types of modulation frequencies such as 3 kHz, 5 kHz, and 7 kHz.
  • the processing procedure of the present embodiment is the same as the processing procedure shown in FIG.
  • the FM wave transmission step two or more types of transmission waves that are swept repeatedly are transmitted.
  • the reflected wave receiving step the reflected wave is received.
  • the beat signal synthesis step a beat signal is synthesized from the transmission wave and the reflected wave.
  • the initial phase acquisition step initial phases of beat signals in a plurality of sweeps are acquired.
  • the Doppler speed candidate acquisition step the difference in the initial phase corresponding to each transmission wave is compared, and a selection is made to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by selecting one that matches the speed axis.
  • the FM-CW radar apparatus can specify the Doppler velocity even when indefiniteness occurs due to folding.
  • FM-CW radar apparatus 0101 FM wave transmission unit 0102 Reflected wave reception unit 0103 Beat signal synthesis unit 0104 Initial phase acquisition unit 0105 Doppler velocity candidate acquisition unit

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

The conventional FM-CW mode radio apparatus combines transmitted and reflected waves to acquire a beat signal and determine a Doppler velocity from a frequency transition corresponding to a relative velocity of the object included in the beat signal. However, in a case of performing weather observations of clouds, rain and/or the like, the frequency deviation corresponding to a relative velocity is very small relative to the frequency deviation proportional to a distance, so that it is extremely difficult to measure the distance and relative velocity of an object only on the basis of the frequency component of a beat signal. In order to solve this problem, an FM-CW radio apparatus is provided which comprises: an FM wave transmitting unit for transmitting FM waves that are repetitively frequency-swept; a reflected wave receiving unit for receiving reflected waves; a beat signal synthesizing unit for synthesizing a beat signal from the transmitted and reflected waves; an initial phase acquiring unit for acquiring the initial phase of the beat signal in each of a plurality of sweepings; and a Doppler velocity candidate acquiring unit for acquiring a Doppler velocity candidate from the difference between two or more acquired initial phases.

Description

ＦＭ－ＣＷレーダ装置、ドップラ速度測定方法FM-CW radar device, Doppler velocity measurement method
　本発明は、対象物のドップラ速度を観測する技術に関する。 The present invention relates to a technique for observing the Doppler velocity of an object.
　近年、地球温暖化をはじめとする地球上の気候変動に対する注目が集まっている。また、竜巻や集中豪雨といった局所的な気象変動による大きな災害が生じている。このような状況において、気象災害の予防と軽減のために、気象観測の果たす役割は大きなものとなっている。 In recent years, attention has been focused on global climate change, including global warming. In addition, major disasters have occurred due to local weather fluctuations such as tornadoes and torrential rains. Under such circumstances, the role of meteorological observation has been significant for the prevention and mitigation of meteorological disasters.
　気象観測などのリモートセンシングにおいて、様々な方式によるレーダ装置の開発が進められている。その中でもＦＭ－ＣＷ（Ｆｒｅｑｕｅｎｃｙ　Ｍｏｄｕｌａｔｅｄ　Ｃｏｎｔｉｎｕｏｕｓ　Ｗａｖｅ）方式は、周波数を変調する連続波を使用することにより、従来のパルス方式に比べ小電力で高感度な観測が可能であり、また、比較的簡易な構成で、対象物の距離と速度を観測することができる。 Development of various types of radar equipment is underway for remote sensing such as weather observation. Among them, the FM-CW (Frequency Modulated Continuous Wave) method uses a continuous wave that modulates the frequency to enable observation with higher sensitivity and lower power compared to the conventional pulse method. With the configuration, the distance and speed of the object can be observed.
　ＦＭ－ＣＷ方式による一般的な観測は、以下のようなものである。まず、周波数が所定の周期及び形状で変化する送信波を送信アンテナから送信する。そして、対象物に反射された反射波は、受信アンテナにより受信波として受信される。ここで、受信波は、対象物までの距離に相当した時間遅れを持つ信号となる。また、送信波と受信波とをミキサで合成して形成されるビート信号の周波数は、レーダと対象物との距離に比例した周波数（ビート周波数）とレーダと対象物の相対速度に比例した周波数（ドップラ周波数）とを足し合わせたものとなる。よって、ビート信号の各周波数を検出することによってレーダと対象物の距離及びレーダと対象物の相対速度を求めることが原理的に可能である。 General observations using the FM-CW method are as follows. First, a transmission wave whose frequency changes with a predetermined period and shape is transmitted from the transmission antenna. The reflected wave reflected by the object is received as a received wave by the receiving antenna. Here, the received wave is a signal having a time delay corresponding to the distance to the object. The frequency of the beat signal formed by combining the transmitted wave and the received wave with a mixer is a frequency proportional to the distance between the radar and the object (beat frequency) and a frequency proportional to the relative speed between the radar and the object. (Doppler frequency) is added. Therefore, it is theoretically possible to obtain the distance between the radar and the object and the relative velocity between the radar and the object by detecting each frequency of the beat signal.
　ここで、ビート信号には、ミキサから生じるノイズや送信系から受信系への電波の直接的な回り込みにより生じるノイズなどの直流や低周波の不要なノイズが混入することがある。対象物までの距離と相対速度によっては、このようなノイズのためにビート信号が埋もれてしまい、対象物の距離と相対速度を検出することが不可能な状態となってしまう。このような状態となってしまう領域のことを不検知領域という。不検知領域は、対象物までの距離と相対速度により一定の幅を持った領域として存在する。 Here, the beat signal may be mixed with unwanted noise of direct current or low frequency such as noise generated from the mixer or noise caused by direct sneaking of radio waves from the transmission system to the reception system. Depending on the distance to the object and the relative speed, the beat signal is buried due to such noise, and it becomes impossible to detect the distance and the relative speed of the object. A region that is in such a state is referred to as a non-detection region. The non-detection area exists as an area having a certain width depending on the distance to the object and the relative speed.
　この問題に対しては、変調周期の異なる２種類の送信波を用い、この２種類の送信波を交互に送信し、異なるビート信号を得ることにより、不検知領域を減少させることが提案されている（特許文献１）。 To solve this problem, it has been proposed to reduce the non-detection area by using two types of transmission waves with different modulation periods and transmitting these two types of transmission waves alternately to obtain different beat signals. (Patent Document 1).
特開平１１－１３３１４４JP-A-11-133144
　しかしながら、従来のＦＭ－ＣＷ方式のレーダ装置は、レーダ装置と対象物との距離が比較的近い観測環境（車間距離の観測等）においては有効であるが、地上から数ｋｍないし数十ｋｍを隔てて存在する雲等の観測を行う場合には、レーダと対象物の距離が大きく離れているため、ドップラ周波数がビート周波数と比較して非常に小さくなり、対象物との相対速度を測定することが極めて困難となっていた。 However, the conventional FM-CW radar device is effective in an observation environment where the distance between the radar device and the object is relatively close (such as observation of the distance between vehicles), but it is several kilometers to several tens of kilometers from the ground. When observing clouds that exist at a distance, since the distance between the radar and the object is far away, the Doppler frequency is very small compared to the beat frequency, and the relative velocity with the object is measured. It has become extremely difficult.
