CN102937586A - Laser radar based water-in-cloud raman scattering full-spectrum measurement system and method thereof - Google Patents

Abstract

The invention discloses a laser radar based water-in-cloud raman scattering full-spectrum measurement system. The system comprises a laser emitting device, a laser receiving device, a spectrum resolution device, a photoelectric detection device, a data collecting device and a double-pulse triggering device, wherein the laser emitting device comprises a laser, a beam expander and a reflector, the spectrum resolution device comprises an optical fiber, an aspherical mirror, a broad bandpass filter, a grating spectrometer and a rotating platform, the photoelectric detection device comprises a photomultiplier which converts optical signals into electric signals, the data collecting device comprises a photon counting card and a computer, and the double-pulse triggering device comprises a sensing triggering module, a single chip microcomputer and a gating device. Simultaneously, the invention discloses a laser radar based water-in-cloud raman scattering full-spectrum measurement method. According to the system and the method, solid water and liquid water in clouds serve as detection objects, the whole system is compact in structure, easy to control and regulate and high in stability.

Description

The full spectral measurement system of water Raman scattering and method thereof in cloud based on laser radar

Technical field

The present invention relates to the full spectral measurement system of water Raman scattering in a kind of cloud, in particular, relate to the full spectral measurement system of water Raman scattering and measuring method thereof in a kind of cloud based on laser radar.

Background technology

Laser radar and spectral technique are in an increasingly wide range of applications in the atmospheric science field.So far, macroscopical observation technology of cloud is comparative maturity, and the multiple means such as artificial observation, ceilometer, total sky imager, weather radar, satellite remote sensing are arranged.But also fewer for the observation procedure of cloud micro-properties, with regard to it being carried out to Continuous Observation, millimetre-wave radar is putative a kind of effective detecting devices at present.But, with millimetre-wave radar, to compare, laser radar is having more advantage aspect spatial resolution, the mode of action, and the every technology comparative maturity of laser radar, and system is simple, and operation expense is cheap, has certain advantage in application.

The laser radar for the observation of cloud different phase water of having developed, comprise polarization lidar, steam DIAL, Raman lidar etc.Wherein, polarization lidar is only the phase of describing qualitatively water in cloud, obtain accurately the raman scattering spectrum knowledge that different phase liquid water content in cloud need to be used water.In addition, with the steam DIAL, compare, Raman lidar all has advantage at aspects such as system complexity, costs.

At present domestic existing Raman lidar is mainly measured the moisture content of atmosphere the inside, and in cloud body inside, and the phase that exists of water be take solid water and aqueous water as main.Up to the present, not yet have and take the laser radar system that solid, liquid state water is detected object in cloud.

Summary of the invention

Technical matters to be solved by this invention is, overcomes the shortcoming of prior art, and a kind of full spectral measurement system of water Raman scattering in the cloud based on laser radar that solid water and aqueous water are detected object in cloud of take is provided.

Simultaneously, the present invention also provides the full spectral measurement method of water Raman scattering in a kind of cloud based on laser radar.

In order to solve above technical matters, the invention provides the full spectral measurement system of water Raman scattering in a kind of cloud based on laser radar, comprise laser beam emitting device, laser receiver, spectrally resolved device, Electro-Optical Sensor Set and data collector,

Described laser beam emitting device is arranged at the below of tested cloud, comprise laser instrument, beam expander and catoptron, the center of described laser instrument, described beam expander and described catoptron is arranged on the same straight line, the laser pulse that described laser instrument is launched enters into the entrance of described beam expander, described beam expander is transmitted into described catoptron by laser pulse, described catoptron is extremely aerial by described laser pulse Vertical Launch, and beats on tested cloud body;

Described laser receiver is telescope, collects the echoed signal of tested cloud body reflection, and echoed signal is sent to described spectrally resolved device;

Described spectrally resolved device comprises optical fiber, aspheric mirror, broad band pass filter, grating spectrograph and rotation platform, the center of the outlet of described optical fiber, described aspheric mirror, described broad band pass filter and described grating spectrograph is arranged on same straight line, the entrance of described optical fiber receives the echoed signal of described telescope output, described echoed signal by after described optical fiber, described aspheric mirror, described broad band pass filter and described grating spectrograph, is delivered to described Electro-Optical Sensor Set successively;

Described Electro-Optical Sensor Set comprises photomultiplier, its input end and described grating spectrograph pass through signal communication, when described grating spectrograph during in open mode, receive the spectral signal that described grating spectrograph sends and signal is forwarded to described data collector;

Described data collector comprises photon counting card and computing machine, and the input end of described photon counting card is connected with the output end signal of described photomultiplier, and the signal that receives described photomultiplier is sampled and counts, and data are sent to described computing machine.

