CN115407306A - Data processing method for improving effective detection distance of wind-measuring laser radar - Google Patents
Data processing method for improving effective detection distance of wind-measuring laser radar Download PDFInfo
- Publication number
- CN115407306A CN115407306A CN202211361887.8A CN202211361887A CN115407306A CN 115407306 A CN115407306 A CN 115407306A CN 202211361887 A CN202211361887 A CN 202211361887A CN 115407306 A CN115407306 A CN 115407306A
- Authority
- CN
- China
- Prior art keywords
- data processing
- power spectrum
- processing method
- wind
- effective detection
- 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
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
-
- 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
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/95—Lidar systems specially adapted for specific applications for meteorological use
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
The invention discloses a data processing method for improving the effective detection distance of a wind lidar, which belongs to the field of data processing, and aims at improving the accuracy and the extraction probability of extracting wind speed by using a power spectrum signal of a coherent Doppler wind lidar, a method for reducing resolution ratio is adopted to construct a power spectrum, so that a background wind field covered by noise can be effectively extracted, an index interval of the wind speed can be locked and reduced according to the background wind field, and the inversion probability of the wind speed is enhanced; the method for fitting and denoising the range gates one by one is simple and effective, low in time complexity and good in real-time performance, and the Gaussian fitting area is used as the signal-to-noise ratio, so that the jitter caused by background noise of the range gates at different distances can be effectively reduced, and the effective detection distance of the laser radar is effectively increased.
Description
Technical Field
The invention relates to the field of data processing, in particular to a data processing method for improving the effective detection distance of a wind lidar.
Background
The wind measurement laser radar is an active laser remote sensing device, has the characteristics of small volume, long dynamic detection distance, high space-time resolution, high precision and the like, and is widely applied to the field of atmospheric wind field remote sensing. The coherent Doppler wind lidar has been demonstrated in foundation, ship-borne and airborne platforms after decades of development, has mature technology, can realize the detection of complex wind fields, atmospheric turbulence, gravity waves, wind shear, wake flow and tornado, and is widely applied to the fields of weather, wind energy, military and civil airports, short-term weather forecast and the like.
However, according to the lidar equation, the intensity of the lidar return signal is rapidly attenuated as the detection distance is increased, and factors such as interference of background light and random noise also have influence during the detection process. Echo signals at far distances are often swamped by noise. Therefore, a proper denoising algorithm is researched, signals are extracted from noise, and the method has an important effect on improving the effective detection distance of the wind lidar. With the development of continuous laser radar signal processing technology, wavelet Transform (WT), empirical Mode Decomposition (EMD), other denoising methods, and the like are widely applied to laser radar signal processing. However, wavelet transforms cannot adaptively find the best combination of different problems. In contrast, EMD techniques compensate for the WT's drawbacks. Based on the conventional EMD, su et al propose a new frequency conversion resolution decomposition method (VFEMD), which extends the original EMD method to a high resolution scale, overcoming the limitation that the resolution depends only on the length of the decomposed signal. Nevertheless, EMD and its variants have some drawbacks, such as mode aliasing, over-decomposition, and end-of-line effects. The existing denoising algorithm is generally high in computation complexity and time complexity, complex and various in noise types and sources, limited in applicability and difficult to extract weak signals from noise. Therefore, how to improve the accuracy and extraction probability of extracting wind speed by using the power spectrum signal of the coherent doppler wind lidar is an urgent problem to be solved.
Disclosure of Invention
1. Technical problem to be solved
Aiming at the problems in the prior art, the invention aims to provide a data processing method for improving the effective detection distance of a wind lidar, which can independently de-noise each range gate by a fitting method, reduce a wind speed inversion interval by a resolution reduction method and effectively improve the effective detection distance of the lidar.
2. Technical scheme
In order to solve the above problems, the present invention adopts the following technical solutions.
A data processing method for improving the effective detection distance of a wind lidar comprises the following steps:
s1, reading original laser radar signal power spectrumIn which representsFrequency, representative ofA distance gate;
s2, according to the original laser radar signal power spectrumPerforming resolution reduction processing to construct a power spectrum;
S3, denoising through distance gate fitting one by one, and obtaining a power spectrumExtracting a center frequency point for each range gate;
S4, repeating S3, and aiming at the original power spectrumDenoising the image in the intervalExtracting the power spectrumCenter frequency point ofAnd calculating the corresponding signal-to-noise ratio,Is a third index frequency bandwidth;
s5, using a Doppler frequency shift formula to point the central frequencyConverted into wind speed;
And S6, performing quality control according to the signal-to-noise ratio and the wind speed variance, and removing abnormal values.
