48 results about "Raman lidar" patented technology

The invention discloses a single-wavelength four-Raman laser radar detection system and a detection method. The system combines three laser radar technologies of atmospheric temperature measurement via pure-rotation Raman scattering, vapor measurement via vibration Raman scattering, and measurement of atmosphere aerosol optical characteristics via Raman Mie scattering and an inversion method. The laser radar system employs 355 nm single-wavelength pulse laser as a detection light source and a large-diameter optical reception telescope with high transmittance for measuring the wavelength to collect atmospheric back scattering light signals, four wavelength atmospheric Raman scattering light signals and Mie scattering echo light signals of 353 nm, 354 nm, 355 nm, 386 nm, and 407 nm are mutually separated via an angle separation method of color separation filters and interference filters by a following optical path, the above five-wavelength scattering light signals are gated via narrowband interference filters, photoelectric conversion of photomultipliers of the same type is accomplished, and data acquisition is accomplished by a five-channel data collector.

The invention relates to a method for acquiring a complex refractive index of urban aerosol on the basis of various ground-based remote sensing technologies. The method comprises the following steps of: acquiring the extinction coefficient and the scattering extinction ratio of the aerosol through an inverse algorithm by virtue of Raman laser radar echo signals, and integrating the extinction coefficient of a certain route to acquire the optical thickness of the aerosol on the route; continuously correcting the extinction coefficient and the scattering extinction ratio by performing iterative alignment on an aerosol optical thickness of a whole atmospheric layer acquired via a sun photometer and the aerosol optical thickness acquired via a laser radar according to a Monte Carlo principle; then acquiring the particle size distribution of the aerosol via a particle spectrometer; and finally, acquiring the complex refractive index of the urban aerosol according to a mie-scattering model by virtue of the known scattering extinction ratio of the aerosol and the particle size distribution of the aerosol. According to the invention, the complex refractive index of the urban aerosol is acquired by the Raman laser radar, the sun photometer and the particle spectrometer, and the method has the advantages of small error, high discriminability and high universality.

The invention relates to a system for detecting atmospheric temperature by a rotational Raman lidar, belonging to the technical field of optics. The system comprises a system control mechanism, a laser, a laser emitting mechanism, a large-caliber receiving telescope, a multi-channel spectrometer mechanism, a collimating lens high-J signal data acquiring mechanism, a low-J signal data acquiring mechanism and a signal processing mechanism, wherein a laser beam sequentially enters a light beam expander, a first emitting light-guiding lens and a second emitting light-guiding lens and then forms a detecting laser beam, a backward scattering backwave optical signal of the laser beam is received by the large-caliber receiving telescope and collected into a micropore diaphragm, then is sent to the multi-channel spectrometer mechanism, splits and filters an interference signal, and then enters a photoelectric detector, an amplifier, an analog digital converter and the signal processing mechanism; and a photoelectric detection signal is inverted according to an equation of the rotational Raman scattering lidar equation to obtain vertically distributed profile data of the atmospheric temperature. The invention can detect the vertically distributed profile of the atmospheric temperature of atmospheric troposphere and has high precision.

The invention discloses a Raman lidar calibration device and a calibration method thereof. The device is characterized in that the output end of a receiving fiber (13) is sheathed with a camera obscura (11), and the side surface of the output port of the receiving fiber (13) is provided with luminescent spectrum range covering nitrogen and a luminous diode (1) of the spectral band of gas to be calibrated; the receiving fiber (13) and the light path of the luminous diode (1) are provided with a collimation lens (10) and a beam splitting sheet (5); the reflective light path of the beam splitting sheet (5) is provided with a first optical filter (3) and a first detector (2); and a transmission light path is provided with a second optical filter (7) and a second detector (6). The method is as follows: the light intensity P1 of the spectral band of gas to be calibrated and the light intensity P2 of the nitrogen which are obtained by the first detector (2) and the second detector (6) as well as I lambda N and I lambda X in the intensity expression are substituted into a Raman lidar equation to obtain the density distribution of the gas to be calibrated. The device has simple structure and convenient use and can be used for the quantitative measurement of atmospheric parameters.