Being further defined to of technical solution of the present invention, described system also comprises the Two-pulse triggering device, described Two-pulse triggering device comprises induction trigger module, single-chip microcomputer and gating device, described induction trigger module is arranged in the Laser emission scope of described laser instrument, be connected with described single-chip microcomputer, transmit electric signal to described single-chip microcomputer; The output terminal of described single-chip microcomputer and described photon counting link and connect, and transmit double trigger to described photon counting card, control opening and closure of described photon counting card; Described single-chip microcomputer is connected with described photomultiplier by described gating device, transmits gate-control signal to described photomultiplier, controls opening and closure of described photomultiplier.The single-chip microcomputer that single-chip microcomputer 15 is AM89 series, preferably model is AT89S52 or AT89LS52.

Further, described spectrally resolved device also comprises rotation platform, and described grating spectrograph is fixedly installed on described rotation platform.

Further, described grating spectrograph adopts the plane reflection grating, and the adjacent spectral line angle interval of described plane reflection grating and the cutting number of every millimeter grating are determined by formula (1), (2), (3), (4), (5):

$d=\frac{1}{N}---\left(1\right)$

$\sin \mathrm{\θ}=k\frac{\mathrm{\λ}}{d}---\left(2\right)$

$D_{\mathrm{\θ}}=\frac{k}{d\·\cos {\mathrm{\θ}}_k}---\left(3\right)$

δθ=D _θ·δλ （4）

$\mathrm{\Δ\θ}=\frac{\mathrm{\λ}}{\mathrm{Nd}\·\cos \mathrm{\θ}}---\left(5\right)$

Wherein d is grating constant; N is the cutting number of every millimeter grating, and unit is millimeter; λ is selected reference wavelength, and unit is millimeter; The angle of diffraction that θ is the one-level spectral line, unit is degree; K is the spectrum rank; D _θFor the angular dispersion ability of grating, unit is degree; δ θ is adjacent spectral line angle interval, and unit is degree; δ λ is adjacent spectral line wavelength difference, and unit is millimeter; The half-angular breadth that Δ θ is spectral line, unit is degree.

Further, described laser instrument is the Nd:YAG laser instrument.

Further, the centre wavelength of described broad band pass filter is 405nm, and pass band width is 40nm.

Further, the temporal resolution of described photon counting card is 100ns, and range resolution is 15m, maximum count rate 200MHz.

Another technical scheme disclosed by the invention is: the full spectral measurement method of water Raman scattering in the cloud based on laser radar, it is characterized in that, and carry out in accordance with the following steps:

(i) laser instrument Emission Lasers pulse, after through beam expander, laser being expanded and being collimated, make laser pulse light beam vertical sand shooting enter in the air by catoptron, and beat on cloud body to be measured;

(ii), after being positioned near induction trigger module laser instrument and sensing laser, transmission of signal is to single-chip microcomputer, the single-chip microcomputer that single-chip microcomputer 15 is AM89 series, and preferred model is AT89S52 or AT89LS52; Single-chip microcomputer issues gate-control signal and double trigger, and described gate-control signal Raman scattered signal after laser sends opens the door photomultiplier before arriving, and prepares to receive the Raman scattering signal;

(iii) step (ii) in first pulse of double trigger while arriving, receive Raman scattering signal and bias light signal by telescope, and the signal of reception be passed in optical fiber, by optical fiber, light wave is collimated;

(iv) the light wave through fiber optic collimator is collimated-is focused on by aspheric mirror, becomes directional light; Described directional light, after broad band pass filter filtering part interference noise, arrives the grating spectrograph rotated, and described grating spectrograph is surveyed the Raman echoed signal with certain angular resolution and wavelength interval, and signal is passed to photomultiplier;

(v) photomultiplier changes the light signal of reception into electric signal, send to the photon counting card, the electric signal that described photon counting card docking is received is sampled and is counted, by analog signal conversion be digital signal and by digital signal transfers to computing machine, computing machine is processed and is stored the digital signal received;

(vi) step (ii) in second pulse of double trigger while arriving, receive the bias light signal by telescope, and the signal of reception be passed in optical fiber, after by optical fiber, light wave being collimated, execution step (iv) with step (v);

(vii) signal step obtained in (v) deducts the signal that step obtains in (vi), obtains the characteristic information of spectrum.

