16 results about "Geoid" patented technology

This invention provides a strategy and method for generating a geoid-like precision grid model. S1: Using the "cyclic empty point method," the "elevation anomaly residual" of GNSS leveling points is calculated. S2: Each grid point of the gravity geoid model is visited sequentially, and GNSS leveling points within a certain range around it are searched. The distance between the current grid point and each searched GNSS leveling point is calculated. S3: Based on the distances between these GNSS leveling points and the current grid point, and the "elevation anomaly residual" of the GNSS leveling points calculated in the previous step, the precision of the current grid point is calculated, resulting in a precision grid model with the same resolution as the geoid model. This method can provide a calculation method for the precision of specific local areas, overcoming the problem that previous geoid model precision evaluations were not refined enough, only providing an overall model precision and not specific local area precision, thus failing to meet engineering application needs.

The invention relates to the technical field of geology, in particular to a geological density information stripping determination method and device, electronic equipment and a medium, and the method comprises the steps: obtaining surface observation data of a target area; the earth surface observation data are input into the stripping model, the stripping model outputs density distribution of a plurality of material layers of a target area, a lower interface of an earth surface shallow layer model of the stripping model target area starts to extend downwards, a new interface in each extension and a lower interface of a previous material layer form a new material layer, and for each material layer, the density distribution of a plurality of material layers in the stripping model target area is determined; performing density filling on the material layer according to the global crustal structure model, optimizing the density distribution of the material layer until the geoid of the material layer is matched with the benchmark of the earth surface observation data, and continuing to extend downwards until the downward extending distance reaches the target distance; and generating geological density information of the target area according to the density distribution of the plurality of material layers. Therefore, the problem that geological density information measured by related technologies is not accurate enough is solved.

The present application belongs to the field of marine surveying and geodetic surveying, and discloses a far-sea GNSS buoy height reference transmission method combined with satellite altimeter, aiming to solve the technical problems of difficult transmission of 1985 national height reference in far-sea area and large height measurement error of GNSS buoy antenna, the method establishes height reference conversion relationship through shore-based leveling joint measurement, carries out precise positioning and calculation on far-sea GNSS buoy observation data, and retains effective sea surface information through low-pass filtering processing; combines satellite altimeter data to carry out space-time matching, inverses and dynamically corrects the height of buoy antenna, converts the ellipsoidal height of buoy sea surface into 1985 national height through geodetic datum difference correction, and finally outputs the results through quality evaluation. The method realizes accurate transmission of far-sea height reference and dynamic correction of the height of buoy antenna, guarantees the reliability of far-sea sea surface height calculation, and provides accurate height data support for far-sea marine observation, marine engineering and other fields.

The invention provides a troposphere minimum scattering angle calculation method based on a geoid, and the method comprises the steps: constructing a troposphere scattering path geometrical relationship through a transmitting antenna, a receiving antenna, a receiving radio wave ray and a geodetic coordinate of the transmitting radio wave ray encountering a highest obstacle, and proposing a mathematical model of the troposphere minimum scattering angle. Compared with a calculation method given by an ITU-R.P.617 proposal and certain academic papers, the troposphere scattering system signal transmission loss prediction method better meets the troposphere scattering system signal transmission loss prediction requirement, and the troposphere scattering transmission annual average loss median, the antenna deviation loss and the antenna low-rack loss calculation accuracy can be improved. The geoid is adopted to well reflect the shape of the earth, and the distance between the earth surfaces can be accurately measured.

The invention provides an ice-covered sea area sea surface elevation monitoring method and system based on satellite height measurement data, and belongs to the technical field of sea surface elevation monitoring. Based on a plurality of characteristic parameters of SAR mode radar echo data, an unsupervised clustering method is adopted to carry out initial classification on waveforms, and then a gradient boosting tree model is combined to optimize a classification result, so that the sea surface elevation of an ice-covered sea area is obtained. Carrying out classification processing on the waveform; according to a waveform classification result, carrying out distance correction on different types of waveforms by adopting different empirical re-tracking algorithms; on the basis of the re-tracked distance data, calculating sea surface elevation data by combining a satellite orbit height, a geophysical correction item and a geoid model; projecting sea surface elevation data to an equal-area grid, performing spatial interpolation and smoothing processing on a missing region, and generating a monthly sea surface elevation data set covering the ice-covered sea area; and comparing and verifying the generated sea surface elevation data with tide station data and an existing data set, and outputting a final sea surface elevation monitoring result.