The invention relates to a rotary Raman laser radar system based on a grating technology light splitting structure, which comprises a laser emitting system, a receiving system, a light splitting system, a photoelectric detection system and an information processing system, wherein the light splitting system comprises a positive lens, a blaze grating, an optical fiber array, optical fiber couplers and an optical fiber Bragg grating, the optical fiber array and the blaze grating are respectively positioned at the front side and the rear side of the positive lens, a plurality of optical fibers are connected to the optical fiber array, the optical fiber coupler is arranged on each optical fiber and provided with three ports which are respectively PA, PB and PC, and the port PB is connected with the optical fiber Bragg grating. According to the invention, regulation freedom of the rotary Raman laser radar system is reduced; and the rotary Raman laser radar system has the advantages of compact structure, small volume and light weight, and has a certain daytime remote sensing detecting capacity so as to be suitable for vehicle-mounted, air-mounted and satellite-mounted application.

The invention provides a vibration Raman laser radar scattering optical processing system based on a narrow bandpass filter and a reflex prism, and a processing method thereof. Aiming at two problems of a wide dynamic range of laser radar signal intensity and strong noise signal relative to a Raman scattering signal, the method and the system divide back scattering light into a high channel and a low channel for detecting and sufficiently utilize the narrow bandpass filter to improve the accuracy of temperature measurement and enlarge the range of the temperature measurement. An upper noise signal is relative weak, and can be fed into a photoelectric detection system for detecting through the narrow bandpass filter for once; and a lower noise signal is strong, the back scattering light of atmosphere passes through the same optical filter for twice by special optical technology, and spectrum of total transmittance is equivalent to squared spectrum of single transmittance so as to furthest suppress photonoise. After elastic scattering and background light of emission wavelength are compressed, under the condition of a multiplier tube is unsaturated, the echo intensity of the Raman scattering signal can be improved by increasing single pulse energy of emission laser, thereby achieving the aims of improving the accuracy of the temperature measurement and enlarging the range of the temperature measurement.

The invention discloses a double-wavelength single receiving channel-based rotation Raman temperature measurement laser radar. The laser radar is based on two working wavelengths and a single receiving channel. The two working wavelengths of the laser radar are respectively composed of odd number pulses and even number pulses. The low-quantum-number rotation Raman signals of one working wavelength and the high-quantum-number rotation Raman signals of the other working wavelength are extracted by the receiving channel of the laser radar. The laser radar is operated alternately at the two working wavelengths in the time division multiplexing manner. The atmospheric temperature is calculated based on the ratio of high-quantum-number rotation Raman signals to low-quantum-number rotation Raman signals. According to the technical scheme of the invention, the rotation Raman temperature measurement is realized only by means of a single filter, a single detector and a single acquisition card. Compared with a single-wavelength double receiving channel-based rotation Raman temperature measurement laser radar, the above laser radar is compact in structure, wherein the difficulty of optical path adjustment and the difficulty of system parameter calibration are lowered. Meanwhile, the double-wavelength single receiving channel-based rotation Raman temperature measurement laser radar is low in cost. The working performance difference between the filter and the detector caused by the inconsistence of working environments can be avoided. Moreover, the detection accuracy, the system stability and the environmental adaptability are improved.

The invention discloses a rotational raman lidar system for absolutely detecting atmosphere temperature and a detecting method. The system comprises a system control platform, a pulse laser and a collimation beam expanding system which are sequentially connected; a beam splitter mirror, a first reflecting mirror, a second reflecting mirror and a third reflecting mirror are sequentially arranged in the light path outgoing direction of the collimation beam expanding system; part of light beams reflected by the beam splitter mirror irradiate to a photoelectric detector; the system control platform is respectively connected with an amplifying circuit, a data processing platform and a photoelectric detector; the data processing platform is sequentially connected with an amplifying circuit, a photoelectric detecting system and a raman spectra type beam splitting system, wherein the raman spectra type beam splitting system is connected with an efficient coupler through a multi-die fiber; the efficient coupler is used for receiving scattered light collected by a large-aperture telescope. With the adoption of the system, the limitation that the measurement device is to be travelled in parallel and the data are to be corrected during detecting the atmosphere temperature through the existing raman lidar system can be solved.

