CN211741577U - Self-calibration polarized atmospheric laser radar device - Google Patents
Self-calibration polarized atmospheric laser radar device Download PDFInfo
- Publication number
- CN211741577U CN211741577U CN202020080785.9U CN202020080785U CN211741577U CN 211741577 U CN211741577 U CN 211741577U CN 202020080785 U CN202020080785 U CN 202020080785U CN 211741577 U CN211741577 U CN 211741577U
- Authority
- CN
- China
- Prior art keywords
- laser
- polarization
- polarized
- self
- atmosphere
- 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.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Abstract
The utility model belongs to the technical field of laser spectroscopy technique is used, a polarization atmosphere laser radar device of self calibration is provided, including laser instrument, linear polarization piece, laser emission device, laser receiving device, narrowband optical filter and polarization plane array camera. The device simultaneously obtains atmosphere backscattering signals of four polarization states on the premise of not additionally adding optical elements, constructs an atmosphere echo signal detection equation of the four polarization states, and obtains an accurate body depolarization ratio in real time through a nonlinear least square methodvAnd the polarization mismatch angle theta solves the problem that the gain ratio of the traditional dual-channel polarization laser radar system is complicated to calibrate. The utility model has the characteristics of simple structure, convenient operation, with low costs, reliability height.
Description
Technical Field
The utility model belongs to the technical field of laser spectroscopy technique is used, concretely relates to polarization atmosphere laser radar device of self calibration for survey atmospheric particulates's form.
Background
The atmospheric Lidar (Light Detection and Ranging) technology is an active optical remote sensing technology, and has the unique advantages of high spatial and temporal resolution, excellent directivity and coherence, real-time monitoring and the like. The polarized atmosphere laser radar is used for emitting high-purity linearly polarized light to the atmosphere and identifying important information such as cloud phases (ice clouds and water clouds), aerosol forms and the like according to a detected depolarization signal. When polarized light enters spherical particles (high-altitude clean atmospheric molecules), backward scattered light is still linearly polarized light, and when the polarized light enters non-spherical particles (such as sand aerosol), the backward scattered light is partially depolarized into non-polarized light and becomes partially polarized light as a whole. According to the change of the polarization state of the backscattering signal, the polarized atmospheric lidar can identify spherical particles and non-spherical particles in the atmosphere, and is widely applied to polar climate research, type identification of atmospheric aerosol and cloud, aerosol classification and the like. However, the polarized lidar still has great challenges in acquiring high-precision atmospheric polarization information.
The two-channel polarized atmospheric lidar is the most common and most widely used polarized atmospheric lidar. The principle is that a pulse laser is used for emitting high-purity linearly polarized light to the atmosphere, after the linearly polarized light is scattered by the atmosphere, backward scattering signals are collected by a large-caliber telescope, parallel polarization components and vertical polarization components are separated through a polarization beam splitter Prism (PBS), and finally two orthogonally polarized light signals are converted into electric signals through a photomultiplier respectively and are processed by a computer. Among them, the most typical polarized atmospheric lidar is a satellite-borne atmospheric lidar transmitted by the united states space agency, and one of the loads is a calip lidar. The CALIP laser radar is a dual-wavelength polarization laser radar system, wherein the 532nm wave band is a dual-channel polarization laser radar. Although the parallel and vertical components are detected simultaneously by using photomultiplier tubes with the same specification, the transmittance, photoelectric conversion coefficient and amplification coefficient of the two components are not completely the same, and the two components are called system gain coefficient in the polarization laser radar. The difference of the gain coefficients of the system has a significant influence on the detection result, so that the gain ratio calibration is needed. The commonly used gain ratio calibration methods at present include a special atmospheric method, a non-polarized light method, a non-linear fitting method and a +/-45-degree calibration method.
The special atmospheric method is to use clean atmosphere as the atmospheric condition of the "standard edition" to realize the calibration of the system gain ratio, and although the method is simple to operate and does not need to add any additional optical element in the system, the clean atmosphere is difficult to measure in general (the clean atmosphere is generally existed in the high-altitude atmosphere above 10 km). In addition, the depolarization ratio of clean atmosphere is affected by system parameters and atmospheric conditions, and the influence of the depolarization ratio is large in uncertainty, which easily causes calibration errors.
