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WO2003100458A1 - Dispositif radar doppler a laser - Google Patents

Dispositif radar doppler a laser Download PDF

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Publication number
WO2003100458A1
WO2003100458A1 PCT/JP2002/005215 JP0205215W WO03100458A1 WO 2003100458 A1 WO2003100458 A1 WO 2003100458A1 JP 0205215 W JP0205215 W JP 0205215W WO 03100458 A1 WO03100458 A1 WO 03100458A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
frequency
optical
code sequence
radar device
Prior art date
Application number
PCT/JP2002/005215
Other languages
English (en)
Japanese (ja)
Inventor
Shumpei Kameyama
Kimio Asaka
Toshiyuki Ando
Yoshihito Hirano
Original Assignee
Mitsubishi Denki Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Denki Kabushiki Kaisha filed Critical Mitsubishi Denki Kabushiki Kaisha
Priority to PCT/JP2002/005215 priority Critical patent/WO2003100458A1/fr
Priority to JP2004507863A priority patent/JP3872082B2/ja
Publication of WO2003100458A1 publication Critical patent/WO2003100458A1/fr

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Classifications

    • 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
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/50—Systems of measurement based on relative movement of target
    • G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/26—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the direct influence of the streaming fluid on the properties of a detecting optical wave

Definitions

  • the present invention relates to a laser-Doppler radar device that detects a moving speed of a reflector by transmitting laser light into the atmosphere, and in particular, the reflector is, for example, an aerosol scattered in the atmosphere.
  • the present invention relates to a method for extracting only signal components from a desired measurement range and measuring a wind speed in the measurement range at a high SZN ratio when signals from a plurality of ranges are superimposed and received.
  • Conventional techniques of this type include transmitting a pulse light having a time width corresponding to a desired distance resolution into the atmosphere, and applying a time-gut to a time zone in which received light from a measurement range is received. It is widely known to detect the Doppler frequency of wind speed by performing spectral analysis at the time gate.
  • FIG. 21 is a configuration diagram of a laser Doppler radar device disclosed in Japanese Patent Application Laid-Open No. 2000-330382.
  • 1 is a light source
  • 2 is an optical distributor
  • 3 is an optical modulator
  • 4 is a code sequence generator
  • 5 is an optical amplifier
  • 6 is a transmitting and receiving optical unit
  • 7 is a heterodyne receiver
  • 13 is a signal.
  • a processing unit, 17 is a correlator
  • 18 is a variable delay unit.
  • the optical signal from the light source 1 is split into two by an optical splitter 2, one of which is sent to an optical modulator 3 and the other Is sent to the heterodyne receiver 7.
  • the signal sent to the optical modulator 3 is phase-modulated by a modulation signal based on the code sequence from the code sequence generator 4.
  • the modulated signal from the code sequence generator 4 is sent to the correlator 18 after being delayed by the variable delay 18 by a time corresponding to the round-trip time to the measurement range of the optical signal.
  • the signal subjected to the code sequence modulation is amplified by the optical amplifier 5 and transmitted to the atmosphere via the transmission / reception optical unit 6.
  • received light from a reflector in the atmosphere, such as an aerosol is received via the transmission / reception optical unit 6 and heterodyne-detected by the heterodyne receiver 7.
  • the heterodyne-detected signal is sent to a correlator 18 and integrated with a time-delayed modulated signal to obtain a correlation.
  • the frequency of the correlation signal from the correlator 17 becomes the Doppler frequency in the measurement range.
  • the signal processing unit 13 analyzes the frequency of the correlation signal from the correlator 17 and detects the Doppler frequency.
  • Japanese Patent Application Laid-Open No. 2000-338046 discloses that the modulation method may be frequency modulation instead of phase modulation.
  • the modulation method had to be phase modulation.
  • Japanese Patent Application Laid-Open No. 2000-3303824 does not provide a specific demodulation method when the modulation method is frequency modulation.
  • FIG. 22 is a configuration diagram of the laser Doppler radar device disclosed in Japanese Patent Application Laid-Open No. 3-75581.
  • 1a and 1b are light sources
  • 21 and 22 are optical splitters
  • 15 is an optical frequency manager
  • 19 is a band-pass filter
  • 20 is a high-pass filter.
  • Japanese Patent Laid-Open Publication No. Hei 3-755581 describes a case in which received light from one place in the atmosphere is received, that is, a case where the reflector is a hard target of an aircraft, a car, or the like. Has been described.
  • an optical signal FSK (Frequency Shift Keying) from the light source 1a is transmitted as transmission light.
  • the modulated signal is delayed by the variable delay unit 18 by a time corresponding to the round trip time to the measurement range of the optical signal, and then sent to the light source lb, and the optical signal FSKed from the light source lb is converted into local light. Occurs.
  • a part of the transmission light and a part of the local light via the optical distributors 21 and 22 are sent to the optical frequency controller 15 and the frequency difference between the optical signals generated from the light source 1a and the light source 1b.
  • the frequency of the optical signal generated from the light source 1b is managed so that the constant becomes constant.
  • the transmission light is transmitted to the atmosphere via the transmission / reception optical unit 6.