A single-line-extracted pure rotational Raman lidar system, including: a transmitter unit configured to emit extremely narrow-band laser light that is guided into atmosphere zenithward; a receiver unit configured to collect backscattered signals from the atmosphere; and a data acquisition and control unit configured to deliver data and guarantee automatic operation of the lidar system orderly. The transmitter unit employs a powerful injection-seeded Nd: YAG laser to emit 532.23 nm laser beam with a pulse energy of approximately 800 mJ, a repetition rate of 30 Hz and linewidth of <0.006 cm−1. The lidar system has an optical bandwidth of approximately 30 pm for the two Raman channels and an optical bandwidth of 0.3 nm for an elastic channel, as well as a field of view of approximately 0.4 mrad. The two Raman channels extract the N2 anti-Stokes pure rotational Raman line signals with J=6 and 16, respectively.

The invention relates to a saturation correction method for temperature measurement of a pure rotational Raman lidar and belongs to the technical field of measurement. The method comprises the first step of obtaining original high-order echo signals and original low-order echo signals of the pure rotational Raman lidar and obtaining high-order channel echo signals with the background removed and low-order channel echo signals with the background removed, and the second step of judging whether the phenomenon of saturation of the near-ground photon number exists, and if yes, achieving saturation correction of the near-ground photon number by selecting electronic identification level values mu of different multiplier systems. In this way, causes of the near-ground saturation phenomenon can be analyzed according to underlying causes of photon counting nonlinearity, namely the pulse height distribution and the electronic identification level; the temperature retrieval process is conducted through the corrected high-order channel echo signals and the corrected low-order channel echo signals, and the accuracy of the pure rotational Raman lidar in measuring the atmosphere temperature profile is improved.

The invention discloses an earth laser radar for aerosol detection and relates to the field of laser atmospheric remote sensing. The ground-based laser radar includes a double-line-of-view laser radarand an inversion processing module. The double-line-of-view laser radar includes a first laser radar and a second laser radar. The first laser radar includes a first transmitting system, a first echoreceiving system, and a first detection acquisition processing system. The second laser radar includes a second transmitting system, a second echo receiving system, and a second detection acquisitionprocessing system. The first laser radar vertically downward observes the ground to obtain a laser radar echo profile. The second laser radar observes the ground by an inclination angle of [theta] toobtain the laser radar echo profile. The data detected by the first and second laser radars is sent to a data processing and inversion module 2 and then an extinction coefficient profile and a laserradar ratio profile can be obtained by inversion. The earth laser radar achieves an aerosol optical property detection accuracy of better than 20%, and also solves the defects of a Raman laser radar and a high-spectral resolution laser radar.

The invention discloses a calibration method for pure rotational Roman laser radar system constants. The method includes that a laser radar performs horizontal detection through a scanning system, a temperature measuring meter is placed nearby a laser radar level detection path, and the laser radar and the temperature measuring meter performs detection simultaneously. Signals detected by the laser radar and the temperature measured through the temperature measuring meter are matched. When number i of times of horizontal data measurement is greater than number k of the system constants, full system constants of the pure rotational temperature measuring laser radar can be calculated. The laser radar system constants can be calibrated by acquiring horizontal Roman scattering signals and temperature measuring meter data close to the ground by the aid of the pure rotational Roman laser radar, time-domain variations calibrated by a conventional air observation balloon are avoided, convenience in the calibration method is improved, application population of the laser radar is greatly improved, inversion accuracy is high, application range is wide, and applicability of the pure rotational Roman laser radar is improved.

The invention provides a detection Raman laser radar light path system and relates to the laser atmosphere remote sensing technology field. The detection Raman laser radar light path system comprises a laser emission module, an optical receiving module and a data acquisition module. Second harmonic generation 532nm pulse laser emitted by the laser emission module to atmosphere is interacted with atmosphere particles so as to generate a scattered light signal. The scattered light signal carries out retroreflection and is received by a telescopic system of the optical receiving module. Received light is successively divided into five layers and simultaneously light splitting processing is performed, and then the light is processed by the data acquisition module. In the prior art, for single detection of an atmospheric temperature, moisture, nitrogen and aerosol, different equipment needs to be used to carry out detection so that detection cost is high; resources are wasted; time is wasted too; a detection personnel workload is large; the size of the equipment is large too; the structure is complex; and a detection system is tedious and so on. By using the detection Raman laser radar light path system provided in the invention, the above problems are solved.

