CN113819999A - Phase demodulation method and system based on full-digital phase shift - Google Patents
Phase demodulation method and system based on full-digital phase shift Download PDFInfo
- Publication number
- CN113819999A CN113819999A CN202111111918.XA CN202111111918A CN113819999A CN 113819999 A CN113819999 A CN 113819999A CN 202111111918 A CN202111111918 A CN 202111111918A CN 113819999 A CN113819999 A CN 113819999A
- Authority
- CN
- China
- Prior art keywords
- phase
- signal
- optical fiber
- signals
- demodulation method
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
- G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Communication System (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention discloses a phase demodulation method and a system based on full-digital phase shift, wherein the phase demodulation method comprises the following steps: acquiring a beat frequency signal; filtering out a direct current component in the beat frequency signal, and leaving an alternating current component containing phase information; performing Hilbert transform on alternating current components in the beat frequency signal to obtain an orthogonal signal; removing fundamental frequency in the orthogonal signal and performing phase shift to obtain three paths of signals with phase difference
The signal of (a); and demodulating the three paths of signals with the phase difference to obtain phase information. The phase demodulation method has the advantages that the phase demodulation method can effectively demodulate the phase of the sensing system through a digital algorithm, does not need a plurality of photoelectric detectors to combine with signal analysis hardware for phase demodulation, and has simple system, low cost and no introduction of extra system noise. In addition, the demodulation method can accurately generate three paths of 120-degree phase difference signals and eliminate system deviation, and an additional optical fiber interference structure is not needed at the demodulation end, so that the demodulation method can also generate three paths of 120-degree phase difference signalsEffectively improving the signal strength and the signal-to-noise ratio.
Description
Technical Field
The invention relates to a full-digital phase-shifting phase demodulation method for a phase-sensitive optical time domain reflectometer system, which is used for phase demodulation and analysis of coherent photoelectric signals of the phase-sensitive optical time domain reflectometer system. The phase-sensitive optical time domain reflectometer system can be digitally demodulated, and then the distributed optical fiber vibration sensing signal can be analyzed in real time, so that information such as external vibration and the like received by the optical fiber can be effectively acquired.
Background
The distributed optical fiber sensing technology has become a research hotspot at home and abroad in the field of optical fiber sensing application at present due to the advantages of small volume, simple structure, high sensitivity, corrosion resistance, high temperature resistance, electromagnetic interference resistance and the like. Wherein the phase-sensitive optical time-domain reflectometer is
The system, as a novel distributed optical fiber sensing technology, has the characteristics of simple structure, high sensitivity, good real-time performance, wide dynamic range, high response speed and the like, and plays an important role in the fields of long-distance perimeter security protection, oil and gas pipeline safety condition monitoring, large-scale structure health monitoring and the like.
Disclosure of Invention
The invention aims to solve the technical problem of providing a full-digital phase-shifting phase demodulation method and system for a phase-sensitive optical time domain reflectometer system, which are used for phase demodulation and analysis of coherent photoelectric signals of the phase-sensitive optical time domain reflectometer system. The phase-sensitive optical time domain reflectometer system can be digitally demodulated, and then the distributed optical fiber vibration sensing signal can be analyzed in real time, so that information such as external vibration and the like received by the optical fiber can be effectively acquired. The phase demodulation method has the advantages that the phase demodulation method can effectively demodulate the phase of the sensing system through a digital algorithm, does not need a plurality of photoelectric detectors to combine with signal analysis hardware for phase demodulation, and has simple system, low cost and no introduction of extra system noise. In addition, the demodulation method can accurately generate three paths of 120-degree phase difference signals and eliminate system deviation, and an additional optical fiber interference structure is not needed at the demodulation end, so that the signal intensity and the signal-to-noise ratio can be effectively improved.
