13 results about "Depolarization ratio" patented technology

The invention provides a Raman-meter signal all-day laser radar ratio inversion method and device, and the method comprises the steps: carrying out the denoising of signal data of a Raman laser radar in a preset time period, and carrying out the inversion, and obtaining a first aerosol backscattering coefficient profile; applying a plurality of preset laser radar ratios to the inversion of the meter laser radar signal at the same moment to obtain a plurality of second aerosol backscattering coefficient profiles; taking the first aerosol backscattering coefficient profiles at the same moment as a reference standard, calculating a relative error average value of each second aerosol backscattering coefficient profile, and obtaining an optimal laser radar ratio corresponding to the minimum relative error average value; fitting the optimal laser radar ratio with the mean value of the aerosol depolarization ratio of the meter laser radar below the boundary layer height at the corresponding moment to obtain a relation curve; and substituting the mean value of the aerosol depolarization ratio at the current moment into the relation curve to obtain the laser radar ratio. According to the invention, the inversion precision of the aerosol laser radar ratio is improved.

The invention discloses a cloud condensation nucleus number concentration inversion method and device, a medium and a product, and relates to the field of atmospheric environment detection.The method comprises the steps that particulate matter parameters observed by a multi-wavelength polarization Raman laser radar are obtained; the particulate matter parameters comprise a radar ratio, a depolarization ratio and a depolarization color ratio; determining the aerosol type according to the particulate matter parameters; based on the aerosol type, extracting an extinction coefficient and a backscattering coefficient of each aerosol; performing relative humidity correction on the extinction coefficient and the backscattering coefficient, and determining a corrected optical parameter; matching the corrected optical parameters with optical parameters in an aerosol optical parameter database to determine aerosol parameters; calculating the critical radius of each aerosol under different supersaturation ratios; and for each aerosol, according to the critical radius and the aerosol parameter, inverting the CCN number concentration under different supersaturation ratios, and according to the method, the CCN number concentration under different supersaturation ratios can be accurately inverted.

The invention discloses a hydraulic concrete structure underwater surface crack detection method, and relates to the technical field of image sensors, and the method comprises the steps: carrying out the transmissivity mapping and background radiation field separation of underwater light field characterization parameters, generating a target reflectivity image, carrying out the multispectral-polarization data fusion of the target reflectivity image, and generating an enhanced feature image; performing multi-scale convolution kernel space transformation and feature pyramid fusion on the enhanced feature image to generate a crack response diagram, and performing anisotropic non-maximum suppression and morphological skeleton refinement on the crack response diagram to generate crack detection data; and performing geometric topology joint optimization and parameter quantification on the crack detection data, and outputting a structured detection report. According to the invention, by constructing the light field transmission model and synchronously carrying out polarization and depolarization ratio combined noise filtering and geometric distortion correction, adaptive noise filtering is realized, and the measurement precision is improved.

The invention relates to the technical field of ocean detection equipment, and particularly provides an ocean laser radar system and a seawater multi-parameter detection method. The system comprises a laser emission subsystem, an optical receiving subsystem and a signal acquisition and control subsystem. The laser emission subsystem can emit multi-wavelength pulse laser to seawater; the optical receiving subsystem adopts a double-receiving telescope structure, respectively receives scattering and fluorescence signals with different properties, and realizes multi-channel signal separation through light splitting, light filtering and polarization light splitting elements; and the signal acquisition and control subsystem realizes synchronous acquisition and processing of multi-channel data. The system can synchronously invert water optical parameters, water particulate matter depolarization ratio and color ratio, chlorophyll concentration, suspended load concentration and other multi-parameter profiles, and is suitable for marine environment unattended monitoring of a fixed platform and a mobile platform.

There is described a device (100) for analyzing particles of a sample, the device (100) comprising: i) an electromagnetic radiation source to illuminate the sample with electromagnetic radiation to thereby generate a scattered signal; ii) a detector to detect a first component (Ivh) of the scattered signal (101), and a second component (Ivv) of the scattered signal (102); and iii) a control device configured to: a) determine (110) the depolarization ratio (Ivh / Ivv) of the sample based on the detected first component (Ivv) and the detected second component (Ivh); b) calculate (122) a polarizability (α) associated with the sample, and c) determine (120) a shape characteristic (p) of the sample particles based on the depolarization ratio (Ivh / Ivv) and the polarizability (α).

A reflectivity correction method using a double polarization variable-based bright band detection result includes a preprocessing operation for correcting a double polarization variable observation error and calculating a depolarization ratio; a fuzzy classifier generation operation for calculating a weighting and a membership function of each characteristic variable using a bright band height extracted from a quasi-vertical profile generated from specific elevation angle data, a bright band detection operation for detecting a bright band using a depolarization ratio and a fuzzy classifier for each elevation angle, and a reflectivity correction operation for correcting reflectivity over-observation for a detected bright band region on the basis of a correction factor calculated using an apparent profile of reflectivity generated by averaging reflectivity data for the bright band region for each elevation angle. Thus, it is possible to improve the accuracy of precipitation estimation by using the corrected reflectivity.

An optical construction includes a reflective polarizer and an optical film. The optical film includes a matrix and a plurality of first particles dispersed in the matrix. Each of the matrix and the plurality of first particles includes a silicone polyoxamide and an acrylate polymer. For substantially normally incident light and for at least a first wavelength in a first wavelength range, the reflective polarizer reflects about 60% for a first polarization state and transmits about 40% for an orthogonal second polarization state. For at least a second wavelength in a second wavelength range, each of the reflective polarizer and the optical film transmits about 60% of an incident light for each of the first and second polarization states. For at least the first wavelength, optical film has an optical haze and a depolarization ratio. A ratio of the depolarization ratio to the optical haze is less than 0.1.

An optical construction includes a reflective polarizer and an optical film. The optical film includes a matrix and a plurality of first particles dispersed in the matrix. Each of the matrix and the plurality of first particles includes a silicone polyoxamide and an acrylate polymer. For substantially normally incident light and for at least a first wavelength in a first wavelength range, the reflective polarizer reflects about 60% for a first polarization state and transmits about 40% for an orthogonal second polarization state. For at least a second wavelength in a second wavelength range, each of the reflective polarizer and the optical film transmits about 60% of an incident light for each of the first and second polarization states. For at least the first wavelength, optical film has an optical haze and a depolarization ratio. A ratio of the depolarization ratio to the optical haze is less than 0.1.

This application provides a method for coarse and fine mode aerosol parameter inversion based on hyperspectral resolution lidar. The method simultaneously receives elastic scattering signals from the main channel and depolarization channel of aerosols, as well as molecular Rayleigh scattering signals, using a lidar system. Based on signal inversion, the total backscattering coefficient and total depolarization ratio of the aerosols are obtained. By clustering historical data, the characteristic depolarization ratios of coarse and fine modes are determined, along with the lidar ratio, to construct a multivariate hybrid model, achieving separation of the coarse and fine mode backscattering coefficients. The extinction coefficients of coarse and fine modes are calculated using the lidar ratio, and further integration yields the optical thickness of the coarse and fine modes. The coarse and fine mode aerosol parameter inversion method based on hyperspectral resolution lidar provided in this application does not require lidar ratio assumptions, possesses continuous all-day observation capability, and effectively overcomes the limitations of traditional passive remote sensing with day-night interruptions and the low signal-to-noise ratio of Raman lidar during the day.

The present application discloses a cloud condensation nucleus number concentration inversion method, equipment, medium and product, which relate to the field of atmospheric environment detection. The method includes obtaining particle parameters observed by a multi-wavelength polarization Raman lidar; the particle parameters include radar ratio, depolarization ratio and depolarization color ratio; determining the aerosol type according to the particle parameters; based on the aerosol type, extracting the extinction coefficient and backscattering coefficient of each aerosol; performing relative humidity correction on the extinction coefficient and backscattering coefficient to determine the corrected optical parameters; matching the corrected optical parameters with the optical parameters in an aerosol optical parameter database to determine the aerosol parameters; calculating the critical radius of each aerosol at different supersaturation ratios; for each aerosol, inverting the CCN number concentration at different supersaturation ratios according to the critical radius and the aerosol parameters. The present application can accurately invert the CCN number concentration at different supersaturation ratios.

A method of analyzing data includes analyzing characteristics of beams of reflected light received by a sensor system with the beams of the reflected light correspond to beams of light directed toward an object, then determining, using the characteristic of an intensity pattern of the beams of the reflected light, whether a reflection position is a position of the object or not. If the characteristic of the intensity pattern is continuity of the intensity pattern, the reflection position is not the position of the object. The beams of emitted light have substantially the same intensity. Analyzing characteristics of beams of reflected light further includes either analyzing a substantially similarity of a polarization of a received light with an expected polarization, or determining whether a depolarization ratio of the received light is near zero. The received light is the reflected light received by the sensor system.

This application provides a method for coarse and fine mode aerosol parameter inversion based on hyperspectral resolution lidar. The method simultaneously receives elastic scattering signals from the main channel and depolarization channel of aerosols, as well as molecular Rayleigh scattering signals, using a lidar system. Based on signal inversion, the total backscattering coefficient and total depolarization ratio of the aerosols are obtained. By clustering historical data, the characteristic depolarization ratios of coarse and fine modes are determined, along with the lidar ratio, to construct a multivariate hybrid model, achieving separation of the coarse and fine mode backscattering coefficients. The extinction coefficients of coarse and fine modes are calculated using the lidar ratio, and further integration yields the optical thickness of the coarse and fine modes. The coarse and fine mode aerosol parameter inversion method based on hyperspectral resolution lidar provided in this application does not require lidar ratio assumptions, possesses continuous all-day observation capability, and effectively overcomes the limitations of traditional passive remote sensing with day-night interruptions and the low signal-to-noise ratio of Raman lidar during the day.

A light detection and ranging (LIDAR) system for a vehicle, includes a laser source configured to output a beam, a transmitter, a receiver, one or more optics and a processor. The transmitter is configured to transmit a transmit signal that is generated based on the beam. The receiver is configured to receive a return signal reflected by an object in response to the transmit signal. The one or more optics are configured to generate a first signal and a second signal based on the return signal, wherein the first signal and the second signal have different polarizations. The processor is configured to determine a type of the object by processing a signal-to-noise ratio (SNR) value of the first signal and a SNR value of the second signal.