The invention discloses an ultraviolet pure rotational Raman temperature measurement laser radar system. The laser radar system is composed by a launcher unit, an optical receiving and double grating polychromator unit, a photoelectric conversion and control unit. The launcher unit adopts a solid-state laser injected by seed to output an extremely narrow line width of 354.7 nm ultraviolet laser light and directs the ultraviolet laser light to the zenith. The optical receiving and double grating polychromator unit is used for collecting the back scattered light from the atmosphere, and extracting the pure rotational Raman spectrum from the scattered spectrum by using 0.2nm of the spectral resolution, then obtain the information of atmospheric temperature by using the different intensity of the pure rotational Raman spectrum with the temperature. The photoelectric conversion and control unit ensure an orderly operation of the whole radar system. In the ultraviolet pure rotational Raman temperature measurement laser radar system, the radar works in the ultraviolet band so that the solar background light can be significantly reduced, which can be used for the measurement of atmospheric temperature throughout the day.

The invention discloses a self-correcting rotating Raman laser radar temperature measuring system and an inversion method thereof. The system comprises a pulse laser device and a collimating beam expander that connected in sequence; a spectroscope and a reflection mirror are sequentially arranged along an outgoing direction of a light path of the collimating beam expander. A photoelectric detectoris arranged in a reflected light path of the spectroscope; the system and also includes a telescope, an optical fiber coupler is fixed on an output light port of the telescope, and the reflection mirror is located at a mouth of the telescope; the optical fiber coupler is sequentially connected with a first-order spectrum beam splitting system, a relative detection system for second-order spectrumbeam splitting and a system control processing platform; an absolute detection system for the second-order spectrum beam splitting is connected between the first-order spectrum beam splitting systemand the system control processing platform, and the system control processing platform is connected with a pulse laser device and the photoelectric detector. The system is advantageous in that relative detection distance is long and correction is not needed for absolute detection. The system can be used for daytime detection and is capable of realizing self-correcting all-time atmospheric temperature remote sensing.

The invention discloses an aerosol extinction coefficient inversion method based on a deep belief network. The method comprises the following steps: S1, echo power signals of a Mie scattering lidar and an aerosol extinction coefficient obtained by inversion of a Raman lidar are obtained, and training and test sample sets are formed; S2, a normalized training sample set is obtained; S3, a deep belief network is built according to the normalized training sample set, network parameters are adjusted, and the network is trained; S4, the echo power signals of the test sample set are inputted to an optimized network to obtain network output, a network output result is compared with the aerosol extinction coefficient of the test sample set to judge whether to meet an expected condition; and S5, ifthe comparison result meets the expected condition, network optimization is ended, and if not, the third step is returned to continue to train the deep belief network until the comparison result meets the expected condition. The Mie scattering lidar detection precision is improved, and quick and accurate inversion of the aerosol extinction coefficient is realized.

The invention relates to laser radar, in particular to a multi-wavelength remote Raman laser radar mechanism. Technical problems that the radar mechanism in the prior art cannot be applied to a subway vehicle, the radar mechanism waggles during use so as to be unstable when focusing a to-be-detected dangerous substance, and spectral analysis is not accurate are mainly solved. The multi-wavelength remote Raman laser radar mechanism comprises a cloud platform (1); the cloud platform (1) is movably connected with a main body (3) through a main body connecting column (2); a laser (4) is fixed at the lower part of the main body; a beam expander (5) is arranged in front of the laser; a lower reflective mirror (6) is arranged in front of the beam expander; an upper reflective mirror (7) is arranged above the lower reflective mirror; a telescope (8) is arranged behind the upper reflective mirror; the telescope is fixed on the main body; the telescope is connected with a spectral analysis system; and the spectral analysis system is connected with a signal analysis and interaction system.