In order to solve the technical problems, the invention adopts the technical scheme that:
the phase demodulation method based on full digital phase shift comprises the following steps:
acquiring a beat frequency signal;
filtering out a direct current component in the beat frequency signal, and leaving an alternating current component containing phase information;
performing Hilbert transform on alternating current components in the beat frequency signal to obtain an orthogonal signal; removing fundamental frequency in the orthogonal signal and performing phase shift to obtain three paths of signals with phase difference
The signal of (a); and demodulating the three paths of signals with the phase difference to obtain phase information.
The invention relates to a full-digital phase-shifting phase demodulation method of a phase-sensitive optical time domain reflectometer system, which is used for phase demodulation and analysis of coherent photoelectric signals of the phase-sensitive optical time domain reflectometer system, and the specific method comprises the following steps: on the basis of performing Hilbert orthogonal transformation on a backscattering heterodyne coherent signal of a distributed optical fiber sensing system, a triangular cross product transformation algorithm is adopted, three paths of phase difference signals of 120 degrees are generated while signal fundamental frequency is eliminated, on the basis, the phase of the heterodyne coherent signal is obtained through differential cross multiplication and integral phase extraction, and finally the phase of the backscattering signal of the phase sensitive optical time domain reflectometer system is analyzed in real time through the algorithm, and information such as external vibration and the like received by an optical fiber is effectively obtained.
The technical scheme for realizing the invention is to use Rayleigh scattered light returned from the optical fiber to be tested and local light separated from a light source to carry out mixed beat frequency. After the signal passes through the balance detector, the direct current component of the signal is filtered out, and an alternating current component containing phase information is left. And then the acquisition module performs analog-to-digital conversion on the signal and sends the signal to the signal processing module to demodulate the information to be detected by using an algorithm. The algorithm firstly utilizes Hilbert transform to transform an orthogonal signal of a signal detected by a detector, then uses triangular transform to remove a delta omega.t term (fundamental frequency) in a beat signal and carries out phase shift, thereby changing into three paths with phase difference
Of the signal of (1). The three signals are then processed by differential cross multiplication to demodulate the phase information.
Generation of beat signals:
local lighting:
in the formula, EL0Is the amplitude of the local light, ω is the optical field frequency,
is the initial phase of the local light;
backward rayleigh scattering light:
in the formula, ER0To be the amplitude of the scattered light, ω is the optical field frequency, Δ ω is the optical frequency shift introduced by the acousto-optic modulator,
is the phase of the interference field;
the beat frequency signal detected by the balance detector is:
transformed by a trigonometric function:
wherein,
the first two terms represent the direct current part of the light intensity, the frequency of the third term and the fourth term is in the optical frequency magnitude, the existing optical detector can not achieve the high response speed, so the two terms do not influence the detector, and the last term is the alternating current part of the light intensity signal, namely the beat frequency signal. Due to the rejection of the common mode signal by the balanced detector (BPD), the ac component is detected by the BPD.
The orthogonal signal of the signal detected by the detector is transformed by using Hilbert transform, which is characterized in that: and performing Hilbert transform on the coherent signal output by the photoelectric detector acquired by the digital acquisition card, and taking the imaginary part of the coherent signal to obtain an orthogonal signal of the beat frequency signal.
In the step, the method for acquiring the orthogonal signal comprises the following steps: the hilbert transform is defined as a 90 ° phase shifter for real signals, and hilbert orthogonal transform is applied to the signal x (t), and is mathematically defined as:
after hilbert (I), i.e., hilbert (I), y ═ I + iQ is obtained; wherein the imaginary part after the change is the quadrature signal and Q ═ imag (y); wherein hilbert (I) is to perform Hilbert transform on the signal I; q ═ imag (y) is the imaginary part corresponding to the hubert transform result; q is the beat signal
Of orthogonal signals, i.e.
The triangular cross product transform removes the fundamental frequency in the beat signal and performs phase shift, characterized by the steps of: by utilizing trigonometric function relation and digital algorithm, the fundamental frequency in the beat frequency signal is removed, and three paths of signals with phase differences are obtained by digital virtual phase shifting
Of the signal of (1).
