CN109270295A - A kind of underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data - Google Patents
A kind of underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data Download PDFInfo
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- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/24—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave
- G01P5/241—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave by using reflection of acoustical waves, i.e. Doppler-effect
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Abstract
The invention discloses a kind of underwater sound Doppler's flow-speed measurement methods screened based on autocorrelation estimation and valid data, it is related to acoustic Doppler field of measuring technique, including estimation complex autocorrelation function value R (τ), estimation total power signal R (0), the precision criterion η (v) for calculating sonar echo samples, decide whether to retain current sample finally by threshold decision.The present invention screens measuring data sample by the relationship of echo auto-correlation estimation precision criterion numerical value and given threshold, improve the precision of underwater sound flow velocity estimation, measured data is analysis shows the variance of flow velocity estimation, the key performance of raising underwater sound speed measuring equipment can be obviously reduced in the method.
Description
Technical field
The present invention relates to acoustic Doppler field of measuring technique, more particularly to one kind to be based on autocorrelation estimation and valid data
Underwater sound Doppler's flow-speed measurement method of screening.
Background technique
Water volume flow rate, movement velocity of submarine target etc. are very important measurement objects in underwater acoustic measurement.Common water
Sound flow-speed measurement method is based on doppler principle mostly, and the equipment of flow measurement includes acoustic Doppler fluid velocity profile instrument and acoustics
Doppler velocimeter etc..The course of work of the common sonar that tests the speed is as follows: emitting a carrier frequency to detection waters first is
The modulation short pulse of tens kHz to several hundred kHz, sound wave encounter the scatterer in water and generate sound scattering, wherein extremely low power dissipate
Penetrate sound wave and can be received energy converter and receive and be converted into electric signal, then through signal condition, quadrature demodulation, analog-to-digital conversion and signal at
Echo strength, the water velocity etc. of the detection each water layer in waters are obtained after reason.
Discovery often will appear some flow velocity numerical value substantial deviation mean values when sonar measured data is tested the speed in analysis
Sampled point, therefore carry out the judgement of the quality of data in signal processing stage and then carry out screening to echo data to be necessary.Stream
The fluctuation of fast numerical value most direct reaction on frequency spectrum is exactly the broadening of echo spectrum width.Lower surface analysis causes echo spectrum wide
The factor of broadening is spent, provides theories integration to generate the criterion of the quality of data.(1) consistency of scatterer speed.Natural water
The volume of middle scatterer is usually very small for the launching beam range of exposures of sonar.Such as the scatterer in seawater
Partial size is mostly distributed in 20 μm~200 μ ms, and the irradiation by taking beam angle is 3 ° of wave beam as an example, at distance R
Diameter is approximately equal to 0.052R, is far longer than the partial size of scatterer.Therefore the doppler information of echo is by beam at distance R
The motion conditions of all scatterers are formed by stacking in range.If the rate uniformity of these scatterers is preferable, echo frequency
The broadening of spectrum is with regard to unobvious；If their speed difference is larger, the obvious broadening of echo spectrum can be brought.Spectrum width more it is wide then
The estimated standard deviation of Doppler frequency shift is bigger, and the flow velocity estimated deviates mean value can be bigger.Here it is estimating according to spectrum width
Evaluation judges the theory support of the quality of data.(2) width and transmitted bandwidth of acoustic wave beam.The width of launching beam is wider,
Mean beam range bigger in same depth, i.e., the superposition of more scatterer kinetic characteristics, this will increase echo
The standard deviation of width and the flow velocity estimation of frequency spectrum.The bandwidth of operation of transmitter and energy converter is bigger, it is meant that is actually transmitted to water
In waveform bandwidth widen, and then bring the increase of echo spectrum width.It is similar with pulse width factor, sound actual for one
For equipment, this factor is determining to the influence degree of spectrum width.(3) factor of signal-to-noise ratio is reduced.Influence echo
The factor of signal-to-noise ratio mainly has transmission power, propagation distance, scattering bulk concentration etc..After signal-to-noise ratio decline, echo spectrum width
It can broaden therewith, the standard deviation of flow velocity estimation can increase with it.Transmission power is smaller, the more remote then echo signal-to-noise ratio of propagation distance more
Small, this is obvious.Scatterer quantity seldom will lead to echo signal-to-noise ratio and be decreased obviously in water.Conversely, scattering bulk concentration
It will form greatly very much and swallow echo blocked, and then reduce its signal-to-noise ratio.(4) velocity flow profile is uneven.Flow velocity is uneven
The even influence to echo spectrum width has two levels.One is, then scattering in each water layer faster along beam direction change in flow
Body speed difference is bigger, and echo spectrum width can broaden naturally, and when being layered flow velocity estimation, standard deviation just be will increase.The second is upper water
The flowing of body is the movement of Acoustic Wave Propagation medium for the echo of lower water column, can bring additional Doppler frequency shift, into
And the frequency spectrum of echo can be broadened.It should be noted that the more big such influence of the difference of upper and lower level flow velocity is more obvious.In short, from estimating
Meter spectrum width angle establish a kind of echo quality judgment method be it is feasible, can make up and be moved by scatterer to a certain extent
Characteristic is inconsistent and echo signal-to-noise ratio decline bring flow velocity estimated standard deviation increases.