9. the full spectral measurement method of water Raman scattering in the cloud based on laser radar according to claim 1, it is characterized in that, described grating spectrograph adopts the plane reflection grating, and the adjacent spectral line angle interval of described plane reflection grating and the cutting number of every millimeter grating are determined by formula (1), (2), (3), (4), (5):

$d=\frac{1}{N}---\left(1\right)$

$\sin \mathrm{\θ}=k\frac{\mathrm{\λ}}{d}---\left(2\right)$

$D_{\mathrm{\θ}}=\frac{k}{d\·\cos {\mathrm{\θ}}_k}---\left(3\right)$

δθ=D _θ·δλ （4）

$\mathrm{\Δ\θ}=\frac{\mathrm{\λ}}{\mathrm{Nd}\·\cos \mathrm{\θ}}---\left(5\right)$

Wherein d is grating constant; N is the cutting number of every millimeter grating, and unit is millimeter; λ is selected reference wavelength, and unit is millimeter; The angle of diffraction that θ is the one-level spectral line, unit is degree; K is the spectrum rank; D _θFor the angular dispersion ability of grating, unit is degree; δ θ is adjacent spectral line angle interval, and unit is degree; δ λ is adjacent spectral line wavelength difference, and unit is millimeter; The half-angular breadth that Δ θ is spectral line, unit is degree.

The invention has the beneficial effects as follows: in the cloud based on laser radar that the present invention proposes, the full spectral measurement system of water Raman scattering and method thereof are compared and are had the following advantages with existing laser radar system:

1. take solid water in cloud, aqueous water is detected object, obtains the full spectral distribution curve of Raman scattering of Yun Zhongshui, contributes to further to obtain different phase liquid water content in cloud, significant to cloud micro-properties research.

2. laser radar system and grating spectrograph are combined, there is the advantages such as spectral resolution is high, volume less.

3. adopt the Two-pulse triggering technology, eliminated to greatest extent the impact of bias light.

4. adopt electric rotating platform to drive grating spectrograph and rotate, guaranteed the fixing diffraction of light angle that enters grating spectrograph, be convenient to the reception of Photodetection system.

5. the whole system compact conformation, be easy to control and regulate, and system stability is high.

The accompanying drawing explanation

The structural representation that Fig. 1 is the full spectral measurement system of water Raman scattering in the cloud based on laser radar of the present invention;

The signal graph that Fig. 2 is the gate-control signal that issues of single-chip microcomputer of the present invention;

The signal graph that Fig. 3 is the double trigger that issues of single-chip microcomputer of the present invention.

In figure:

1, laser instrument; 2, beam expander; 3, catoptron; 4, telescope; 5, optical fiber; 6, optical filter; 7, aspheric mirror; 8, grating spectrograph; 9, rotation platform; 10, photomultiplier; 11, photon counting card; 12, computing machine; 13, PMT gate; 14, induction trigger module; 15, single-chip microcomputer.

Embodiment

Embodiment 1

The full spectral measurement system of water Raman scattering in a kind of cloud based on laser radar that the present embodiment provides, structure as shown in Figure 1, comprises laser beam emitting device, laser receiver, spectrally resolved device, Electro-Optical Sensor Set, data collector and Two-pulse triggering device.

Described laser beam emitting device is arranged at the below of tested cloud, comprises laser instrument 1, beam expander 2 and catoptron 3, and the center of described laser instrument 1, described beam expander 2 and described catoptron 3 is arranged on the same straight line.The laser pulse that described laser instrument 1 is launched enters into the entrance of described beam expander 2, and described beam expander 2 is transmitted into described catoptron 3 by laser pulse, and described catoptron 3 is extremely aerial by described laser pulse Vertical Launch, and beats on tested cloud body.Described laser instrument 1 is the Nd:YAG laser instrument, and the pulse laser beam wavelength is 355nm, and single pulse energy is 70mJ, and pulsewidth is<7ns, repetition frequency 20Hz, the angle of divergence≤1mrad.Beam expander 2 adopts 30 times and expands.The inclination angle of described catoptron 3 is 45 degree.The function of laser instrument 1 is the Emission Lasers pulse, and the function of beam expander 2 is collimated light beams, reduces the angle of divergence of laser, and the function of catoptron 3 is to make laser pulse light beam vertical sand shooting enter in the air.