In the step, three paths with phase differences are obtained
The method of (2):
as used in us
In the system, Δ ω ═ 2 pi × Δ f, Δ f is the frequency shift amount generated by the acousto-optic modulator; i is0＝EL0ER0；
Differential cross multiplication processes three signals, characterized by comprising the steps of:
step one, three paths of alternating current signals P1、P2、P3Respectively marked as a, b and c;
step two, differentiating a, b and c respectively and recording as d, e and f;
multiplying the differential difference of each path of signal a, b and c with the other two paths of signals, and recording as N1, N2 and N3;
step four, adding N1, N2 and N3, and recording as NN;
step five, in order to eliminate I0The influence is caused by that 3 input signals, namely squares of a, b and c, are marked as MM;
step six, dividing NN by MM to eliminate I0 2Noted as dNM;
step seven, integrating dNM;
in the second step, the first step is carried out,
in the third step, the first step is that,
in the fourth step of the method, the first step of the method,
in the fifth step, the process is carried out,
in the sixth step, in the step III,
in the seventh step, the number of the first step,
the phase is extracted. Namely, it is
The invention aims to provide a full-digital phase-shifting phase demodulation method of a phase-sensitive optical time domain reflectometer system by utilizing data acquired from a data acquisition card, which is used for phase demodulation and analysis of coherent photoelectric signals of the phase-sensitive optical time domain reflectometer system. The phase-sensitive optical time domain reflectometer system can be digitally demodulated, and then the distributed optical fiber vibration sensing signal can be analyzed in real time, so that information such as external vibration and the like received by the optical fiber can be effectively acquired. The phase demodulation method has the advantages that the phase demodulation method can effectively demodulate the phase of the sensing system through a digital algorithm, does not need a plurality of photoelectric detectors to combine with signal analysis hardware for phase demodulation, and has simple system, low cost and no introduction of extra system noise. In addition, the demodulation method can accurately generate three paths of 120-degree phase difference signals and eliminate system deviation, and an additional optical fiber interference structure is not needed at the demodulation end, so that the signal intensity and the signal-to-noise ratio can be effectively improved.
Has the advantages that: compared with the prior art, the invention has the following characteristics:
the algorithm uses the structural characteristics and the demodulation method of the 3 multiplied by 3 coupler for reference, realizes full digitalization of removing the fundamental frequency and phase shift, and finally realizes phase demodulation. Compared with the traditional 3 multiplied by 3 coupler demodulation method, the method has the advantages that the phase of the sensing system can be effectively demodulated through a digital algorithm, a plurality of photoelectric detectors are not required to be combined with signal analysis hardware for phase demodulation, the system is simple, the cost is low, and extra system noise is not introduced. In addition, the demodulation method can accurately generate three paths of 120-degree phase difference signals and eliminate system deviation, and an additional optical fiber interference structure is not needed at the demodulation end, so that the signal intensity and the signal-to-noise ratio can be effectively improved.
Drawings
Fig. 1 is a schematic diagram of a specific structure of the present invention.
FIG. 2 is a flow chart of the algorithm of the present invention.
Fig. 3 is a comparison graph of the effect of the simulation test of the present invention.
Fig. 4 is a graph of the effect of the simulation test of the present invention.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings, but the scope of the present invention should not be limited thereto.
Example 1:
the present embodiment will be described in detail with reference to fig. 1.