Summary of the invention
The purpose of the present invention is to provide a kind of underwater sound Doppler's flow velocitys screened based on autocorrelation estimation and valid data
Measurement method, the flow velocity autocorrelation estimation precision criterion based on echo, according to the relationship of criterion numerical value and given threshold to testing the speed
The method that sonar is screened when time sample.
To achieve the above object, technical scheme is as follows:
A kind of underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data, including walk as follows
It is rapid:
S1, according toIt is multiple from phase by the plural echo estimation of effective water layer
The value for closing function R (τ), according toIt estimates total power signal R (0), wherein { x1,x2,...,xmBe
The complex data of m the currently active water layers, fsFor echo samples rate,N indicates that in sample rate be fsShi Xiangguan interval τ
Corresponding data points, operatorIt indicates to be rounded downwards；
S2, according to flow velocity autocorrelation estimation precision criterionThe sonar real-time estimation that tests the speed sampling
η (v) value of echo, wherein v is radial flow speed, and λ is the wavelength for emitting sound wave, and τ is the interval of complex autocorrelation, and R (τ) is effective
The auto-correlation function value of water layer, R (0) are total power signal；
S3, threshold decision then give up current sample, when η (v) value is greater than or equal to when η (v) value is less than given threshold
When given threshold, then retain current sample.
In above scheme, the threshold value is 0.2~0.4.
The underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data of the invention, according to the underwater sound
In flow velocity measurement the characteristics of echo-signal and the knowledge of signal power Power estimation, propose a kind of based on flow velocity autocorrelation estimation precision
Criterion, and then measuring data sample is screened in real time according to the relationship of criterion numerical value and given threshold, to improve the underwater sound
The precision of flow velocity measurement.Measured data analysis shows the variance of flow velocity estimation can be obviously reduced in the method, survey by raising underwater sound flow velocity
Measure the key performance of equipment.
Detailed description of the invention
Fig. 1 is the underwater sound Doppler's flow velocity measurement screened in one embodiment of the invention based on autocorrelation estimation and valid data
The flow chart of method；
Fig. 2 is radial flow velocity profile in one embodiment of the invention；
Fig. 3 is flow velocity autocorrelation estimation precision criterion curve graph in one embodiment of the invention；
Fig. 4 is bent to standard deviation and flow velocity autocorrelation estimation precision criterion η (v) relationship before flow velocity in one embodiment of the invention
Line chart；
Fig. 5 is the flow velocity autocorrelation estimation precision criterion curve graph in one embodiment of the invention after screening.
Specific embodiment
Technical solution of the present invention is described in further detail with reference to the accompanying drawings and examples.
The underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data of the invention, such as Fig. 1 institute
Show, includes the following steps:
Step 1 estimates complex autocorrelation function R (τ) according to formula 1, according to formula 2 by the plural echo of effective water layer
Estimate the value of total power signal R (0)；
Wherein, { x1,x2,…,xmBe m the currently active water layer complex data, fsFor echo samples rate,n
Indicate that in sample rate be fsThe corresponding data points of Shi Xiangguan interval τ, operatorIt indicates to be rounded downwards.