　本発明はかかる課題を解決するために、以下のＦＭ－ＣＷレーダを提供するものである。すなわち、第一の発明として、繰返し周波数掃引されるＦＭ波を送信するＦＭ波送信部と、反射波を受信する反射波受信部と、送信波と反射波とからビート信号を合成するビート信号合成部と、複数の掃引におけるビート信号の初期位相を取得する初期位相取得部と、取得した二以上の初期位相の差分からドップラ速度候補を取得するドップラ速度候補取得部と、を有するＦＭ－ＣＷレーダ装置を提案する。 The present invention provides the following FM-CW radar in order to solve such a problem. That is, as a first aspect of the invention, an FM wave transmitting unit that transmits an FM wave that is swept repeatedly, a reflected wave receiving unit that receives a reflected wave, and beat signal synthesis that synthesizes a beat signal from the transmitted wave and the reflected wave FM-CW radar comprising: an initial phase acquisition unit that acquires an initial phase of a beat signal in a plurality of sweeps; and a Doppler velocity candidate acquisition unit that acquires a Doppler velocity candidate from a difference between two or more acquired initial phases Propose the device.
　第二の発明として、前記ＦＭ波送信部は、二種以上の送信波を送信する複数波送信手段を有し、前記ドップラ速度候補取得部は、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う絞込演算手段を有する請求項１に記載のＦＭ－ＣＷレーダ装置を提案する。 As a second invention, the FM wave transmission unit has a plurality of wave transmission means for transmitting two or more types of transmission waves, and the Doppler velocity candidate acquisition unit calculates the difference in the initial phase corresponding to each transmission wave. The FM-CW radar apparatus according to claim 1, further comprising: a narrowing calculation means for performing narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by selecting a matching one on the speed axis.
　第三の発明として、繰返し周波数掃引されるＦＭ波を送信するＦＭ波送信ステップと、反射波を受信する反射波受信ステップと、送信波と反射波とからビート信号を合成するビート信号合成ステップと、複数の掃引におけるビート信号の初期位相を取得する初期位相取得ステップと、取得した二以上の初期位相の差分からドップラ速度候補を取得するドップラ速度候補取得ステップと、からなるドップラ速度測定方法を提案する。 As a third aspect of the invention, an FM wave transmission step for transmitting an FM wave that is swept repeatedly, a reflected wave reception step for receiving a reflected wave, and a beat signal synthesis step for synthesizing a beat signal from the transmitted wave and the reflected wave, Proposing a Doppler velocity measurement method comprising an initial phase acquisition step for acquiring an initial phase of a beat signal in a plurality of sweeps, and a Doppler velocity candidate acquisition step for acquiring a Doppler velocity candidate from a difference between two or more acquired initial phases. To do.
　第四の発明として、前記ＦＭ波送信ステップは、二種以上の送信波を送信する複数波送信サブステップを有し、前記ドップラ速度候補取得ステップは、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う絞込演算サブステップを有する請求項３に記載のドップラ速度測定方法を提案する。 As a fourth invention, the FM wave transmission step includes a plurality of wave transmission sub-steps for transmitting two or more types of transmission waves, and the Doppler velocity candidate acquisition step includes a difference in the initial phase corresponding to each transmission wave. 4. The Doppler speed measurement method according to claim 3, further comprising a narrowing calculation sub-step for performing narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by comparing the speed axes and selecting a matching one on the speed axis. .
　本発明によって、雲のような遠距離に存在する観測対象物の距離と相対速度を測定することが可能となり、より詳細な気象状況の観測を行うことができる。 According to the present invention, it becomes possible to measure the distance and relative velocity of an observation object that exists at a long distance such as a cloud, and it is possible to observe a more detailed weather condition.
実施形態１に係るＦＭ－ＣＷレーダ装置の機能ブロックの一例図1 is a functional block diagram of an FM-CW radar apparatus according to Embodiment 1. FIG. 本実施形態のＦＭ－ＣＷレーダ装置の回路構成の一例図An example of the circuit configuration of the FM-CW radar apparatus of this embodiment ＦＭ－ＣＷ方式により対象物の距離及びドップラ速度を測定する原理Principle of measuring object distance and Doppler velocity by FM-CW method ドップラ周波数のスペクトルDoppler frequency spectrum 実施形態１に係るドップラ速度測定方法の処理の流れの一例図FIG. 3 is an example of a process flow of the Doppler velocity measurement method according to the first embodiment. 実施形態２に係るＦＭ－ＣＷレーダ装置の機能ブロックの一例Example of functional block of FM-CW radar apparatus according to embodiment 2 ある時刻におけるビート信号の位相変化率の分布Distribution of phase change rate of beat signal at a certain time
　以下本発明を実施するための形態について説明する。なお、本発明はこれら実施の形態になんら限定されるべきものではなく、その要旨を逸脱しない範囲において種々なる態様で実施し得る。 Hereinafter, embodiments for carrying out the present invention will be described. The present invention should not be limited to these embodiments at all, and can be implemented in various modes without departing from the scope of the invention.
　実施形態１は、主に請求項１、３について説明する。 Embodiment 1 will mainly describe claims 1 and 3.
　実施形態２は、主に請求項２、４について説明する。
＜実施形態１＞
＜実施形態１　概要＞ The second embodiment will mainly describe claims 2 and 4.
<Embodiment 1>
<Overview of Embodiment 1>
　本実施形態では、複数の掃引におけるビート信号の初期位相を取得し、取得した二以上の初期位相の差分からドップラ速度候補を取得することを特徴とするＦＭ－ＣＷレーダ装置及びドップラ速度測定方法を説明する。
＜実施形態１　構成＞ In the present embodiment, an FM-CW radar apparatus and a Doppler velocity measurement method are characterized in that initial phases of beat signals in a plurality of sweeps are obtained, and Doppler velocity candidates are obtained from a difference between two or more obtained initial phases. explain.
<Configuration of Embodiment 1>
　図１は、本実施形態に係るＦＭ－ＣＷレーダ装置の機能ブロックの一例を示すための図である。「ＦＭ－ＣＷレーダ装置」（０１００）は、「ＦＭ波送信部」（０１０１）と、「反射波受信部」（０１０２）と、「ビート信号合成部」（０１０３）と、「初期位相取得部」（０１０４）と、「ドップラ速度候補取得部」（０１０５）とにより構成される。また、図２は、本実施形態のＦＭ－ＣＷレーダ装置の回路構成の一例を示す図である。 FIG. 1 is a diagram for illustrating an example of functional blocks of the FM-CW radar apparatus according to the present embodiment. The “FM-CW radar device” (0100) includes an “FM wave transmission unit” (0101), a “reflected wave reception unit” (0102), a “beat signal synthesis unit” (0103), and an “initial phase acquisition unit”. "(0104)" and "Doppler speed candidate acquisition unit" (0105). FIG. 2 is a diagram illustrating an example of a circuit configuration of the FM-CW radar apparatus according to the present embodiment.