The invention
The system comprises a narrow-linewidth semiconductor laser light source 1, a first optical fiber coupler 2, an acousto-optic modulator 3, a signal generator, a first erbium-doped optical fiber amplifier 4, a first filter 5, a circulator 6, a second erbium-doped optical fiber amplifier 8, a second filter 9, a second optical fiber coupler 10, a photoelectric detector 11, a data acquisition card 12, a phase demodulation unit 13 and a computer 14. The connection mode of the system is as follows: the output end of a narrow-linewidth semiconductor laser light source 1 is connected with the input end of a first optical fiber coupler 2, the first output end of the first optical fiber coupler 2 is sequentially connected with the input end of an acousto-optic modulator 3, the output end of the acousto-optic modulator 3 is connected with the input end of a first erbium-doped optical fiber amplifier 4, the output end of the first erbium-doped optical fiber amplifier 4 is connected with the input end of a first filter 5, the output end of the first filter 5 is connected with the input end of a circulator 6, the reflecting end of the circulator 6 is connected with a sensing optical fiber 7, the output end of the circulator 6 is connected with the input end of a second erbium-doped optical fiber amplifier 8, the output end of the second erbium-doped optical fiber amplifier 8 is connected with the input end of a second filter 9, the output end of the second filter 9 is connected with the first input end of a second optical fiber coupler 10, the second input end of the second optical coupler 10 is connected with the second output end of the first coupler 2, the first output end of the second optical coupler 10 is connected with the input end of a data acquisition card 12, the output end of the data acquisition card 12 is connected with the phase demodulation unit 13 and the computer 14.
Light emitted by a narrow-linewidth semiconductor laser light source 1 enters a first coupler 2 and then is divided into two paths (one path of local light and the other path of detection light), one path of detection light directly enters an acousto-optic modulator 3 for pulse modulation and generates a frequency shift delta f, the detection light sequentially passes through a first erbium-doped optical fiber amplifier 4, a first filter 5 and a circulator 6 and then enters a sensing optical fiber 7 to generate backward Rayleigh scattering light and is transmitted back to the circulator and then enters a second erbium-doped optical fiber amplifier 8, a second filter 9 and a second optical fiber coupler 10, the other path of detection light is connected with a second coupler 10, the second optical fiber coupler 10 is connected with a photoelectric detector 11, the local light and the detection light are subjected to beat frequency interference, and the photoelectric detector 11 is sequentially connected with a data acquisition card 12, a phase demodulation unit 13 and a computer 14.
The specific implementation process of the invention comprises the following steps: an optical signal with the working wavelength of 1550nm emitted by a narrow-linewidth laser 1 passes through a first coupler 2 with the splitting ratio of 9:1 and then is divided into two paths for transmission, wherein 90% of one path of light enters an acoustic-optical modulator 3 and is modulated into pulse light with the frequency shift of 200MHz, the pulse light is amplified by a first erbium-doped optical fiber amplifier 4 to generate ASE noise, the ASE noise generated by the amplification of the amplifier is filtered by a first band-pass filter 5 with the bandwidth of 1550nm and the bandwidth of 1nm, the signal light enters a sensing optical fiber 7 subjected to external vibration by a circulator 6, backward scattered light Rayleigh is generated at each point on the optical fiber during transmission on the sensing optical fiber 7, the backward scattered light is transmitted by the circulator to enter a second erbium-doped optical fiber amplifier 8 to be amplified again to generate the ASE noise, and then the backward scattered light is filtered by a second filter 9 and then enters a coupler 10 of a 1:1 second optical fiber coupler. The other 10% of the light enters a 1:1 second optical fiber coupler 10 as local light to generate interference mixing with the backward scattered light, and the generated light after beat frequency contains differential phase
The signal of the difference frequency term is finally converted into an electric signal by the detector 11 from an optical signal, the electric signal is finally analyzed by the phase demodulation unit through the data acquisition card 12, the distributed optical fiber vibration sensing signal is analyzed in real time, and information such as external vibration and the like of the optical fiber can be effectively acquired by comparing phases at different moments.
Example 2:
the invention also provides a phase demodulation method based on full-digital phase shift, which comprises the following steps with reference to fig. 2:
acquiring a beat frequency signal;
filtering out a direct current component in the beat frequency signal, and leaving an alternating current component containing phase information;
performing Hilbert transform on alternating current components in the beat frequency signal to obtain an orthogonal signal; removing fundamental frequency in the orthogonal signal and performing phase shift to obtain three paths of signals with phase difference
The signal of (a); and demodulating the three paths of signals with the phase difference to obtain phase information.
The specific implementation steps of this embodiment are as follows:
step one, extracting direct current component I of beat frequency signal I (t) detected by a detectorL(t) of (d). Wherein:
wherein, I (t) is the real-time intensity of the beat signal; eL0Amplitude of the local light; omega is the optical field frequency;
is the initial phase of the local light; eR0Amplitude of the backward rayleigh scattered light; delta omega is the optical frequency shift introduced by the acousto-optic modulator;
is the phase of the interference field.
Performing trigonometric function transformation on the beat frequency signal to obtain:
wherein,
extracting an alternating current component of the light intensity signal:
in the formula, EL0Amplitude of the local light; eR0Amplitude of the backward rayleigh scattered light; delta omega is the optical frequency shift introduced by the acousto-optic modulator;
is phase information; t is time;
and secondly, transforming an orthogonal signal of the signal detected by the detector by using Hilbert orthogonal transformation, and obtaining an imaginary part of the orthogonal signal to obtain an orthogonal signal of the beat frequency signal. The method for acquiring the orthogonal signal comprises the following steps: MATLAB, y ═ hilbert (i); q ═ imag (y); wherein y ═ hilbert (I) is a hilbert transform on signal I; q ═ imag (y) is the imaginary part of the hilbert transform result pair; q is the beat signal
Of orthogonal signals, i.e.
Step three, triangular cross product transformation removes a delta omega t term (fundamental frequency) in the beat frequency signal and carries out phase shift, namely cos (alpha-beta) ═ cos alpha. sin beta + sin alpha. cos beta. removes the fundamental frequency in the beat frequency signal and carries out phase shift so as to obtain three paths of signals with phase difference
Of the signal of (1). Obtaining three paths with phase difference
The method of (2):
as used in us
In the system, Δ ω ═ 2 pi ═ Δ f, Δ f ═ 200 MHZ; i is0＝EL0ER0；
Step four, differential cross multiplication processing three-way signals: will three-way signal P1、P2、P3Respectively removing direct current items, and marking as a, b and c;
further differentiating a, b, c, respectively, as d, e, f:
further, multiplying the difference of the signals a, b and c with the differential of the other two paths, and recording the difference as N1, N2 and N3:
further add N1, N2, N3, denoted as NN:
further in order to eliminate I0The influence is caused by that 3 input signals, namely squares of a, b and c, are marked as MM;
further dividing NN by MM to eliminate I0 2And is recorded as dNM:
further integrate dNM;
step five, extracting phase
To illustrate the reliability of the algorithm, the effectiveness of the invention is illustrated by comparing the following simulation test and test analysis results:
1. analog vibration loading arrangement
The frequency f1 of the vibration signal loaded on the optical fiber is simulated to be 5000, and the data acquisition cardThe sampling rate fs is 1GHz, and the total sampling N is 4 x 106And point, the frequency shift delta f of the acousto-optic modulator is 200 MHz.
2. Simulation results
Simulating a vibration signal phi 10 cos (2 pi f1 t) loaded on the optical fiber based on the MATLAB platform; beat frequency signal
Phase demodulation is performed according to the above real-time scheme of the present invention, and fig. 3 is a comparison of the demodulated phase signal with the analog applied vibration signal, i.e., the original signal waveform and spectrum. In order to distinguish the demodulated signal from the original signal conveniently from the figure, the demodulation result is output
I.e. the original vibration signal
And (4) doubling. As can be seen from fig. 3, the demodulated waveform spectrum completely coincides with the original signal, and fig. 4 is a result of analyzing the spectrum of the demodulated signal, which shows that the frequency of the demodulated signal is 5000, which coincides with the frequency of the applied original signal, thus proving the feasibility and reliability of the algorithm.