Further, in S3, the denoising algorithm process is as follows:
in the intervalLifting devicePower spectrum of measurementPeak position ofWhereinFor the first index frequency bandwidth,doppler shift location.
Further, deducting the intervalCorresponding power spectrumObtaining a power spectrumResidual power spectrumIs mainly composed of noise, and the noise is generated,the frequency bandwidth is indexed by a second index.
Further, for the remaining power spectrumCarrying out noise fitting modeling, wherein the noise fitting modeling prefers a polynomial fitting mode:
And obtaining a noise curve according to a polynomial fitting result:
extracting the center frequency point of each range gate by Gaussian fittingThe Gaussian fitting model is:
in order to be the strength of the signal,the area calculation of the Gaussian fitting curve is the aerosol spectral width and the signal-to-noise ratio, and the expression is。
Further, when the signal to noise ratio is small,The value is assigned to be NaN,is a first signal-to-noise ratio threshold.
Further, wind speed is calculatedVariance of (2) ,Variance is measuredWind speed greater than a specified threshold from a doorBy replacement with。
3. Advantageous effects
Compared with the prior art, the invention has the advantages that:
(1) The invention adopts a method for reducing resolution ratio to construct a power spectrumThe background wind field covered by noise can be effectively extracted, the index interval of the wind speed can be locked and reduced according to the background wind field, and the inversion probability of the wind speed is enhanced;
(2) The method adopts a fitting denoising method of distance gates one by one, is simple and effective, has low time complexity and good real-time performance, and can effectively reduce the jitter caused by background noise of different distance gates by using the Gaussian fitting area as the signal-to-noise ratio.
Drawings
Fig. 1 is a flowchart of a data processing method for increasing an effective detection distance of a wind lidar according to an embodiment of the present invention;
FIG. 2 is an example diagram of a power spectrum provided by an embodiment of the present invention;
fig. 3 is a comparison graph of results of a conventional data processing method provided in the embodiment of the present invention and a data processing method provided in the present invention.
Detailed Description
The drawings in the embodiments of the invention will be combined; the technical scheme in the embodiment of the invention is clearly and completely described; obviously; the described embodiments are only some of the embodiments of the invention; but not all embodiments, are based on the embodiments of the invention; all other embodiments obtained by a person skilled in the art without making any inventive step; all fall within the scope of protection of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "provided", "fitted/connected", "connected", and the like, are to be interpreted broadly, such as "connected", which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Example 1:
referring to fig. 1, a data processing method for increasing an effective detection distance of a wind lidar includes the following steps:
s1, reading original laser radar signal power spectrumIn which representsFrequency, representative ofA distance gate;
in this embodiment, the power spectra corresponding to the range gates 288, 289, 290, 291, 292、、As shown in fig. 2 (1), 2 (2), 3 (3) and 4 (4) of fig. 2 and 5 (2), respectively, it can be seen that the power spectrum signals corresponding to the range gates 288-292 are all buried by noise, and no signal peak is seen.
S2, according to the power spectrum of the original laser radar signalPerforming resolution reduction processing to construct a power spectrum;
In this embodiment, the structural power spectrum corresponding to the range gate 290As shown in (3) of FIG. 2, the power spectrum is shownWith distinct signal peaks.
S3, denoising through fitting of one-by-one range gate, and obtaining a power spectrumExtracting a center frequency point for each range gate;
The denoising algorithm process is as follows:
in the intervalExtracting the power spectrumPeak position ofWhereinFor the first index frequency bandwidth,doppler shift location.
Wherein the deduction intervalCorresponding power spectrumThat is, the signal region of the power spectrum is deducted to obtain the power spectrumResidual power spectrumMainly consisting of noise.The frequency bandwidth is indexed by a second index.
noise fitting modeling prefers the way of polynomial fitting:
Obtaining a noise curve according to a polynomial fitting result
Extracting the center frequency point of each range gate by Gaussian fittingThe Gaussian fitting model is:
in order to be the strength of the signal,the area calculation of the Gaussian fitting curve is the aerosol spectral width and the signal-to-noise ratio, and the expression is。
In this embodiment, the structural power spectrum corresponding to the range gate 290As shown in (3) in FIG. 2, a power spectrumCorresponding center frequency pointIs 86MHz.