　「ＦＭ波送信部」（０１０１）は、繰返し周波数掃引されるＦＭ波を送信する機能を有する。ここで、繰返し周波数掃引されるとは、所定の周波数範囲で周波数を繰返し変調させることをいう。当該周波数の範囲や繰返す回数等は観測対象や観測環境に合わせて適宜変更する。気象観測には、Ｃバンド（５ＧＨｚ）やＸバンド（１０ＧＨｚ）の周波数が用いられることが多いが、雲などを観測する場合にはより高い周波数を用いることが望ましい。また、雲を構成している水や氷の粒子は、概ね数μｍから数十μｍの大きさであるため、降雨を伴わないような薄い雲を観測できる感度を得るために送信波としてミリ波（３０ＧＨｚ～３００ＧＨｚ）を用いることが望ましい。 The “FM wave transmitter” (0101) has a function of transmitting FM waves that are swept repeatedly. Here, the repeated frequency sweep means that the frequency is repeatedly modulated in a predetermined frequency range. The frequency range, the number of repetitions, etc. are appropriately changed according to the observation target and the observation environment. For weather observation, frequencies of C band (5 GHz) and X band (10 GHz) are often used, but it is desirable to use a higher frequency when observing clouds or the like. In addition, the water and ice particles that make up the clouds are approximately several μm to several tens of μm in size, so millimeter waves are used as transmitted waves in order to obtain sensitivity that enables observation of thin clouds without accompanying rain. It is desirable to use (30 GHz to 300 GHz).
　ＦＭ波は、振幅が一定の状態で周波数変調する波をいう。ＦＭ波送信部においては、信号発生器Ａ（０２０１）にて１５０±１０ＭＨｚのＦＭ－ＣＷ信号を作る。そして、信号発生器Ｂ（０２０２）にて作る２段の局部発振周波数と混合してアップコンバートし、９４．７９ＧＨｚ（波長＝３．１６ｍｍ）の送信信号を生成し送信用アンテナ（０２２０）を介して送信する。ＦＭ波送信部は、上記の信号発生器や送信用アンテナなどの他に、ディバイダ（０２０３、０２０４）、スプリッタ（０２２４、０２２５）、ミキサ（０２０５、０２０６）、バンド・パス・フィルタ（０２１０、０２１１）、アンプ（０２１５、０２１６）、フェイズロック発振器（０２２２、０２２３）、逓倍器（０２２７）を備える。 An FM wave is a wave that undergoes frequency modulation with a constant amplitude. In the FM wave transmission unit, the signal generator A (0201) generates an FM-CW signal of 150 ± 10 MHz. Then, it is mixed with the two-stage local oscillation frequency produced by the signal generator B (0202) and up-converted to generate a transmission signal of 94.79 GHz (wavelength = 3.16 mm) via the transmission antenna (0220). To send. In addition to the signal generator and the transmitting antenna, the FM wave transmission unit includes a divider (0203, 0204), a splitter (0224, 0225), a mixer (0205, 0206), a band pass filter (0210, 0211). ), An amplifier (0215, 0216), a phase lock oscillator (0222, 0223), and a multiplier (0227).
　「反射波受信部」（０１０２）は、反射波を受信する機能を有する。本実施形態においては、送信用アンテナとは別に受信用アンテナ（０２２１）を備えている。このアンテナについては反射波を受信可能なものである限り何ら限定を加えない。使用するＦＭ波の周波数などに応じて従来技術により実施可能である。反射波受信部は、上記の受信用アンテナなどの他に、ミキサ（０２０７、０２０８）、バンドパスフィルタ（０２１２、０２１３、０２１４）、アンプ（０２１７、０２１８、０２１９）を備える。 The “reflected wave receiver” (0102) has a function of receiving a reflected wave. In this embodiment, a receiving antenna (0221) is provided separately from the transmitting antenna. This antenna is not limited as long as it can receive reflected waves. It can be implemented by conventional techniques depending on the frequency of the FM wave used. The reflected wave receiving unit includes a mixer (0207, 0208), a bandpass filter (0212, 0213, 0214), and an amplifier (0217, 0218, 0219) in addition to the above-described receiving antenna.
　「ビート信号合成部」（０１０３）は、送信波と反射波とからビート信号を合成する機能を有する。ビート信号は送信信号と受信信号の位相の差である位相を有する信号である。具体的には、送信信号の電界成分をＥｔ＝Ａｔｃｏｓ（2πｆｔ＋φｔ）、位相信号の電界成分をＥｒ＝Ａｒｃｏｓ（2πｆｒ＋φｒ）とした場合、ビート信号の強度はＩｂ＝2ＡｔＡｒｃｏｓ｛2π（ｆｒ－ｆｔ）ｔ＋（φｒ－φｔ）｝と表わされる。受信用アンテナ（０２２１）により受信された反射波は、低ノイズアンプ（０２１９）及びバンド・パス・フィルタ（０２１２）を経て、局部発振周波数でダウンコンバートされた後、信号発生器Ａの信号と混合されてビート信号を生成する。 The “beat signal synthesis unit” (0103) has a function of synthesizing a beat signal from a transmission wave and a reflected wave. The beat signal is a signal having a phase that is a phase difference between the transmission signal and the reception signal. Specifically, when the electric field component of the transmission signal is E t = A t cos (2πf t + φ t ) and the electric field component of the phase signal is E r = A r cos (2πf r + φ r ), the intensity of the beat signal is expressed as I b = 2A t a r cos {2π (f r -f t) t + (φ r -φ t)}. The reflected wave received by the receiving antenna (0221) passes through the low noise amplifier (0219) and the band pass filter (0212), is down-converted at the local oscillation frequency, and then mixed with the signal of the signal generator A. To generate a beat signal.
　「初期位相取得部」（０１０４）は、複数の掃引におけるビート信号の初期位相を取得する機能を有する。初期位相取得部は、ビート信号合成部により生成されるビート信号に基づき、パーソナルコンピュータ（０２２６）などの計算機を用いて、以下に示す演算処理を行うことにより初期位相を取得する。 The “initial phase acquisition unit” (0104) has a function of acquiring initial phases of beat signals in a plurality of sweeps. The initial phase acquisition unit acquires the initial phase by performing the following arithmetic processing using a computer such as a personal computer (0226) based on the beat signal generated by the beat signal synthesis unit.
　図３は、ＦＭ－ＣＷ方式により対象物の距離及びドップラ速度を測定する原理を示す図である。実線にて示され鋸波状に変調しているのが送信信号である。この変調は、中心周波数ｆ０からＦの周波数幅で変調される。掃引の周期はＴｍである。対象物により反射された受信波の信号は、図３において破線で示される。この図から分かるように、受信信号は対象物までの距離に相当した時間遅れτを持つ信号となる。対象物までの距離が大きいとき、ビート信号は時間遅れ（距離）に比例した周波数（ビート周波数）を有する波と近似することができるため、ビート信号の周波数を検出することで対象物までの距離を測定することができる。なお、実際のビート信号は距離の異なる複数の対象物からの反射信号から構成されるが、ビート信号をＦＦＴ（高速フーリエ変換）処理して周波数のスペクトルを求めることで、複数の対象物までの距離を求めることが可能になる。 FIG. 3 is a diagram illustrating the principle of measuring the distance and Doppler velocity of an object by the FM-CW method. The transmission signal is indicated by a solid line and modulated in a sawtooth shape. This modulation is modulated from the center frequency f 0 at a frequency width of F. Period of the sweep is T m. The signal of the received wave reflected by the object is indicated by a broken line in FIG. As can be seen from this figure, the received signal is a signal having a time delay τ corresponding to the distance to the object. When the distance to the object is large, the beat signal can be approximated as a wave having a frequency (beat frequency) proportional to the time delay (distance), so the distance to the object is detected by detecting the frequency of the beat signal. Can be measured. The actual beat signal is composed of reflection signals from a plurality of objects at different distances, but the beat signal is subjected to FFT (Fast Fourier Transform) processing to obtain a frequency spectrum, so that a plurality of objects can be obtained. It becomes possible to obtain the distance.