The invention discloses a high-power side-pumping 1525nm (human-eye safe waveband) automatic self-raman laser, and a core part of the filter is a side pump head. The side pump head comprises an LD array and a laser crystal rod, wherein the LD array is used for the pumping of the laser crystal rod, and the laser crystal rod is used for laser transmission and stimulated raman scattering. The LD array and the laser crystal rod operate in a resonant cavity formed by laser, a raman total-reflection mirror, and a raman light output mirror, thereby achieving the fundamental frequency light vibration, and achieving the conversion from fundamental frequency light to raman light through an acousto-optic Q-switching under the action of the laser crystal rod, wherein the raman light output mirror outputs 1525nm laser. The laser solves problems that an end-face pumping solid laser is low in output power and is lower in practicality, and also solve a problem that a common side-pumping solid laser is complex in structure.

The invention discloses a Raman laser radar system for surface layer non-blind area atmospheric temperature detection. The Raman laser radar system comprises a laser emission subsystem, a lateral telescope receiving and light splitting subsystem and a data acquisition and inversion subsystem. The laser emission subsystem can emit laser with a specific wavelength, and the laser is vertically emitted to the atmosphere; the lateral telescope group receiving and light splitting subsystem is used for receiving, separating, extracting, detecting and extracting pure rotational Raman scattering echo signals relative to the lateral scattering high and low quantum number channel of the laser emission spectrum; and the data acquisition and inversion subsystem is used for acquiring lateral pure rotation Raman scattering echo signals with high and low quantum channels relative to the laser emission spectrum and performing data inversion of the atmospheric temperature, and the data acquisition and inversion subsystem is connected with the lateral telescope receiving and splitting subsystem. The invention further discloses a surface layer non-blind area temperature detection Raman laser radar method.

The present invention discloses a rotational Raman lidar system for high-precision measurement of atmospheric temperature in a height range of 0-35km. The system employs a layered receiving technology, a low altitude detection module and a high altitude detection module are employed to perform detection of atmosphere in the height ranges of 0-15km and 8-25km; and the system employs two work modes of simulation AD and photon counting PC to effectively record echo data of high and low altitude detection modules. Finally, the system realizes high-precision complete-coverage measurement of atmospheric temperature in the height range of 0-35km.

The invention discloses a remote sensing detection system for the condensable water amount of an air cloud system. The remote sensing detection system includes a mie-scattering laser radar which is used for acquiring height values of a cloud bottom and a cloud top, a rotating Raman laser radar which is used for acquiring atmospheric temperature profile data, a wind measurement laser radar which is used for acquiring a vertical movement speed of an air flow, and a micro-rain radar which is used for judging whether rainfall exists. The Mie scattering laser radar, the rotating Raman laser radar, the wind measurement laser radar and the micro rain radar are all connected to the data processing system. The detection method comprises the following steps: 1, vertically observing the sky; 2, obtaining the height of the cloud bottom and the height of the cloud top; 3, calculating the saturated water vapor density of the cloud bottom and the cloud top; 4, obtaining the vertical airflow movement speed;5, calculating the condensable water quantity in the atmosphere within a period of time; and 6, calculating the condensable water quantity in the cloud. according to the invention, high-precision detection of the air condensable water quantity can be realized, and the problem that the air condensable water quantity cannot be observed in the existing atmospheric science field is solved.

A continuous wave self-Raman laser of wavelength-locked LD resonance pumping is disclosed. The invention relates to the technical field of solid laser structures. The continuous wave self-Raman laser comprises a wavelength-locked LD pumping source; and a collimation focusing coupling system, a laser input cavity mirror, a bonding self-Raman crystal and an output cavity mirror are arranged in the laser output direction of the pumping source LD along the same optical axis in sequence. The continuous wave self-Raman laser overcomes the problems of low absorption rate, low output stability, high temperature sensitivity and the like of the resonance pumping lasers, and further improves the performance of the continuous wave self-Raman laser, and finally obtains the continuous Raman laser output with high efficiency, high power and high stability.

