CN113030919A - Waveform detection method and system based on model fitting - Google Patents
Waveform detection method and system based on model fitting Download PDFInfo
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- CN113030919A CN113030919A CN202110279037.2A CN202110279037A CN113030919A CN 113030919 A CN113030919 A CN 113030919A CN 202110279037 A CN202110279037 A CN 202110279037A CN 113030919 A CN113030919 A CN 113030919A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- 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
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/487—Extracting wanted echo signals, e.g. pulse detection
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- 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
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- 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
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/487—Extracting wanted echo signals, e.g. pulse detection
- G01S7/4876—Extracting wanted echo signals, e.g. pulse detection by removing unwanted signals
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- 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
- G01S7/491—Details of non-pulse systems
- G01S7/493—Extracting wanted echo signals
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- Optical Radar Systems And Details Thereof (AREA)
Abstract
The invention provides a novel waveform detection method and system based on model fitting. The method comprises the steps of firstly removing noise points and land laser points, and selecting laser points on the water surface; then, acquiring a water bottom echo waveform and a water surface echo waveform by using a Gaussian decomposition algorithm; then extracting the emission signal waveform and the echo signal waveform of each water laser spot; extracting water surface and water bottom echo waveforms from the sounding LiDAR echo waveforms by using a Gaussian decomposition algorithm; and finally, constructing a new function model, and fitting the water body backscattering waveform with the laser intensity being exponentially attenuated. Compared with the traditional model fitting method, the method has two remarkable advantages: firstly, the fitting obtained water body backscattering waveform is closer to the actual waveform. Secondly, the method can improve the detection precision of the laser echo position and the echo intensity.
Description
Technical Field
The invention relates to the technical field of laser communication, in particular to a waveform detection method and system based on model fitting.
Background
Depth measurement LiDAR can acquire the marine topography fast, and LiDAR also calls airborne laser depth measurement system, has characteristics such as high accuracy, high efficiency, high resolution. The data collected by the depth measurement LiDAR generally includes laser point cloud data, laser echo full waveform data, camera picture data, and the like. The method is characterized in that a processing algorithm for laser echo full waveform data is a key, a model fitting method takes a laser echo waveform as superposition of a plurality of different waveform functions, and the laser echo waveform is fitted into three parts, namely a water bottom echo waveform, a water surface echo waveform and a water body backscattering waveform, by constructing a model, so that information such as an echo position, echo intensity and the like is solved. The common model fitting method is to fit an echo waveform by using a Gaussian function and fit a water back scattering waveform by using a polygon function, however, each edge of the traditional polygon function is a linear function and cannot completely accord with the characteristic of exponential attenuation of laser intensity in a water body, so that the polygon function is used for fitting the water back scattering waveform in the prior art, and the accuracy of the solved laser echo position and echo intensity is low.
Disclosure of Invention
The invention provides a novel waveform detection method based on model fitting, which is mainly characterized in that a novel nonlinear function fitting water body backscattering waveform is constructed, and the characteristic that the laser intensity is exponentially attenuated in a water body is better met.