  • the received light from the reflector in the atmosphere is received via the transmission / reception optical unit 6.
  • the received light and the local light are detected by a heterodyne receiver 7.
  • the signal from the receiver Dyne receiver 2 is divided into two and sent to the band-pass filter 19 and the high-pass filter 20, respectively.
  • the above operation is performed while changing the delay time of the variable delay unit 18 to detect the distance from the delay time at which the output of the high-pass filter 20 becomes maximum to the target. Further, the target moving speed is detected by analyzing the frequency of the output signal of the band-pass filter 19.
  • the laser Doppler radar device disclosed in Japanese Patent Application Laid-Open No. 3-755558 detects the moving speed of a reflector when it is a hard target such as an aircraft or an automobile. Was to do.
  • the reflector is, for example, air in the atmosphere.
  • PC orchid 15 sol where signals from multiple ranges are superimposed on the received light, it was not possible to extract only the signal components from the desired measurement range and detect the wind speed in the measurement range.
  • the present invention has been made in view of the above circumstances, and enables measurement at a high S / N ratio due to a pulse compression effect using a FSK (Frequency Shift Keying) method even when there is phase fluctuation of received light.
  • FSK Frequency Shift Keying
  • a laser Doppler radar device includes: a light source; a code sequence generator that generates a modulation signal based on a code sequence including a + or one code; and an optical signal from the light source.
  • An optical modulator that performs FSK (Frequency Shift Keying) modulation with two frequencies based on a modulation signal from the optical modulator, and transmits an optical signal FSK-modulated by the optical modulator to the atmosphere, and
  • a transmission / reception optical unit that receives reception light from a plurality of ranges, an optical splitter that distributes an optical signal from the light source to generate local light, a reception light from the transmission / reception optical unit, and the light splitter
  • a heterodyne receiver that converts an optical signal into an electrical signal by performing a mouth-to-mouth dyne detection with an optical signal from the optical receiver; an AZD converter that performs AZD conversion of the electrical signal from the heterodyne receiver;
  • a signal processing unit that processes the signal that has been
  • the optical modulator shifts the frequency f0 of the optical signal from the light source by two frequencies f1 and f2 corresponding to + and 1 of the modulation signal.
  • the optical modulator is an optical switch that selects and outputs one of the optical signals from the two light sources based on a modulation signal from the code sequence generator.
  • the code sequence is an M sequence. Further, the code sequence is a complementary sequence, and the optical modulator has a pulse modulation function.
  • the signal processing unit includes a Gut division function for dividing a signal A / D-converted by the A / D converter into time intervals corresponding to one bit of a code sequence, and a Gut division function.
  • a spectrum analysis function for calculating a power spectrum of a signal included in each of the gates obtained, and a code sequence used for transmission with respect to the spectrum of each gate obtained by the spectrum analysis function.
  • a first oscillator that outputs an oscillation signal having a frequency of (f 1 + f 2) 2 is mixed with the output signal from the Dyne receiver and the oscillation signal from the first oscillator.
  • a 90 ° divider for dividing an oscillation signal from an oscillator into two a second mixer for mixing one output from the 0 ° divider and one output from the 90 ° divider,
  • a third mixer for mixing the other output from the 0 ° divider with the other output from the 90 ° divider; and a power spectrum obtained by the outputs of the second and third mixers.
  • the frequency at which the signal intensity of the signal component from the atmosphere exists is Response to the frequency one I d and the frequency + ⁇ d, or in response to + and one sign-series to realize that the frequency + fd and the frequency one fd.
  • a first oscillator for outputting an oscillation signal having a frequency of (f 1 + f 2) / 2; and mixing the output signal from the Dyne receiver with the oscillation signal from the first oscillator.
  • a first mixer, and the signal processing unit It has a function of subtracting the value of (f 2 ⁇ f 1) / 2 from the value of the frequency axis of the power spectrum. The output of the first mixer and the signal processing unit are used in the power spectrum in the air.
  • the frequency at which the signal strength of the signal component from is present corresponds to the frequency + fd and the frequency + fd corresponding to + and 1 of the code sequence, or the frequency + fd and the frequency + fd corresponding to the + and 1 of the code sequence.
  • the signal processing unit has a function of subtracting the value of (f 2 + f 1) Z 2 from the value of the frequency axis of the power spectrum, and a function of subtracting (f 2 ⁇ f 1) with respect to the frequency in the positive frequency domain. It has a function of shifting by 2 and a function of shifting the frequency in the negative frequency range by (f 2-f 1) / 2 and inverting the sign of the frequency.
  • the frequency at which the signal strength of the signal component from the inside exists is expressed as frequency fd and frequency + fd corresponding to + and 1 in the code sequence, or frequency + fd and frequency + fd corresponding to + and 1 in the code sequence.
  • FIG. 1 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention
  • FIG. 2 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention
  • FIG. 3 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 4 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 5 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 6 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 7 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention
  • FIG. 8 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention
  • FIG. 9 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 10 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 11 is a diagram for explaining a laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 12 is a diagram for explaining the laser Doppler radar device according to Embodiment 1 of the present invention.
