CN106970046A - Cloud particle detection system and method based on Polarization Detection - Google Patents
Cloud particle detection system and method based on Polarization Detection Download PDFInfo
- Publication number
- CN106970046A CN106970046A CN201710217629.5A CN201710217629A CN106970046A CN 106970046 A CN106970046 A CN 106970046A CN 201710217629 A CN201710217629 A CN 201710217629A CN 106970046 A CN106970046 A CN 106970046A
- Authority
- CN
- China
- Prior art keywords
- light
- polarization
- laser
- reflective mirror
- particle
- 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.)
- Pending
Links
- 239000002245 particle Substances 0.000 title claims abstract description 111
- 230000010287 polarization Effects 0.000 title claims abstract description 96
- 238000001514 detection method Methods 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title abstract description 32
- 239000013078 crystal Substances 0.000 claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000000523 sample Substances 0.000 claims abstract description 12
- 239000000428 dust Substances 0.000 claims abstract description 11
- 230000003287 optical effect Effects 0.000 claims abstract description 10
- 239000005357 flat glass Substances 0.000 claims description 34
- 239000011521 glass Substances 0.000 claims description 16
- 238000012545 processing Methods 0.000 claims description 8
- 238000012544 monitoring process Methods 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 6
- 210000000056 organ Anatomy 0.000 claims description 2
- 230000000007 visual effect Effects 0.000 claims description 2
- 230000000149 penetrating effect Effects 0.000 claims 2
- 230000028161 membrane depolarization Effects 0.000 abstract description 24
- 239000007788 liquid Substances 0.000 abstract description 6
- 230000003595 spectral effect Effects 0.000 abstract description 3
- 238000005259 measurement Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 238000003384 imaging method Methods 0.000 description 8
- 238000011160 research Methods 0.000 description 8
- 230000004044 response Effects 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- 239000011159 matrix material Substances 0.000 description 6
- 238000003908 quality control method Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 230000001235 sensitizing effect Effects 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 4
- 230000005622 photoelectricity Effects 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000009738 saturating Methods 0.000 description 3
- 101100256918 Caenorhabditis elegans sid-2 gene Proteins 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000013598 vector Substances 0.000 description 2
- 241000208340 Araliaceae Species 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 101100256922 Caenorhabditis elegans sid-3 gene Proteins 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 1
- 235000003140 Panax quinquefolius Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 235000008434 ginseng Nutrition 0.000 description 1
- 230000004313 glare Effects 0.000 description 1
- 239000008276 ice cloud Substances 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000013152 interventional procedure Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000004579 marble Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000000790 scattering method Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/47—Scattering, i.e. diffuse reflection
- G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses the cloud particle detection system based on Polarization Detection and method, the system includes producing Laser emission optical unit, forward scattering probe unit and the backscatter sounding unit of polarised light；Wherein, Laser emission optical unit produces polarised light by using laser diode, polarizer and half-wave plate；Determine whether particle is recorded and draws the size of cloud particle by forward scattering probe unit；Obtain the depolarization of scattered light to determine the phase of particle by backscatter sounding unit.The inventive method determines the information such as the size and phase of particle by forward scattering probe unit and backscatter sounding unit jointly, and draws the particle diameter Spectral structure of water dust and ice crystal, and then obtains solid-state water content and Liquid water content in cloud.
Description
Technical field
The present invention relates to the cloud particle detection system based on Polarization Detection and method, and in particular to based on continuous photosemiconductor
Laser, scattering multi-angle are received, the cloud particle detection system and method for Polarization Detection, belong to cloud particle detection technology field.
Background technology
Small ice crystal particle diameter spectrum information has critical role in cloud radiology and cloud physics scientific research in cloud.IPCC the 5th
Point out that effect of the cloud in Radiative Forcing and climate change also has very big uncertainty in secondary assessment report, it is probabilistic
One important sources is that cold cloud radiation is caused.Cold cloud radiation characteristic depends not only on ice water content, additionally depend on its shape and
Scale spectrum distributed intelligence, for deep its radiation transmission characteristic of understanding, the ice crystal information in cloud is essential physical parameter, special
Be not to occupied the majority in cloud be less than 50 μm ice crystalses understanding it is particularly important.In cloud physics research, cold cloud
It is the main object of weather modification, key player is play in the forming process of precipitation.Small ice crystal is in convective cloud ice crystal
Play the part of important role in forming process.Ice crystal is either catalyzed or in cumulus power catalytic process in cold cloud static(al) in cloud
In, all directly affect the formation of precipitation.Modernization cloud particle Detection Techniques promote people to have further cloud physics process
Understanding.But the understanding to small ice crystal (subcooled water) to the Microphysical of precipitation this process is not very clear.To this process
Scale-model investigation needs lot of experimental data as support and verified.Using ground cloud chamber can in wide time scale it is (several small
When) research ice-nucleus development and change, but modern observation requires time scale in minute magnitude, and cloud chamber simulation can not be completed, and
And, inevitably there is certain difference in cloud chamber environment and nature environment.Airborne cloud particle observation is the another of cloud physics research
One important means, airborne collection ice crystal experiment is carried out from the forties so far, airborne observation has deepened people to cloud physics first
The understanding of science.But it is capable of generation, the evolution of observational record ice crystal into cold cloud without related onboard instrument so far,
People are caused still to have very big difficulty in the understanding of precipitation forming process in cold cloud.If ice crystal early stage in cloud can be observed
Forming process, our understanding to Ice Formation Process in mixed cloud will be broken through, become beneficial to the Microphysical understood in depth in cloud
Change process and mechanism.In a word, ice crystal information is radiated to cloud in cold cloud and cloud physics research is particularly significant, but corresponding due to lacking
Airborne detection instrument, carrying out the research in cold cloud in terms of small ice crystal detection principle and method is extremely necessary, can be again on the basis of this
Airborne small ice crystal detector is set up, effective detection of small ice crystal in cold cloud is realized, solves at present to radiate and cloud thing ice crystal in cloud
Manage the problem of understanding.