In order to achieve the above purpose, the invention provides the following technical scheme:
a waveform detection method based on model fitting comprises the following steps:
A. collecting effective waveform data of depth measurement LiDAR, reading full waveform data from airborne laser radar depth measurement data, removing invalid points caused by system errors and noise, removing land laser points according to the position and depth information of laser depth measurement points, and selecting effective water laser points;
B. extracting the transmitting signal waveform and the echo signal waveform of each water laser point, and solving the sounding LiDAR echo signal intensity through the following equations:
wherein, PbRepresenting the bottom echo intensity, P, acquired by a sounding LiDAR receiverwRepresenting the water backscatter echo intensity, PTRepresenting the laser emission intensity, ρ representing the substrate reflectivity, η representing the overall attenuation coefficient of the system, FpDenotes the field angle coefficient, nwDenotes the refractive index of the water body, ArDenotes the aperture area of the sounding LiDAR laser receiver, theta denotes the zenith angle, M (theta)i) Indicating a hot spot effect, N (θ)i) The pulse stretching effect H represents the flight height of the airplane, D represents the water depth, tau represents the optical thickness of the atmosphere, and beta represents the volume scattering coefficient; the sounding LiDAR return signal consists of three parts: water surface echo, water bottom echo, water body back scattering echo;
C. extracting water surface and water bottom echo waveforms from depth sounding LiDAR echo waveforms by using Gaussian decomposition algorithm, and Gaussian function fs(t) can be expressed as:
wherein WR(t) represents the received echo signal strength, αiSignal strength, mu, representing the ith Gaussian functioniIndicating the position of the echo, deltaiRepresenting the waveform width (standard deviation), N representing the number of Gaussian functions used for fitting, by solving for the function fs(t) taking N as 2 to obtain the water surface echo and the water bottom echo waveform;
D. constructing a new water body backscattering waveform function model, fitting a water body backscattering waveform with exponentially decayed laser intensity, wherein a fitting function fv (t) is as follows:
according to the characteristics of the water body, the water body backscattering waveform model is decomposed into five sections, wherein aB, c and d are respectively water back scattering waveform points X1,X2,X3And X4The abscissa (time, abbreviated as t, in ns); k. m and d are points X2,X3And X4The corresponding ordinate on the wave curve;
in the above formula, when t is less than or equal to a, fv(t) is 0; when t is more than 1 and less than or equal to b or c is more than t and less than or equal to d, fv(t) is a line segment, the function of which can be represented by X1,X2,X3And X4Obtaining coordinates; when b is more than t and less than or equal to c, fv(t) is an exponentially decaying curve according to X2,X3Coordinates, and a water body backscattering wave function model can be obtained by applying an undetermined coefficient method;
E. the water body backscattering waveform constructed by the method is combined with the water surface echo waveform and the water bottom echo waveform to calculate the laser echo position and the echo intensity.
A model fitting based waveform detection system includes a processor for executing instructions to implement a model fitting based waveform detection method.
The invention has the beneficial effects that:
the invention establishes a novel waveform detection method and system based on model fitting. Different from the traditional water body linear fitting method, the method constructs a new water body backscattering waveform model according to the characteristic of exponential attenuation of laser in the water body, the acquired water body backscattering waveform is closer to the actual water body echo waveform, and a solution is provided for high-precision detection of the laser echo.
The invention can improve the detection precision of the echo position and the echo intensity. The traditional waveform fitting method assumes that the echo waveform of the laser water body is linearly attenuated, although the detection efficiency is high, the error is relatively large, the method can improve the detection precision of the echo position and intensity, and has certain superiority.
Drawings
FIG. 1 is a schematic diagram of a linear function fitting echo waveform in the prior art;
FIG. 2 is a schematic diagram of a fitted echo waveform of the present invention;
FIG. 3 is a diagram of a prior art linear function fitting water backscatter waveform;
FIG. 4 is a schematic diagram of a fitted water backscatter waveform of the present invention;
FIG. 5 is a schematic diagram of a backscatter waveform model constructed in accordance with the invention;
fig. 6 is a block schematic diagram of the waveform detection method of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
a waveform detection method based on model fitting comprises the following steps:
A. collecting effective waveform data of depth measurement LiDAR, reading full waveform data from airborne laser radar depth measurement data, removing invalid points caused by system errors and noise, removing land laser points according to the position and depth information of laser depth measurement points, and selecting effective water laser points;
B. extracting the transmitting signal waveform and the echo signal waveform of each water laser point, and solving the sounding LiDAR echo signal intensity through the following equations:
wherein, PbRepresenting the bottom echo intensity, P, acquired by a sounding LiDAR receiverwRepresenting the water backscatter echo intensity, PTRepresenting the laser emission intensity, ρ representing the substrate reflectivity, η representing the overall attenuation coefficient of the system, FpDenotes the field angle coefficient, nwDenotes the refractive index of the water body, ArDenotes the aperture area of the sounding LiDAR laser receiver, theta denotes the zenith angle, M (theta)i) Indicating a hot spot effect, N (θ)i) The pulse stretching effect H represents the flight height of the airplane, D represents the water depth, and tau representsAtmospheric optical thickness, β represents the bulk scattering coefficient; the sounding LiDAR return signal consists of three parts: water surface echo, water bottom echo, water body back scattering echo;