Described laser receiver is for collecting the telescope 4 of Raman scattering echoed signal, and telescope 4 adopts Meade LX200 telescope, and the telescope bore is 400mm, and focal length is 2000mm.Utilize telescope 4 to collect the backscattering echo of laser radars and the bias light during without laser.

Described spectrally resolved device comprises optical fiber 5, aspheric mirror 6, broad band pass filter 7, grating spectrograph 8 and rotation platform 9.The center of the outlet of described optical fiber 5, described aspheric mirror 6, described broad band pass filter 7 and described grating spectrograph 8 is arranged on same straight line, the entrance of described optical fiber 5 receives the echoed signal of described telescope 4 outputs, described echoed signal by after described optical fiber 5, described aspheric mirror 6, described broad band pass filter 7 and described grating spectrograph 8, is delivered to described Electro-Optical Sensor Set successively.

The numerical aperture of described optical fiber 5 adopts NA=0.12, and optical fiber is flexible, has improved systematically dirigibility.Described grating spectrograph 8 is fixedly installed on described rotation platform 9, with certain angular resolution and wavelength interval, surveys the Raman echoed signal.The centre wavelength of described broad band pass filter 7 is 405nm, and pass band width is 40nm.

Described grating spectrograph 8 adopts the plane reflection grating, for the Raman scattering signal to obtaining after separating, carries out spectral separation, and the minimum wavelength that this grating can be differentiated is spaced apart 0.05nm.The adjacent spectral line angle interval of described plane reflection grating and the cutting number of every millimeter grating are determined by formula (1), (2), (3), (4), (5):

$d=\frac{1}{N}---\left(1\right)$

$\sin \mathrm{\&theta;}=k\frac{\mathrm{\&lambda;}}{d}---\left(2\right)$

$D_{\mathrm{\&theta;}}=\frac{k}{d\&CenterDot;\cos {\mathrm{\&theta;}}_k}---\left(3\right)$

δθ=D _θ·δλ （4）

$\mathrm{\&Delta;\&theta;}=\frac{\mathrm{\&lambda;}}{\mathrm{Nd}\&CenterDot;\cos \mathrm{\&theta;}}---\left(5\right)$

Wherein d is grating constant; N is the cutting number of every millimeter grating, and unit is millimeter; λ is selected reference wavelength, and unit is millimeter; The angle of diffraction that θ is the one-level spectral line, unit is degree; K is the spectrum rank; D _θFor the angular dispersion ability of grating, unit is degree; δ θ is adjacent spectral line angle interval, and unit is degree; δ λ is adjacent spectral line wavelength difference, and unit is millimeter; The half-angular breadth that Δ θ is spectral line, unit is degree.

Select 15cm wide, the plane grating that grating constant is 1/1200mm, the angular spacing δ θ that calculates adjacent spectral line by formula is 0.23 ', the half-angular breadth Δ θ of every spectral line is 0.009 '.

Described electric rotating platform 9 is rotated for driving grating spectrograph 8, with the light signal that guarantees certain wavelength interval, with the angle of diffraction of fixing, enters grating spectrograph.For the poor corresponding angular spacing of minimum wavelength that can differentiate with grating spectrograph adapts, choose TRB-m series electric rotating platform, its mesa dimensions diameter is 200mm, ratio of gear is 1:360, motor synchronizing operation resolution is 0.01 ° and (moves under 10 finely divided states, resolution is 0.01 ° of ÷ 10=0.001 °=0.06 '), range of adjustment is ± 15 °.

The function of spectrally resolved device is:

1. the optical echo signal is assembled and entered optical fiber 5, re-use 6 pairs of backscatter signal of aspheric mirror and collimate.

2. come filtering part ground unrest and elastic scattering noise with broad band pass filter 7.

3. carry out spectral separation with the grating spectrograph 8 rotated, realize spectral scan.