The onboard instrument of most widely used cloud micro-properties observation at present be mainly based upon single-particle scattering technology and into
As technology.Cloud particle within wherein 50 μm is mainly measured using scattering method, and this method collects cloud particle in certain space
Scattered energy in solid angle, the optical equivalence grain of cloud particle is calculated according to the calibration results and spheroidal particle Mie scattering principle
Footpath.Mie scattering principle of this method based on spheroidal particle, only detection scatters energy information, the area without aqueous water and ice crystal
The ability of dividing, produces very big error when measuring ice crystal.Two-dimensional particles probe based on imaging technique is obtained using linear array detector
Each particle is taken by projection during laser beam, it is contemplated that the error that detector spatial resolution and AD zone of transformation come, the instrument
The yardstick lower limit of device detection cloud particle is 100 μm, can not also realize that small size ice crystal is observed.Baumgardner is reported for 2001
Improved scattering-type cloud particle detector, system receives back scattering while cloud particle forward scattering is received, according to preceding
To scattering and the phase of the ratio in judgement cloud particle of back scattering, but due to the oscillatory of cloud particle Mie scattering, before and after causing to
Ratio vibrates, the accuracy that influence particle phase judges.Lawson reports a kind of high-resolution cloud particle imaging system for 2001
System, the system is imaged using the laser illumination cloud particle that pulse is 20ns using CCD record cloud particles, the systematic survey
Lower limit is 25 μm, and CCD film speeds are 40Hz, is far not enough to record the distribution of small ice crystal in cloud.Fugal is built for 2004
The holographic imaging systems measured for online cloud particle are found, because light field is empty in the limitation of CCD response speeds and interventional procedures
The holographic imaging algorithm of noise caused by portion and complexity, makes the system produce very big measurement when cloud particle Particle density is larger
Error.The small ice crystal detector (SID that Hirst is reported based on scattered striation for 2001：Small Ice Detector), ice
Brilliant scattered striation differs greatly with water dust Ai Li shape of stripes, judges the phase of cloud particle accordingly, first generation SID uses 6
The linear array of individual detector composition, angle resoluting ability is limited.Cotton reports second generation ice crystal detector SID-2 for 2010
The phase function detector (32 detectors) being distributed using the concentric circles of customization, detector sensitivity there has also been very big carry
Height, but when cloud particle concentration is more than 20/cm3When, SID-2 can not tell single particle.Third generation SID-3 uses high-resolution
Camera, the resolution ratio that two-dimensional imaging obtains high angle is carried out to striped, but because the speed of the processing of camera is slower, when ice crystal grain
When sub- concentration is larger, there is particle degeneracy phenomenon, actual measurement population is less than actual particle book.Due to the phase based on SHAPE DETECTION
Differentiating method can be limited by particle degeneracy phenomenon, and scientists transfer research and utilization polarization technology to distinguish grain again in recent years
Sub- phase.
Comprehensive domestic and international cloud particle detector development, the small ice crystal Detection Techniques occurred at present mainly have scattering ratio survey
Amount, holographic imaging, scattered striation are imaged three kinds.Scattering ratio measuring method is limited by the vibration of Mie scattering phase function, and is imaged skill
Art can produce degeneracy phenomenon when ice crystalses are more, the small ice based on Polarization Detection due to reasons such as imaging detector responses
Crystalline substance detection then rarely has research.Therefore, in ice cloud or mixing phase cloud small ice crystal (being less than 50 μm) detection, being still one does not have
The problem of solution.
The content of the invention
The technical problems to be solved by the invention are：Cloud particle detection system and method based on Polarization Detection, profit are provided
Polarization discrimination particle phase is moved back to laser with cloud particle, the cloud particle detection system based on Polarization Detection is set up, realizes water dust
With the split-phase state quantitative detection of ice crystal.