  • FIG. 13 is a diagram for explaining a laser Doppler radar device according to Embodiment 2 of the present invention.
  • FIG. 14 is a diagram for explaining a laser Doppler radar device according to Embodiment 2 of the present invention.
  • FIG. 15 is a diagram for explaining a laser Doppler radar device according to Embodiment 3 of the present invention.
  • FIG. 16 is a diagram for explaining a laser Doppler radar device according to Embodiment 3 of the present invention.
  • FIG. 17 is a diagram for explaining a laser Doppler radar device according to Embodiment 3 of the present invention.
  • FIG. 18 is a diagram for explaining a laser Doppler radar device according to Embodiment 4 of the present invention.
  • FIG. 19 is a diagram for explaining a laser Doppler radar device according to Embodiment 4 of the present invention.
  • FIG. 20 is a diagram for explaining a laser Doppler radar device according to Embodiment 4 of the present invention.
  • FIG. 21 is a diagram for explaining a conventional laser Doppler radar device
  • FIG. 22 is a diagram for explaining a conventional laser Doppler radar device. 5215
  • FIG. 1 is a configuration diagram of a laser Doppler radar device according to Embodiment 1 of the present invention.
  • 1 is a light source
  • 2 is an optical distributor
  • 3 is an optical modulator
  • 4 is a code sequence generator
  • 5 is an optical amplifier.
  • Reference numeral 6 denotes a transmission / reception optical unit having a function as an optical circuit. Transmission light is transmitted to the atmosphere via the transmission / reception optical unit 6.
  • 7 is a heterodyne receiver
  • 81, 82 and 83 are mixers
  • 91 and 92 are oscillators
  • 10 is a 0 ° distributor
  • 11 is a 90 ° distributor.
  • Reference numeral 12 denotes an AZD converter
  • reference numeral 13 denotes a signal processing unit.
  • a light source 1 is connected to an optical splitter 2, and one of the two outputs of the optical splitter 2 is connected to a hollow dyne receiver 7. The other is connected to the optical modulator 3.
  • the optical modulator 3 is connected to a code sequence generator 4 and an optical amplifier 5.
  • the code sequence generator 4 is connected to the AZD converter 12.
  • the optical amplifier 5 is connected to the transmission / reception optical unit 6.
  • the transmission / reception optical unit 6 is connected to the heterodyne receiver 7.
  • Heterodyne receiver 7 is connected to 0 ° distributor 10.
  • the input of the 0 ° distributor 10 is connected to the mixer 81.
  • the mixer 81 is connected to the oscillator 91 and the 0 ° distributor 10.
  • the two outputs of the 0 ° distributor 10 are connected to mixers 82 and 83, respectively.
  • the oscillator 92 is connected to the 90 ° distributor 11.
  • the two outputs of the 90 ° divider 11 are connected to mixers 82 and 83, respectively.
  • Mixers 82 and 83 are connected to A / D converter 12.
  • the AZD converter 12 is connected to the signal processing unit 13.
  • optical amplifier 5 and the transmission / reception optical unit 6 and the transmission / reception optical unit 6 and the heterodyne receiver 7 are connected by an optical fiber cable. Other parts are connected by electric cables.
  • the light source 1 has a function of generating an optical signal having a frequency f 0 by a continuous wave.
  • the code sequence generator 4 generates a modulated signal based on the code sequence and transmits it to the optical modulator 3. It has the function to do. Also, it has a function of transmitting a trigger signal for notifying the transmission timing of the modulation signal to the A / D converter 12.
  • the optical modulator 3 has a function of modulating an optical signal based on a modulation signal from the code sequence generator 4.
  • the optical modulator 3 shifts the frequency f0 and f2 of the optical signal generated from the light source 1 by two frequencies f1 and f2, corresponding to + and 1 of the modulation signal. Therefore, the frequency of the output signal of the optical modulator 3 is subjected to FSK (Frequency Shift Keying), and becomes f0 + f1 and f0 + f2 corresponding to + and one of the code sequence.
  • the optical modulator 3 also has a pulse modulation function in which the output is ON only during the time when the modulation signal is being input.
  • FIG. 2 shows a schematic diagram of an output signal from the optical modulator 3 when the code sequence is +, 1, +, or 1.
  • the code sequence generated by the code sequence generator 4 is shown in Document [1] ( ⁇ kawa et al., Coding Theory, Published by Shokodo, Fifth Edition, pp. 476-499).
  • a “sequence with a sharp correlation function” examples include an adaptive sequence, an M sequence, and the like.
  • the code sequence generator 4 The case where the generated code sequence is a complementary sequence is described. Below, as a specific example of the complementary sequence,
  • the mixers 81, 82, and 83 of the present invention have a function of outputting a signal having a frequency corresponding to the absolute value of the difference between the frequency of the input signal and the frequency of the oscillation signal from the oscillators 91 and 92. Having.
  • an optical signal having a frequency f 0 is transmitted from the light source 1 as a continuous wave, and the optical distributor 2 divides this signal.
  • One of the two split signals is sent to the Dyne receiver 7 as local light.