S4, repeating S3, and aiming at the original power spectrumDenoising the image in the intervalExtracting the power spectrumCenter frequency point ofAnd calculating the corresponding signal-to-noise ratio。
S6, performing quality control according to the signal-to-noise ratio and the wind speed variance, and eliminating abnormal values:
when signal to noise ratio,The value is assigned to be NaN,is a first signal-to-noise ratio threshold.
Wherein the wind speed is calculatedVariance of (2) ,Variance is measuredWind speed greater than a specified threshold from doorBy replacement with,
As shown in FIG. 3, the effective detection of the data processing algorithm result of the invention is obviously more than that of the traditional processing algorithm, the effective detection range gates are more than 70, and the effectiveness of the invention is verified.
As described above; are merely preferred embodiments of the invention; the scope of the invention is not limited thereto; any person skilled in the art is within the technical scope of the present disclosure; the technical scheme and the improved concept of the invention are equally replaced or changed; are intended to be covered by the scope of the present invention.
Claims (10)
1. A data processing method for improving effective detection distance of a wind lidar is characterized by comprising the following steps: the method comprises the following steps:
s1, reading the power spectrum of the original laser radar signalIn which representsFrequency, representative ofA distance gate;
s2, according to the original laser radar signal power spectrumPerforming resolution reduction processing to construct a power spectrum;
S3, denoising through fitting of one-by-one range gate, and obtaining a power spectrumExtracting the center frequency point of each range gate;
S4, repeating S3, and aiming at the original power spectrumDenoising the image in the intervalExtracting the power spectrumCenter frequency point ofAnd calculating the corresponding signal-to-noise ratioSaidA third indexed frequency bandwidth;
s5, using a Doppler frequency shift formula to point the central frequencyConverted into wind speed;
And S6, performing quality control according to the signal-to-noise ratio and the wind speed variance, and removing abnormal values.
3. The data processing method for improving the effective detection distance of the wind lidar according to claim 2, wherein the data processing method comprises the following steps: in S3, the denoising algorithm process is as follows:
4. The data processing method for improving the effective detection distance of the wind lidar according to claim 3, wherein: deduction intervalCorresponding power spectrumObtaining a power spectrumResidual power spectrumIs mainly composed of noise, theThe frequency bandwidth is indexed by a second index.
5. The laser mine for improving wind measurement according to claim 4The data processing method for achieving the effective detection distance is characterized by comprising the following steps: for the remaining power spectrumCarrying out noise fitting modeling, wherein the noise fitting modeling prefers a polynomial fitting mode:
And obtaining a noise curve according to a polynomial fitting result:
6. The data processing method for improving the effective detection distance of the wind lidar according to claim 5, wherein: the describedDenoising power spectrum:
extracting center frequency points of each range gate by Gaussian fittingThe Gaussian fitting model is as follows:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211361887.8A CN115407306B (en) | 2022-11-02 | 2022-11-02 | Data processing method for improving effective detection distance of wind lidar |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211361887.8A CN115407306B (en) | 2022-11-02 | 2022-11-02 | Data processing method for improving effective detection distance of wind lidar |
Publications (2)
Publication Number | Publication Date |
---|---|
CN115407306A true CN115407306A (en) | 2022-11-29 |
CN115407306B CN115407306B (en) | 2023-05-16 |
Family
ID=84169310
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202211361887.8A Active CN115407306B (en) | 2022-11-02 | 2022-11-02 | Data processing method for improving effective detection distance of wind lidar |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN115407306B (en) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2212717A2 (en) * | 2007-10-09 | 2010-08-04 | Danmarks Tekniske Universitet | Coherent lidar system based on a semiconductor laser and amplifier |
CN101881824A (en) * | 2009-05-05 | 2010-11-10 | 何平 | Objective and fast determination method of noise threshold of power spectrum density data |