The present invention uses following technical scheme to solve above-mentioned technical problem：
Cloud particle detection system based on Polarization Detection, including Laser emission optical unit, the forward direction of generation polarised light dissipate
Penetrate probe unit, backscatter sounding unit, four-way capture card and data processing unit；Wherein, Laser emission optics list
Member includes laser, polarizer, half-wave plate and the first total reflective mirror；Forward scattering probe unit includes being sealed in the first glass container
Internal the second total reflective mirror, LASER Energy Monitor, forward scattering light collecting lens, narrow band pass filter, the 3rd total reflective mirror, first
Convergent lens, beam splitter prism, the first photodetector, aperture and the second photodetector, the first glass container include the
One window glass；The first rear orientation light that backscatter sounding unit includes being sealed in inside the second glass container collects saturating
Mirror, the second convergent lens, the second rear orientation light collecting lens, polarization beam splitter prism, the 3rd convergent lens, parallel polarization detection
Device, the 4th convergent lens, vertical polarization detector, the second glass container include the second window glass；
The laser of the laser transmitting passes sequentially through polarizer, half-wave plate and reaches the first total reflective mirror, and the first total reflective mirror will
Laser reflection produces forward scattering light and rear orientation light to the center of first window glass and the second window glass；
After the forward scattering light is by first window glass, a part is transmitted to laser energy through the second total reflective mirror and monitored
Device carries out energy monitoring, and another part is collected by forward scattering light collecting lens, and by the 3rd total reflective mirror after narrow band pass filter
Introduce the first convergent lens and enter line convergence, the scattered light of convergence is divided into 3 by beam splitter prism:1, wherein, 25% enters the first photoelectricity
Detector, 75% enters the second photodetector through aperture；
After the rear orientation light is by the second window glass, collected by the first rear orientation light collecting lens, through second
After the telescope that convergent lens and the second rear orientation light collecting lens are constituted, by polarization beam splitter prism be divided into parallel polarized light and
Orthogonal polarized light, parallel polarized light is detected after the 3rd convergent lens by parallel polarization detector, and orthogonal polarized light is through
Detected after four convergent lenses by vertical polarization detector；
First photodetector, the second photodetector, parallel polarization detector, vertical polarization detector respectively with
Four-way capture card is connected, and four-way capture card is connected with data processing unit.
As a preferred embodiment of the present invention, the first window glass, the second window glass are quartzy flat board.
As a preferred embodiment of the present invention, the laser wavelength is 660nm, and power output is 120mW.
As a preferred embodiment of the present invention, the formed solid angle that receives of the forward scattering light collecting lens is 4-
14 °, the formed solid angle that receives of the first rear orientation light collecting lens is 146-176 °.
As a preferred embodiment of the present invention, it is 660nm that the center of the narrow band pass filter, which passes through wavelength, with a width of
Transmitance is 90% in 10nm, bandwidth.
As a preferred embodiment of the present invention, first total reflective mirror, the second total reflective mirror and the 3rd total reflective mirror are
45 ° of 660nm are all-trans.
As a preferred embodiment of the present invention, the size of the aperture is 200 μm * 200 μm.
Cloud particle detection method based on Polarization Detection, comprises the following steps：
Step 1, laser output laser, sequentially passes through polarizer, half-wave plate and reaches the first total reflective mirror, the first total reflective mirror will
Laser reflection produces forward scattering light and backward to the center that measured zone is first window glass and the second window glass
Scattered light；
Step 2, after forward scattering light is by first window glass, a part is transmitted to laser energy by the second total reflective mirror supervises
Visual organ carries out energy monitoring, and another part is collected by forward scattering light collecting lens, and is all-trans after narrow band pass filter by the 3rd
Mirror introduces the first convergent lens and enters line convergence, and the scattered light of convergence is divided into 3 by beam splitter prism:1, wherein, 25% enters the first light
Electric explorer, 75% enters the second photodetector through aperture；
Step 3, after rear orientation light is by the second window glass, collected by the first rear orientation light collecting lens, through the
After the telescope that two convergent lenses and the second rear orientation light collecting lens are constituted, parallel polarized light is divided into by polarization beam splitter prism
And orthogonal polarized light, parallel polarized light detected after the 3rd convergent lens by parallel polarization detector, orthogonal polarized light warp
Detected after 4th convergent lens by vertical polarization detector；
Step 4, the electric signal that the detection of each detector is obtained is gathered using four-way capture card, and judges that the second photoelectricity is visited
Survey whether device detects electric signal, be then to enter step 5, otherwise, return to step 1；
Step 5, the depolarization of cloud particle is calculated according to the result of detection of parallel polarization detector and vertical polarization detector, and
Contrasted with predetermined threshold value, if more than or equal to predetermined threshold value, being judged as ice crystal, and ice crystal number is added one, if less than pre-
If threshold value, then it is judged as aqueous water, and water dust number is added one.
The present invention uses above technical scheme compared with prior art, with following technique effect：
1st, the present invention determines particle phase using the depolarization of particle, is compared with traditional cloud particle detector and adds polarization
Factor, the cloud particle detection system of foundation has a separating capacity of water dust and ice crystal, and modern laser and detection skill
Art is that the polarization degree of purity of current polarization laser can reach 100 the invention provides feasibility:1, polarizing beam splitter mirror every
1000 can be reached from degree:1, all provide facility for Polarization Detection.
2nd, present invention comprehensive utilization actual measurement forward scattering and depolarization result, obtain the particle diameter Spectral structure of water dust and ice crystal, from
And solid-state water content and Liquid water content in cloud are obtained, realize the split-phase state quantitative detection of water dust and ice crystal.
Brief description of the drawings
Fig. 1 is the light path schematic diagram of the cloud particle detection system of the invention based on Polarization Detection.
Fig. 2 is the flow chart of the cloud particle detection method of the invention based on Polarization Detection.
Fig. 3 is response curve of the airborne cloud particle detector of existing forward scattering to drop.
Fig. 4 is that particle equivalent redius is 0.5 micron, and transverse and longitudinal is than the nonspherical particle and the depolarization of spheroidal particle for 2 with dissipating
The relation of firing angle.
Fig. 5 is particle equivalent redius when being 0.5 micron, different shape particle depolarization and its transverse and longitudinal ratio in back scattering direction
Relation.
Wherein, 1- lasers, 2- polarizers, 3- half-wave plates, the total reflective mirrors of 4- first, 5- first windows glass, 6- second are complete
Anti- mirror, 7- LASER Energy Monitors, 8- forward scattering light collecting lens, 9- narrow band pass filters, the total reflective mirrors of 10- the 3rd, 11- first
Convergent lens, 12- beam splitter prisms, the photodetectors of 13- first, 14- apertures, the photodetectors of 15- second, 16- second
Window glass, the first rear orientation lights of 17- collecting lens, the convergent lenses of 18- second, the second rear orientation lights of 19- collecting lens,
20- polarization beam splitter prisms, the convergent lenses of 21- the 3rd, 22- parallel polarizations detector, the convergent lenses of 23- the 4th, 24- vertical polarizations
Detector.
Embodiment
Embodiments of the present invention are described below in detail, the example of the embodiment is shown in the drawings, wherein from beginning
Same or similar element or element with same or like function are represented to same or similar label eventually.Below by ginseng
The embodiment for examining accompanying drawing description is exemplary, is only used for explaining the present invention, and is not construed as limiting the claims.
Cloud particle detection system and method for the invention based on Polarization Detection, realize that the split-phase state of water dust and ice crystal is quantitatively visited
Survey, the system include producing the Laser emission optical unit of polarised light, forward scattering probe unit, backscatter sounding unit,
Four-way capture card and data processing unit, as shown in Figure 1 and Figure 2, wherein, four-way capture card and data processing unit figure
In be not drawn into.
Laser emission optical unit includes：One photodiode superpower laser 1, polarizer 2, half-wave plate 3 and
One total reflective mirror 4.
Forward scattering probe unit includes：First window glass 5, the second total reflective mirror 6, LASER Energy Monitor 7, forward direction dissipate
Penetrate light collecting lens 8, narrow band pass filter 9, the 3rd total reflective mirror 10, the first convergent lens 11, beam splitter prism 12, the first photodetection
Device 13, the photodetector 15 of aperture 14 and second.
Backscatter sounding unit includes：Second window glass 16, the first rear orientation light collecting lens 17, second are assembled
Lens 18, the second rear orientation light collecting lens 19, polarization beam splitter prism 20, the 3rd convergent lens 21, parallel polarization detector
22nd, the 4th convergent lens 23, vertical polarization detector 24.
The laser that photodiode superpower laser 1 is launched, making to shake by rotatory polarization piece 2 is oriented parallel to laser
Polarization direction, the vertical component of laser can be compressed, more pure polarised light is obtained, ambient noise is reduced；Half-wave plate 3 is used
In the polarization direction of rotary laser, transmitting laser is set to match with follow-up polarization beam splitter prism 20, can be suitable so as to launch laser
Profit is sent by polarization beam splitter prism 20, and back scattering luminous energy enters respective detector by polarization beam splitter prism 20 and put down
Row polarization detector 22 and vertical polarization detector 24, the first total reflective mirror 4 will be the first window in the middle of laser reflection to measured zone
Center between mouth glass 5, the second window glass 16.
Collected by 4-14 ° of forward scattering light after first window glass 5 by forward scattering light collecting lens 8,0-4 °
Forward scattering light transmits to LASER Energy Monitor 7 through the second total reflective mirror 6 and carries out energy monitoring, and the forward scattering light of collection is through narrow
First convergent lens 11 is introduced by the 3rd total reflective mirror 10 after band optical filter 9, the scattered light of convergence is for 12 points by energy beam splitter prism
3:1,25% forward scattering light enters the combination mark timing system response curve of detection channels photodetector 13 and draws particle
Size, system response curve is prepared by the following：From various sizes of normal glass spherolite, by the glass of identical size
Glass spherolite feeding detection system, sends into multiple glass marble particles every time, and Measurement channel photodetector is used to determine the size
The response amplitude of particle, according to the response amplitude, response amplitude of the system to water is transformed into according to Mie scattering, the contents of the section is led to
For existing forward scattering cloud particle detector.
75% forward scattering light enters quality control multi-channel photodetector 15 to distinguish cloud particle through aperture 14
The position of son determines whether the particle is recorded, when particle from the center of measured zone by when, this time is focused
Very little, aperture can be passed through, as particle enters the off-center position in position of light path, imaging becomes big, causes part
Light is blocked by aperture, more at off-center position, and the light being blocked is also more, causes quality control passage photoelectricity to be visited
The output for surveying device 15 and detection channels photodetector 13 is changed into 1:1, the path that now particle passes through is measurement sensitizing range
Most edge.
Collected by 146-176 ° of the rear orientation light of the second window glass 16 by the first rear orientation light collecting lens 17,
By polarization beam splitter prism 20 after the telescopic system constituted through the second convergent lens 18 and the second rear orientation light collecting lens 19
Parallel polarization and vertical polarization are separated, by parallel polarization after being assembled respectively through the 3rd convergent lens 21 and the 4th convergent lens 23
Detector 22 and vertical polarization detector 24 are detected, and parallel polarization component I is obtained respectively//With vertical polarisation component I⊥, lead to
Cross formulaDepolarization is calculated, wherein,WithRespectively without parallel polarization under the conditions of particle and vertical polarization
Background value.
