11 results about "Refraction coefficient" patented technology

The invention provides an underwater terrain inversion method based on a height measurement satellite, belongs to the technical field of remote sensing geoscience application, and constructs an automatic processing flow integrating space screening, elevation correction, signal denoising, double-strategy surface and bottom recognition and physical correction. The method is suitable for underwater topography generation in complex water body environments such as lakes and reservoirs, and the efficiency of underwater topography data acquisition is greatly improved. A strategy of combining adaptive kernel density estimation and clustering analysis is adopted to remarkably improve the water surface and water bottom signal recognition capability, and a multi-temporal collaborative analysis and refractive index physical correction model is introduced to realize high-precision underwater terrain extraction of water bodies such as inland reservoirs. The method has obvious advantages in the aspects of automation degree, application range and result stability, and has important engineering application and popularization value.

The invention discloses a water area change whole process identification method and system based on a remote sensing image, and relates to the technical field of remote sensing monitoring, and the method comprises the steps: collecting a water area image through a multi-source remote sensing device, obtaining a water body reflection spectrum signal, and extracting water quality spectrum characteristic information and wave band parameters; identifying pollution polarization characteristic parameters in the water body reflection spectrum; based on the pollution gradient of the intersection of the main stream and the branch stream of the water area, pollutant scattering characteristic parameters are extracted; introducing wave band parameters as adjusting variables, determining wave band dependence terms, evaluating the pollution change degree of each monitoring section according to the corrected water body spectral refractive index, and generating a water area pollution change thermodynamic diagram. The technical problem that the water area pollution monitoring precision is insufficient due to the fact that an existing water quality monitoring method cannot effectively recognize the dynamic change of the complex water area is solved, and the technical effect of improving the water area pollution monitoring precision and efficiency through high-precision recognition and dynamic monitoring of the complex water area pollution characteristics is achieved.

The application discloses a seawall protection structure design method and system based on a winding space metasurface technology, relates to the technical field of seawall protection engineering, and comprises the following steps: selecting a suitable winding space metasurface unit model according to frequency parameters and wave height parameters of sea waves; designing and optimizing the winding space metasurface unit model based on a preset refractive index distribution; arranging and installing the designed winding space metasurface unit model array outside a seawall and debugging; and adjusting the arrangement and refractive index of the winding space metasurface unit model to cope with different sea wave conditions by monitoring sea conditions in real time. The application modulates the energy distribution of water surface waves, realizes focusing, scattering or absorption of the waves, effectively reduces the direct impact of the sea waves on the seawall, enhances the protection effect, and reduces the long-term maintenance cost.

The invention provides an underwater environment three-dimensional reconstruction pixel point mapping relation construction method and a reconstruction method. The method comprises the following steps: acquiring parameters of a physical camera, a refraction coefficient of water in a reconstruction water area, a distance between the physical camera and the inner surface of a visual light-transmitting plate, the thickness of the visual light-transmitting plate and a refraction coefficient of the visual light-transmitting plate; obtaining a virtual pixel point position of the imaging plane of the virtual camera; analyzing to obtain a virtual object point position Pw; calculating a refracted light path after the virtual object point passes through the visible light-transmitting plate; calculating the physical pixel point position Pp of each virtual object point on the imaging plane of the physical camera according to the parameters of the physical camera and the refraction path; and establishing a mapping relation table according to the corresponding relation between the virtual pixel point position {Pv} and the physical pixel point position {Pp}. By calculating the position relation between the physical pixel points on the physical camera and the virtual pixel points on the virtual camera, the position relation of each pixel is established into a mapping relation table, so that the image of the physical camera can be corrected underwater in real time, and the distortion of the image is eliminated.

The invention discloses a shipborne marine atmospheric boundary layer refractive index profile detection system and method, and relates to the technical field of marine atmospheric environment monitoring and electromagnetic wave propagation safeguard.The method comprises the steps that sea-air downlink infrared radiation spectrum data and sea surface air temperature, relative humidity and air pressure data are obtained; constructing a background atmosphere profile by using the reanalysis data, and correcting an initial profile bottom layer by using sea surface observation air temperature, relative humidity and air pressure data to form a prior state vector; constructing an inversion cost function including an observation residual term, a background prior term and a sea surface boundary constraint term, and performing inversion to obtain an atmospheric temperature profile and a relative humidity profile; and calculating an atmospheric refractive index profile according to the temperature profile, the relative humidity profile and the air pressure profile. According to the method, the marine atmospheric refractive index profile can be continuously obtained under the shipborne dynamic observation condition, and reliable data support is provided for marine electromagnetic propagation environment analysis and waveguide diagnosis.

Provided is a device for measuring a refraction coefficient and an extinction coefficient. The device for measuring a refraction coefficient and an extinction coefficient may comprise: a light source for generating EUV light; a target for transmitting and reflecting the EUV light generated from the light source; a reflector disposed under the target to reflect the EUV light having been transmitted through the target; and a detector for detecting an interference pattern by collecting the EUV light having re-transmitted through the target after being reflected from the reflector and the EUV light reflected from the target, wherein a refraction coefficient and an extinction coefficient of the target may be detected by comparing a first interference pattern detected through the target and having a first thickness with a second interference pattern detected through the target and having a second thickness.

The invention discloses a cloud scene spectral radiance simulation method based on space-based observation and a related device, and relates to the technical field of spectral radiance simulation, and the method comprises the steps: obtaining simulation parameters of a cloud-containing layer, atmosphere, a position and a wave band; calculating a cloud layer optical characteristic coefficient by using a Mie scattering theory, and solving a cloud layer refraction coefficient in combination with a Kramers-Kronig relationship; based on the refraction coefficients of the atmosphere and the cloud layer, the cloud layer surface reflectivity is obtained through the Fresnel reflection law; and solving a radiation transfer equation by adopting a two-flow approximation method, enabling the non-uniform atmosphere to be equivalent to a plurality of uniform sub-layers, introducing reflectivity into the cloud sub-layer to represent the reflection contribution of the cloud sub-layer, and finally obtaining the spectral radiance at the zenith. According to the method, parameters are accurately set to adapt to various scenes, the calculation precision of optical parameters and reflectivity is ensured by means of a physical mechanism, the calculation burden is remarkably reduced through two-stream approximation, efficiency and precision are considered, and the problems that an existing method is time-consuming in calculation and large in burden on complex clouds, especially clouds with high optical thickness are effectively solved; and the spectral radiance of the cloud scene can be accurately simulated.

The application discloses a shipborne marine atmospheric boundary layer refractive index profile detection system and method, relates to the technical field of marine atmospheric environment monitoring and electromagnetic wave propagation guarantee, and comprises the following steps: acquiring sea-air downward infrared radiation spectrum data and sea surface air temperature, relative humidity and air pressure data; constructing a background atmospheric profile by using reanalysis data, and correcting the initial profile bottom layer by using the sea surface observation air temperature, relative humidity and air pressure data to form a prior state vector; constructing an inversion cost function containing an observation residual term, a background prior term and a sea surface boundary constraint term, and inverting to obtain an atmospheric temperature profile and a relative humidity profile; and calculating an atmospheric refractive index profile according to the temperature profile, the relative humidity profile and the air pressure profile. The application can continuously acquire the marine atmospheric refractive index profile under the shipborne dynamic observation condition, and provides reliable data support for marine electromagnetic propagation environment analysis and waveguide diagnosis.

The invention discloses a sea radar rapid display drawing method based on critical refraction coordinate transformation. According to the method, the current atmospheric refractive index gradient is assumed to be the negative reciprocal of the earth radius, at the moment, electromagnetic waves of a sea radar are propagated towards the sea, coordinate transformation in a Cartesian coordinate system is utilized, and forward and reverse calculation analytical expressions of the spatial position of a sea target are deduced; and a rapid display drawing method of the radar video data is established so as to realize error reduction of a sea surface target space display position. The method improves the positioning precision and the drawing rendering precision, and can be applied to the fields of sea target position calculation, multi-radar joint detection and data fusion.

The application discloses an atmospheric waveguide monitoring and diagnosing method and system, and the method comprises the following steps: acquiring meteorological data of a FY-4 satellite, wherein the meteorological data comprises water vapor pressure, air pressure and temperature; pre-processing the meteorological data to obtain a first data set; processing the first data set based on a horizontal high-resolution construction algorithm to obtain a high-resolution second data set; obtaining atmospheric refractive index according to the second data set; and obtaining atmospheric waveguide data according to the atmospheric refractive index. The meteorological data of the meteorological satellite is processed based on the horizontal high-resolution construction algorithm to obtain high-resolution atmospheric refractive index; the atmospheric waveguide is generated due to atmospheric refraction effect, and therefore, the parameters of the atmospheric waveguide can be obtained according to the atmospheric refractive index and its profile, so that the atmospheric waveguide in a sea area range can be monitored.

The application relates to a flexible direct current power grid line fault recognition method based on a voltage wave refraction coefficient, which is characterized in that: 1-mode wave impedance of a line is analyzed to obtain a relatively accurate fault component 1-mode voltage wave; Peterson equivalent circuit is used to quantitatively analyze the voltage wave refraction coefficient when a positive direction fault occurs, and the voltage wave refraction coefficient under a reverse direction fault is obtained through qualitative analysis; a fault recognition criterion is constructed according to the difference of the voltage wave refraction coefficient, and judgment is made. The fault recognition method can recognize the power grid fault type only by calculating the voltage wave refraction coefficient, has strong adaptability to the primary topology of the power grid, does not need a large amount of data transmission, has a low requirement on a sampling frequency, and has strong engineering applicability.