Unpolarized light methods use unpolarized light sources, such as incandescent lamps, halogen lamps, etc., to scale the gain ratio. When the telescope is calibrated, a non-polarized light source needs to be arranged in front of the telescope through a complex means, and the operation is inconvenient to repeat rapidly. This approach makes the optical signal incident on the detector still different from the true lidar signal in terms of the angular distribution of the optical signal intensity and spectral characteristics, and these errors are often not easily assessable.
The nonlinear fitting method (or half-wave plate multiple rotation method) is to rotate the half-wave plate before the PBS multiple times, artificially change the intensity ratio of the PBS reflection channel and transmission channel, and establish the functional relationship between the half-wave plate rotation angle and the intensity ratio. And finally, obtaining a gain ratio through inversion by nonlinear fitting. The method can obtain not only the system gain ratio, but also the polarization mismatch angle and the atmospheric depolarization ratio of a calibration area. However, this method takes a long time and requires that the atmospheric conditions during calibration be relatively stable.
The +/-45-degree calibration method is to adjust the polarization direction of the emitted laser to form an angle of 45 degrees with the incident plane of the PBS through a half-wave plate, so that the intensity ratio detected by the two channel detectors after passing through the PBS is the gain ratio. This approach requires two channels without polarization crosstalk, placing extremely high demands on the performance of the PBS, which is difficult to meet in practice.
These calibration methods either depend on atmospheric conditions or require additional optical components, which makes the calibration process cumbersome. Furthermore, the system gain ratio varies with the environment, so that the gain ratio calibration needs to be performed periodically, which presents a great challenge to practical measurement applications. To address this challenge, the present invention contemplates a self-calibrating polarized atmospheric lidar apparatus and method.
The above statements in the background of the invention are merely intended to facilitate a thorough understanding of the present invention (including the use of technical means, solutions to problems, technical effects, etc.) and are not to be construed as admissions or any suggestion that this information constitutes prior art known to a person skilled in the art.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a polarization atmosphere laser radar device of self calibration to solve traditional polarization atmosphere laser radar system gain than the calibration complicated, loaded down with trivial details wait a great deal of difficult problem.
The technical scheme of the utility model:
a self-calibration polarized atmospheric laser radar device comprises a diode laser 1, a linear polaroid 2, a laser emitting device, a laser receiving device, a narrow-band filter 8 and a polarization area array camera 7;
the laser device 1 is arranged at the incident end of the laser emitting device, the linear polaroid 2 is arranged in the laser emitting device and is positioned at the front end of the laser device 1, and the center of the laser device 1, the center of the linear polaroid 2 and the center of the lens of the laser emitting device are positioned on the same straight line; the polarization state direction of the linear polarizer 2 is consistent with the polarization state direction of the laser 1, the linear polarizer 2 can purify the polarization degree of the laser, and the purified laser is emitted into the atmosphere after being collimated by the laser emitting device;
one end of the detector installation cylinder 9 is fixedly installed on the laser receiving device, and the other end of the detector installation cylinder is provided with the polarization area array camera 7; the narrow-band filter 8 is arranged in the detector installation cylinder 9; the backscatter signals of the laser beams emitted into the atmosphere are collected by a laser receiving device, and are imaged on a polarization area array camera 7 after atmospheric background signals are filtered by a narrow-band filter 8, and the polarization area array camera 7 can simultaneously detect atmosphere backscatter signals in four polarization states of 0 degree, 45 degrees, 90 degrees and 135 degrees;
the polarization area array camera 7, the laser receiving device and the laser transmitting device satisfy any one of the following relations: (1) the plane of the sensor of the polarization area array camera 7, the plane of the equivalent lens of the laser receiving device and the optical axis of the laser emitting device are intersected to meet the Shake imaging principle; (2) the plane where the sensor of the polarization area array camera 7 is located is placed in parallel with the focal point of the laser receiving device;
the laser emitting device and the laser receiving device are connected through a connecting plate 4, and a driving circuit 5 and a main controller 6 are arranged on the connecting plate 4 and connected with each other; the polarization area array camera 7 is connected with the main controller 6, and the laser 1 is connected with the drive circuit 5.