Claims (10)
1. The phase demodulation method based on full digital phase shift is characterized by comprising the following steps:
acquiring a beat frequency signal;
filtering out a direct current component in the beat frequency signal, and leaving an alternating current component containing phase information;
performing Hilbert transform on alternating current components in the beat frequency signal to obtain an orthogonal signal; removing fundamental frequency in the orthogonal signal and performing phase shift to obtain three paths of signals with phase difference
The signal of (a); and demodulating the three paths of signals with the phase difference to obtain phase information.
2. The fully digital phase shift based phase demodulation method according to claim 1, wherein the obtained beat signal is:
wherein, I (t) is the real-time intensity of the beat signal; eL0Amplitude of the local light; omega is the optical field frequency;
is the initial phase of the local light; eR0Amplitude of the backward rayleigh scattered light; delta omega is the optical frequency shift introduced by the acousto-optic modulator;
is the phase of the interference field.
3. The fully digital phase-shifting based phase demodulation method according to claim 2, wherein the method for filtering out the dc component of the beat signal and leaving the ac component containing the phase information comprises:
performing trigonometric function transformation on the beat frequency signal to obtain:
wherein,
extracting an alternating current component of the light intensity signal:
in the formula IL(t) is an alternating current component of the light intensity signal.
4. The fully digital phase shift based phase demodulation method according to claim 3, wherein the method for demodulating three signals with phase difference to obtain phase information comprises the following steps:
step one, three paths of alternating current signals P1、P2、P3Respectively marked as a, b and c;
step two, differentiating a, b and c respectively and recording as d, e and f;
multiplying the differential difference of each path of signal a, b and c with the other two paths of signals, and recording as N1, N2 and N3;
step four, adding N1, N2 and N3, and recording as NN;
fifthly, squaring 3 input signals a, b and c, and recording the squared input signals as MM;
dividing the MM by the NN, and recording as dNM;
and step seven, integrating dNM and extracting the phase.
5. The fully digital phase shift based phase demodulation method according to claim 1,
the quadrature signal Q of the beat signal is obtained as:
6. the fully digital phase shift based phase demodulation method according to claim 4,
in the second step, the first step is carried out,
in the formula I0＝EL0ER0。
7. The fully digital phase shift based phase demodulation method according to claim 6,
in the third step, the first step is that,
in the fourth step of the method, the first step of the method,
in the fifth step, the process is carried out,
in the sixth step, in the step III,
in the seventh step, the number of the first step,
extracting phase
8. The fully digital phase shift based phase demodulation method according to claim 4, wherein the obtained phase difference
The three signals are respectively:
in the formula, Δ ω ═ 2 pi × Δ f, Δ f is the frequency shift amount generated by the acousto-optic modulator; i is0＝EL0ER0。
9. A phase demodulation system based on full-digital phase shifting comprises a narrow-linewidth semiconductor laser light source, a first coupler, an acousto-optic modulator, a first optical fiber amplifier, a first filter, a circulator, a sensing optical fiber, a second optical fiber amplifier, a second filter, a second optical fiber coupler and a photoelectric detector which are sequentially connected with a data acquisition card and a phase demodulation unit; light emitted by the narrow-linewidth semiconductor laser light source enters the first coupler and then is divided into a path of detection light and a path of local light, one path of detection light directly enters the acousto-optic modulator for pulse modulation and generates a frequency shift delta f, the detection light sequentially passes through the first optical fiber amplifier, the first filter and the circulator and then enters the sensing optical fiber to generate backward Rayleigh scattering light, the generated backward Rayleigh scattering light is transmitted back and enters the second optical fiber amplifier, the second filter and the second optical fiber coupler through the circulator, the other path of local light is connected with the second coupler, the second optical fiber coupler is connected with the balance photoelectric detector, the local light and the detection light are subjected to beat frequency interference, and the balance photoelectric detector is sequentially connected with the data acquisition card and the phase demodulation unit; after the signal passes through the balanced photoelectric detector, the direct current component is filtered out, and an alternating current component containing phase information is left; the data acquisition card performs analog-to-digital conversion on the signals and sends the signals to the phase demodulation unit to demodulate the information to be detected.
