CN109521222A - A method of improving laser velocimeter precision - Google Patents
A method of improving laser velocimeter precision Download PDFInfo
- Publication number
- CN109521222A CN109521222A CN201811333089.8A CN201811333089A CN109521222A CN 109521222 A CN109521222 A CN 109521222A CN 201811333089 A CN201811333089 A CN 201811333089A CN 109521222 A CN109521222 A CN 109521222A
- Authority
- CN
- China
- Prior art keywords
- value
- current time
- velocity
- precision
- speed
- 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
- 238000000034 method Methods 0.000 title claims abstract description 26
- 230000003595 spectral effect Effects 0.000 claims description 26
- 238000005259 measurement Methods 0.000 claims description 16
- 238000001228 spectrum Methods 0.000 claims description 14
- 230000003321 amplification Effects 0.000 claims description 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 2
- 238000001914 filtration Methods 0.000 abstract 1
- 238000012545 processing Methods 0.000 description 6
- 230000008901 benefit Effects 0.000 description 4
- 239000013307 optical fiber Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 239000000835 fiber Substances 0.000 description 2
- 238000012937 correction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
- G01P3/68—Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
The invention discloses a kind of methods for improving laser velocimeter precision, belong to laser Doppler velocity technique field, this method comprises the following steps, a method of improving laser velocimeter precision, this method includes, S1: at current time, the mixed frequency signal of the echo-signal for local oscillator light and the target object reflection that exploring laser light source issues；S2: the distance and speed data in mixed frequency signal are obtained, distance and the velocity component in speed data are calculated；S3: estimating the velocity information at current time, and is filtered calculating to the velocity component according to discreet value.The method of the present invention solves the problems, such as in the prior art simply using the large error that amplitude highest dot frequency is generated as Doppler frequency value in amplitude-frequency characteristic, while further improving the precision of laser velocimeter by filtering to calculate.
Description
Technical field
The present invention relates to laser Doppler velocity technique field more particularly to a kind of methods for improving laser velocimeter precision.
Background technique
Laser Doppler Velocimeter is by the laser Doppler signal of measurement moving target reflection, further according to speed and more
The general relationship for strangling frequency obtains speed.Due to being laser measurement, flow field is not interfered with, the range that tests the speed is wide, and due to more
General to strangle the temperature that frequency and speed are linear relationship and the point, pressure is not related, therefore Laser Doppler speed is relative to micro-
Wave radar velocity measurement application aspect has significant advantage.Laser Doppler velocity technique can be widely used in the measurement of fluid, Wind field measurement, vehicle
The applications such as precise speed measurement when carrying independent navigation, aircraft lands.
Existing Laser Doppler speed is generally by measurement laser Doppler shift come measuring speed.Laser-Doppler frequency
The measurement accuracy of shifting is just related to rate accuracy.Laser Doppler speed is due to Fast Fourier Transform (FFT) (Fast Fourier
Transformation, FFT) calculated result is in frequency and discontinuous, and precision depends on sample rate and FFT counts, simply
Ground can generate biggish error using amplitude highest dot frequency in amplitude-frequency characteristic as Doppler frequency value.
Summary of the invention
The embodiment of the present invention provide it is a kind of improve laser velocimeter precision method, to solve it is existing in the prior art compared with
The problem of big error.
The embodiment of the present invention provides a kind of method for improving laser velocimeter precision, and this method comprises the following steps,
Laser source is connect with other components by optical fiber, by the local oscillator light of frequency modulation and the echo by target object reflection
After signal mixing, mixed frequency signal is detected using PIN type silicon photoelectric diode；
The electric signal detected is filtered, signal amplification, FFT operation, then adjusts the distance and solved with velocity information
It calculates.
FFT operation can be realized using FPGA, before amplified signal carries out FFT transform in FPGA, amplified signal
It is multiplied point by point with Hanning window coefficient.
To reduce spectral leakage, the signal long Hanning window of the window the same with FFT points is weighted, progress FFT operation, then
Available one group of spectrum value, maximum value corresponds to spectral line and is denoted as n in frequency spectrum, takes two, the left side maximum spectral line n spectral line n-1 and n-2,
Two, the right spectral line n+1 and n+2 and maximum spectral line n itself forms one group of 5 spectral line to be corrected.Obtaining correction value is
In formula, S (n) indicates the FFT spectrum at n point.
The above are the amendments done after FFT operation to every spectrum value to n point data.According to formula
Moving object speed can be calculated, wherein λ is wavelength, and θ is the angle in laser beam direction and movement direction of object.