The application discloses a gravity anomaly calculation method, device, equipment, storage medium and product, relates to the satellite altimetry data processing technical field, and the gravity anomaly calculation method comprises: obtaining sea surface height data observed by an altimetry satellite; according to the sea surface height data, a plurality of residual geoid gradients in different directions are calculated; the plurality of residual geoid gradients in different directions are fused by a Bayesian triangular cap method, and an east-west direction component and a south-north direction component of the residual geoid gradient are obtained; and based on the east-west direction component and the south-north direction component of the residual geoid gradient, the marine gravity anomaly of a target region is calculated by a gravity anomaly inversion algorithm. The application solves the technical problems of low utilization rate of multi-direction gradient information of a single altimetry satellite and insufficient component extraction precision, realizes mining and optimization of multi-direction gradient information of a single satellite, and improves the inversion precision of the marine gravity anomaly.

According to the geoid-based distance measurement difference system geometric positioning precision factor analysis method provided by the invention, a geoid-based distance measurement difference positioning equation is constructed through a station position and a geodetic coordinate-based distance measurement difference positioning equation, a geoid-based GDOP mathematical model is provided, and compared with a position line normal spacing GDOP algorithm, the geoid-based distance measurement difference system geometric positioning precision factor analysis method is more in line with the positioning performance requirement of the system; the accuracy of positioning precision analysis is improved, and through distance difference measurement precision, index conversion from a geometric positioning precision factor GDOP to a circular probability error CEP can be realized.

The application discloses a large lake water level time series encryption method based on multi-track satellite foot point fusion. Multi-track laser altimetry satellite foot point data located in a lake to be measured is extracted, and lake water level elevation values of all foot points are calculated based on a unified geodetic datum elevation coordinate system to obtain daily observation water levels of the multi-track. The track with the most observation times of each lake to be measured is taken as a reference track, and the remaining tracks are taken as correction tracks, offset between the reference track and the correction tracks is calculated, the correction track is translated and corrected, and multi-track fusion is realized. The water level time series after multi-track correction and fusion is optimized through a filtering method to obtain a dense lake water level time series after multi-track fusion. The method does not depend on measured water level data, can be popularized to lakes covered by multi-track altimetry satellites all over the world, and has important application significance for management and protection of lake water resources.

A geoid construction method based on least square spectrum combination and spherical wavelets specifically comprises the steps that firstly, multi-source gravity data, including global gravity field model data, airborne gravity data and ground gravity data, of an area to be constructed are obtained; then, according to the signal and error spectrum characteristics of each data source, the effective contributions are respectively assigned to low-frequency, intermediate-frequency and high-frequency components; firstly, a frequency spectrum weight function is constructed based on a modified spherical Butterworth function so as to accurately define low-frequency, intermediate-frequency and high-frequency wavebands; then performing weighted modeling on the multi-source gravity observation data by utilizing the determined spectral weight, and respectively establishing low-frequency, intermediate-frequency and high-frequency geoid component models; and obtaining a zero-order term and a conversion parameter, and then combining the optimal weights of the low-frequency component, the intermediate-frequency component and the high-frequency component with the zero-order term and the conversion parameter to obtain a final geoid result. The geoid modeling stability in the complex terrain area is good.

This invention belongs to the field of geodesy technology, specifically providing a rigorous method, electronic device, and storage medium for atmospheric reduction in geoid determination that takes into account topography and three-dimensional density distribution. The method includes constructing a global three-dimensional atmospheric density model; establishing a precise calculation model of atmospheric effects; and determining the impact of atmospheric reduction on the geoid. This invention proposes a rigorous atmospheric mass adjustment scheme using the generalized Helmert condensation method; it constructs a global three-dimensional atmospheric density model using actual atmospheric data and establishes a precise calculation model of atmospheric effects in conjunction with a global digital elevation model; and it employs a high-precision gravity forward modeling algorithm based on spherical prisms and thin-layer spherical units, taking into account the effects of Earth's curvature, to accurately calculate the direct atmospheric effects, major indirect atmospheric effects, and minor indirect atmospheric effects.

The application discloses a geoid construction method based on least square spectrum combination and spherical wavelet, and specifically comprises the following steps: obtaining multi-source gravity data of a region to be constructed, including global gravity field model data, aviation gravity data and ground gravity data; then, according to signal and error spectrum characteristics of each data source, effectively contributing to low-frequency, medium-frequency and high-frequency components is respectively attributed; first, a spectrum weight function is constructed based on a modified spherical Butterworth function form to accurately define low-frequency, medium-frequency and high-frequency bands; then, the determined spectrum weight is used to weight model multi-source gravity observation data, and low-frequency, medium-frequency and high-frequency geoid component models are respectively established; first, a zero-order term and a conversion parameter are obtained, then the optimal weight of the low-frequency component, the medium-frequency component and the high-frequency component, the zero-order term and the conversion parameter are combined to obtain a final geoid result. The application has good stability in geoid modeling in a complex terrain region.