It is special by the scattering of the technique study nonspherical particles such as T- matrix methods, finite difference time domain and geometric optics algorithm
Property, T- matrix methods are calculated by the following method：The Muller square that the Stokes vectors of incident beam and scattered beam pass through a 4*4
Battle array F is associated, and for each scatteringangleθ, there is following relational expression：
Wherein, Iin、Qin、UinAnd VinRespectively 4 Stokes parameters of incident light；Isc、Qsc、UscAnd VscRespectively dissipate
Penetrate 4 Stokes parameters of light；λ is wavelength；D is distance of the particle to detector.
Here the polarization state of light beam is described with 4 Stokes parameters I, Q, U, V, it is defined as follows：
In formula,WithRepresent the amplitude of electric field in the x and y direction, δxAnd δ (t)y(t) represent in this direction
Position phase.
Aforementioned four parameter represents a four-dimensional parameter, referred to as Stokes Stokes vectors as the column matrix of element.
[I Q U V]TThis group of parameter can represent the state of the random polarization light including degree of polarization.I, Q, U, V have light intensity
The dimension of degree.I- represents total light intensity degree；Q- represents X-direction linear polarization light component；U- represents 45 ° of direction rectilinearly polarized lights point
Amount；V- represents right-hand circular polarization light component.
Vertical line polarised light, -45 ° rectilinearly polarized lights and the left circularly polarized light orthogonal with above-mentioned polarized light state, then
Represented with Q, U, V negative value.
When laser polarization direction is parallel to scattering section, the parallel component and vertical component of scattered light can be written as：
When laser polarization direction is perpendicular to scattering section, the parallel component and vertical component of scattered light can be written as：
The stokes parameters of parallel polarization incident light：Qin=Iin, Uin=Vin=0；
The stokes parameters of vertical polarization incident light：Qin=-Iin, Uin=Vin=0；
The Stokes parameters of scattered light can be obtained by being then multiplied by Muller matrix with the Stokes parameters of incident light：
The stokes expressed as parameters of the scattered light of parallel polarization incident light is：
The stokes expressed as parameters of the scattered light of vertical polarization incident light is：
Formula can be passed through between wave number k and wavelength XConverted, have F for Arbitrary Particles direction21=
F12。
The linear Depolarization Ratio of the scattered light of parallel polarization incident light can be written as：
The linear Depolarization Ratio of the scattered light of vertical polarization incident light can be written as：
Different shape, various sizes of particle are calculated by the above method, its depolarization is drawn, for different particles
Model sets up polarization characteristic database.
It is 0.5 micron that Fig. 4, which gives the particle equivalent redius calculated by T- matrix methods, and transverse and longitudinal is than the aspherical for 2
The relation of particle and spheroidal particle depolarization and angle of scattering.Wherein the Depolarization Ratio of spheroidal particle is compared with elliposoidal particle and cylindrical grain
Small 10 orders of magnitude of Depolarization Ratio of son.146 ° -176 ° of the depolarization in these three particle backscattering angles is averaging, this kind is drawn
The depolarization of elliposoidal particle is 0.227, and the depolarization of this kind of cylindrical particle is 0.207, and equivalent redius is 0.5 micron of spherical grain
The depolarization of son is 2.51*10-11, nearly close to 0, it can be deduced that threshold value distinguishes spheroidal particle and nonspherical particle, examines
Consider sizes different from the depolarization of shape, and judge that the present invention uses Depolarization Ratio 0.01 for threshold value to reduce, less than this
Threshold value is liquid spheroidal particle, is solid particles more than or equal to the threshold value.
Fig. 5 gives the particle equivalent redius calculated by T- matrix methods when being 0.5 micron, in back scattering direction not
Similar shape particle depolarization and its transverse and longitudinal than relation, it can be seen that the shape of ellipsoidal particle to spheroidal particle when approaching, depolarization
Value is also approached to 0, but because the spatial angle range that we receive is larger, also can guarantee that the difference of solid-state and liquid.
Scattered signal information gathering of the system to each cloud particle, the depolarization that back scattering module is obtained and depolarization threshold value
It is compared, is nonspherical particle, i.e. ice crystalses when more than or equal to depolarization threshold value；When less than threshold value, it can determine whether as liquid
State.
System receives the scattering of cloud particle in the two directions, and forward scattering and back scattering, photodetection are collected respectively
Device converts optical signal into electric signal, by sample rate for 60M/s four-way A/D capture cards according to collection signal, can push away
The size and phase of disconnected particle to be measured.