Described Electro-Optical Sensor Set comprises the photomultiplier 10 that light signal is changed into to electric signal, the response wave length scope of photomultiplier 10 is 200nm-900nm, for normally off, its input end and described grating spectrograph 8 pass through signal communication, during in open mode, receive the spectral signal that described grating spectrograph 8 sends when photomultiplier 10; The output terminal of described photomultiplier 10 is communicated with described data collector.

The function of described Electro-Optical Sensor Set is to change light signal into electric signal with photomultiplier 10.Suppress the impact of daylight in environment, parasitic light with PMT gate 13.Usually make photomultiplier in closed condition, before laser sends rear Raman scattered signal and arrives, photomultiplier opens the door and prepares to receive the Raman scattering signal.

Described data collector comprises photon counting card 11 and computing machine 12, and the input end of described photon counting card 11 is connected by signal with the output terminal of described photomultiplier 10, and the electric signal that receives described photomultiplier 10 is sampled and counts; The input end of described computing machine 12 is connected sampling and the count signal that receives described photon counting card 11 and is analyzed and store with the output terminal of described photon counting card 11.The output terminal of described computing machine 12 is connected with the control end of rotation platform 9, controls rotation platform 9 and rotates.

Described photon counting card 11 is used P7882 photon counting card, and temporal resolution is 100ns, and range resolution is 15m, maximum count rate 200MHz.

The function of described data collector is:

1. the output signal of detector is sampled and counted.

2. by the situation of change of the echoed signal intensity wavelength of water Raman scattering, record is preserved and is shown on computing machine 12.

Described Two-pulse triggering device comprises induction trigger module 14, single-chip microcomputer 15 and gating device 13, described induction trigger module 14 is arranged in the Laser emission scope of described laser instrument 1, with described single-chip microcomputer 15, be connected, after sensing the laser of described laser instrument 1 emission, transmit electric signal to described single-chip microcomputer 15.The single-chip microcomputer that single-chip microcomputer 15 is AM89 series, preferably model is AT89S52 or AT89LS52.

Described single-chip microcomputer 15 and described computing machine 12 two-way communications; The output terminal of described single-chip microcomputer 15 is connected with described photon counting card 11, and is connected with described photomultiplier 10 by described gating device 13, for 1. transmitting gate-control signal to described photomultiplier 10, controls opening and closure of described photomultiplier 10; 2. transmit double trigger to described photomultiplier 10 and described photon counting card 11, photomultiplier 10 and photon counting card 11 are opened in first pulse when the Raman scattering echo is arranged, collection comprises the light intensity signal of Raman scattering signal, photomultiplier 10 and photon counting card 11 are opened in second pulse without laser the time, gather the background light intensity signal.

In cloud based on laser radar of the present invention, the method for work of the full spectral measurement system of water Raman scattering is to carry out in accordance with the following steps:

(i) laser instrument 1 Emission Lasers pulse, after 2 pairs of laser of beam expander are expanded and collimated, make laser pulse light beam vertical sand shooting enter in the air by catoptron 3, and beat on cloud body to be measured.

(ii) after being positioned near induction trigger module 14 laser instrument 1 and sensing laser, transmission of signal is to single-chip microcomputer 15, single-chip microcomputer 15 issues gate-control signal and double trigger, the signal graph of described gate-control signal as described in Figure 2, the signal graph of described double trigger as shown in Figure 3, described gate-control signal Raman scattered signal after laser sends opens the door photomultiplier 10 before arriving, and prepares to receive the Raman scattering signal.

(iii) step (ii) in first pulse of double trigger while arriving, receive Raman scattering signal and bias light signals by telescope 4, and the signal of reception be passed in optical fiber 5, by 5 pairs of light waves of optical fiber, collimated.

(iv) the light wave through optical fiber 5 collimations is collimated-is focused on by aspheric mirror 6, becomes directional light; Described directional light, after broad band pass filter 7 filtering part interference noises, arrives the grating spectrograph 8 rotated, and described grating spectrograph 8 is surveyed the Raman echoed signal with certain angular resolution and wavelength interval, and signal is passed to photomultiplier 10.

The every rotation of grating spectrograph can be set once, measure 1000 subpulses, to improve signal to noise ratio (S/N ratio).