10. The fully digital phase shift based phase demodulation system of claim 9, wherein: the first optical fiber amplifier is a first erbium-doped optical fiber amplifier; the second optical fiber amplifier is a second erbium-doped optical fiber amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111111918.XA CN113819999B (en) | 2021-09-23 | 2021-09-23 | Phase demodulation method and system based on full-digital phase shift |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111111918.XA CN113819999B (en) | 2021-09-23 | 2021-09-23 | Phase demodulation method and system based on full-digital phase shift |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113819999A true CN113819999A (en) | 2021-12-21 |
| CN113819999B CN113819999B (en) | 2024-07-16 |
Family
ID=78915141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111111918.XA Active CN113819999B (en) | 2021-09-23 | 2021-09-23 | Phase demodulation method and system based on full-digital phase shift |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113819999B (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2387944A1 (en) * | 1999-10-29 | 2001-05-17 | David B. Hall | Optical method for the transmission of signals from remote arrays of electrical sensors |
| US20060061769A1 (en) * | 2004-09-03 | 2006-03-23 | California Institute Of Technology | Homodyne based optical coherence microscope |
| CN102322880A (en) * | 2011-08-18 | 2012-01-18 | 天津大学 | Polarization sensitive distributive optical frequency domain reflection disturbance sensor and demodulation method |
| CN102538845A (en) * | 2011-12-08 | 2012-07-04 | 北京航空航天大学 | Multi-point disturbance location method and optical fiber distribution type disturbance sensor |
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN105092015A (en) * | 2015-05-18 | 2015-11-25 | 清华大学 | Non-contact fiber vibration sensing system and method |
| CN105915481A (en) * | 2016-05-20 | 2016-08-31 | 中国电子科技集团公司第十研究所 | Multi-path high-speed wideband signal analog phase modulation method |
| US9651477B1 (en) * | 2016-04-01 | 2017-05-16 | The United States Of America, As Represented By The Secretary Of The Army | Method and apparatus for simultaneous observation of three-degrees of vibrational freedom using single heterodyne beam |
| CN107505041A (en) * | 2017-07-31 | 2017-12-22 | 南京发艾博光电科技有限公司 | A kind of phase demodulating device and method based on phase sensitive optical time domain reflectometer |
| CN110470376A (en) * | 2019-08-16 | 2019-11-19 | 天津大学 | A kind of interference distribution type fiber-optic sound sensing device and its method for sensing |
| CN111157098A (en) * | 2019-12-31 | 2020-05-15 | 中国科学院长春光学精密机械与物理研究所 | Demodulation device for simultaneously obtaining amplitude and phase of vibration signal |
| CN111294046A (en) * | 2020-02-18 | 2020-06-16 | 广州全盛威信息技术有限公司 | Divider circuit and method for generating IQ signal and ultra-wideband local oscillation generator |
| US20200209020A1 (en) * | 2017-07-26 | 2020-07-02 | Terra15 Pty Ltd | Distributed optical sensing systems and methods |
-
2021
- 2021-09-23 CN CN202111111918.XA patent/CN113819999B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2387944A1 (en) * | 1999-10-29 | 2001-05-17 | David B. Hall | Optical method for the transmission of signals from remote arrays of electrical sensors |
| US20060061769A1 (en) * | 2004-09-03 | 2006-03-23 | California Institute Of Technology | Homodyne based optical coherence microscope |
| CN102322880A (en) * | 2011-08-18 | 2012-01-18 | 天津大学 | Polarization sensitive distributive optical frequency domain reflection disturbance sensor and demodulation method |
| WO2013023425A1 (en) * | 2011-08-18 | 2013-02-21 | 天津大学 | Polarization sensitive distributed optical frequency domain reflection turbulence sensing device and demodulation method |
| CN102538845A (en) * | 2011-12-08 | 2012-07-04 | 北京航空航天大学 | Multi-point disturbance location method and optical fiber distribution type disturbance sensor |
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN105092015A (en) * | 2015-05-18 | 2015-11-25 | 清华大学 | Non-contact fiber vibration sensing system and method |