The laser emitting device is composed of a lens barrel and a lens.
The laser 1 is a diode laser, the emitted light beam of the diode laser is linearly polarized light, and the working wavelength of the diode laser is controlled by a temperature control and drive circuit.
The laser receiving device is a Newtonian telescope 10.
The laser emitting device and the laser receiving device have a certain interval.
The transmission center wavelength of the narrow-band filter 8 is matched with the working wavelength of the laser 1.
A self-calibration polarized atmospheric lidar method comprises the following steps:
s1, rotating the angle of the linear polarizer and the polarization camera to make the backscattered signals of 135-degree and 45-degree polarization states detected by the polarization camera coincide, namely P135°＝P45°Then recording the original backscattering signal data of the atmosphere;
s2, carrying out background subtraction, signal interpolation and filtering operation on the recorded original data to obtain a laser radar signal with pixel-intensity; obtaining a laser radar signal with distance-intensity by using a geometric optical model according to the calibration pixel points and the distance;
s3, adjusting the system to adjust P135°＝P45°The polarization mismatch angle θ is considered to be 0 °, and the polarization camera can simultaneously detect the backscatter signals of four polarization states (0 °, 45 °, 90 °, 135 °), and the total backscatter signal intensity is equal to the sum of the backscatter signal intensities of the mutually orthogonal polarization components: p ═ P⊥+P||＝P45°+P135°(ii) a At this time, the body depolarization ratiov＝Ps/Pp＝P⊥/P||＝β⊥/β||，P135°/P45°＝1；
S4, in the actual measurement process, when the polarization mismatch angle theta is changed due to factors such as system drift and the like, namely theta is not equal to 0 DEG, and P is135°≠P45°Constructing an atmospheric echo signal detection equation of four polarization states, and solving a resolution depolarization ratio by a nonlinear least square methodvAnd a polarization mismatch angle, and finally obtaining the atmospheric depolarization ratio on the whole laser path.
The utility model has the advantages that: the utility model provides a polarization atmosphere laser radar device of self calibration. The device simultaneously obtains atmosphere backscattering signals of four polarization states on the premise of not additionally adding optical elements, constructs an atmosphere echo signal detection equation of the four polarization states, and obtains an accurate body depolarization ratio in real time through a nonlinear least square methodvAnd the polarization mismatch angle theta solves the problem that the gain ratio of the traditional dual-channel polarization laser radar system is complicated to calibrate. The utility model has the characteristics of simple structure, convenient operation, with low costs, reliability height.
Drawings
Fig. 1 is a schematic structural diagram of a self-calibrated polarized atmospheric lidar provided in an embodiment of the present invention.
Fig. 2 is a front view of a polarization camera of a self-calibrated polarized atmospheric lidar system provided in an embodiment of the present invention.
Fig. 3 is a schematic diagram of the emitted light beam polarization state and the polarization detection channel of the polarization camera provided in the embodiment of the present invention.
In the figure: 1 a diode laser; 2 a linear polarizer; 3, a transmitting telescope; 4, connecting plates; 5 a drive circuit; 6, a main controller; 7 a polarization area array camera; 8 narrow-band filters; 9 detector mounting cylinder; 10 Newton telescope.
P in FIG. 3||The direction of the beam represents the polarization state of the laser beam at the emitting end, PpThe direction represents the direction of the polarization state of the 0 DEG channel of the polarization area array camera. P||，P⊥，P′45°，P′135°The signal intensities of the polarization states of 0 °, 90 °, 45 ° and 135 ° detected by the polarization plane array camera when the direction of the polarization state of the laser beam at the transmitting end is parallel to the direction of the polarization state of the 0 ° channel of the polarization plane array camera are shown. Pp，Ps，P45°，P135°The signal intensity of the polarization states of 0 °, 90 °, 45 ° and 135 ° detected by the polarization area array camera is shown when the included angle between the polarization direction of the laser beam at the emitting end and the polarization direction of the 0 ° channel of the polarization area array camera is θ.