The invention relates to the technical field of point cloud extraction, in particular to a point cloud topographic feature intelligent extraction method based on regional quasi-geoid constraint. The method comprises the following steps: acquiring airborne laser radar point cloud and global navigation satellite observation data, constructing a regional quasi-geoid refinement model, and realizing point cloud elevation datum unification; constructing a ground point cloud triangulation network model based on the constrained point cloud elevation, calculating a terrain inclination angle and a linear expression error of a triangular surface, and adaptively determining a feature extraction parameter; and traversing the point cloud data in the triangular surface projection range, extracting the significant topographic feature points meeting the relative height condition, optimizing the triangulation network structure through iterative subdivision until a termination condition is met, and outputting a topographic feature extraction result. According to the method, through the synergistic effect of the regional quasi-geoid constraint and the adaptive feature discrimination mechanism, the unification of the elevation reference of the complex terrain point cloud, the effective suppression of the pseudo features and the synchronous improvement of the terrain feature extraction precision and stability are realized.

The invention discloses an inland water level monitoring method and system based on altimetry satellite altitude difference data, and the method comprises the steps: obtaining a target water remote sensing image and an altimetry satellite data set, and carrying out the superposition selection of altimetry data points completely falling into the surface of a water body; the height measurement data points are preprocessed, height difference data are obtained, and after preset conditions are supplemented, a water level change time sequence is obtained through least square adjustment calculation; the system correspondingly implements the method. The height difference data are obtained through the intersection point method or the overlapped trajectory method, the geoid model residual error is offset, the problem of height errors caused by the spatial position in a traditional method is solved, and the water level monitoring accuracy is improved.

The invention discloses a gravity anomaly calculation method, device and equipment, a storage medium and a product, and relates to the technical field of satellite altimetry data processing, and the gravity anomaly calculation method comprises the steps: obtaining sea surface height data observed by an altimetry satellite; according to the sea surface height data, a plurality of residual geoid gradients in different directions are obtained through calculation; performing fusion processing on the residual geoid gradients in the different directions through a Bayesian triangular cap method to obtain east-west direction components and south-north direction components of the residual geoid gradients; and based on the east-west direction component and the south-north direction component of the residual geoid gradient, calculating through a gravity anomaly inversion algorithm to obtain the ocean gravity anomaly of the target area. According to the method, the technical problems of low utilization rate of multi-directional gradient information and insufficient component extraction precision of a single altimetry satellite are solved, mining and optimization of the multi-directional gradient information of the single satellite are realized, and the inversion precision of ocean gravity anomaly is improved.

The present application relates to the field of satellite navigation technology, specifically to a GNSS-R based real-time ground water level inversion method and system, comprising the following steps: collecting multi-band GNSS signals, combining an elevation model to solve the specular reflection point, extracting the delay Doppler characteristics of the reflected signal, using environmental parameters to compensate for the calculation of the vertical distance from the antenna to the water surface, and combining the antenna geodetic height to generate the absolute water level of the ground water body. In the present application, by synchronously collecting multi-constellation data and achieving time alignment, the data fusion accuracy and response speed are improved, the clock error is corrected by analyzing the orbit parameters, the reflection points are accurately selected by combining the elevation model to exclude interference, the delay Doppler grid is constructed to perform coherent integration, the peak value characteristics are extracted to enhance the spectrum resolution and capture robustness, the height error is compensated by introducing multi-source environmental parameters, the geodetic datum is applied to unify the reference, and the accuracy and continuous stability of the centimeter-level absolute water level monitoring are ensured, effectively supporting real-time application of large-scale water bodies.

The application discloses a method and system for transmitting a unified global height datum by using an empty carrier time-frequency signal, and the method comprises the following steps: obtaining time-frequency observation values based on the empty carrier time-frequency signal transmission; calculating the gravity potential difference of two ground stations based on the transmitted time-frequency observation values; obtaining the altitude of a to-be-measured ground station on a regional geoid according to a conversion model of the gravity potential difference and the altitude; and converting the altitude on the regional geoid to a global unified height datum surface according to a height conversion relationship between the regional geoid and the global unified height datum surface. The application can overcome the defects of high cost, low efficiency and poor precision of traditional altitude measurement, realize cross-sea height measurement, realize the unification of the global height datum in a centimeter level precision, and combine the unification principle of the height datum with the time-frequency transmission technology, thereby providing a new research method for realizing the unification of the global height datum.