  • Embodiment 1 of the present invention two complementary sequences, code sequence 1 5215 and code sequence 2 are used.
  • code sequence 1 is selected, and a code signal based on this code sequence is transmitted from code sequence generator 4 to optical modulator 3.
  • a trigger signal for notifying the transmission timing of the modulation signal is transmitted to the A / D converter 12.
  • One of the two outputs of the optical distributor 2 is sent to the optical modulator 3.
  • the optical modulator 3 has two frequencies f 1 and f 2 corresponding to + and 1 of the modulation signal from the code sequence generator 4, and has a frequency corresponding to the frequency ⁇ 0 of the optical signal generated from the light source 1. Shift.
  • the output of the optical modulator 3 is turned ON only during the time when the modulation signal is input, and pulse modulation is performed.
  • the frequency of the output signal of the optical modulator 3 is subjected to FSK (Frequency Shift Keying), and becomes f0 + f1 and f0 + f2 corresponding to + and one of the code sequence.
  • the pulse width ⁇ ⁇ of the output signal from the optical modulator 3 is the time width of the modulated signal. That is, from the time width ⁇ corresponding to one bit of the code sequence and the number of bits ⁇ of the code sequence, a value represented by ⁇ ⁇ 2 ⁇ ⁇ is obtained.
  • the output signal from the optical modulator 3 is amplified by the optical amplifier 5.
  • the signal from the optical amplifier 5 is transmitted to the atmosphere via the transmission / reception optical unit 6 as transmission light.
  • the transmitted light transmitted to the atmosphere is received after being reflected by a reflector in the atmosphere such as an aerosol.
  • the frequency of the received light is a value shifted from the frequency of the transmitted light by the Doppler frequency of the wind speed in the transmission direction.
  • the Doppler frequency of the wind speed is fd
  • the frequency of the reflected light of the transmitted light corresponding to the sign + is f O + fl + fd
  • the sign one shift frequency f 2
  • the frequency of the reflected light with respect to the corresponding transmitted light is ⁇ 0 + f2 + fd.
  • FIG. 3 is a diagram for explaining received light from the atmosphere.
  • reference numeral 14 denotes a laser-Doppler radar device.
  • R- 3 to R 3 is Ri der part of the range of atmospheric here R. Is the measurement range. The distance width of each range is the desired distance resolution d in measurement.
  • d 1 is the measurement range R from the laser Doppler radar device 14. Is the distance to Transmitting light sent into the atmosphere, not only the measurement range R 0, other range other than the measurement range, for example, R _ 3 to R - have Is also reflected from. Therefore, the reflected light from the measurement range in the atmosphere In addition to light, reflected light from other ranges than the measurement range is superimposed.
  • the range R- 3, R- 2, R- I R 0, the R have R 2, R wind speed in 3 dots blur frequency fd, fd- 3, id- 2, fd a victory fd 0, id physician id 2 and fd 3 That is, a signal having a frequency shifted by these Doppler frequencies with respect to the frequency of the transmitted light is superimposed on the received light.
  • the symbol fd is a general term for wind speed Doppler frequencies having different values in each range.
  • the Doppler frequency of wind speed in each range: E d and the reflectance for transmission light in each range are constant within the measurement time.
  • the received light is sent to the heterodyne receiver 7 via the transmission / reception optical unit 6.
  • the oral light and the received light are subjected to the optical dyne detection, the optical signal is converted into an electric signal, and the beat signal of the two signals is output.
  • the frequency of the beat signal for the transmitted light corresponding to the sign + (shift frequency f 1) is fd + f 1
  • the frequency of the beat signal for the transmitted light corresponding to the sign 1 (shift frequency ⁇ 2) is f d + f 2.
  • the beat signal is sent to a mixer 81 and mixed with an oscillation signal from an oscillator 91.
  • the frequency of the oscillation signal from the oscillator 91 should be (f1 + f2) / 2.
  • the values of f 1 and f 2 are calculated for all possible values of the Doppler frequency f d of the wind speed.
  • the output signal from the mixer 81 is divided into two by a 0 ° distributor 10 and then sent to two mixers 82 and 83.
  • the frequency (f 2 — f 1) Z2 An oscillation signal is oscillated and sent to the 90 ° divider 11.
  • the output of the 90 ° distributor 11 is sent to two mixers 82 and 83 and mixed with the two output signals from the 0 ° distributor 10.
  • Mixing by mixers 8 2 and 8 3 corresponds to IQ detection, and the signals from the two mixers 8 2 and 8 3 are, for example, the I signal from the mixer 8 2 and the I signal from the mixer 8 3. It can be regarded as an IQ signal as a Q signal.
  • the frequency of the IQ signal from the mixers 82 and 83 relating to the transmitted light corresponding to the sign + (shift frequency fl) is
  • the frequencies of the IQ signals from mixers 82 and 83 are 1 ⁇ d and + fd, corresponding to + and 1 of the modulation code.
  • the IQ signals of the two mixers 82 and 83 are sent to the AZD converter 12.
  • a / D converter 1 2 A / D converts IQ signals from mixers 8 2 and 8 3
  • the measurement range R existing at a distance d1 from the laser Doppler radar device 14 is shown.
  • the round-trip time of the optical signal up to is r.
  • the timing to start A / D conversion is
  • FIG. 4 schematically shows the time zone for A / D conversion.
  • FIG. 4A is a schematic diagram of an output signal of the optical modulator 3
  • FIG. 4B is a schematic diagram showing an operation timing of the A / D converter 12. Note that the measurement range R is from the optical modulator 3.
  • the round trip time of the optical signal to and from the laser Doppler radar device 14 is the measurement range R.
  • the propagation time of the optical signal in the laser Doppler radar device 14 is the value obtained by adding the round trip time of the optical signal up to and the propagation time of the optical signal in the laser Doppler radar device 14. Since it is a small value that can be ignored compared to However, the propagation time of the optical signal in the laser Doppler radar device 14 is not considered.
  • the AZD-converted signals are sequentially sent to the signal processing unit 12 and stored in a memory in the signal processing unit 13 (not shown).
  • the operation described above is for the case where the code generated in the code sequence generator 4 is the code sequence 1.
  • the code sequence 2 is generated by the code sequence generator 4, the same operation as when the code sequence 1 is generated is performed.
  • the AZD-converted signals are sequentially sent to the signal processing unit 12 and stored in a memory (not shown) in the signal processing unit 13.
  • the signal included in the gate g includes:
  • code sequence 1 (+ + + -) in the case of performing transmission and reception by using, in the signal contained in the gate g 4 is
  • FIG. 5 shows the list.
  • FIG. 5 (a) relates to code sequence 1
  • FIG. 5 (b) relates to code sequence 2.
  • 0 is entered for the range in each gate that does not include the corresponding signal component.
  • the signal contained in the gate Gi ⁇ g 4 which are each divided, is Pawasu Bae-vector since the scan Bae spectrum analysis using a scan Bae spectrum analyzing means such as F FT or D FT is determined (process 2) .
  • the spectrum corresponding to the sign + is a function having a signal strength of one fd
  • the spectrum corresponding to the sign 1 is a function having a signal strength of + fd.
  • Fig. 6 is a diagram schematically showing a power spectrum corresponding to the sign +
  • Fig. 6 (a) is a power spectrum corresponding to the sign +
  • Fig. 6 (b) is a sign corresponding to the sign +. It is a corresponding power spectrum.
  • FIG. 6 shows the case where the value of the Doppler frequency fd is a positive value.
  • FIG. 7 schematically shows the power spectrum obtained by performing processing 2 for each of the gates gi to g 4 in the case of transmission and reception using code sequence 1 and dividing it into components from each range.
  • FIG. 7 (a) is have a gate g diagram. 7 (b) gate g 2
  • FIG. 7 (c) gate g 3 is a diagram regarding gate g 4. Also the figure
  • FIG. 8 schematically shows the case where transmission / reception is performed using code sequence 2 by performing processing 2 for each gate of gi to g 4 to divide the power spectrum into components from each range.
  • FIG. 8 the gate g intentions. 8 (b) gate g 2, FIG. 8 (c)
  • FIGS. 7 and 8 show the case where the Doppler frequencies f d ⁇ 3 to fd 3 in each range are all positive values, these values do not necessarily have to be positive values. Also the figure
  • a Pawasu Bae vector signal strength of the signal components from the range R- 3 in P- 3 the Pawasu Bae-vector signal strength of the signal components from the range R-2 with P- 2, or range R- i
  • the power spectrum signal strength of these signal components is Pi, and the signal components from range R-o Power spectrum signal strength of P—.
  • the Pawasu Bae-vector signal strength of the signal components from the range in P i the Pawasu Bae-vector signal strength of the signal components from the range R 2 in P 2, the power spectrum signal of the signal components from the range R 3 the strength in P 3, represent their respective.
  • Processing 3 is specifically performed in the first embodiment of the present invention as follows.
  • the signal relating to the code sequence 1 have four gate g g 2, g 3, the power spectrum of g 4 to code +, +, +, is performed processing corresponding to one, four for the signal relating to a code sequence 2 the gate g have g 2, g 3, g 4 of the scan Bae spectrum to sign +, ten, one, a process corresponding to the + is performed.
  • the power spectrum of the gate corresponding to the + sign is kept as it is, and the power spectrum of the gate corresponding to the one sign is inverted symmetrically with respect to the frequency 0.
  • FIGS. 9 and 10 show the results of processing 3 for the power spectrum of each gate when code sequences 1 and 2 shown in FIGS. 7 and 8 are used.
  • the power spectrum of each gate subjected to 3 is integrated between the gates and between the code sequences (process 4).
  • FIG. 11 shows the result obtained by performing the integration of the processing 4 on the power spectrum that has been subjected to the processing 3 of FIGS. 9 and 10. In FIG. 11, the integration result is divided and shown for each component from each range.
  • the signal strength in the negative frequency domain in the result of the processing 4 is multiplied by 1 and the signal strength obtained by multiplying the signal strength of the positive frequency having the same absolute value by the above 1 is added.
  • the negative frequency range is turned back to the positive frequency range and the signal strength is added (Process 5). This process 5 is performed on the spectrum shown in FIG. 11, and the result of displaying only the positive frequency region is shown in FIG.
  • the component from the measurement range R0 that is, the Doppler frequency fd. It can be seen that only the power spectrum components of the remaining range remain, and the power spectra for the other ranges are canceled out. This gives the measuring range R. Doppler frequency at. Detection, that is, measurement range R. Can be detected. In the operation of the signal processing unit 13 described above, the measurement range R. Other range The reason why the signal components of the PC leakage 15 can be canceled out to be 0 is that the range sidelobe is canceled out to be 0 in the sum of the autocorrelation functions of the two series of the complementary series. It depends on the nature.
  • the added signal strength is a negative value.
  • a negative signal strength cannot be in the analog domain.
  • performing the operation of process 5 in the digital domain can result in a negative value as the operation result.
  • measurement range R Doppler frequency at. If is a positive value, the calculation result of the signal strength by the process 5 becomes a negative value as shown in FIG. 12 and f d. If is a negative value, the calculation result of the signal strength by the processing 5 is a positive value. Therefore, in the result of the processing 5, the measurement range R is obtained from the peak frequency at which the absolute value of the signal strength becomes a peak and the positive and negative values of the signal strength at the peak frequency. Doppler frequency at. As well as the absolute value of Doppler frequency f d. Is positive or negative.
  • the reflector is a so-called soft target such as an aerosol in the atmosphere, and is used not only for the measurement range but also for other than the measurement range. Even when signals from one range are received in a superimposed manner, the signal components from other ranges can be canceled and the Doppler frequency of the signal components from the measurement range can be detected. That is, when the reflector is an aerosol in the atmosphere, the wind speed can be detected.
  • Embodiment 1 of the present invention FSK (Frequency Shift Keying) is used as a modulation scheme.
  • FSK Frequency Shift Keying
  • the phase of the received light from the atmosphere fluctuates randomly, a desired effect can be realized if the Doppler frequency and the reflectance in each range are constant during the measurement time.
  • the reason is that the power spectrum from which the phase information has been removed in the processing 2 during operation of the signal processing unit 13 is obtained, and this function is used in the subsequent processing (processing 3 to processing 5). Fluctuates randomly, and even if the phase of the signal of each gate obtained by dividing in the process 1 fluctuates randomly between the guts, this is not related to the subsequent processes.
  • the complementary sequence was used as the code sequence
  • other sequences in the “sequence having a sharp correlation function” shown in Ref. [1] for example, when n is an integer, 2 n — 1-bit M sequence May be used.
  • the height of the range side lobe does not become 0, but it is reduced to 1 / n compared to the height of the main lobe. Therefore, the M-sequence in which the value of n is increased is used as the code sequence, and the transmission timing of the trigger signal from the code sequence generator 4 to the AZD converter 12 is determined when the operation of the code sequence generator 4 starts, that is, when the code sequence is generated.
  • the start of transmission from A / D converter to optical modulator 3 is defined as measurement range R after the trigger signal is input. If the same processing is performed in the signal processing unit 13 when the AZD conversion stop time is the measurement end time, the processing result is the measurement range R. Signal from the dominant. In this case, since continuous wave transmission light modulated according to the M sequence that repeats infinitely is transmitted, the effect that the optical modulator 3 does not need to have the pulse modulation function is produced.
  • FIG. 13 shows a laser Doppler radar device according to Embodiment 2 of the present invention. This will be described with reference to FIG. FIG. 13 is a configuration diagram of a laser Doppler radar device according to Embodiment 2 of the present invention.
  • the mixers 82 and 83, the oscillator 92, the 0 ° distributor 10, and the 90 ° distributor 11 in FIG. 1 are eliminated, and a single mixer 8 and an oscillator 9 are used. 8 is directly connected to the A / D converter 12 so that the output signal of the mixer 8 is A / D converted.
  • the frequency of the output signal from mixer 8 with respect to the transmission light corresponding to the sign + (shift frequency f l) is
  • FIG. 14 shows a schematic diagram of the power spectrum before and after performing this process 2d.
  • FIG. 14 (a) is a schematic diagram corresponding to the sign +
  • FIG. 14 (b) is a schematic diagram corresponding to the sign 1.
  • the mixers 82 and 8 performed in the first embodiment are used.
  • FIG. 7 is a diagram schematically illustrating the power spectrum obtained by performing the process 2 for each gate of FIG. 4 divided into components from each range. Therefore, this By performing the processes 3 to 5 after performing the process 2d, the same effect as that described in the first embodiment can be obtained.
  • the laser Doppler radar device shown in the second embodiment is different from the laser Doppler radar device shown in the first embodiment in that mixers 82 and 83 and an oscillator
  • FIG. 15 is a configuration diagram of a laser Doppler radar device according to Embodiment 3 of the present invention.
  • the mixer 8 and the oscillator 9 in Fig. 13 are eliminated, the heterodyne receiver 7 is directly connected to the A / D converter 12, and the beat signal from the heterodyne receiver 7 is A / D converted. Configuration.