CN102043144A (en) * | 2010-10-22 | 2011-05-04 | 中国科学院上海光学精密机械研究所 | All- optical- fiber coherent Doppler wind lidar signal processing device |
CN104122538A (en) * | 2013-04-24 | 2014-10-29 | 何平 | Method for determining noise power of wind profile radar |
CN112526547A (en) * | 2020-11-18 | 2021-03-19 | 董晶晶 | Atmospheric boundary layer classification method and device based on wind lidar |
CN114488200A (en) * | 2022-04-17 | 2022-05-13 | 中国科学技术大学 | Power spectrum signal processing method for improving wind measurement precision of laser radar |
US20220308174A1 (en) * | 2020-10-19 | 2022-09-29 | Aeva, Inc. | Techniques to use power spectrum density in coherent lidar systems |
-
2022
- 2022-11-02 CN CN202211361887.8A patent/CN115407306B/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2212717A2 (en) * | 2007-10-09 | 2010-08-04 | Danmarks Tekniske Universitet | Coherent lidar system based on a semiconductor laser and amplifier |
CN101881824A (en) * | 2009-05-05 | 2010-11-10 | 何平 | Objective and fast determination method of noise threshold of power spectrum density data |
CN102043144A (en) * | 2010-10-22 | 2011-05-04 | 中国科学院上海光学精密机械研究所 | All- optical- fiber coherent Doppler wind lidar signal processing device |
CN104122538A (en) * | 2013-04-24 | 2014-10-29 | 何平 | Method for determining noise power of wind profile radar |
US20220308174A1 (en) * | 2020-10-19 | 2022-09-29 | Aeva, Inc. | Techniques to use power spectrum density in coherent lidar systems |
CN112526547A (en) * | 2020-11-18 | 2021-03-19 | 董晶晶 | Atmospheric boundary layer classification method and device based on wind lidar |
CN114488200A (en) * | 2022-04-17 | 2022-05-13 | 中国科学技术大学 | Power spectrum signal processing method for improving wind measurement precision of laser radar |
Non-Patent Citations (1)
Title |
---|
左渝: "复图像域SAR运动目标参数估计性能分析", 《中国科学》 * |
Also Published As
Publication number | Publication date |
---|---|
CN115407306B (en) | 2023-05-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN107678003B (en) | Target detection method under ground wave radar sea clutter background | |
CN106529478A (en) | Radar radiation source signal identification method according to three-dimensional entropy characteristic | |
CN111624574A (en) | Target detection method, system, storage medium and device for weak target detection | |
CN110852201A (en) | Pulse signal detection method based on multi-pulse envelope spectrum matching | |
CN102944871A (en) | Method for extracting ocean wave parameter in radar image | |
CN109871733A (en) | A kind of adaptive sea clutter signal antinoise method | |
CN114488200B (en) | Power spectrum signal processing method for improving wind measurement precision of laser radar | |
CN101334469A (en) | Wind profile radar clutter suppression method based on fraction order Fourier transform | |
CN107255806B (en) | A method of fitting inverting sea level horizontal air extinction coefficient | |
Golbon-Haghighi et al. | Ground clutter detection for weather radar using phase fluctuation index | |
Uysal et al. | Dynamic clutter mitigation using sparse optimization | |
CN113075706A (en) | GNSS-R based snow depth inversion method and application thereof | |
CN105929380A (en) | Full-waveform laser radar data denoising method for satellite laser altimeter | |
CN104764714A (en) | Method for improving terahertz frequency spectrum resolution based on EMD (Empirical Mode Decomposition) | |
CN105717494A (en) | Design method for sea clutter inhibition curve of marine radar based on wavelet transformation | |
CN117368880B (en) | Millimeter wave cloud radar turbulence clutter filtering method | |
CN115407306A (en) | Data processing method for improving effective detection distance of wind-measuring laser radar | |
CN108387882B (en) | Design method of MTD filter bank based on second-order cone optimization theory | |
Song et al. | Analysis and Detection of S-Shaped NLFM Signal Based on Instantaneous Frequency. | |
CN112394353B (en) | Sea wave number spectrum reconstruction method based on steep function appraisal | |
Su et al. | Enhancement of weak lidar signal based on variable frequency resolution EMD | |
CN116359854A (en) | YOLOv 5-based anti-air warning radar composite interference parameter estimation method | |
CN104346516A (en) | Wavelet denoising optimal decomposition level selection method of laser-induced breakdown spectroscopy | |
CN113848532A (en) | FMCW radar signal noise reduction system and method based on noise reduction model | |
Xu et al. | A Probability-Constraints-Based Method for Robust Wind Velocity Estimation in Lidar Doppler Spectrograms with Low Signal-to-Noise Ratio |
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 |