Calculated velocity component is filtered:
A: setting system initial value and initial coefficients；
B: the velocity amplitude at current time is estimated, v is metj=vi, wherein vjFor the discreet value of current time velocity amplitude, viTable
Show system speed value；
C: estimating the variance of current time speed, meetsWherein pjFor current time speed
The discreet value of variance, q1For coefficient, piFor the corresponding variance of current system velocity amplitude；
D: calculating yield value, meets:Wherein, wherein q2For coefficient；
E: the velocity amplitude for obtaining current time is calculated by the discreet value and actual measurement speed of current time velocity amplitude, is met:
vt=vj+kg(v-vj)
Wherein, v indicates actual measurement speed；
F: calculating the variance of current time speed, meets
G: system value, v are updatedi=vt, pi=pt；
H: in target object in search coverage or before manual stopping calculating, step b-g is repeated, to any following instant
Velocity component be filtered calculating, obtain any time accurate velocity amplitude.
The embodiment of the present invention believes speed therein by extracting mixed frequency signal and carrying out signal processing to mixed frequency signal
Breath is filtered calculating, thus solves in the prior art simply using amplitude highest dot frequency in amplitude-frequency characteristic as Doppler
The large error problem that frequency values generate.
The above description is only an overview of the technical scheme of the present invention, in order to better understand the technical means of the present invention,
And it can be implemented in accordance with the contents of the specification, and in order to allow above and other objects of the present invention, feature and advantage can
It is clearer and more comprehensible, the followings are specific embodiments of the present invention.
Detailed description of the invention
By reading the following detailed description of the preferred embodiment, various other advantages and benefits are common for this field
Technical staff will become clear.The drawings are only for the purpose of illustrating a preferred embodiment, and is not considered as to the present invention
Limitation.And throughout the drawings, the same reference numbers will be used to refer to the same parts.In the accompanying drawings:
Fig. 1 is laser doppler velocimeter system figure；
Fig. 2 is flow chart of the present invention.
Specific embodiment
Exemplary embodiments of the present disclosure are described in more detail below with reference to accompanying drawings.Although showing the disclosure in attached drawing
Exemplary embodiment, it being understood, however, that may be realized in various forms the disclosure without should be by embodiments set forth here
It is limited.On the contrary, these embodiments are provided to facilitate a more thoroughly understanding of the present invention, and can be by the scope of the present disclosure
It is fully disclosed to those skilled in the art.
First embodiment of the invention provides a kind of method for improving laser velocimeter precision, as shown in Figure 1, this method is corresponding
System is laser velocimeter system, includes laser and the laser control circuit connecting with laser, wherein laser also connects
It is connected to fiber optic circuit, fiber optic circuit is respectively connected to PIN photodiode and transmitting-receiving camera lens, and transmitting-receiving camera lens acquires target object
Relevant information.The information of PIN photodiode acquisition passes through amplifying circuit for collected signal transmission value signal acquisition and place
Circuit is managed, is finally shown by Signal sampling and processing circuit to carrying out output after the collected signal processing of institute.
Use laser for narrow-line width single frequency optical fiber laser in the present embodiment, it is small in size, light-weight, low in energy consumption, together
When its linewidth requirements be not more than 10kHz.The principle of the present invention is that laser source is connect with other components by optical fiber, by frequency modulation
Local oscillator light detects mixed frequency signal using PIN type silicon photoelectric diode with after the echo-signal that target object reflects is mixed, right
The electric signal detected is filtered, signal amplifies, FFT operation, is then adjusted the distance and is resolved with velocity information.
Specifically, the method for the present invention can be described as following steps:
Step S1: the local oscillator light and target object issued using PIN type silicon photoelectric diode detection optical fiber laser is reflected
Echo-signal mixed frequency signal.
Step S2: carrying out signal processing to the mixed frequency signal detected, obtain distance and speed data in mixed frequency signal,
Calculate distance and the velocity component in speed data.
Step S3: according to the velocity information of last moment, estimating the velocity information of subsequent time, and according to estimating
Value is filtered calculating to velocity component.
Optionally, FFT operation of the invention is realized using FPGA, before amplified signal carries out FFT transform in FPGA,
Amplified signal is multiplied point by point with Hanning window coefficient, is can reduce due to the truncation on signal time and in frequency domain in this way
Caused by spectral leakage.Direct truncated signal, can generate biggish spectral leakage, and the frequency spectrum revealed in subsequent processing causes frequency spectrum
Aliasing influences the extraction of target velocity.To reduce spectral leakage, the signal Hanning window that the window the same with FFT points is grown is added
Power carries out FFT operation, then available one group of spectrum value, and maximum value corresponds to spectral line and is denoted as n in frequency spectrum, takes the left side maximum spectral line n
Two spectral lines n-1 and n-2, two, the right spectral line n+1 and n+2 and maximum spectral line n itself form one group of 5 spectral line to carry out school
Just.