  • the frequency of the beat signal related to the transmitted light corresponding to code + is fd + f1
  • the frequency of the beat signal related to the transmitted light corresponding to code 1 is fd + f It was 2.
  • mixing was performed by the mixers 81, 82 and 83, but the laser Doppler radar device according to the third embodiment was used.
  • the operation of subtracting the values of f1 and f2 is performed not as an analog stage but as an operation in the signal processing unit 13. The operation of the signal processing unit 13 will be described below.
  • Figure 1 shows a schematic diagram of the power spectrum before and after performing this process 2d d.
  • FIG. 16 (a) is a schematic diagram corresponding to the sign +
  • FIG. 16 (b) is a schematic diagram corresponding to the sign 1.
  • the frequency is shifted by 1 ( ⁇ 2 ⁇ f 1) / 2 in the positive frequency domain.
  • the frequency is shifted by (f 2 ⁇ f 1) Z 2, and the sign of the frequency is inverted (process 2 ddd).
  • Fig. 17 shows a schematic diagram of the power spectrum before and after performing this process 2dd.
  • FIG. 17 (a) is a schematic diagram corresponding to the sign +
  • FIG. 17 (b) is a schematic diagram corresponding to the sign 1.
  • the laser Doppler radar device shown in the third embodiment is different from the laser Doppler radar device shown in the first embodiment in that mixers 81, 82, and 83, oscillators 91 and 92, and 0 ° Since there is no need to use the distributor 10 and the 90 ° distributor 11, the number of components is small. Further, compared with the laser Doppler radar apparatus shown in the second embodiment, since there is no need to use the mixer 81 and the oscillator 91, the number of components is small. Therefore, the effect of lowering the cost of the entire system occurs.
  • FIG. 18 is a configuration diagram of a laser Doppler radar device according to Embodiment 4 of the present invention.
  • two light sources are shown, which are shown as light sources la and lb, respectively.
  • three light splitters are shown, which are shown as light splitters 21, 22, and 23, respectively. Note that
  • 15 is an optical frequency manager and 16 is an optical switch.
  • the light source 1a is connected to the light distributor 21 and the light source 1b is Distributor 22 is connected to 2.
  • One of two outputs of the optical distributor 21 is connected to the optical frequency controller 15, and the other is connected to the optical switch 16.
  • One of the two outputs of the optical distributor 22 is connected to the optical frequency manager 15, and the other is connected to the optical distributor 23.
  • One of two outputs of the optical distributor 23 is connected to the optical switch 16, and the other is connected to the heterodyne receiver 7.
  • the output of the optical frequency controller 15 is connected to the light source 1a.
  • the optical switch 16 is connected to the optical amplifier 5 and the code sequence generator 4.
  • the light source 1a generates an optical signal having a frequency f2 in a continuous wave.
  • the light source 1b generates an optical signal having a frequency f0 as a continuous wave.
  • the code sequence generator 4 generates a modulated signal based on the code sequence and transmits the modulated signal to the optical switch 16. Also, a trigger signal indicating the transmission timing of the modulation signal is transmitted to the A / D converter 12.
  • the optical switch 16 selects and outputs one of the two optical signals based on the modulation signal from the code sequence generator 4. Therefore, the frequency of the output signal of the optical modulator 3 is subjected to FSK (Frequency Shift Keying), and becomes f0 and f2 corresponding to + and one of the code sequence.
  • FSK Frequency Shift Keying
  • the optical frequency controller 15 manages the frequency difference between the optical signals from the two light sources 1a and 1b, and controls the light source 1a so that the frequency difference maintains a constant value (f2-f0). multiply. As a result, even when the frequency of the optical signal generated from the light source 1a is unstable and fluctuates with time, there is an effect that this fluctuation can be automatically compensated. A part of the optical signal from the light source 1 b (one of the two outputs from the optical distributor 23) is sent to the heterodyne receiver 7 as a light beam.
  • the transmission light subjected to FSK at the frequencies f0 and f2 and the local light having the frequency f0 were generated.

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  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Multimedia (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
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Abstract

La présente invention concerne un dispositif radar Doppler à laser capable de mesurer avec un rapport N/S élevé même lorsque la phase de la lumière reçue fluctue et capable de détecter la vitesse d'un vent dans une plage de mesure même lorsque les composants du signal d'une pluralité de plage se chevauchent sur la lumière reçue. Ce dispositif comprend une source lumineuse, un générateur de série de codes destiné à générer un signal de modulation conformément à une série de codes, un dispositif de modulation optique destiné à la modulation FSK d'un signal lumineux en provenance de la source lumineuse par deux fréquences en conformité avec le signal de modulation, un bloc d'émission/réception optique destiné à émettre le signal optique modulé FSK dans l'atmosphère et à recevoir une lumière de réception d'une pluralité de plage dans l'atmosphère, un diviseur optique destiné à diviser le signal lumineux en provenance de la source lumineuse et à générer une lumière locale, un convertisseur destiner à transformer le signal détecté analogique en signal numérique, un récepteur hétérodyne destiné à détecter par effet hétérodyne la lumière reçue et, un bloc de traitement de signal destiné à traiter le signal. Ce bloc de traitement de signal annule un composant de signal issu d'une plage différente de la plage de mesure dans l'atmosphère et il détecte une fréquence Doppler dans la plage de mesure.