Detailed Description
The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.
It is to be understood that the appended drawings are not to scale, but are merely drawn with appropriate simplifications to illustrate various features of the basic principles of the invention. Specific design features of the invention disclosed herein, including, for example, specific dimensions, orientations, locations, and configurations, will be determined in part by the particular intended application and environment of use.
(1) Basic concept
Polarization mismatch angle θ: the included angle between the plane of the polarization state of the laser emitted by the diode laser and the plane of the polarization state of the 0-degree channel of the camera in the receiving optical path is formed.
Body depolarization ratiov: the ratio of the backscattering coefficient of the total perpendicular polarization component to the backscattering coefficient of the total parallel polarization component.
(2) Detailed principle of technical scheme
First, the working principle of the polarization lidar system is as follows: the diode laser emits a beam of linearly polarized laser, the beam firstly passes through a linear polarizer (the polarization state of the beam is consistent with the polarization state of the laser) to purify the polarization degree of the laser, and finally the laser beam is collimated by a telescope and then emitted into the atmosphere. Backscattering signals formed by interaction of the laser and molecules, particles and the like in the atmosphere are collected through a Newton telescope, the background is compressed through a narrow band filter, and finally backscattering signals in four different polarization states are detected by a polarization camera at the same time.
For single-scatter lidar, the variation of the backward-scattered signal intensity p (r) with distance r can be expressed in the lidar equation,
P(r)＝P0ηβ(r)τ2(r) (1)
P0is the laser emission power, eta is the system constant, beta (r) is the total backscattering coefficient, and can be decomposed into the vertical component (beta)⊥) And a parallel component (beta)||)，τ2(r) is the atmospheric transmittance. In general, particles in the atmosphere are considered to be isotropic, i.e., the atmospheric light has equal transmittance to light signals of different polarization states. Besides, it is also necessary to assume that the transmission efficiency of the optical signals with different polarization states is the same at the transmitting end and the receiving end. Because the same polarization camera is used for detecting four polarization states of the atmosphere backscatter signal, the method has no system gain coefficient.
When the polarization mismatch angle theta is 0, the system transmitting end and the system receiving end are completely aligned at the moment, the polarization camera can simultaneously detect the backscattering signals of four polarization states, the total backscattering signal intensity is equal to the sum of the backscattering signal intensities of the polarization components which are orthogonal to each other, wherein P is||，P⊥，P′45°，P′135°Respectively represents the strength of the backscattered signals detected by the polarization plane array camera in the polarization state channels of 0 degree, 90 degrees, 45 degrees and 135 degrees,
P＝P⊥+P||＝P45°+P135°(2)
the backscatter signals of different polarization states can be represented by the following four equations respectively,
P⊥＝P0ηβ⊥τ2(3)
P||＝P0ηβ||τ2(4)
P′135°＝P||sin245+P⊥cos245 (5)
P′45°＝P||cos245+P⊥sin245 (6)
at this time, the body depolarization ratiov＝Ps/Pp＝P⊥/P||＝β⊥/β||，P′135°/P′45°＝1。
However, in practice the polarization mismatch θ angle is a significant source of systematic error for polarized lidar. In the method of the present invention, the laser radar signals of 135 ° and 45 ° polarization directions are tuned to completely coincide, i.e. P, during the process of tuning the system135°＝P45°This indicates that the polarization mismatch angle θ at this time is 0. However, in the actual measurement process, the polarization mismatch angle θ changes due to system drift or the like, that is, θ ≠ 0 °. At this time, the equation of the backscatter intensity of the four polarization channels detected by the polarization camera is:
Ps＝P||sin2θ+P⊥cos2θ (7)
Pp＝P||cos2θ+P⊥sin2θ (8)
P135°＝P||sin2(45-θ)+P⊥cos2(45-θ) (9)
P45°＝P||cos2(45-θ)+P⊥sin2(45-θ) (10)
the following equations are obtained by dividing equations (7), (8) and (9), (10) respectively,
Ps/Ppand P135°/P45°The ratio can be calculated by actually measuring the intensity of the backscattered signals with different polarization angles, and two equations are formed according to the formulas (11) and (12), because only the body depolarization ratio exists in the equationsvAnd the polarization mismatch angle theta, and the two unknowns can be solved by a nonlinear least square method. After the body depolarization ratio is calculatedv. Therefore, no matter whether the polarization states of the transmitting end and the receiving end are completely aligned or not, the volume depolarization ratio can be calculated through four-channel polarization backscatter signals in actual atmospheric measurementvAnd a polarization mismatch angle theta, eliminating the need to calibrate the polarization mismatch angle.