　ビート信号の初期位相を取得するために、まず、一の掃引内の時間での送信波の位相について考える。送信波は、図示したように線形に周波数掃引されるので、掃引開始時の周波数をｆｌ、周波数変化率をΔｆ（＝２Ｆ／Ｔｍ）とすると、その位相θｔ（ｔ）は数１で表せる。
Figure JPOXMLDOC01-appb-M000001
 To obtain the initial phase of the beat signal, first consider the phase of the transmitted wave at a time within one sweep. Since the transmission wave is linearly swept as shown in the figure, assuming that the frequency at the start of the sweep is f 1 and the frequency change rate is Δf (= 2F / T m ), the phase θ t (t) is It can be expressed as
Figure JPOXMLDOC01-appb-M000001
　ここで、θｔ（０）は送信波の初期位相である。 Here, θ t (0) is the initial phase of the transmission wave.
　次に、受信波であるが、振幅は対象物の散乱断面積で決まり時間的に一定であるから、位相成分のみ考慮する。対象物の視線方向の速度をｖ、対象物までの距離をｒ（ｔ）＝ｒ（０）＋ｖｔ（ｖ＝ｄｒ／ｄｔ）、対象物で反射した後に受信されるまでの時間遅れをτ（ｔ）＝２ｒ（ｔ）／ｃとすると、受信波の位相θｒ（ｔ）は、数２で求められる。
Figure JPOXMLDOC01-appb-M000002
 Next, although it is a received wave, since the amplitude is determined by the scattering cross section of the object and is constant in time, only the phase component is considered. The velocity of the object in the line-of-sight direction is v, the distance to the object is r (t) = r (0) + vt (v = dr / dt), and the time delay until the object is received after being reflected by the object is τ ( Assuming that t) = 2r (t) / c, the phase θ r (t) of the received wave can be obtained by Equation 2.
Figure JPOXMLDOC01-appb-M000002
　ここで、Θは対象物に反射したときの位相変化である。数１及び数２より積分し整理するとビート信号の位相θｂ（ｔ）は送信信号と受信信号の位相の差であることから、数３、数４で表せる。
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
 Here, Θ is a phase change when reflected by the object. When integrating and organizing from Equations 1 and 2, the phase θ b (t) of the beat signal is the difference between the phases of the transmission signal and the reception signal, and can be expressed by Equations 3 and 4.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000004
　ここで数３から、ビート信号の周波数は、ビート周波数ｆbと、ドップラ周波数ｆｄの値で決まることが分かる。また数４から、ビート周波数ｆｂは対象物までの距離に依存し、ドップラ周波数ｆｄは対象物との相対速度に依存することが分かる。ただし、対象物との距離が大きい場合は一般的にｆｂ≫ｆｄ（ｆｂ～ｆｂ＋ｆｄ）であるから、このビート信号の周波数から数５を利用して対象物までの距離を求めることができる。また、初期位相は数３の右辺第二項と第三項の和である。
Figure JPOXMLDOC01-appb-M000005
 Here the number 3, the frequency of the beat signal, it can be seen that determined the beat frequency f b, the value of the Doppler frequency f d. Also from Equation 4, the beat frequency f b dependent on the distance to the object, the Doppler frequency f d is seen to be dependent on the relative velocity of the object. However, when the distance to the object is large, generally, f b >> f d (f b to f b + f d ), and therefore the distance to the object is calculated from the frequency of the beat signal using Equation 5. Can be sought. The initial phase is the sum of the second term and the third term on the right side of Equation 3.
Figure JPOXMLDOC01-appb-M000005
　「ドップラ速度候補取得部」（０１０５）は、取得した二以上の初期位相の差分からドップラ速度候補を取得する機能を有する。「ドップラ速度」とは、レーダ装置に対する対象物の相対速度であり、ドップラ速度が正である場合には、対象物はレーダ装置から遠ざかる相対速度を有することになる。反対に負である場合には、対象物はレーダ装置に対して近づく相対速度を有することになる。原理的には数４から、ドップラ周波数を用いて対象物との相対速度を求めることが可能である。しかしながら、上述のようにドップラ周波数はビート周波数に比べて小さく検知するのが困難な場合が多い。よって、以下に示すように二以上の初期位相の差分からドップラ周波数を検知する。 The “Doppler speed candidate acquisition unit” (0105) has a function of acquiring a Doppler speed candidate from the difference between two or more acquired initial phases. The “Doppler speed” is a relative speed of the object with respect to the radar apparatus. When the Doppler speed is positive, the object has a relative speed away from the radar apparatus. Conversely, if it is negative, the object will have a relative velocity approaching the radar device. In principle, it is possible to obtain the relative speed with the object using the Doppler frequency from Equation 4. However, as described above, it is often difficult to detect the Doppler frequency smaller than the beat frequency. Therefore, as shown below, the Doppler frequency is detected from the difference between two or more initial phases.
　ＦＭ－ＣＷ方式では掃引を周期Ｔｍで繰り返し行なう。そこで、ｎ番目の掃引とｎ＋１番目の掃引について考える。このとき対象物が運動をしているならば、それぞれの掃引での対象物までの距離は、ｖＴｍだけ変化している。ｎ番目の掃引での対象物までの距離と、ｎ＋１番目の掃引での対象物までの距離を、それぞれｒｎ、ｒｎ＋１とすると、これらの関係は、数６で表せる。
Figure JPOXMLDOC01-appb-M000006
 Repeating the sweep cycle the T m in FM-CW method. Therefore, consider the n-th sweep and the (n + 1) -th sweep. If the object at this time is the movement distance to the object in each sweep is changed by vT m. If the distance to the object in the n-th sweep and the distance to the object in the (n + 1) -th sweep are r n and r n +1, respectively, these relationships can be expressed by Equation 6.
Figure JPOXMLDOC01-appb-M000006
　ここで、第三項の反射時の位相変化はＴｍが短いため一定とみなすことができ、それぞれの掃引のビート信号の初期位相の差分Δθｂを考えると、数７で表せる。
Figure JPOXMLDOC01-appb-M000007
 Here, the phase change on reflection of the third term can be regarded as constant for a short T m, considering the difference [Delta] [theta] b of the initial phase of the beat signal for each sweep, represented by the number 7.
Figure JPOXMLDOC01-appb-M000007
　数７は、ビート信号の初期位相がドップラ周波数ｆｄで回転していることを示すものである。したがって、この初期位相の変化を測定することによりドップラ速度を得ることができる。 The number 7 shows that the initial phase of the beat signal is rotating at a Doppler frequency f d. Therefore, the Doppler velocity can be obtained by measuring the change in the initial phase.
　取得した二以上のビート信号の初期位相の差分からドップラ速度候補を取得するための処理を、以下具体的に説明する。まずビート信号の一掃引時間のデータから複数の周波数成分を検出する。データの取得は１掃引時間Ｔｍ中にＭポイントサンプリングし、これをＦＦＴ（高速フーリエ変換）処理をすることによりＭ／２個の周波数成分が得られる。ここで得られる各周波数成分は、数５で関係付けられた距離からの反射信号に相当する。したがって、１掃引で距離方向にＭ／２個のデータを取得しているといえる。さらに、掃引数をＮ回とすると時間方向にＮ個のデータが得られる。ここで、距離方向にｍ番目でかつ時間方向にｎ番目の位相のデータをφｍｎと表わすと、位相データは数８のようになる。
Figure JPOXMLDOC01-appb-M000008
 A process for acquiring a Doppler velocity candidate from the difference between the initial phases of two or more acquired beat signals will be specifically described below. First, a plurality of frequency components are detected from data of one sweep time of the beat signal. Data acquisition M points sampled during one sweep time T m, M / 2 pieces of frequency components are obtained by the FFT (Fast Fourier Transform) processing thereto. Each frequency component obtained here corresponds to a reflected signal from the distance related in Equation 5. Therefore, it can be said that M / 2 pieces of data are acquired in the distance direction by one sweep. Further, when the sweep argument is N times, N pieces of data are obtained in the time direction. Here, when the data of the m-th phase in the distance direction and the n-th phase in the time direction is expressed as φ mn , the phase data is as shown in Equation 8.
Figure JPOXMLDOC01-appb-M000008
　また、ある距離方向にｍ番目の行の位相データを時間方向に並べたものが数９である。　
Figure JPOXMLDOC01-appb-M000009
 Further, Expression 9 is obtained by arranging the phase data of the mth row in a certain distance direction in the time direction.
Figure JPOXMLDOC01-appb-M000009
　このデータ列は、前述のとおり周波数がｆｄである信号をＴｍごとにサンプリングしたものとみなせる。したがって、このデータ列をもう一度ＦＦＴすることにより距離がｍ番目の行にある対象物のドップラ周波数ｆｄのスペクトルを求めることができる。ドップラ周波数ｆｄをサンプリング周波数ｆｍ（＝１／Ｔｍ）でサンプリングしているものと同等であるので、サンプリング定理（２ｆｄ＜ｆｍ）を満たしている範囲であればドップラ周波数は一意で求めることができる。このときの測定可能範囲は数１０のようになる。
Figure JPOXMLDOC01-appb-M000010
 This data sequence can be regarded as those frequencies as described above was sampled signal is f d for each T m. Therefore, it is possible to obtain the spectrum of the Doppler frequency f d of the object in the distance by FFT the data string once more to m-th row. Since the Doppler frequency f d is equivalent to that sampled at the sampling frequency f m (= 1 / T m ), the Doppler frequency is unique as long as the sampling theorem (2f d <f m ) is satisfied. Can be sought. The measurable range at this time is as shown in Equation 10.
Figure JPOXMLDOC01-appb-M000010
　上記の測定可能範囲を超えた場合には折り返しを生じ、ドップラ周波数は一意に定まらず、不定性が生じてしまう。このような場合のドップラ周波数のスペクトルを示したものが図４である。Ａで示されているスペクトルが真のドップラ速度を表すものであった場合に、折り返しが生じることにより、Ｂで示されているように、複数のドップラ速度候補が周期的に現れる。 When the above measurable range is exceeded, aliasing occurs, the Doppler frequency is not uniquely determined, and indefiniteness occurs. FIG. 4 shows the spectrum of the Doppler frequency in such a case. When the spectrum indicated by A represents the true Doppler velocity, aliasing occurs, so that a plurality of Doppler velocity candidates appear periodically as indicated by B.
　実際の観測においては、このように折り返しによる不定性が生じる場合であっても、サンプリング周波数をなるべく高くしたり、観測パラメータを調整したり、雨や雲などの対象物の物理的性質を考慮したりすることにより、真のドップラ速度を判別することが可能である。 In actual observation, even if instability due to aliasing occurs, the sampling frequency should be set as high as possible, the observation parameters should be adjusted, and the physical properties of the object such as rain and clouds should be taken into account. It is possible to determine the true Doppler speed.
＜処理手順＞
　図５は、本実施例の処理手順の一例を表す流れ図である。まずＦＭ波送信ステップ（ステップＳ０５０１）では、繰返し周波数掃引されるＦＭ波を送信する。次に反射波受信ステップ（ステップＳ０５０２）では、反射波を受信する。ビート信号合成ステップ（ステップＳ０５０３）では、送信波と反射波とからビート信号を合成する。初期位相取得ステップ（ステップＳ０５０４）では、複数の掃引におけるビート信号の初期位相を取得する。ドップラ速度候補取得ステップ（ステップＳ０５０５）では、取得した二以上の初期位相の差分からドップラ速度候補を取得する。 <Processing procedure>
FIG. 5 is a flowchart showing an example of the processing procedure of the present embodiment. First, in the FM wave transmission step (step S0501), an FM wave that is repeatedly swept in frequency is transmitted. Next, in the reflected wave receiving step (step S0502), the reflected wave is received. In the beat signal synthesis step (step S0503), a beat signal is synthesized from the transmitted wave and the reflected wave. In the initial phase acquisition step (step S0504), initial phases of beat signals in a plurality of sweeps are acquired. In a Doppler speed candidate acquisition step (step S0505), a Doppler speed candidate is acquired from the difference between two or more acquired initial phases.
＜実施形態１　効果＞ <Embodiment 1 effect>
　本実施形態のＦＭ－ＣＷレーダ装置、ドップラ速度測定方法により、折り返しによる不定性が生じた場合であっても、ドップラ速度を判別するためのドップラ速度候補が得られることにより、対象物の距離と相対速度の観測を行うことができる。
＜実施形態２＞
＜実施形態２　概要＞ The FM-CW radar apparatus and the Doppler velocity measurement method of the present embodiment can obtain the Doppler velocity candidates for determining the Doppler velocity, even when indefiniteness due to the aliasing occurs. Relative velocity can be observed.
<Embodiment 2>
<Overview of Embodiment 2>
　本実施形態では、実施形態１のＦＭ－ＣＷレーダ装置を基本として、二種以上の送信波を送信することにより、折り返しが生じた場合であっても、複数のドップラ速度候補の内から最適ドップラ速度を得ることができるＦＭ－ＣＷレーダ装置及びドップラ速度測定方法を説明する。
＜実施形態２　構成＞ In the present embodiment, based on the FM-CW radar apparatus of the first embodiment, the optimal Doppler is selected from among a plurality of Doppler speed candidates even if a return occurs by transmitting two or more types of transmission waves. An FM-CW radar device and a Doppler velocity measurement method capable of obtaining velocity will be described.
<Configuration of Embodiment 2>
　図６は、本実施形態に係るＦＭ－ＣＷレーダ装置の機能ブロックの一例を示すための図である。「ＦＭ－ＣＷレーダ装置」（０６００）は、「ＦＭ波送信部」（０６０１）と、「反射波受信部」（０６０２）と、「ビート信号合成部」（０６０３）と、「初期位相取得部」（０６０４）と、「ドップラ速度候補取得部」（０６０５）とにより構成され、ＦＭ波送信部は、さらに「複数波送信手段」（０６０６）を有し、ドップラ速度候補取得部は、さらに「絞込演算手段」（０６０７）を有する。「複数送信手段」と「絞込演算手段」以外の各構成は実施形態１における各構成と同様であるため、説明を省略する。 FIG. 6 is a diagram for illustrating an example of functional blocks of the FM-CW radar apparatus according to the present embodiment. The “FM-CW radar device” (0600) includes an “FM wave transmission unit” (0601), a “reflected wave reception unit” (0602), a “beat signal synthesis unit” (0603), and an “initial phase acquisition unit”. ”(0604) and“ Doppler velocity candidate acquisition unit ”(0605), the FM wave transmission unit further includes“ multi-wave transmission means ”(0606), and the Doppler velocity candidate acquisition unit further includes“ “Refinement calculation means” (0607). Since the components other than the “multiple transmission unit” and the “squeezing calculation unit” are the same as those in the first embodiment, the description thereof is omitted.
　「複数波送信手段」（０６０６）は、二種以上の送信波を送信する機能を有する。ここで送信される送信波は、実施形態１で述べたように所定の周期で周波数変調を繰り返すＦＭ波である。そして、二種以上の送信波は、それぞれの変調周期のみを異なるものとしたものである。例えば、一の送信波の１掃引の時間をＴｍ＝２５０μｓｅｃとすれば、この送信波の変調周波数はｆｍ＝４ｋＨｚ（Ｔｍ＝１／ｆｍ）となる。この場合に、例えば、変調周波数ｆｍ＝３ｋＨｚとなる送信波をもう一つの送信波として用いる。複数波送信手段は、このように異なる変調周期を有する二種以上の送信波を送信する。二種以上の送信波におけるそれぞれの変調周期は任意に定めることができる。この点については、絞込演算手段にも関連するので後述する。 The “multiple wave transmission means” (0606) has a function of transmitting two or more types of transmission waves. The transmission wave transmitted here is an FM wave that repeats frequency modulation at a predetermined period as described in the first embodiment. The two or more types of transmission waves differ only in their modulation periods. For example, if the time for one sweep of one transmission wave is T m = 250 μsec, the modulation frequency of this transmission wave is f m = 4 kHz (T m = 1 / f m ). In this case, for example, a transmission wave having a modulation frequency f m = 3 kHz is used as another transmission wave. The multiple wave transmission means transmits two or more types of transmission waves having different modulation periods in this way. Each modulation period in two or more types of transmission waves can be arbitrarily determined. Since this point is also related to the narrowing down calculation means, it will be described later.
　「絞込演算手段」（０６０７）は、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う機能を有する。「速度軸で一致するものを選ぶ」とは、ある時刻における複数の送信波に基づいて得られる観測データの中で一致するものを選ぶという意である。以下に絞込演算手段における処理を具体的に説明する。 The “squeezing calculation means” (0607) compares the differences of the initial phases corresponding to the respective transmission waves, and selects the ones that match on the speed axis, thereby narrowing down to obtain the optimum Doppler speed from a plurality of Doppler speed candidates. It has a function to perform. “Choose one that matches on the speed axis” means to select one that matches among the observation data obtained based on a plurality of transmission waves at a certain time. The processing in the narrowing down calculation means will be specifically described below.
　実施形態１において述べたように、対象物のドップラ速度を得るために、複数の掃引におけるビート信号の初期位相の差分を求める。この初期位相の差分を、変調周波数の異なる二種以上の送信波のそれぞれについて求める。図７（Ａ）は、変調周波数が４ｋＨｚのＦＭ波を一の送信波として用いて地上から鉛直方向に送信して雲を観測した場合の観測データである。縦軸を高度、横軸を位相差及び速度として、ある時刻におけるビート信号の位相変化率の分布をＦＦＴにより求めて示したものである。図のように、高度３ｋｍから６ｋｍの範囲の領域において、位相変化率の分布が高い頻度で生じているのが分かる。したがって、この領域で雲が運動していることが分かる。しかし、２πの周期で折り返しが生じているため、この観測データのみでは雲のドップラ速度を特定することはできない。 As described in the first embodiment, in order to obtain the Doppler velocity of the object, the difference between the initial phases of the beat signals in a plurality of sweeps is obtained. The initial phase difference is obtained for each of two or more types of transmission waves having different modulation frequencies. FIG. 7A shows observation data when a cloud is observed by transmitting an FM wave having a modulation frequency of 4 kHz as one transmission wave in the vertical direction from the ground. The distribution of the phase change rate of the beat signal at a certain time is obtained by FFT, with the vertical axis representing altitude and the horizontal axis representing phase difference and velocity. As shown in the figure, it can be seen that the phase change rate distribution occurs at a high frequency in the region of altitude 3 km to 6 km. Therefore, it can be seen that the clouds are moving in this region. However, since folding occurs at a period of 2π, the cloud Doppler velocity cannot be specified only by this observation data.
　ここで、変調周波数が４ｋＨｚのＦＭ波と、変調周波数が３ｋＨｚのＦＭ波を二種の送信波とした場合には、図７（Ａ）に示す観測データの他に、図７（Ｂ）に示すように、変調周波数が３ｋＨｚのＦＭ波による観測データを得ることができる。したがって、ある時刻の雲の運動を、変調周波数の異なる二のＦＭ波によってドップラ速度を観測したものになる。 Here, in the case where FM waves with a modulation frequency of 4 kHz and FM waves with a modulation frequency of 3 kHz are used as two types of transmission waves, in addition to the observation data shown in FIG. As shown, observation data by FM waves with a modulation frequency of 3 kHz can be obtained. Therefore, the Doppler velocity of the cloud motion at a certain time is observed by the two FM waves having different modulation frequencies.
　図７に示すように、それぞれの観測データは速度（ｍ／ｓ）のスケールを等しくして、かつ、位相差ゼロの位置を揃えて表示している。一方、それぞれの変調周波数が異なるため、速度に対応する位相差は相違したものとなる。図７（Ａ）において、位相変化率の分布が高い頻度で生じている速度域は、１周期（２π）ごとに存在する（０７０１、０７０２、０７０３）。図７（Ｂ）においても、位相変化率の分布が高い頻度で生じている速度域は、１周期（２π）ごとに存在する（０７１１、０７１２、０７１３）。そこで、それぞれの観測データにおける位相変化率の分布が高い頻度で生じている速度域を比較してみると、速度において一致するものは、約＋２．４（ｍ／ｓ）～＋２．９（ｍ／ｓ）の速度域（０７０１、０７１１）に限られ、他の速度域においては一致しない。一致せずに他に現れているものは、折り返しにより現れているに過ぎず、実体を伴わない。したがって、実際の雲のドップラ速度は、両観測データにおいて一致した約＋２．４（ｍ／ｓ）～＋２．９（ｍ／ｓ）であると特定することができる。よって、この速度で雲が上昇しているということが観測できる。 As shown in FIG. 7, each observation data is displayed with the same speed (m / s) scale and with the position of zero phase difference aligned. On the other hand, since each modulation frequency is different, the phase difference corresponding to the speed is different. In FIG. 7A, the velocity range where the phase change rate distribution is generated with a high frequency exists for each period (2π) (0701, 0702, 0703). In FIG. 7B as well, a velocity region in which the phase change rate distribution occurs at a high frequency exists for each period (2π) (0711, 0712, 0713). Therefore, when comparing the speed ranges where the distribution of the phase change rate in each observation data occurs at a high frequency, the ones that coincide in the speed are about +2.4 (m / s) to +2.9 (m / S) is limited to the speed range (0701, 0711) and does not match in other speed ranges. Anything that doesn't match and appears elsewhere only appears by wrapping, with no substance. Therefore, the actual Doppler velocity of the cloud can be specified to be about +2.4 (m / s) to +2.9 (m / s) which coincides in both observation data. Therefore, it can be observed that the clouds are rising at this speed.
　折り返しは図示した範囲のほかにも存在するため、上述した約＋２．４（ｍ／ｓ）～＋２．９（ｍ／ｓ）の速度域のほかにも一致する速度域が現れる。位相差が－π～＋πの１周期を基準とし、変調周波数が４ｋＨｚの場合の±３周期目と、変調周波数が３ｋＨｚの場合の±４周期目とにおける速度域が一致する。具体的には、約＋２１．４（ｍ／ｓ）～＋２１．９（ｍ／ｓ）の速度域と、約－１６．６（ｍ／ｓ）～－１６．１（ｍ／ｓ）の速度域とにおいて一致する。しかし、雲の速度は早くても１０ｍ／ｓ程度なので、これらの速度が現実的でないことが分かる。このようにして、折り返しにより生じるドップラ速度候補の中から特定ドップラ速度を絞り込むことができる。 Since the folding exists in addition to the illustrated range, a matching speed range appears in addition to the above-described speed range of about +2.4 (m / s) to +2.9 (m / s). With reference to one period of phase difference of −π to + π, the speed ranges in the ± 3 period when the modulation frequency is 4 kHz and the ± 4 period when the modulation frequency is 3 kHz are the same. Specifically, a speed range of about +21.4 (m / s) to +21.9 (m / s) and a speed of about -16.6 (m / s) to -16.1 (m / s) It matches in the area. However, since the speed of the clouds is about 10 m / s at the fastest, it can be seen that these speeds are not realistic. In this way, the specific Doppler speed can be narrowed down from the Doppler speed candidates generated by the folding.
　なお、上記の例では変調周波数として３ｋＨｚと４ｋＨｚを選択したが、例えば３ｋＨzと７ｋＨｚのように公倍数の大きな組み合わせを選択して速度軸で一致する間隔を広くすることもできる。これにより、広い速度範囲でドップラ速度を検出することが可能になる。また、３ｋＨｚと５ｋＨｚと７ｋＨｚなどの三種の変調周波数を用いることも同様に可能である。 In the above example, 3 kHz and 4 kHz are selected as the modulation frequencies. However, for example, a combination having a large common multiple such as 3 kHz and 7 kHz can be selected to widen the interval on the speed axis. This makes it possible to detect the Doppler speed in a wide speed range. It is also possible to use three types of modulation frequencies such as 3 kHz, 5 kHz, and 7 kHz.
＜処理手順＞
　本実施例の処理手順は実施例１の図５で示した処理手順と同様である。まずＦＭ波送信ステップでは、繰返し周波数掃引される二種以上の送信波を送信する。次に反射波受信ステップでは、反射波を受信する。ビート信号合成ステップでは、送信波と反射波とからビート信号を合成する。初期位相取得ステップでは、複数の掃引におけるビート信号の初期位相を取得する。ドップラ速度候補取得ステップでは、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う。
＜実施形態２　効果＞ <Processing procedure>
The processing procedure of the present embodiment is the same as the processing procedure shown in FIG. First, in the FM wave transmission step, two or more types of transmission waves that are swept repeatedly are transmitted. Next, in the reflected wave receiving step, the reflected wave is received. In the beat signal synthesis step, a beat signal is synthesized from the transmission wave and the reflected wave. In the initial phase acquisition step, initial phases of beat signals in a plurality of sweeps are acquired. In the Doppler speed candidate acquisition step, the difference in the initial phase corresponding to each transmission wave is compared, and a selection is made to obtain an optimal Doppler speed from a plurality of Doppler speed candidates by selecting one that matches the speed axis.
<Embodiment 2 Effect>
　本実施形態のＦＭ－ＣＷレーダ装置により、折り返しによる不定性が生じた場合であっても、ドップラ速度を特定することが可能となる。 The FM-CW radar apparatus according to the present embodiment can specify the Doppler velocity even when indefiniteness occurs due to folding.
　　０１００　ＦＭ－ＣＷレーダ装置
　　０１０１　ＦＭ波送信部
　　０１０２　反射波受信部
　　０１０３　ビート信号合成部
　　０１０４　初期位相取得部
　　０１０５　ドップラ速度候補取得部 0100 FM-CW radar apparatus 0101 FM wave transmission unit 0102 Reflected wave reception unit 0103 Beat signal synthesis unit 0104 Initial phase acquisition unit 0105 Doppler velocity candidate acquisition unit

Claims (4)

  1. 　繰返し周波数掃引されるＦＭ波を送信するＦＭ波送信部と、
    　反射波を受信する反射波受信部と、
    　送信波と反射波とからビート信号を合成するビート信号合成部と、
    　複数の掃引におけるビート信号の初期位相を取得する初期位相取得部と、
    　取得した二以上の初期位相の差分からドップラ速度候補を取得するドップラ速度候補取得部と、
    を有するＦＭ－ＣＷレーダ装置。     An FM wave transmitter that transmits FM waves that are swept at a repetitive frequency;
    A reflected wave receiver for receiving the reflected wave;
    A beat signal synthesis unit that synthesizes a beat signal from a transmission wave and a reflected wave;
    An initial phase acquisition unit for acquiring an initial phase of a beat signal in a plurality of sweeps;
    A Doppler speed candidate acquisition unit that acquires a Doppler speed candidate from the difference between two or more acquired initial phases;
    FM-CW radar apparatus having
  2. 　前記ＦＭ波送信部は、二種以上の送信波を送信する複数波送信手段を有し、
    　前記ドップラ速度候補取得部は、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う絞込演算手段を有する請求項１に記載のＦＭ－ＣＷレーダ装置。     The FM wave transmission unit includes a plurality of wave transmission means for transmitting two or more types of transmission waves,
    The Doppler speed candidate acquisition unit compares the difference of the initial phase corresponding to each transmission wave, and selects the one that matches on the speed axis, thereby narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates. The FM-CW radar apparatus according to claim 1, further comprising a calculation unit.
  3. 　繰返し周波数掃引されるＦＭ波を送信するＦＭ波送信ステップと、
    　反射波を受信する反射波受信ステップと、
    　送信波と反射波とからビート信号を合成するビート信号合成ステップと、
    　複数の掃引におけるビート信号の初期位相を取得する初期位相取得ステップと、
    　取得した二以上の初期位相の差分からドップラ速度候補を取得するドップラ速度候補取得ステップと、
    からなるドップラ速度測定方法。     An FM wave transmission step of transmitting an FM wave that is swept at a repetitive frequency;
    A reflected wave receiving step for receiving the reflected wave;
    A beat signal synthesis step for synthesizing a beat signal from a transmission wave and a reflected wave;
    An initial phase acquisition step of acquiring an initial phase of a beat signal in a plurality of sweeps;
    A Doppler speed candidate acquisition step of acquiring a Doppler speed candidate from the difference between the acquired two or more initial phases;
    A Doppler velocity measurement method comprising:
  4. 　前記ＦＭ波送信ステップは、二種以上の送信波を送信する複数波送信サブステップを有し、
    　前記ドップラ速度候補取得ステップは、各送信波に対応した前記初期位相の差分を比較し、速度軸で一致するものを選ぶことで複数のドップラ速度候補から最適ドップラ速度を得るための絞り込みを行う絞込演算サブステップを有する請求項３に記載のドップラ速度測定方法。     The FM wave transmission step includes a multi-wave transmission sub-step for transmitting two or more types of transmission waves,
    The Doppler speed candidate acquisition step compares the initial phase differences corresponding to each transmission wave, and selects the ones that match on the speed axis, thereby narrowing down to obtain an optimal Doppler speed from a plurality of Doppler speed candidates. The Doppler velocity measurement method according to claim 3, further comprising a calculation substep.