PCT/JP2002/005215 2002-05-29 2002-05-29 Dispositif radar doppler a laser WO2003100458A1 (fr)

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US7209222B2 (en) 2002-12-27 2007-04-24 Mitsubishi Denki Kabushiki Kaisha Laser radar apparatus
US7274437B2 (en) 2003-02-19 2007-09-25 Mitsubishi Denki Kabushiki Kaisha Laser detection and ranging apparatus
US7391506B2 (en) 2004-05-19 2008-06-24 Qinetiq Limited Laser radar device and method
JP2009162678A (ja) * 2008-01-09 2009-07-23 Mitsubishi Electric Corp レーザレーダ装置
JP2009300133A (ja) * 2008-06-11 2009-12-24 Japan Aerospace Exploration Agency 航空機搭載用光学式遠隔気流計測装置
US8179521B2 (en) 2009-11-18 2012-05-15 Onera Measurement of speed or vibration characteristics using a LIDAR device with heterodyne detection
US9817121B2 (en) 2013-12-26 2017-11-14 Kabushiki Kaisha Toyota Chuo Kenkyusho Radar apparatus and method of determining sign of velocity
EP3413087A4 (fr) * 2016-02-05 2019-01-16 Mitsubishi Electric Corporation Dispositif de radar laser et système de contrôle de turbine éolienne
JPWO2021044534A1 (fr) * 2019-09-04 2021-03-11
JP2021515904A (ja) * 2018-09-21 2021-06-24 南京牧▲レー▼激光科技有限公司Ｎａｎｊｉｎｇ Ｍｏｖｅｌａｓｅｒ Ｔｅｃｈｎｏｌｏｇｙ Ｃｏ．，Ｌｔｄ． パルス干渉ドップラー風計測レーザーレーダー及び風計測方法
CN115951332A (zh) * 2023-03-15 2023-04-11 中国人民解放军国防科技大学 二元脉冲幅度编码测风激光雷达风速测量方法及系统

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CN113176581B (zh) * 2021-03-15 2021-12-31 北京华信科创科技有限公司 一种多普勒脉冲激光测风装置、方法及系统

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JPH02114241A (ja) * 1988-10-25 1990-04-26 Matsushita Electric Ind Co Ltd 光コヒーレント周波数シフトキーイング送信器
JPH06148326A (ja) * 1992-11-05 1994-05-27 Nkk Corp 光ｔｄｒによる計測方法及び装置
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JP2000338246A (ja) * 1999-05-28 2000-12-08 Mitsubishi Electric Corp コヒーレントレーザレーダ装置

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7209222B2 (en) 2002-12-27 2007-04-24 Mitsubishi Denki Kabushiki Kaisha Laser radar apparatus
US7274437B2 (en) 2003-02-19 2007-09-25 Mitsubishi Denki Kabushiki Kaisha Laser detection and ranging apparatus
US7391506B2 (en) 2004-05-19 2008-06-24 Qinetiq Limited Laser radar device and method
JP2009162678A (ja) * 2008-01-09 2009-07-23 Mitsubishi Electric Corp レーザレーダ装置
JP2009300133A (ja) * 2008-06-11 2009-12-24 Japan Aerospace Exploration Agency 航空機搭載用光学式遠隔気流計測装置
US8179521B2 (en) 2009-11-18 2012-05-15 Onera Measurement of speed or vibration characteristics using a LIDAR device with heterodyne detection
US9817121B2 (en) 2013-12-26 2017-11-14 Kabushiki Kaisha Toyota Chuo Kenkyusho Radar apparatus and method of determining sign of velocity
EP3413087A4 (fr) * 2016-02-05 2019-01-16 Mitsubishi Electric Corporation Dispositif de radar laser et système de contrôle de turbine éolienne
US10253756B2 (en) 2016-02-05 2019-04-09 Mitsubishi Electric Corporation Laser radar device and wind turbine control system
JP2021515904A (ja) * 2018-09-21 2021-06-24 南京牧▲レー▼激光科技有限公司Ｎａｎｊｉｎｇ Ｍｏｖｅｌａｓｅｒ Ｔｅｃｈｎｏｌｏｇｙ Ｃｏ．，Ｌｔｄ． パルス干渉ドップラー風計測レーザーレーダー及び風計測方法
JP7029620B2 (ja) 2018-09-21 2022-03-04 南京牧▲レー▼激光科技有限公司 パルス干渉ドップラー風計測レーザーレーダー及び風計測方法
JPWO2021044534A1 (fr) * 2019-09-04 2021-03-11
WO2021044534A1 (fr) * 2019-09-04 2021-03-11 日本電気株式会社 Dispositif de mesure de distance optique et procédé de mesure de distance optique
JP7248132B2 (ja) 2019-09-04 2023-03-29 日本電気株式会社 光測距装置及び光測距方法
CN115951332A (zh) * 2023-03-15 2023-04-11 中国人民解放军国防科技大学 二元脉冲幅度编码测风激光雷达风速测量方法及系统

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