(v) photomultiplier 10 changes the light signal of reception into electric signal, send to photon counting card 11, the electric signal that described photon counting card 11 receives is sampled and is counted, by analog signal conversion be digital signal and by digital signal transfers to computing machine 12, the digital signal of 12 pairs of receptions of computing machine is processed and is stored.

(vi) step (ii) in second pulse of double trigger while arriving, receive the bias light signals by telescope 4, and the signal of reception be passed in optical fiber 5, after being collimated by 5 pairs of light waves of optical fiber, execution step (iv) with step (v).

(vii) signal step obtained in (v) deducts the signal that step obtains in (vi), obtains the characteristic information of spectrum.In addition to the implementation, the present invention can also have other embodiments.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection domain of requirement of the present invention.

Claims (9)

1. the full spectral measurement system of water Raman scattering in the cloud based on laser radar, comprise laser beam emitting device, laser receiver, spectrally resolved device, Electro-Optical Sensor Set and data collector,

Described laser beam emitting device is arranged at the below of tested cloud, comprise laser instrument (1), beam expander (2) and catoptron (3), the center of described laser instrument (1), described beam expander (2) and described catoptron (3) is arranged on the same straight line, the laser pulse that described laser instrument (1) is launched enters into the entrance of described beam expander (2), described beam expander (2) is transmitted into described catoptron (3) by laser pulse, described catoptron (3) is extremely aerial by described laser pulse Vertical Launch, and beats on tested cloud body;

Described laser receiver is telescope (4), collects the echoed signal of tested cloud body reflection, and echoed signal is sent to described spectrally resolved device;

Described spectrally resolved device comprises optical fiber (5), aspheric mirror (6), broad band pass filter (7), grating spectrograph (8) and rotation platform (9), the outlet of described optical fiber (5), described aspheric mirror (6), the center of described broad band pass filter (7) and described grating spectrograph (8) is arranged on same straight line, the entrance of described optical fiber (5) receives the echoed signal of described telescope (4) output, described echoed signal is successively by described optical fiber (5), described aspheric mirror (6), after described broad band pass filter (7) and described grating spectrograph (9), be delivered to described Electro-Optical Sensor Set,

Described Electro-Optical Sensor Set comprises photomultiplier (10), its input end and described grating spectrograph (8) pass through signal communication, when described grating spectrograph (8) during in open mode, receive the spectral signal that described grating spectrograph (8) sends and signal is forwarded to described data collector;

Described data collector comprises photon counting card (11) and computing machine (12), the input end of described photon counting card (11) is connected with the output end signal of described photomultiplier (10), the signal that receives described photomultiplier (10) is sampled and is counted, and data are sent to described computing machine (12).

2. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, it is characterized in that, described system also comprises the Two-pulse triggering device, described Two-pulse triggering device comprises induction trigger module (14), single-chip microcomputer (15) and gating device (13), described induction trigger module (14) is arranged in the Laser emission scope of described laser instrument (1), be connected with described single-chip microcomputer (15), transmit electric signal to described single-chip microcomputer (15); The output terminal of described single-chip microcomputer (15) is connected with described photon counting card (11), transmits double trigger to described photon counting card (11), controls opening and closure of described photon counting card (11); Described single-chip microcomputer (15) is connected with described photomultiplier (10) by described gating device (13), transmits gate-control signal to described photomultiplier (10), controls opening and closure of described photomultiplier (10).

3. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, it is characterized in that, described spectrally resolved device also comprises rotation platform (9), and described grating spectrograph (8) is fixedly installed on described rotation platform (9).

4. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, it is characterized in that, described grating spectrograph (8) adopts the plane reflection grating, and the adjacent spectral line angle interval of described plane reflection grating and the cutting number of every millimeter grating are determined by formula (1), (2), (3), (4), (5):

$d=\frac{1}{N}---\left(1\right)$

$\sin \mathrm{\&theta;}=k\frac{\mathrm{\&lambda;}}{d}---\left(2\right)$

$D_{\mathrm{\&theta;}}=\frac{k}{d\&CenterDot;\cos {\mathrm{\&theta;}}_k}---\left(3\right)$

δθ=D _θ·δλ（4）

$\mathrm{\&Delta;\&theta;}=\frac{\mathrm{\&lambda;}}{\mathrm{Nd}\&CenterDot;\cos \mathrm{\&theta;}}---\left(5\right)$

Wherein d is grating constant; N is the cutting number of every millimeter grating, and unit is millimeter; λ is selected reference wavelength, and unit is millimeter; The angle of diffraction that θ is the one-level spectral line, unit is degree; K is the spectrum rank; D _θFor the angular dispersion ability of grating, unit is degree; δ θ is adjacent spectral line angle interval, and unit is degree; δ λ is adjacent spectral line wavelength difference, and unit is millimeter; The half-angular breadth that Δ θ is spectral line, unit is degree.

5. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, is characterized in that, described laser instrument (1) is the Nd:YAG laser instrument.

6. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, is characterized in that, the centre wavelength of described broad band pass filter (7) is 405nm, and pass band width is 40nm.

7. the full spectral measurement system of water Raman scattering in the cloud based on laser radar according to claim 1, is characterized in that, the temporal resolution of described photon counting card (11) is 100ns, and range resolution is 15m, maximum count rate 200MHz.

8. the full spectral measurement method of water Raman scattering in the cloud based on laser radar, is characterized in that, carries out in accordance with the following steps:

(i) laser instrument (1) Emission Lasers pulse, after beam expander (2) is expanded laser and collimated, make laser pulse light beam vertical sand shooting enter in the air by catoptron (3), and beat on cloud body to be measured;

(ii) after being positioned near induction trigger module (14) laser instrument (1) and sensing laser, transmission of signal is to single-chip microcomputer (15), single-chip microcomputer (15) issues gate-control signal and double trigger, described gate-control signal Raman scattered signal after laser sends opens the door photomultiplier (10) before arriving, and prepares to receive the Raman scattering signal;

(iii) step (ii) in first pulse of double trigger while arriving, receive Raman scattering signal and bias light signal by telescope (4), and the signal of reception be passed in optical fiber (5), by optical fiber (5), light wave is collimated;

(iv) the light wave through optical fiber (5) collimation is collimated-is focused on by aspheric mirror (6), becomes directional light; Described directional light is after broad band pass filter (7) filtering part interference noise, arrive the grating spectrograph (8) rotated, described grating spectrograph (8) is surveyed the Raman echoed signal with certain angular resolution and wavelength interval, and signal is passed to photomultiplier (10);

(v) photomultiplier (10) changes the light signal of reception into electric signal, send to photon counting card (11), described photon counting card (11) is sampled and is counted the electric signal received, by analog signal conversion be digital signal and by digital signal transfers to computing machine (12), computing machine (12) is processed and is stored the digital signal received;

(vi) step (ii) in second pulse of double trigger while arriving, receive the bias light signal by telescope (4), and the signal of reception be passed in optical fiber (5), after by optical fiber (5), light wave being collimated, execution step (iv) with step (v);

(vii) signal step obtained in (v) deducts the signal that step obtains in (vi), obtains the characteristic information of spectrum.

9. the full spectral measurement method of water Raman scattering in the cloud based on laser radar according to claim 1, it is characterized in that, described grating spectrograph (8) adopts the plane reflection grating, and the adjacent spectral line angle interval of described plane reflection grating and the cutting number of every millimeter grating are determined by formula (1), (2), (3), (4), (5):

$d=\frac{1}{N}---\left(1\right)$

$\sin \mathrm{\&theta;}=k\frac{\mathrm{\&lambda;}}{d}---\left(2\right)$

$D_{\mathrm{\&theta;}}=\frac{k}{d\&CenterDot;\cos {\mathrm{\&theta;}}_k}---\left(3\right)$

δθ=D _θ·δλ（4）

$\mathrm{\&Delta;\&theta;}=\frac{\mathrm{\&lambda;}}{\mathrm{Nd}\&CenterDot;\cos \mathrm{\&theta;}}---\left(5\right)$

Wherein d is grating constant; N is the cutting number of every millimeter grating, and unit is millimeter; λ is selected reference wavelength, and unit is millimeter; The angle of diffraction that θ is the one-level spectral line, unit is degree; K is the spectrum rank; D _θFor the angular dispersion ability of grating, unit is degree; δ θ is adjacent spectral line angle interval, and unit is degree; δ λ is adjacent spectral line wavelength difference, and unit is millimeter; The half-angular breadth that Δ θ is spectral line, unit is degree.

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