Above-mentioned steps are specially following steps:
Step S201: by the signal Hanning window weighting for identical window length of counting with FFT operation, and FFT operation is carried out, obtained
Obtain one group of corresponding spectrum value.
Step S202: taking the spectral line of maximum value in this group of spectrum value to be denoted as n, and two, spectral line left side spectral line is taken to be denoted as n-1
And n-2, two, the right spectral line n+1 and n+2, totally 5 spectral lines are corrected, and corrected value meets:
In formula, S (n) indicates the FFT spectrum at n point, f0' indicate corrected value；
Step S203: according toCalculate the speed of target object, wherein λ is wavelength, and θ is laser wave
The angle of Shu Fangxiang and movement direction of object.
According to calculated target object velocity amplitude, velocity component is filtered, the optional step if it is
Processing in real time is then realized using FPGA, if it is post-processing, then can also use general-purpose computer processes.
Calculating is filtered to velocity component to specifically include the following steps:
S31: setting system initial value and initial coefficients；
S32: the velocity amplitude at current time is estimated, v is metj=vi, wherein vjFor the discreet value of current time velocity amplitude, vi
Indicate system speed value；
S33: estimating the variance of current time speed, meetsWherein pjFor current time speed
Spend the discreet value of variance, q1For coefficient, piFor the corresponding variance of current system velocity amplitude；
S34: calculating yield value, meets:Wherein, wherein q2For coefficient；
S35: calculating the velocity amplitude for obtaining current time by the discreet value and actual measurement speed of current time velocity amplitude, full
Foot:
vt=vj+kg(v-vj)
Wherein, v indicates actual measurement speed；
S36: calculating the variance of current time speed, meets
S37: system value, v are updatedi=vt, pi=pt；
S38: in target object in search coverage or before manual stopping calculating, step S32-S37 is repeated, after any
The velocity component at continuous moment is filtered calculating, obtains any time accurate velocity amplitude.
In above-mentioned steps, the initial value of system and the specific setting of initial coefficients meet: velocity original value is set as
0.5, corresponding variance initial value is set as 10, coefficient q1、q2It is respectively set to 0.5 and 0.8.Wherein the initial value of system and
The specific setting of initial coefficients can change in a certain range, finally can converge to above-mentioned setting value.
The embodiment of the present invention is described with above attached drawing, but the invention is not limited to above-mentioned specific
Embodiment, the above mentioned embodiment is only schematical, rather than restrictive, those skilled in the art
Under the inspiration of the present invention, present inventive concept is not being departed from and claim is protected
Under the ambit of shield, many forms can be also made, all of these belong to the protection of the present invention.
Claims (6)
1. a kind of method for improving laser velocimeter precision, which is characterized in that this method includes,
S1: at current time, the mixed frequency signal of the echo-signal for local oscillator light and the target object reflection that exploring laser light source issues；
S2: the distance and speed data in mixed frequency signal are obtained, distance and the velocity component in speed data are calculated；
S3: estimating the velocity information at current time, and is filtered calculating to the velocity component according to discreet value.
2. improving the method for laser velocimeter precision as described in claim 1, which is characterized in that step S2 further include:
The mixed frequency signal detected is filtered, signal amplifies and Fast Fourier Transform (FFT) FFT operation, acquisition mixed frequency signal
In distance and speed data, calculate distance and the velocity component in speed data.
3. improving the method for laser velocimeter precision as claimed in claim 2, which is characterized in that step S2 further include:
Mixed frequency signal is filtered and signal amplification after, by amplified mixed frequency signal and the point-by-point phase of Hanning window coefficient progress
Multiply, carries out FFT operation again later.
4. improving the method for laser velocimeter precision as claimed in claim 3, which is characterized in that described to carry out again in step S2
FFT operation includes:
S201: by the Hanning window weighting for identical window length of counting with FFT operation of amplified mixed frequency signal, and FFT fortune is carried out
It calculates, obtains one group of corresponding spectrum value；
S202: taking the spectral line of maximum value in this group of spectrum value to be denoted as n, and two, spectral line left side spectral line is taken to be denoted as n-1 and n-2, right
Two, side spectral line n+1 and n+2, totally 5 spectral lines are corrected, and corrected value meets:
In formula, S (n) indicates the FFT spectrum at n point, f '0Indicate corrected value；
S203: according toCalculate the actual measurement speed of target object, wherein λ is wavelength, and θ is laser beam side
To the angle with movement direction of object.