The invention discloses an ultraviolet band quasi-single pure rotation raman spectral line signal detection device which consists of a spectral filter unit and a signal acquisition unit. Under the irradiation of ultraviolet laser with the wavelength of 354.82nm, N2 molecules and O2 molecules produce a series of discrete spectral line scattering signals. The spectral filter unit uses an ultra-narrow band filter for filterng, uses a Fabry-Perot etalon to compress sky background noise, and uses simultaneous work of double channels to extract N2 molecule anti-Stokes pure rotation raman J=8 and J=14 characteristic spectral lines and O2 molecule anti-Stokes pure rotation raman J=11 and J=19 characteristic spectral lines, and at the same time suppression greater than 6 orders of magnitude is produced on the intensity of an elastic scattering signal with the wavelength of 354.82nm. The signal acquisition unit comprises a photodetector and a data collector to realize real-time acquisition and storage of measurement data. According to the invention, the sky background noise is effectively compressed; the detection signal-to-noise ratio is greatly enhanced; and the device is suitable for a pure rotation raman laser radar for all-day detection.

The invention discloses a dual-band pure rotational raman lidar system constant self-calibration method. A lidar transmitting system 1 transmits two bands of laser beams 2 and 3. Backscattered light 4 of lidar is collected via a receiving system 5 of lidar. The light-splitting and photoelectric system of lidar divides the received backscattered light into four paths of signals 6,7,8 and 9. Equation solving or fitting is performed through an equation obtained by two bands of lidar measurement signals. When the number i of the selected measurement points is greater than the number k of system constants, all the system constants of pure rotational temperature measurement lidar can be solved. According to the method, automatic calibration of the pure rotational raman lidar system constants can be realized by utilizing the lidar signals without using other measuring instruments. The method is high in inversion precision and wide in range of application so that automatic inversion and measurement of lidar atmospheric temperature can be realized.

The invention discloses a laser radar detection system and method with an ozone absorption self-correcting function. The system includes a detector module, wherein the detector module comprises threedichroic mirrors and three detector units, each dichroic mirror divides a light beam into two paths, one path is reflected to the corresponding detector unit, the other path is reflected to the next dichroic mirror for beam splitting, and the three detector units correspondingly comprise vibration-rotation Raman scattering echo signals for receiving water vapor molecules, nitrogen molecules and oxygen molecules. A channel for receiving an oxygen molecular vibration-to-Raman scattering echo signal is added in the solar blind water vapor Raman laser radar, the laser radar directly measures Ramanscattering echo signals of water vapor molecules, nitrogen molecules and oxygen molecules, a hardware basis is provided for obtaining the vertical distribution of the water-vapor mixing ratio withoutthe measurement of other equipment or the inversion of the ozone concentration distribution from the measurement signal of the solar blind laser radar so that the measurement cost is reduced, and themeasurement precision is improved.

The invention discloses a small-angle light-splitting light engine device and a rapid mounting and adjusting method thereof. The small-angle light-splitting light engine device is composed of a lightengine device body and a calibration device; the light engine device body comprises a light-splitting light path box and light beam guiding elements, the light beam guiding elements are arranged in the light-splitting light path box, and the light-splitting light path box and the light beam guiding elements are combined to efficiently separate and output a target input compound color light signal;and the calibration device comprises an external threaded interface, an achromatic lens and a CMOS camera for assisting in quickly adjusting all the light beam guiding elements in the light engine device body to the predetermined working state. The light engine device is integrally designed, has the advantages of small size, concise light engine structure, convenient connection and the like, is very effective for separation of the compound color light signal, close to the nm magnitude, on a frequency spectrum, and can be applied in the development process of a rotating Raman laser radar system.

The invention provides a Raman laser radar system device for atmospheric space three-dimensional temperature detection. The device comprises a laser emission optical path system which carries out thebeam expanding and shaping of a laser beam, enables the laser beam to enter the atmosphere, and forms a back scattering signal which is received by an optical signal receiving system; the optical signal receiving system which is used for receiving original optical signals from the laser emission optical path system and transmitting the original optical signals to a light splitting system; the light splitting system which is used for filtering and screening the original optical signals, separating required optical signals with a specific wavelength and transmitting the optical signals to an optical signal conversion module; the optical signal conversion module which is used for receiving the optical signals screened and separated by the light splitting system and having the wavelength required by the system and converting the optical signals into electric signals; an electric signal processing system which processes the electric signals and transmits the processed electric signals to adata acquisition, calculation and processing system; and the data acquisition, calculation and processing system which is used for acquiring, processing and calculating the conditioned electric signals to obtain a final result. The signal receiving effect is improved, the detection distance is long, the precision is high, and the normal radar data can be ensured all day long.