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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104169828A (en) * 2011-12-22 2014-11-26 英特尔公司 Deterministic clock crossing
KR20150108876A (en) * 2013-03-15 2015-09-30 오토리브 에이에스피, 인크. Vehicle radar system with blind spot detection
JP2017058291A (en) * 2015-09-17 2017-03-23 富士通テン株式会社 Radar device, signal processing device for radar device, and method for measuring speed
JP2017090066A (en) * 2015-11-02 2017-05-25 富士通テン株式会社 Radar device, signal processing device of radar device, and signal processing method
KR101742868B1 (en) * 2015-06-03 2017-06-02 한국과학기술원 Frequency modulated continuous wave chain radar system for detecting unmanned aerial vehicle
KR101777011B1 (en) 2015-10-01 2017-09-26 재단법인대구경북과학기술원 Apparatus and method for processing radar signal in accordance with the energy of the radar sensor
WO2017200041A1 (en) * 2016-05-18 2017-11-23 株式会社デンソー Speed detecting device
WO2017208670A1 (en) * 2016-05-30 2017-12-07 日本電気株式会社 Object sensing device, vehicle-mounted radar system, surveillance radar system, object sensing method, and program
TWI667488B (en) * 2018-08-27 2019-08-01 呈鎬科技股份有限公司 A target detection method by stepped-frequency modulation signals
WO2019182043A1 (en) * 2018-03-23 2019-09-26 株式会社Ｓｏｋｅｎ Radar device
JP2019168449A (en) * 2018-03-23 2019-10-03 株式会社Ｓｏｋｅｎ Radar device
CN110927717A (en) * 2019-12-11 2020-03-27 深圳大学 Imaging method, device and imaging system of frequency modulated continuous wave radar
JP2020173163A (en) * 2019-04-10 2020-10-22 株式会社デンソー Radar device

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001500621A (en) * 1996-09-18 2001-01-16 セルシウステク エレクトロニクス エービー A process for determining the relative velocity between two moving objects
JP2003194924A (en) * 2001-12-25 2003-07-09 Mitsubishi Electric Corp Doppler radar equipment
JP2004085452A (en) * 2002-08-28 2004-03-18 Toyota Central Res & Dev Lab Inc Fm-cw radar system
JP2004151022A (en) * 2002-10-31 2004-05-27 Denso Corp Fmcw radar device
WO2006134912A1 (en) * 2005-06-17 2006-12-21 Murata Manufacturing Co., Ltd. Radar apparatus
JP2009510410A (en) * 2005-09-29 2009-03-12 バレオ・シャルター・ウント・ゼンゾーレン・ゲーエムベーハー Radar method for automatic vehicle and radar device for automatic vehicle

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001500621A (en) * 1996-09-18 2001-01-16 セルシウステク エレクトロニクス エービー A process for determining the relative velocity between two moving objects
JP2003194924A (en) * 2001-12-25 2003-07-09 Mitsubishi Electric Corp Doppler radar equipment
JP2004085452A (en) * 2002-08-28 2004-03-18 Toyota Central Res & Dev Lab Inc Fm-cw radar system
JP2004151022A (en) * 2002-10-31 2004-05-27 Denso Corp Fmcw radar device
WO2006134912A1 (en) * 2005-06-17 2006-12-21 Murata Manufacturing Co., Ltd. Radar apparatus
JP2009510410A (en) * 2005-09-29 2009-03-12 バレオ・シャルター・ウント・ゼンゾーレン・ゲーエムベーハー Radar method for automatic vehicle and radar device for automatic vehicle

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104169828A (en) * 2011-12-22 2014-11-26 英特尔公司 Deterministic clock crossing
KR20150108876A (en) * 2013-03-15 2015-09-30 오토리브 에이에스피, 인크. Vehicle radar system with blind spot detection
KR102065626B1 (en) 2013-03-15 2020-01-13 비오니어 유에스, 인크. Vehicle radar system with blind spot detection
KR101742868B1 (en) * 2015-06-03 2017-06-02 한국과학기술원 Frequency modulated continuous wave chain radar system for detecting unmanned aerial vehicle
JP2017058291A (en) * 2015-09-17 2017-03-23 富士通テン株式会社 Radar device, signal processing device for radar device, and method for measuring speed
US10527718B2 (en) 2015-09-17 2020-01-07 Fujitsu Ten Limited Radar device, signal processing device for radar device and velocity measuring method for radar device
KR101777011B1 (en) 2015-10-01 2017-09-26 재단법인대구경북과학기술원 Apparatus and method for processing radar signal in accordance with the energy of the radar sensor
JP2017090066A (en) * 2015-11-02 2017-05-25 富士通テン株式会社 Radar device, signal processing device of radar device, and signal processing method
WO2017200041A1 (en) * 2016-05-18 2017-11-23 株式会社デンソー Speed detecting device
JP2017207368A (en) * 2016-05-18 2017-11-24 株式会社デンソー Speed detector
WO2017208670A1 (en) * 2016-05-30 2017-12-07 日本電気株式会社 Object sensing device, vehicle-mounted radar system, surveillance radar system, object sensing method, and program
JPWO2017208670A1 (en) * 2016-05-30 2019-03-28 日本電気株式会社 Object detection apparatus, in-vehicle radar system, surveillance radar system, object detection method and program
US11194033B2 (en) 2016-05-30 2021-12-07 Nec Corporation Object sensing device, automotive radar system, surveillance radar system, object sensing method, and program
WO2019182043A1 (en) * 2018-03-23 2019-09-26 株式会社Ｓｏｋｅｎ Radar device
JP2019168449A (en) * 2018-03-23 2019-10-03 株式会社Ｓｏｋｅｎ Radar device
US11709246B2 (en) * 2018-03-23 2023-07-25 Soken, Inc. Radar apparatus
JP7168493B2 (en) 2018-03-23 2022-11-09 株式会社Soken radar equipment
US20210003695A1 (en) * 2018-03-23 2021-01-07 Soken, Inc. Radar apparatus
TWI667488B (en) * 2018-08-27 2019-08-01 呈鎬科技股份有限公司 A target detection method by stepped-frequency modulation signals
JP2020173163A (en) * 2019-04-10 2020-10-22 株式会社デンソー Radar device
JP7196744B2 (en) 2019-04-10 2022-12-27 株式会社デンソー radar equipment
CN110927717B (en) * 2019-12-11 2022-01-11 深圳大学 Imaging method, device and imaging system of frequency modulated continuous wave radar
CN110927717A (en) * 2019-12-11 2020-03-27 深圳大学 Imaging method, device and imaging system of frequency modulated continuous wave radar

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