The utility model provides a polarization atmosphere laser radar device of self calibration, the device adopt a linear polarization diode laser instrument as the light source, and a polarization camera surveys, utilizes the geometry optics to calculate the atmosphere backscatter signal that obtains four kinds of polarization states of distance resolution, can obtain accurate big gas in real time and move back to compare partiallyvAnd the system polarization mismatch angle theta solves the problem that the gain ratio of the traditional dual-channel pulse polarization laser radar system is complicated to calibrate, and has the characteristics of simple structure, convenience in operation, low cost, high reliability and the like.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is merely exemplary in nature, and is not intended to intimate that the scope of the disclosure is limited to these examples; within the idea of the invention, also combinations between technical features in the above embodiments or in different embodiments are possible, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included within the protection scope of the present invention.
Claims (8)
1. The self-calibration polarized atmospheric lidar device is characterized by comprising a laser (1), a linear polarizer (2), a laser transmitting device, a laser receiving device, a narrow-band filter (8) and a polarization area array camera (7);
the laser (1) is arranged at the incident end of the laser emitting device, the linear polaroid (2) is arranged in the laser emitting device and is positioned at the front end of the laser (1), and the center of the laser (1), the center of the linear polaroid (2) and the center of a lens of the laser emitting device are positioned on the same straight line; the polarization state direction of the linear polarizer (2) is consistent with that of the laser (1), the linear polarizer (2) can purify the polarization degree of the laser, and the purified laser is collimated by the laser emitting device and then emitted into the atmosphere;
one end of the detector installation cylinder (9) is fixedly installed on the laser receiving device, and the other end of the detector installation cylinder is provided with the polarization area array camera (7); the narrow-band filter (8) is arranged in the detector installation cylinder (9); the backscatter signals of laser beams emitted into the atmosphere are collected by a laser receiving device, and are imaged on a polarization area array camera (7) after atmosphere background signals are filtered by a narrow-band filter (8), and the polarization area array camera (7) can simultaneously detect atmosphere backscatter signals in four polarization states of 0 degree, 45 degrees, 90 degrees and 135 degrees;
the polarization area array camera (7), the laser receiving device and the laser emitting device meet any one of the following relations: (1) the plane of a sensor of the polarization area array camera (7), the plane of an equivalent lens of the laser receiving device and the optical axis of the laser transmitting device are intersected, so that the Sabourdon imaging principle is satisfied; (2) the plane where the sensor of the polarization plane array camera (7) is located is placed in parallel with the focal point of the laser receiving device;
the laser emitting device and the laser receiving device are connected through a connecting plate (4), and a driving circuit (5) and a main controller (6) are arranged on the connecting plate (4) and connected with each other; the polarization area array camera (7) is connected with the main controller (6), and the laser (1) is connected with the driving circuit (5).
2. The self-calibrating polarized atmospheric lidar device of claim 1, wherein the laser transmitter comprises a lens barrel and a lens.
3. The self-calibrating polarized atmospheric lidar device according to claim 1 or 2, characterized in that the laser (1) is a diode laser, emitting linearly polarized light, the operating wavelength of which is controlled by a temperature control and drive circuit.
4. The self-calibrating polarized atmospheric lidar device of claim 1 or 2, wherein the laser receiving device is a newtonian telescope (10).
5. A self-calibrating polarising atmospheric lidar means according to claim 3, wherein the laser receiving means is a newtonian telescope (10).
6. The self-calibrating polarized atmospheric lidar device of claim 1, 2, or 5, wherein the transmission center wavelength of the narrowband filter (8) matches the operating wavelength of the laser (1).