5. improving the method for laser velocimeter precision as claimed in claim 4, which is characterized in that step S3 specifically:
S31: the velocity information at current time is estimated；
S32: the velocity information at current time is calculated according to the velocity information and actual measurement speed estimated；
S33: repeating step S31-S32, be continuously filtered calculating to the velocity component of target object, until target object is detached from
Search coverage stops calculating manually.
6. improving the method for laser velocimeter precision as claimed in claim 5, which is characterized in that step S3 specifically includes following step
It is rapid:
S301: setting system initial value and initial coefficients；
S302: the velocity amplitude at current time is estimated, v is metj=vi, wherein vjFor the discreet value of current time velocity amplitude, viIt indicates
System speed value；
S303: estimating the variance of current time speed, meetsWherein pjFor current time speed side
The discreet value of difference, q1For coefficient, piFor the corresponding variance of current system velocity amplitude；
S304: calculating yield value, meets:Wherein, wherein q2For coefficient；
S305: the velocity amplitude for obtaining current time is calculated by the discreet value and actual measurement speed of current time velocity amplitude, is met:
vt=vj+kg(v-vj)
Wherein, v indicates actual measurement speed；
S306: calculating the variance of current time speed, meets
S307: system value, v are updatedi=vt, pi=pt；
S308: in target object in search coverage or before manual stopping calculating, step S302-S307 is repeated, after any
The velocity component at continuous moment is filtered calculating, obtains any time accurate velocity amplitude.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811333089.8A CN109521222B (en) | 2018-11-09 | 2018-11-09 | Method for improving laser speed measurement precision |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811333089.8A CN109521222B (en) | 2018-11-09 | 2018-11-09 | Method for improving laser speed measurement precision |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109521222A true CN109521222A (en) | 2019-03-26 |
| CN109521222B CN109521222B (en) | 2020-12-18 |
Family
ID=65773798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811333089.8A Active CN109521222B (en) | 2018-11-09 | 2018-11-09 | Method for improving laser speed measurement precision |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109521222B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110824184A (en) * | 2019-10-12 | 2020-02-21 | 中国科学院西安光学精密机械研究所 | Data retrieval method for laser Doppler velocimeter |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101887126A (en) * | 2010-06-27 | 2010-11-17 | 清华大学 | Double-frequency laser Doppler velocity measurement method and device |
| KR20120040492A (en) * | 2010-10-19 | 2012-04-27 | 한국표준과학연구원 | Detection method of doppler signals as measured by laser doppler anemometry |
| CN102706367A (en) * | 2012-06-19 | 2012-10-03 | 北京航空航天大学 | Accuracy testing and calculating method of single-beam laser speedometer for combined navigation |
| CN103076611A (en) * | 2013-01-09 | 2013-05-01 | 中国电子科技集团公司第十一研究所 | Method and device for measuring speed and distance by coherent detecting laser |
| CN103777034A (en) * | 2014-01-22 | 2014-05-07 | 天津大学 | Two-dimensional point range type laser Doppler speed measurement device |
| CN104833816A (en) * | 2015-04-29 | 2015-08-12 | 中国人民解放军国防科学技术大学 | Laser doppler velocity measurement device based on rotating grating and velocity measurement method of laser doppler velocity measurement device |
| CN205690996U (en) * | 2016-06-08 | 2016-11-16 | 无锡机电高等职业技术学校 | A kind of photoelectrical velocity measure equipment |
| CN106199631A (en) * | 2016-09-28 | 2016-12-07 | 成都凯天电子股份有限公司 | Coherent wind radar wind measurement method |
| CN108279317A (en) * | 2018-01-23 | 2018-07-13 | 江西省智成测控技术研究所有限责任公司 | A kind of space filtering tachogenerator device and the method for improving rate accuracy |
| JP2018128279A (en) * | 2017-02-06 | 2018-08-16 | 公益財団法人鉄道総合技術研究所 | Elastic wave measurement system |
-
2018
- 2018-11-09 CN CN201811333089.8A patent/CN109521222B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101887126A (en) * | 2010-06-27 | 2010-11-17 | 清华大学 | Double-frequency laser Doppler velocity measurement method and device |
| KR20120040492A (en) * | 2010-10-19 | 2012-04-27 | 한국표준과학연구원 | Detection method of doppler signals as measured by laser doppler anemometry |
| CN102706367A (en) * | 2012-06-19 | 2012-10-03 | 北京航空航天大学 | Accuracy testing and calculating method of single-beam laser speedometer for combined navigation |
| CN103076611A (en) * | 2013-01-09 | 2013-05-01 | 中国电子科技集团公司第十一研究所 | Method and device for measuring speed and distance by coherent detecting laser |
| CN103777034A (en) * | 2014-01-22 | 2014-05-07 | 天津大学 | Two-dimensional point range type laser Doppler speed measurement device |
| CN104833816A (en) * | 2015-04-29 | 2015-08-12 | 中国人民解放军国防科学技术大学 | Laser doppler velocity measurement device based on rotating grating and velocity measurement method of laser doppler velocity measurement device |
| CN205690996U (en) * | 2016-06-08 | 2016-11-16 | 无锡机电高等职业技术学校 | A kind of photoelectrical velocity measure equipment |
| CN106199631A (en) * | 2016-09-28 | 2016-12-07 | 成都凯天电子股份有限公司 | Coherent wind radar wind measurement method |
| JP2018128279A (en) * | 2017-02-06 | 2018-08-16 | 公益財団法人鉄道総合技術研究所 | Elastic wave measurement system |
| CN108279317A (en) * | 2018-01-23 | 2018-07-13 | 江西省智成测控技术研究所有限责任公司 | A kind of space filtering tachogenerator device and the method for improving rate accuracy |
Non-Patent Citations (4)
| Title |
|---|
| GURDEV L L等: "《High-resolution Doppler-velocity estimation techniques for processing of coherent heterodyne pulsed lidar data》", 《JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A》 * |
| 刘昌文等: "《激光多普勒测速中的频谱校正及其应用》", 《中国激光》 * |
| 周金男等: "《车载激光多普勒测速仪的卡尔曼滤波算法研究》", 《中国激光》 * |
| 白宏阳等: "《多普勒雷达测速信号滤波方法分析》", 《火力与指挥控制》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110824184A (en) * | 2019-10-12 | 2020-02-21 | 中国科学院西安光学精密机械研究所 | Data retrieval method for laser Doppler velocimeter |
| CN110824184B (en) * | 2019-10-12 | 2020-11-17 | 中国科学院西安光学精密机械研究所 | Data retrieval method for laser Doppler velocimeter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109521222B (en) | 2020-12-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106405570A (en) | Laser distance measurement method and device | |
| JP7074311B2 (en) | Optical distance measuring device and measuring method | |
| JP6806347B2 (en) | Optical distance measuring device and measuring method | |
| CN105629258A (en) | Speed measurement and distance measurement system and speed measurement and distance measurement method based on pseudo-random code phase modulation and heterodyne detection | |
| CN111948664B (en) | Dispersion compensation method of frequency modulation continuous wave laser radar based on dispersion coefficient modulation | |
| EP2866050B1 (en) | Wind measurement coherent lidar device | |
| CN114355387A (en) | Wind field inversion method and system based on eight-beam wind profile laser radar | |
| CN105487067B (en) | Bigness scale and accurate measurement distance signal processing method, the processing module and chirped modulation photon counting laser radar system based on the module | |
| CN104243067B (en) | A kind of Doppler frequency shift detection method and device based on photon technology | |
| CN101788671B (en) | Multicycle modulation method applied to laser ranging device using chirp amplitude modulation based on heterodyne detection | |
| CN111562564B (en) | Frequency modulation continuous wave laser ranging nonlinear correction device and method | |
| CA3034765A1 (en) | Method for processing a signal arising from coherent lidar and associated lidar system | |
| CN105259548A (en) | Dispersion mismatch correction method used in FMCW absolute distance measurement technology | |
| WO2022061828A1 (en) | Radar detection method and related apparatus | |
| CN109613503B (en) | Calibration method and device for radar echo signals | |
| CN109001698A (en) | A kind of linearity calibration method of small depth of field Modulation Continuous Wave Radar | |
| CN103954937B (en) | A kind of wide region High-precision Microwave range radar design method | |
| CN109541636A (en) | A kind of non-blind area High Range Resolution laser radar wind measuring system and method | |
| CN112505719A (en) | Laser wind measuring radar wind measuring method and system with Doppler frequency correction secondary compensation | |
| CN107765239A (en) | A kind of design and implementation method of economical short distance range radar | |
| CN109521222A (en) | A method of improving laser velocimeter precision | |
| CN109541621A (en) | A kind of method for compensating vibration of frequency scanning interference Models of Absolute Distance Measurement Based system | |
| WO2022000332A1 (en) | Radar detection method and related device | |
| US20150145715A1 (en) | Radio altimeter | |
| CN109031341B (en) | Object movement speed measuring method using continuous frequency modulation laser radar device |
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 |