C. extracting water surface and water bottom echo waveforms from depth sounding LiDAR echo waveforms by using Gaussian decomposition algorithm, and Gaussian function fs(t) can be expressed as:
wherein WR(t) represents the received echo signal strength, αiSignal strength, mu, representing the ith Gaussian functioniIndicating the position of the echo, deltaiRepresenting the waveform width (standard deviation), N representing the number of Gaussian functions used for fitting, by solving for the function fs(t) taking N as 2 to obtain the water surface echo and the water bottom echo waveform, as shown in FIG. 2;
D. constructing a new water body backscattering waveform function model, and fitting a water body backscattering waveform with exponentially decaying laser intensity, wherein a fitting function fv (t) is as shown in fig. 4:
according to the characteristics of the water body, the water body backscattering waveform model is decomposed into five segments as shown in fig. 5, wherein a, b, c and d are respectively water body backscattering waveform points X1,X2,X3And X4The abscissa (time, abbreviated as t, in ns); k. m and d are points X2,X3And X4The corresponding ordinate on the wave curve;
in the above formula, when t is less than or equal to a, fv(t) is 0; when t is more than 1 and less than or equal to b or c is more than t and less than or equal to d, fv(t) is a line segment, the function of which can be represented by X1,X2,X3And X4Obtaining coordinates; when b is more than t and less than or equal to c, fv(t) is an exponentially decaying curve according to X2,X3The coordinates of the position of the object to be imaged,a water body backscattering wave function model can be obtained by applying a undetermined coefficient method, as shown in FIG. 4;
E. the water body backscattering waveform constructed by the method is combined with the water surface echo waveform and the water bottom echo waveform to calculate the laser echo position and the echo intensity.
A model fitting based waveform detection system includes a processor for executing instructions to implement a model fitting based waveform detection method.
The invention establishes a novel waveform detection method and system based on model fitting. Different from the traditional water body linear fitting method, the method constructs a new water body backscattering waveform model according to the characteristic of exponential attenuation of laser in the water body, the acquired water body backscattering waveform is closer to the actual water body echo waveform, and a solution is provided for high-precision detection of the laser echo.
The invention can improve the detection precision of the echo position and the echo intensity. The traditional waveform fitting method assumes that the echo waveform of the laser water body is linearly attenuated, although the detection efficiency is high, the error is relatively large, the method can improve the detection precision of the echo position and intensity, and has certain superiority.
The above description is not intended to limit the technical scope of the present invention in any way, and any modifications to the above embodiments in accordance with the technical spirit of the present invention are possible; equivalent changes and modifications are also within the scope of the technical solution of the present invention.
Claims (2)
1. A waveform detection method based on model fitting is characterized in that: the method comprises the following steps:
A. collecting effective waveform data of depth measurement LiDAR, reading full waveform data from airborne laser radar depth measurement data, removing invalid points caused by system errors and noise, removing land laser points according to the position and depth information of laser depth measurement points, and selecting effective water laser points;
B. extracting the transmitting signal waveform and the echo signal waveform of each water laser point, and solving the sounding LiDAR echo signal intensity through the following equations:
wherein, PbRepresenting the bottom echo intensity, P, acquired by a sounding LiDAR receiverwRepresenting the water backscatter echo intensity, PTRepresenting the laser emission intensity, ρ representing the substrate reflectivity, η representing the overall attenuation coefficient of the system, FpDenotes the field angle coefficient, nwDenotes the refractive index of the water body, ArDenotes the aperture area of the sounding LiDAR laser receiver, theta denotes the zenith angle, M (theta)i) Indicating a hot spot effect, N (θ)i) The pulse stretching effect H represents the flight height of the airplane, D represents the water depth, tau represents the optical thickness of the atmosphere, and beta represents the volume scattering coefficient; the sounding LiDAR return signal consists of three parts: water surface echo, water bottom echo, water body back scattering echo;
C. extracting water surface and water bottom echo waveforms from depth sounding LiDAR echo waveforms by using Gaussian decomposition algorithm, and Gaussian function fs(t) can be expressed as:
wherein WR(t) represents the received echo signal strength, αiSignal strength, mu, representing the ith Gaussian functioniIndicating the position of the echo, deltaiRepresenting the waveform width (standard deviation), N representing the number of Gaussian functions used for fitting, by solving for the function fs(t) taking N as 2 to obtain the water surface echo and the water bottom echo waveform;
D. constructing a new water body backscattering waveform function model, fitting a water body backscattering waveform with exponentially decayed laser intensity, wherein a fitting function fv (t) is as follows:
according to the characteristics of the water body, the water body backscattering waveform model is decomposed into five sections, wherein a, b, c and d are respectively water body backscattering waveform points X1,X2,X3And X4The abscissa (time, abbreviated as t, in ns); k. m and d are points X2,X3And X4The corresponding ordinate on the wave curve;
in the above formula, when t is less than or equal to a, fv(t) is 0; when t is more than 1 and less than or equal to b or c is more than t and less than or equal to d, fv(t) is a line segment, the function of which can be represented by X1,X2,X3And X4Obtaining coordinates; when b is more than t and less than or equal to c, fv(t) is an exponentially decaying curve according to X2,X3Coordinates, and a water body backscattering wave function model can be obtained by applying an undetermined coefficient method;
E. the water body backscattering waveform constructed by the method is combined with the water surface echo waveform and the water bottom echo waveform to calculate the laser echo position and the echo intensity.
2. A waveform detection system based on model fitting is characterized in that: comprising a processor for executing instructions for implementing the waveform detection method of claim 1.
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113534096A (en) * | 2021-07-19 | 2021-10-22 | 东莞理工学院 | LiDAR signal geometric feature extraction method and system based on spline function |
CN116609758A (en) * | 2023-07-17 | 2023-08-18 | 山东科技大学 | Extraction method for airborne laser sounding waveform during travel |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106125088A (en) * | 2016-08-29 | 2016-11-16 | 天津大学 | Sea water advanced method is determined based on laser radar sounding system |
CN106556824A (en) * | 2016-10-14 | 2017-04-05 | 深圳大学 | A kind of noise echo elimination method and system of all-wave graphic data |
CN106802289A (en) * | 2017-01-20 | 2017-06-06 | 深圳大学 | Unrestrained attenuation coefficient extracting method and system based on depth measurement laser all-wave graphic data |
CN110031856A (en) * | 2019-04-04 | 2019-07-19 | 山东科技大学 | A kind of unrestrained attenuation coefficient extracting method of airborne LiDAR depth measurement data |
CN110134976A (en) * | 2018-02-09 | 2019-08-16 | 中国人民解放军战略支援部队信息工程大学 | A kind of airborne laser sounding method for extracting signal and system |
-
2021
- 2021-03-16 CN CN202110279037.2A patent/CN113030919A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106125088A (en) * | 2016-08-29 | 2016-11-16 | 天津大学 | Sea water advanced method is determined based on laser radar sounding system |
CN106556824A (en) * | 2016-10-14 | 2017-04-05 | 深圳大学 | A kind of noise echo elimination method and system of all-wave graphic data |
CN106802289A (en) * | 2017-01-20 | 2017-06-06 | 深圳大学 | Unrestrained attenuation coefficient extracting method and system based on depth measurement laser all-wave graphic data |
CN110134976A (en) * | 2018-02-09 | 2019-08-16 | 中国人民解放军战略支援部队信息工程大学 | A kind of airborne laser sounding method for extracting signal and system |
CN110031856A (en) * | 2019-04-04 | 2019-07-19 | 山东科技大学 | A kind of unrestrained attenuation coefficient extracting method of airborne LiDAR depth measurement data |
Non-Patent Citations (3)
Title |
---|
KAI DING等: "A New Algorithm for Retrieving Diffuse Attenuation Coefficient Based on Big LiDAR Bathymetry Data", 《INTERNATIONAL SYMPOSIUM ON CYBERSPACE SAFETY AND SECURITY》 * |
KAI DING等: "An Improved Quadrilateral Fitting Algorithm for the Water Column Contribution in Airborne Bathymetric Lidar Waveforms", 《SENSORS》 * |
丁凯: "单波段机载测深激光雷达全波形数据处理算法及应用研究", 《中国优秀博硕士学位论文全文数据库(博士)信息科技辑(月刊)》 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113534096A (en) * | 2021-07-19 | 2021-10-22 | 东莞理工学院 | LiDAR signal geometric feature extraction method and system based on spline function |
CN113534096B (en) * | 2021-07-19 | 2023-09-15 | 东莞理工学院 | LiDAR signal geometric feature extraction method and system based on spline function |
CN116609758A (en) * | 2023-07-17 | 2023-08-18 | 山东科技大学 | Extraction method for airborne laser sounding waveform during travel |
CN116609758B (en) * | 2023-07-17 | 2023-10-27 | 山东科技大学 | Extraction method for airborne laser sounding waveform during travel |
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