7. The self-calibrating polarized atmospheric lidar device of claim 3, wherein the transmission center wavelength of the narrowband filter (8) matches the operating wavelength of the laser (1).
8. The self-calibrating polarized atmospheric lidar device of claim 4, wherein the transmission center wavelength of the narrowband filter (8) matches the operating wavelength of the laser (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020080785.9U CN211741577U (en) | 2020-01-15 | 2020-01-15 | Self-calibration polarized atmospheric laser radar device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020080785.9U CN211741577U (en) | 2020-01-15 | 2020-01-15 | Self-calibration polarized atmospheric laser radar device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211741577U true CN211741577U (en) | 2020-10-23 |
Family
ID=72881316
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020080785.9U Active CN211741577U (en) | 2020-01-15 | 2020-01-15 | Self-calibration polarized atmospheric laser radar device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211741577U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112698354A (en) * | 2020-12-04 | 2021-04-23 | 兰州大学 | Atmospheric aerosol and cloud identification method and system |
| CN113093223A (en) * | 2021-04-12 | 2021-07-09 | 广州降光科技有限公司 | Laser ceilometer |
-
2020
- 2020-01-15 CN CN202020080785.9U patent/CN211741577U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112698354A (en) * | 2020-12-04 | 2021-04-23 | 兰州大学 | Atmospheric aerosol and cloud identification method and system |
| CN112698354B (en) * | 2020-12-04 | 2022-03-18 | 兰州大学 | Atmospheric aerosol and cloud identification method and system |
| CN113093223A (en) * | 2021-04-12 | 2021-07-09 | 广州降光科技有限公司 | Laser ceilometer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Freudenthaler | About the effects of polarising optics on lidar signals and the Δ90 calibration | |
| CN106597414B (en) | Method for calibrating gain ratio of polarization laser radar | |
| CN111123293A (en) | Self-calibration polarized atmospheric laser radar device and method | |
| WO2020063073A1 (en) | Laser radar system apparatus for multi-wavelength measurement of atmospheric carbon dioxide concentration and vertical aerosol profile | |
| CN101464256B (en) | Polarization precision scaling system for polarization optical spectrometer | |
| CN100451621C (en) | High precision forward multiangle atmosphere scattering measuring method | |
| CN211741577U (en) | Self-calibration polarized atmospheric laser radar device | |
| CN105974397B (en) | Polarization lidar scaling method and polarization lidar based on Jones matrix | |
| David et al. | Sensitive and accurate dual-wavelength UV-VIS polarization detector for optical remote sensing of tropospheric aerosols | |
| CN107064957B (en) | Multi-view-field laser radar detection system and method for liquid water cloud measurement | |
| RU188541U1 (en) | MULTIWAVE LIDAR FOR SENSING ATMOSPHERE | |
| CN105334519A (en) | Laser radar system for simultaneously detecting multiple atmospheric parameters at high precision on the basis of three-channel F-P etalon | |
| US11536849B2 (en) | High resolution molecular LIDAR | |
| CN105444882B (en) | Realize eight passage radiometers of self calibration function | |
| CN114624731A (en) | Inversion method for optical thickness of aerosol above cloud layer based on polarization remote sensing data | |
| Kong et al. | A polarization-sensitive imaging lidar for atmospheric remote sensing | |
| US20100067007A1 (en) | Systems for measuring backscattered light using finite speed of light | |
| US20160069724A1 (en) | High-speed volume measurement system and method | |
| RU186572U1 (en) | TWO-WAVE POLARIZATION LIDAR | |
| CN106767656B (en) | A kind of high-accuracy calibration device and scaling method of rolling angle measurement system | |
| CN114234854B (en) | Method and device for simultaneously measuring three-degree-of-freedom angles | |
| Kong et al. | Visible, near-infrared dual-polarization lidar based on polarization cameras: system design, evaluation and atmospheric measurements | |
| CN207515908U (en) | A kind of multi-pass self calibration polarization detecting device and system | |
| CN210037540U (en) | Particulate matter concentration detection device | |
| CN110907316A (en) | Light path system for single particle forward and backward scattering and depolarization ratio measurement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |