9 results about "Reference ellipsoid" patented technology

The invention relates to the technical field of satellite remote sensing, in particular to a geometric simulation and registration method for an infrared hyperspectral atmospheric detector, which comprises the following steps of: constructing a visual vector of a pixel in a reference ellipsoid coordinate system by acquiring detection time, ground longitude, ground latitude and satellite position of the pixel FOV of the HIRAS; simulating the imaging range of an HIRAS pixel on the ground based on the size of a pixel field angle by adopting a Rodrigues rotation formula, searching an MERSI pixel in the same platform by using a KD-tree, and respectively calculating the equivalent brightness temperature of the HIRAS pixel and the equivalent brightness temperature of an MERSI simulation image according to a spectrum convolution function and a blackbody radiation formula; and counting the root mean square error of the brightness temperature difference between the HIRAS pixel and the MERSI pixel through multi-row accumulation, and arranging the root mean square error according to an OR row time sequence to obtain the geometric positioning accuracy of the HIRAS in the along-rail and cross-rail directions. According to the invention, the rapid search of the pixel closest to the visual vector range is realized, and the accurate position determination of the registration error is realized.

The invention provides a troposphere minimum scattering angle calculation method based on an earth reference ellipsoid, and the method comprises the steps: constructing a troposphere scattering path geometrical relationship, and calculating a spherical distance between a transmitting antenna and a receiving antenna; calculating the prime circle curvature radius of the earth reference ellipsoid at the latitude of the transmitting antenna and the latitude of the receiving antenna, the spherical distance between the highest obstacle of the transmitting antenna and the transmitting antenna, the included angle between the connecting line of the transmitting antenna and the receiving antenna and the transmitting view plane, and the spherical distance between the highest obstacle of the receiving antenna and the receiving antenna; and the included angle between the antenna connecting line and the receiving view plane line is received, so that the minimum troposphere scattering angle is calculated. According to the method, the geometrical relationship of the troposphere scattering path is constructed through the geodetic coordinates of the transmitting antenna, the receiving antenna and the electric wave ray encountering the highest obstacle, the mathematical model for calculating the minimum scattering angle of the troposphere is provided, the troposphere scattering signal transmission requirement is better met, and accurate calculation of the minimum scattering angle of the troposphere can be achieved.

The invention relates to the technical field of submarine topography surveying and mapping, and discloses a submarine topography elevation measurement method and device, electronic equipment and a storage medium. The method comprises the following steps: determining a fixed reference difference, namely a first reference difference, between a first geoid and a second geoid according to monitoring data of a tide gauge station; calculating the reference difference between a second geoid and a reference ellipsoid at a plurality of positions of the engineering area, i.e., a second reference difference, and solving a comprehensive reference difference through a fitting mode; and finally, calculating a submarine topography elevation value taking the first geoid as the benchmark at the target position by combining the water depth at the target position and the sea water surface elevation value taking the reference ellipsoid as the benchmark. The deployment problem caused by severe sea conditions and complex submarine topography is avoided, the equipment cost is reduced, and the surveying and mapping efficiency is improved.

The invention provides a method for calculating the connecting line height from the lowest scattering point of a troposphere to a receiving and transmitting antenna. The connecting line height from the lowest scattering point of the troposphere to the receiving and transmitting antenna is calculated. The spherical distance between the transmitting antenna and the receiving antenna is calculated; the prime unitary circle curvature radius of the earth reference ellipsoid at the transmitting antenna latitude and the receiving antenna latitude is calculated; the linear distance between the transmitting end and the receiving end is calculated; and the connecting line height from the lowest troposphere scattering point to the receiving antenna and the transmitting antenna is calculated. On the basis of the distance between the transmitting antenna and the receiving antenna and the included angle between the receiving antenna and the transmitting antenna, a mathematical model of the height between the lowest troposphere scattering point and the connecting line between the receiving antenna and the transmitting antenna is provided, compared with a method of an ITU-R.P.617 proposal, the troposphere scattering transmission requirement is better met, and in troposphere scattering loss prediction, the troposphere scattering loss prediction accuracy is improved. And the calculation accuracy of parameters such as a scatterer dependency coefficient, elevation angle offset loss and antenna low-frame loss can be improved.

The invention relates to the technical field of computers, in particular to a method, a device, equipment, a medium and a program product for determining an underwater gravity field, and the method comprises the steps: obtaining digital topographic data and seawater dynamic topographic data of a target area; generating a surface shallow three-dimensional space model of the target area according to the digital topographic data, the seawater dynamic topographic data and the reference ellipsoid continuation data, and performing density filling on the surface shallow three-dimensional space model by using a refined crustal density model; gravitational potential information generated by the target area is calculated based on the surface shallow three-dimensional space model after density filling, and an underwater gravitational field of the target area can be calculated by combining an external gravitational field model. Therefore, by comprehensively applying multi-source data and a high-precision calculation method, the calculation efficiency of the underwater gravity field and the accuracy of the result are improved.

The invention provides a spectrum-combined high-resolution gravity field modeling method, which comprises the following steps of: collecting satellite gravity field model data, high-order gravity field model data and topographic data, performing gravity field spectrum analysis, and screening an optimal spectrum combination; standardization processing based on tidal system consistency conversion and reference ellipsoid parameter unification is carried out; performing weighted combination on the satellite gravity field model and the high-order gravity field model by adopting a least square weighted combination method to obtain a medium-long wave gravity field model of spectrum combination; calculating a medium-long wave gravity field; obtaining a terrain forward modeling gravitational field model used for representing a high-frequency gravitational field based on the terrain data through fusion based on a space domain and a frequency spectrum domain, and calculating a terrain forward modeling high-frequency gravitational field; and fusing the medium-long wave gravitational field with the terrain forward modeling high-frequency gravitational field to obtain a full-spectrum gravitational field. The problems that leakage errors exist in combination of medium-long wave gravity field modeling and the influence of selection of a reference plane on the modeling precision of a high-frequency gravity field is ignored are solved.

The present application relates to the technical field of satellite remote sensing, and particularly relates to a kind of infrared hyperspectral atmospheric probe geometry simulation and registration method, by obtaining the detection time of HIRAS one pixel FOV, ground longitude, ground latitude and satellite position, the view vector of the pixel under the reference ellipsoid coordinate system is constructed;Rodriguez rotation formula is used, based on the size of pixel field of view, the imaging range of HIRAS pixel on the ground is simulated, the pixel of MERSI in the same platform is searched using KD-tree, according to the spectral convolution function and blackbody radiation formula, the equivalent brightness temperature of HIRAS pixel and the equivalent brightness temperature of MERSI simulation image are calculated respectively;The root mean square error of brightness temperature difference between HIRAS pixel and MERSI pixel is accumulated and counted by multiple rows, the root mean square error is arranged according to the FOR row timing, and the geometric positioning accuracy of HIRAS in the along-track and across-track directions is obtained.The present application realizes the fast search of the nearest pixel in the range of view vector, and realizes the accurate position determination of registration error.

This invention discloses a three-dimensional spatial discrete coding method and system based on cubic spherical topology, relating to the fields of geospatial information processing and three-dimensional discrete grid technology. It addresses the problems of high-latitude distortion, poor elevation dimension fusion, and low computational efficiency across scales and surfaces in existing coding systems. This invention establishes a geocentric coordinate system and an Earth reference ellipsoid model, transforming and separating the spherical position and elevation components of the target point. After cubic mapping, nonlinear tangent transformation, fixed-point quantization, and three-dimensional Morton interleaving, it combines dynamic sentinel positions to form a 64-bit unsigned integer code, which can be quickly deconstructed and hierarchically analyzed using tail-zero counting. This invention effectively avoids high-latitude projection distortion, achieves native three-dimensional spatial fusion, supports cross-scale recursive addressing and O(1) complexity cross-surface neighborhood resolution, and is suitable for the efficient organization and retrieval of global three-dimensional spatial data.

The invention relates to a wide area coverage planning simulation method and device, computer equipment, a readable storage medium and a program product. The method comprises the following steps: acquiring a first environment coordinate of an environment point in a to-be-simulated scene according to a projection map of the to-be-simulated scene, acquiring a second environment coordinate of the environment point on a reference ellipsoid, and updating the second environment coordinate according to the first environment coordinate, determining a target simulation coordinate of the wireless communication device based on the updated second environment coordinate, converting the updated second environment coordinate sum into a coordinate in a three-dimensional space to obtain a third environment coordinate, and performing wireless signal propagation simulation based on the third environment coordinate and the target simulation coordinate to obtain a wide area coverage simulation result. By adopting the method, the accuracy of simulation results can be improved.