Cloud particle detection system light path based on Polarization Detection, comprises the following steps：
1) photodiode superpower laser output laser, power output is 120mW, and spot size is 0.5mm；
2) rotatory polarization piece obtains pure polarised light identical with polarizing beam splitter mirror；
3) measurement sensitizing range (first window glass and the second window glass are reflected the laser light to using 45 ° of first total reflective mirror
Center position between glass)；
4) sensitizing range of system is determined by depth of field limiting orifice.200 μm of * 200 μm of apertures are placed in the middle of sensitizing range
Position, and by the detector of two passages of quality control passage and Measurement channel on oscillograph, for showing its voltage
Value.Using three-dimensional adjustment platform, aperture is finely tuned to the position of voltage all maximums of two passages, because Amici prism will be assembled
Signal afterwards is divided into 3:1 two parts, saturating 3 anti-1, so change of the change more than detection channels signal of quality control channel signal
Change, now the ratio of two passages is 3 to the maximum:1, the magnitude of voltage of now two passages is recorded respectively, until quality control passage and spy
Untill the ratio of survey passage is less than 0.5.Equally, similar method can be used for the effective width of measurement irradiation laser beam, enter
And determine the sampling area of system；
5) LASER Energy Monitor is reflexed to by 45 ° of second total reflective mirror by measuring the laser direct light behind sensitizing range to enter
Row monitoring；
6) forward scattering receiving device is isolated by window glass with outside air；
7) forward scattering lens collect the scattered light signal within 14 °；
8) suppress the veiling glare collected using narrow band pass filter, increase signal to noise ratio；
9) forward scattering light is all-trans using total reflective mirror；
10) forward scattering light enters line convergence by convergent lens；
11) the forward scattering light after focusing is divided into 3 by beam splitter prism:1 two parts, Amici prism saturating 3 anti-1；
12) aperture is put before beam splitter prism reflecting part corresponding mass control passage, detector is used for quality control, thoroughly
Part is penetrated directly to be detected by photodetector.
13) back scattering partial optical element is isolated by window glass with ambient atmosphere；
14) rear orientation light is entered line convergence by convergent lens；
15) rear orientation light is further entered line convergence by one group of telescopic system；
16) rear orientation light after focusing is divided into parallel polarized light and orthogonal polarized light by polarization beam splitter prism；
17) respectively by parallel polarization detection channels and vertical after parallel polarized light and the concentrated lens of orthogonal polarized light are assembled
Polarization Detection passage is detected；
18) result obtained according to Measurement channel, with reference to sound of the forward scattering cloud particle detector developed to drop
Curve (as shown in Figure 3) is answered, the yardstick of cloud particle is inquired；
19) according to formulaCalculated with reference to the result of detection of parallel polarization passage and vertical polarization passage
The depolarization of particle, the threshold value with 0.01 is contrasted, if more than or equal to the threshold value, being set to ice crystal, and add in ice crystal number
One, if less than the threshold value, being judged as aqueous water, and Jia one in water dust number；
20) above-mentioned processing is carried out to each KPT Scatter signal, then can obtains the different phase grain in the unit interval
Sub- number, it is considered to the measurement sensitive area and aircraft flight speed of system, then can obtain the particle diameter Spectral structure of water dust and ice crystal,
And then solid-state water content and Liquid water content in cloud can be obtained.
The technological thought of above example only to illustrate the invention, it is impossible to which protection scope of the present invention is limited with this, it is every
According to technological thought proposed by the present invention, any change done on the basis of technical scheme each falls within the scope of the present invention
Within.
Claims (8)
1. the cloud particle detection system based on Polarization Detection, it is characterised in that the Laser emission optics list including producing polarised light
Member, forward scattering probe unit, backscatter sounding unit, four-way capture card and data processing unit；Wherein, laser is sent out
Penetrating optical unit includes laser (1), polarizer (2), half-wave plate (3) and the first total reflective mirror (4)；Forward scattering probe unit bag
Include the second total reflective mirror (6) being sealed in inside the first glass container, LASER Energy Monitor (7), forward scattering light collecting lens
(8), narrow band pass filter (9), the 3rd total reflective mirror (10), the first convergent lens (11), beam splitter prism (12), the first photodetector
(13), aperture (14) and the second photodetector (15), the first glass container include first window glass (5)；It is backward to dissipate
Penetrating probe unit includes being sealed in the first rear orientation light collecting lens (17), the second convergent lens inside the second glass container
(18), the second rear orientation light collecting lens (19), polarization beam splitter prism (20), the 3rd convergent lens (21), parallel polarization are visited
Device (22), the 4th convergent lens (23), vertical polarization detector (24) are surveyed, the second glass container includes the second window glass
(16)；
The laser of laser (1) transmitting passes sequentially through polarizer (2), half-wave plate (3) and reaches the first total reflective mirror (4), first
Total reflective mirror (4) reflects the laser light to the center of first window glass (5) and the second window glass (16), and produces preceding to scattered
Penetrate light and rear orientation light；
After the forward scattering light is by first window glass (5), a part is transmitted to laser energy by the second total reflective mirror (6) supervises
Visual organ (7) carry out energy monitoring, another part by forward scattering light collecting lens (8) collect, and after narrow band pass filter (9) by
3rd total reflective mirror (10) introduces the first convergent lens (11) and enters line convergence, and the scattered light of convergence is divided into 3 by beam splitter prism (12):1,
Wherein, 25% enters the first photodetector (13), and 75% enters the second photodetector (15) through aperture (14)；
After the rear orientation light is by the second window glass (16), collected by the first rear orientation light collecting lens (17), warp
After the telescope that second convergent lens (18) and the second rear orientation light collecting lens (19) are constituted, by polarization beam splitter prism (20)
It is divided into parallel polarized light and orthogonal polarized light, parallel polarized light is after the 3rd convergent lens (21) by parallel polarization detector (22)
Detected, orthogonal polarized light is detected after the 4th convergent lens (23) by vertical polarization detector (24)；
First photodetector (13), the second photodetector (15), parallel polarization detector (22), vertical polarization detection
Device (24) is connected with four-way capture card respectively, and four-way capture card is connected with data processing unit.
2. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that the first window glass
Glass (5), the second window glass (16) are quartzy flat board.
3. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that the laser (1)
Wavelength is 660nm, and power output is 120mW.
4. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that the forward scattering light
The formed solid angle that receives of collecting lens (8) is 4-14 °, and the first rear orientation light collecting lens (17) is formed to receive solid angle
For 146-176 °.
5. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that the narrow band pass filter
(9) center is 660nm through wavelength, with a width of 10nm, and transmitance is 90% in bandwidth.
6. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that first total reflective mirror
(4), the second total reflective mirror (6) and the 3rd total reflective mirror (10) are that 45 ° of 660nm are all-trans.
7. the cloud particle detection system based on Polarization Detection according to claim 1, it is characterised in that the aperture
(14) size is 200 μm * 200 μm.
8. the cloud particle detection method based on Polarization Detection, it is characterised in that comprise the following steps：
Step 1, laser (1) output laser, sequentially passes through polarizer (2), half-wave plate (3) and reaches the first total reflective mirror (4), first
Total reflective mirror (4) reflects the laser light to the measured zone i.e. center of first window glass (5) and the second window glass (16), production
Before death to scattered light and rear orientation light；
Step 2, after forward scattering light is by first window glass (5), a part is transmitted to laser energy by the second total reflective mirror (6)
Monitor (7) carries out energy monitoring, and another part is collected by forward scattering light collecting lens (8), and after narrow band pass filter (9)
First convergent lens (11) is introduced by the 3rd total reflective mirror (10) and enters line convergence, the scattered light of convergence is divided into 3 by beam splitter prism (12):
1, wherein, 25% enters the first photodetector (13), and 75% enters the second photodetector (15) through aperture (14)；
Step 3, after rear orientation light is by the second window glass (16), collected by the first rear orientation light collecting lens (17),
After the telescope constituted through the second convergent lens (18) and the second rear orientation light collecting lens (19), by polarization beam splitter prism
(20) it is divided into parallel polarized light and orthogonal polarized light, parallel polarized light is after the 3rd convergent lens (21) by parallel polarization detector
(22) detected, orthogonal polarized light is detected after the 4th convergent lens (23) by vertical polarization detector (24)；
Step 4, the electric signal that the detection of each detector is obtained is gathered using four-way capture card, and judges the second photodetector
(15) whether electric signal is detected, is then to enter step 5, otherwise, return to step 1；
Step 5, moving back for cloud particle is calculated according to the result of detection of parallel polarization detector (22) and vertical polarization detector (24)
Partially, and with predetermined threshold value contrasted, if more than or equal to predetermined threshold value, being judged as ice crystal, and ice crystal number is added one, if small
In predetermined threshold value, then it is judged as aqueous water, and water dust number is added one.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710217629.5A CN106970046A (en) | 2017-04-05 | 2017-04-05 | Cloud particle detection system and method based on Polarization Detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710217629.5A CN106970046A (en) | 2017-04-05 | 2017-04-05 | Cloud particle detection system and method based on Polarization Detection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106970046A true CN106970046A (en) | 2017-07-21 |
Family
ID=59337318
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710217629.5A Pending CN106970046A (en) | 2017-04-05 | 2017-04-05 | Cloud particle detection system and method based on Polarization Detection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106970046A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108344671A (en) * | 2018-04-16 | 2018-07-31 | 成都信息工程大学 | A kind of airborne back scattering cloud particle survey meter, meteorological detection equipment and cloud particle detection method |
| CN108645819A (en) * | 2018-07-27 | 2018-10-12 | 成都信息工程大学 | A kind of backscatter sounding instrument for group's mist alarm |
| CN110907316A (en) * | 2019-12-16 | 2020-03-24 | 中国科学院大气物理研究所 | Light path system for single particle forward and backward scattering and depolarization ratio measurement |
| CN110927025A (en) * | 2019-12-05 | 2020-03-27 | 北京华泰诺安探测技术有限公司 | Aerosol particle monitoring facilities |
| CN113075097A (en) * | 2021-03-22 | 2021-07-06 | 厦门理工学院 | Particle size measuring method, device and equipment based on scattered light polarization detection |
| CN114663273A (en) * | 2022-03-21 | 2022-06-24 | 中国人民解放军国防科技大学 | Light-weight cloud particle field measurement method and system based on direct imaging |
| CN115684025A (en) * | 2022-09-23 | 2023-02-03 | 长春理工大学 | Cloud state polarization detection device and detection method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101629903A (en) * | 2009-08-19 | 2010-01-20 | 南京信息工程大学 | Optical system of scattering-type cloud particle detector |
| US20100110431A1 (en) * | 2008-11-05 | 2010-05-06 | Goodrich Corporation | Apparatus and method for in-flight detection of airborne water droplets and ice crystals |
| CN102830107A (en) * | 2012-09-04 | 2012-12-19 | 南京信息工程大学 | Laser radar detection method and system for measuring contents of solid water and liquid water in cloud |
| CN103868831A (en) * | 2014-02-26 | 2014-06-18 | 天津大学 | Cloud particle spectrum distribution measuring method and system |
| CN105115862A (en) * | 2015-07-02 | 2015-12-02 | 南京信息工程大学 | Cloud particle detection method and cloud particle detector |
| CN206638586U (en) * | 2017-04-05 | 2017-11-14 | 南京信息工程大学 | Cloud particle detection system based on Polarization Detection |
-
2017
- 2017-04-05 CN CN201710217629.5A patent/CN106970046A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100110431A1 (en) * | 2008-11-05 | 2010-05-06 | Goodrich Corporation | Apparatus and method for in-flight detection of airborne water droplets and ice crystals |
| CN101629903A (en) * | 2009-08-19 | 2010-01-20 | 南京信息工程大学 | Optical system of scattering-type cloud particle detector |
| CN102830107A (en) * | 2012-09-04 | 2012-12-19 | 南京信息工程大学 | Laser radar detection method and system for measuring contents of solid water and liquid water in cloud |
| CN103868831A (en) * | 2014-02-26 | 2014-06-18 | 天津大学 | Cloud particle spectrum distribution measuring method and system |
| CN105115862A (en) * | 2015-07-02 | 2015-12-02 | 南京信息工程大学 | Cloud particle detection method and cloud particle detector |
| CN206638586U (en) * | 2017-04-05 | 2017-11-14 | 南京信息工程大学 | Cloud particle detection system based on Polarization Detection |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108344671A (en) * | 2018-04-16 | 2018-07-31 | 成都信息工程大学 | A kind of airborne back scattering cloud particle survey meter, meteorological detection equipment and cloud particle detection method |
| CN108645819A (en) * | 2018-07-27 | 2018-10-12 | 成都信息工程大学 | A kind of backscatter sounding instrument for group's mist alarm |
| CN110927025A (en) * | 2019-12-05 | 2020-03-27 | 北京华泰诺安探测技术有限公司 | Aerosol particle monitoring facilities |
| CN110927025B (en) * | 2019-12-05 | 2023-03-10 | 北京华泰诺安探测技术有限公司 | Aerosol particle monitoring equipment |
| CN110907316A (en) * | 2019-12-16 | 2020-03-24 | 中国科学院大气物理研究所 | Light path system for single particle forward and backward scattering and depolarization ratio measurement |
| CN113075097A (en) * | 2021-03-22 | 2021-07-06 | 厦门理工学院 | Particle size measuring method, device and equipment based on scattered light polarization detection |
| CN114663273A (en) * | 2022-03-21 | 2022-06-24 | 中国人民解放军国防科技大学 | Light-weight cloud particle field measurement method and system based on direct imaging |
| CN114663273B (en) * | 2022-03-21 | 2023-04-28 | 中国人民解放军国防科技大学 | Light-weight cloud particle on-site measurement method and system based on direct imaging |
| CN115684025A (en) * | 2022-09-23 | 2023-02-03 | 长春理工大学 | Cloud state polarization detection device and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106970046A (en) | Cloud particle detection system and method based on Polarization Detection | |
| CN103868831B (en) | Cloud particle Spectral structure measuring method and measuring system | |
| Schnaiter et al. | Influence of particle size and shape on the backscattering linear depolarisation ratio of small ice crystals–cloud chamber measurements in the context of contrail and cirrus microphysics | |
| Hirst et al. | Discrimination of micrometre-sized ice and super-cooled droplets in mixed-phase cloud | |
| Um et al. | Dependence of the single-scattering properties of small ice crystals on idealized shape models | |
| Abdelmonem et al. | PHIPS–HALO: The airborne particle habit imaging and polar scattering probe–Part 1: Design and operation | |
| CN105911562B (en) | A kind of three-dimensional scanning type many reference amounts laser radar system for environmental monitoring | |
| CN107064957B (en) | Multi-view-field laser radar detection system and method for liquid water cloud measurement | |
| CN206638586U (en) | Cloud particle detection system based on Polarization Detection | |
| Baumgardner et al. | The Cloud Particle Spectrometer with Polarization Detection (CPSPD): A next generation open-path cloud probe for distinguishing liquid cloud droplets from ice crystals | |
| CN108291863A (en) | System and method for using light scattering technique to carry out individual particles dimensional measurement | |
| Scollo et al. | Monitoring Etna volcanic plumes using a scanning LiDAR | |
| CN206638826U (en) | A kind of more visual field Airborne Lidar examining systems for the measurement of liquid water cloud | |
| CN105115862A (en) | Cloud particle detection method and cloud particle detector | |
| US8502975B2 (en) | Standoff determination of the size and concentration of low concentration aerosols | |
| CN109581408A (en) | A kind of method and system carrying out target identification using laser complex imaging | |
| CN108344671A (en) | A kind of airborne back scattering cloud particle survey meter, meteorological detection equipment and cloud particle detection method | |
| Jurányi et al. | Dual-wavelength light-scattering technique for selective detection of volcanic ash particles in the presence of water droplets | |
| CN207882442U (en) | The continuous ray laser radar system of EO-1 hyperion of underwater finely ground particles detection | |
| KR20110087206A (en) | Apparatus and method for measuring characteristic about water ingredient of object using laser scattering signal of muti-wavelength | |
| Glienke et al. | Fast cloud droplet probe (FCDP) instrument handbook | |
| Marchant et al. | Aglite lidar: a portable elastic lidar system for investigating aerosol and wind motions at or around agricultural production facilities | |
| CN204718956U (en) | A kind of cloud particle detector | |
| Smith et al. | Exact and near backscattering measurements of the linear depolarisation ratio of various ice crystal habits generated in a laboratory cloud chamber | |
| CN218886153U (en) | Laser radar device, equipment and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170721 |
|
| RJ01 | Rejection of invention patent application after publication |