Step 2, according to flow velocity autocorrelation estimation precision criterion, η (v) value for the sonar real-time estimation sampled echo that tests the speed；
Wherein, v is radial flow speed, and λ is the wavelength for emitting sound wave, and τ is the interval of complex autocorrelation, and R (τ) is effective water layer
Complex autocorrelation function value, R (0) are total power signal, and formula 1 and formula 2 are estimated that obtained R (τ) and R (0) bring formula 3 into
In, the value of sampled echo η (v) can be obtained.
Step 3 is compared by the precision criterion η (v) of sonar echo samples with given threshold, when η (v) value is less than
When threshold value, then give up current sample, when η (v) value is greater than or equal to threshold value, then retains current sample, it is generally the case that threshold value
Value range 0.2~0.4.
When actual measurement, the flow velocity autocorrelation estimation precision criterion η (v) of general shallow-layer water body is greater than swallow, so,
Acoustic Doppler fluid velocity profile instrument is used as sample after the echo data once emitted, calculates effective water layer second layer first
Flow velocity echo autocorrelation estimation precision criterion η (v), when threshold value value be 0.3 when, if the value of η (v) be less than threshold value 0.3,
Then give up current sample, if the value of η (v) is greater than or equal to threshold value 0.3, retains current sample.
By taking the test data of one time, the Nanjing Qinhuaihe River as an example, the depth of water of section is sampled all in 5m or more, the 1st layer is blind area, institute
All it is effective water layer with the 2nd~10 layer, chooses the 2nd layer of wave beam 3 as analysis object, total number of samples 100.Test sound used
The parameter for learning Doppler's flow velocity section plotter (ADCP) is tranmitting frequency 600kHz, wavelength X 2.5mm, complex autocorrelation counting period τ
For 140 μ s, water body lift height is 0.42m, and transmitted waveform is coding phase-modulated signal.
Fig. 2 is the curve graph drawn out in 100 samples using the radial flow speed that complex autocorrelation method estimates, 100
The error of the radial flow speed estimated value and mean value that have multiple samples in sample is significantly greater than other samples, belongs to outlier.Fig. 3 is original
In 100 samples use flow velocity autocorrelation estimation precision criterion η (v) curve graph, from Fig. 2 and Fig. 3 it does not appear that
The relationship of flow velocity autocorrelation estimation precision criterion η (v) and the value of flow velocity estimation, for this purpose, certainly by the flow velocity of 100 samples in Fig. 3
The value of correlation estimation precision criterion η (v) by being ranked up from small to large, and by the sample order of ranking results to the number in Fig. 1
According to being reset, then calculate reset after in Fig. 1 at each sample point before to all samples standard deviation, Fig. 4 is in 100 samples
To standard deviation and flow velocity autocorrelation estimation precision criterion η (v) graph of relation before flow velocity, figure 4, it is seen that with η (v)
The dull of numerical value increases, and the standard deviation of ADCP flow velocity estimation reduces in approximation is dull, this phenomenon and theory analysis coincide, and demonstrate
The validity of the method for the present invention.
As shown in Fig. 2, the standard deviation of 100 sample point radial flow speeds is in the case where no progress data screening
0.779m/s；As shown in figure 5, remaining the data of 70 sample points after the screening of flow velocity estimated accuracy criterion, screening is surplus
The standard deviation of 70 remaining sample points is 0.422m/s, and how general the underwater sound of the invention screened based on autocorrelation estimation and valid data is
It strangles flow-speed measurement method and flow velocity estimated standard deviation is reduced about 46%, hence it is evident that reduce the variance of flow velocity estimation, improve underwater sound stream
The performance of fast measuring device.
Above-described specific embodiment has carried out further the purpose of the present invention, technical scheme and beneficial effects
It is described in detail, it should be understood that the foregoing is merely a specific embodiment of the invention, the guarantor that is not intended to limit the present invention
Range is protected, all within the spirits and principles of the present invention, any modification, equivalent substitution, improvement and etc. done should all be contained in this hair
Within bright protection scope.
Claims (2)
1. a kind of underwater sound Doppler's flow-speed measurement method screened based on autocorrelation estimation and valid data, which is characterized in that packet
Include following steps:
S1, according toPass through the plural echo estimation complex autocorrelation function of effective water layer
The value of R (τ), according toIt estimates total power signal R (0), wherein { x1,x2,...,xmWork as m
The complex data of preceding effective water layer,fsFor echo samples rate, it is f that n, which is in sample rate,sShi Xiangguan interval τ is corresponding
Data points；
S2, according to flow velocity autocorrelation estimation precision criterionTest the speed sonar real-time estimation sampled echo
η (v) value, wherein v is radial flow speed, and λ is the wavelength for emitting sound wave, and τ is the interval of complex autocorrelation, and R (τ) is complex autocorrelation
Functional value, R (0) are total power signal；
S3, threshold decision then give up current sample when η (v) value is less than given threshold, when η (v) value is greater than or equal to setting
When threshold value, then retain current sample.
2. the underwater sound Doppler's flow velocity measurement side according to claim 1 screened based on autocorrelation estimation and valid data
Method, it is characterised in that: the threshold value is 0.2~0.4.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110824193A (en) * | 2019-11-11 | 2020-02-21 | 南京世海声学科技有限公司 | Non-uniform water velocity estimation method based on multi-beam radial flow velocity measurement |
| CN116027307A (en) * | 2022-11-02 | 2023-04-28 | 哈尔滨工程大学 | Acoustic Doppler instantaneous speed measurement quality evaluation method |
| CN116125459A (en) * | 2023-02-03 | 2023-05-16 | 水利部南京水利水文自动化研究所 | Determination method for effective speed measurement unit of side scanning radar |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1093676A (en) * | 1977-04-21 | 1981-01-13 | Noel Clavelloux | Liquid flow rate metering system |
| CN1438496A (en) * | 2003-03-19 | 2003-08-27 | 中国科学院声学研究所 | Method for measuring flow-layer speed by related velocity sonar, and system thereof |
| CN102564508A (en) * | 2011-12-14 | 2012-07-11 | 河海大学 | Method for implementing online tests of stream flow based on video images |
| CN105572418A (en) * | 2016-01-19 | 2016-05-11 | 浙江工业大学 | FPGA-based acoustic doppler current profiler signal processing method and system |
| CN105572650A (en) * | 2015-12-15 | 2016-05-11 | 宁波大学 | Broadband multiple correlation flow velocity measurement method |
-
2018
- 2018-08-20 CN CN201810950528.3A patent/CN109270295B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1093676A (en) * | 1977-04-21 | 1981-01-13 | Noel Clavelloux | Liquid flow rate metering system |
| CN1438496A (en) * | 2003-03-19 | 2003-08-27 | 中国科学院声学研究所 | Method for measuring flow-layer speed by related velocity sonar, and system thereof |
| CN102564508A (en) * | 2011-12-14 | 2012-07-11 | 河海大学 | Method for implementing online tests of stream flow based on video images |
| CN105572650A (en) * | 2015-12-15 | 2016-05-11 | 宁波大学 | Broadband multiple correlation flow velocity measurement method |
| CN105572418A (en) * | 2016-01-19 | 2016-05-11 | 浙江工业大学 | FPGA-based acoustic doppler current profiler signal processing method and system |
Non-Patent Citations (2)
| Title |
|---|
| 朱昊 等: "脉冲对实现回波频偏测量的算法研究", 《传感技术学报》 * |
| 项宁 等: "直流偏置对ADCP系统测量的影响及去除", 《声学与电子工程》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110824193A (en) * | 2019-11-11 | 2020-02-21 | 南京世海声学科技有限公司 | Non-uniform water velocity estimation method based on multi-beam radial flow velocity measurement |
| CN116027307A (en) * | 2022-11-02 | 2023-04-28 | 哈尔滨工程大学 | Acoustic Doppler instantaneous speed measurement quality evaluation method |
| CN116027307B (en) * | 2022-11-02 | 2023-09-01 | 哈尔滨工程大学 | Acoustic Doppler instantaneous speed measurement quality evaluation method |
| CN116125459A (en) * | 2023-02-03 | 2023-05-16 | 水利部南京水利水文自动化研究所 | Determination method for effective speed measurement unit of side scanning radar |
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