| US9651477B1 (en) * | 2016-04-01 | 2017-05-16 | The United States Of America, As Represented By The Secretary Of The Army | Method and apparatus for simultaneous observation of three-degrees of vibrational freedom using single heterodyne beam |
| CN105915481A (en) * | 2016-05-20 | 2016-08-31 | 中国电子科技集团公司第十研究所 | Multi-path high-speed wideband signal analog phase modulation method |
| US20200209020A1 (en) * | 2017-07-26 | 2020-07-02 | Terra15 Pty Ltd | Distributed optical sensing systems and methods |
| CN107505041A (en) * | 2017-07-31 | 2017-12-22 | 南京发艾博光电科技有限公司 | A kind of phase demodulating device and method based on phase sensitive optical time domain reflectometer |
| CN110470376A (en) * | 2019-08-16 | 2019-11-19 | 天津大学 | A kind of interference distribution type fiber-optic sound sensing device and its method for sensing |
| CN111157098A (en) * | 2019-12-31 | 2020-05-15 | 中国科学院长春光学精密机械与物理研究所 | Demodulation device for simultaneously obtaining amplitude and phase of vibration signal |
| CN111294046A (en) * | 2020-02-18 | 2020-06-16 | 广州全盛威信息技术有限公司 | Divider circuit and method for generating IQ signal and ultra-wideband local oscillation generator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113819999B (en) | 2024-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113852416B (en) | Phase demodulation method and device with fading noise identification and elimination function | |
| CN103954348B (en) | Based on the distributed optical fiber vibration sensing system of differential pulse sequence | |
| CN102628698B (en) | Distributed optical fiber sensor and information demodulating method | |
| CN105136175B (en) | A kind of phase sensitive optical time domain reflection system based on self-mixing technology | |
| EP4042116B1 (en) | Signal processing methods for an optical detection system | |
| CN102645268A (en) | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer | |
| CN107560644B (en) | Distributed optical fiber sensing device based on signal multiplexing perception and demodulation | |
| AU2020102296A4 (en) | A distributed optical fiber sensing system based on heterodyne detection technology | |
| CN109459126A (en) | A kind of distributed optical fiber vibration sensing device and method reducing detection dead zone probability | |
| US10656083B2 (en) | Chirped laser dispersion spectroscopy sensitivity booster | |
| CN113091782B (en) | Phase-sensitive optical time-domain reflectometry system and phase demodulation method based on PGC | |
| CN116295782B (en) | Distributed optical fiber vibration sensing system based on phi-OTDR and phase demodulation method | |
| CN110487308A (en) | A kind of high-performance coherent detection type Φ-OTDR realization system and method based on PGC demodulation | |
| CN113124994A (en) | Distributed vibration sensing demodulation method based on weak signal-to-noise ratio signal | |
| CN113203552A (en) | Quick vector measurement device and measurement method based on double-optical-frequency comb | |
| CN110411334B (en) | Improved phase carrier PGC demodulation method and system | |
| CN205898286U (en) | Distributed Fiber Optic Vibration Sensing System Can Eliminate Fading Noise | |
| CN113819999B (en) | Phase demodulation method and system based on full-digital phase shift | |
| CN113390446A (en) | Phase-locked phi-OTDR system with high operation efficiency | |
| CN205785254U (en) | A kind of phase demodulating system of phase sensitive OTDR | |
| CN115901043B (en) | Power cable external force monitoring system and method based on distributed optical fiber sensing | |
| CN117129023A (en) | A coherence and polarization fading suppression method for phase-sensitive light time domain reflectometry | |
| CN113820000A (en) | Phase demodulation method of phase sensitive optical time domain reflection optical fiber sensing system | |
| CN115560784A (en) | Device and method for improving dynamic strain range of phase-sensitive optical time domain reflectometer | |
| CN114050867A (en) | Signal compensation method, device, equipment and storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |