1394 results about "Geodesy" patented technology

The invention discloses an InSAR (Interferometric Synthetic Aperture Radar) and GNSS (Global Navigation Satellite System) robust adaptive fusion method for high-precision three-dimensional surface deformation monitoring, which belongs to the technical field of space geodetic survey and remote sensing, and comprises the following steps of: constructing a time sequence deformation field based on a small baseline set time sequence InSAR processing technology, and resampling GNSS observation data to a grid consistent with the InSAR by using Kriging spatial interpolation; a Helmert variance component estimation method is adopted to adaptively estimate variance components of InSAR and GNSS data, and reasonable weight fixing of a multi-source observation value is achieved; iterative reweighted least square estimation is introduced, outlier influences in various observation data are dynamically restrained through a Tukey double-weight function, robust optimization of a fusion model is achieved, and therefore a high-precision three-dimensional deformation field is reconstructed. The method comprises the steps of Helmert weight fixing, IRLS robust, variance component updating and a closed-loop feedback mechanism of weight matrix optimization.

The invention provides a global magnetic disturbance compensation method in aviation magnetic survey. The method comprises the following steps: S1, performing high-altitude calibration flight through a motion platform, and acquiring total magnetic field data based on detection data of an optical pump magnetometer; s2, obtaining geomagnetic background gradient information and obtaining geomagnetic field data based on the geomagnetic background gradient information; s3, obtaining motion platform magnetic interference data according to the total magnetic field data and the geomagnetic field data; s4, motion platform attitude information, motion platform current information and fluxgate magnetometer detection data are acquired; s5, obtaining a motion platform magnetic interference coefficient according to the motion platform magnetic interference data, the motion platform attitude information, the motion platform current information and the fluxgate magnetometer detection data; and S6, according to the geomagnetic background gradient information and the motion platform magnetic interference coefficient, performing data compensation on the total magnetic field data in real time during actual aviation magnetic measurement.

The invention relates to the technical field of coal mine goaf exploration, in particular to a goaf combined detection and identification method fusing gravity, earthquake and transient electromagnetism, which comprises the following steps of: (1) arranging an earthquake, transient electromagnetism and gravity method combined observation system according to a detection geological task and a field condition of a coal goaf; (2) seismic data, transient electromagnetic data and gravity data are collected through the combined observation system; (3) performing independent inversion on the gravity data, the transient electromagnetic data and the seismic data to obtain density distribution, resistivity distribution and wave velocity distribution of the goaf; (4) carrying out a joint inversion method based on improved cross gradient seismic data, transient electromagnetic data and gravity data; (5) obtaining a joint inversion resistivity profile map, a joint inversion wave velocity profile map and a joint inversion density profile map of the goaf through joint inversion of the seismic data, the transient electromagnetic data and the gravity data of the goaf; and identifying development characteristics of the goaf.

The invention discloses a millimeter wave radar and range finder golf sports monitoring system and method and a medium, and relates to the field of sports monitoring, the system comprises a handheld integrated terminal, a laser ranging module, a millimeter wave radar module, a processing unit and a display unit are integrated in the handheld integrated terminal, and a first communication module is connected with the processing unit; the data interaction module is used for performing data interaction with an external mobile terminal; the mobile terminal comprises a second communication module, a trajectory prediction module and a recommendation decision module, and is used for comparing the predicted flight trajectory with a target trajectory preset by a user and generating a swing suggestion in a training mode; and in the motion mode, the central processing unit is used for planning and recommending a ball hitting strategy based on the expected drop point distance input by the user and the real-time environment data measured by the handheld integrated terminal in combination with historical training data of the user. According to the invention, accurate monitoring and dynamic analysis of the golf ball flight path are realized.

To eliminate the influence of station position fluctuations in a satellite navigation system. [Solution] In satellite navigation systems, including the US GPS and Japan's Quasi-Zenith Satellite System, when multiple reference stations are installed to form a wide-area differential correction system (WADGPS), previously, position errors caused by fluctuations in station position would remain in the position information calculated by the user receiver.However, by adding a correction amount to the correction information provided by WADGPS in advance to cancel this, the position errors caused by fluctuations in station position at the user station can be reduced without changing the calculation processing content at the WADGPS user station, thereby improving the accuracy of the position information calculated by the user station.

The invention relates to a ship berthing position detection method and system based on shore end laser radars, and the method comprises the steps: deploying a plurality of laser radars at a shore end, and collecting original point clouds in parallel through an asynchronous thread model; constructing a rigid transformation matrix based on the radar installation attitude parameters, and further generating fusion point cloud data under a unified world coordinate system; then extracting 3D geometric edge points in a preset range of the front edge of the wharf as near-shore point cloud data, and further calculating the minimum ship-shore distance; based on the ship bow direction and a preset segmentation threshold value, the coastal point cloud data are segmented into ship bow area point cloud and ship stern area point cloud in the x-axis direction, the coordinate mean value of the ship bow area point cloud and the ship stern area point cloud is calculated and compared with an expected position in a wharf operation system, and berthing accuracy is judged; and the drift distance is calculated in real time, the drift distance, the attitude angle and the change rate of the attitude angle are compared with corresponding preset threshold values respectively for graded early warning and drift alarm, and high-precision ship berthing position dynamic detection is achieved.

The invention relates to the technical field of ocean engineering digital twinning and three-dimensional visualization, and provides a method and system for generating dredging terrain twinning based on a right-angle triangular mesh, and the method comprises the steps: obtaining regular grid elevation unified to an engineering plane coordinate system or preprocessed sampling height data, determining a covered space range, reading the space range and density parameters, and calculating the total row number and the total column number of the grids based on the space range and the density parameters; generating regularly arranged vertexes in the covered space, and constructing a topological structure of an isosceles right triangle grid; dividing the global grid into a plurality of Chunk blocks according to a fixed size by taking a vertex as a unit, establishing a triangular index mapping relationship between global rows and columns and the Chunk blocks, filling three vertexes of an isosceles right triangle and elevation / height data in each Chunk block in parallel, and generating local VBO, IBO and AABB; and performing batch rendering and coloring according to a height color table on all Chunk blocks to realize visualization of the terrain.

A design method of a trust region satellite-borne dual-base interference SAR system is provided, relating to the field of radar measurement. Firstly, error sources of the interference SAR system are classified and analyzed, phase errors caused by image decoherence are calculated according to wave positions, and an analytical expression of baseline-related errors is reserved; a maximum phase error caused by imaging processing and an electronic device are estimated; and a baseline error is estimated. Then, the phase errors and the baseline errors are converted into elevation errors through an elevation fuzzy number, thereby obtaining an analytical expression of the elevation errors and the baseline parameters (length and dip angle). With a relative height measurement accuracy index of the system as an optimization object, a feasible solution interval between the baseline length and the baseline dip angle of the system is solved through a trust region algorithm. A minimum value of the baseline length is corrected according to a flying-around safety distance of a dual-satellite formation. According to the method of the present disclosure, the design of the satellite-borne dual-base interference SAR system can be guided, so that the satellite-borne dual-base interference SAR system is ensured to carry out terrain elevation surveying and mapping tasks with high accuracy and high reliability.

The invention relates to the technical field of geographic information engineering, in particular to a surveying and mapping geographic system based on a remote sensing technology, which is characterized in that a multi-modal remote sensing data acquisition module synchronously acquires satellite remote sensing images, aviation LiDAR point cloud, unmanned aerial vehicle oblique photography and ground Internet of Things sensing data; the data fusion collaboration module carries out geographic coordinate calibration and position coding, and generates a surveying and mapping data set with unified precision in combination with an improved Mamba fusion model; the dynamic terrain high-precision inversion module performs three-dimensional terrain reconstruction, and completes terrain deformation monitoring in combination with an InSAR interference measurement technology and a time sequence analysis algorithm; the real-time error correction module constructs a BP neural network optimized by an ISSA algorithm, and dynamically corrects a terrain three-dimensional model and a terrain deformation result; the intelligent visual application module constructs a digital twinborn simulation model and automatically generates a standardized surveying and mapping result report. Therefore, the problems of weak multi-source data fusion, low terrain inversion precision and the like in the prior art are solved.

The invention discloses a multi-wave chromatography and reflection combined detection method and device for a thin-covering-layer urban active fault and a medium. The method comprises the steps that longitudinal wave seismic data and transverse wave seismic data are collected; recording vertical component data based on the longitudinal wave seismic data for first arrival travel time pickup and tomography inversion to obtain a longitudinal wave velocity structure model Vp; extracting Rayleigh surface wave frequency dispersion through the vertical component data and carrying out multichannel surface wave analysis inversion to obtain a transverse wave velocity structure model Vs; calculating a longitudinal and transverse wave velocity ratio parameter structure model Vp / Vs, and calculating to obtain a Poisson's ratio parameter structure model v; obtaining a longitudinal wave (P wave) reflection profile and a transverse wave (S wave) reflection profile; identifying and summarizing into an interpretation fracture set Fc, and recording key elements; and by taking the interpretation fracture set Fc as a structural skeleton, completing unified registration and superposition display on Vp, Vs, Vp / Vs and v, a longitudinal wave reflection profile and a transverse wave reflection profile, and outputting a shallow underground structure comprehensive interpretation map of the thin covering layer region.

The invention relates to a dam slope deformation monitoring method based on fusion of a measuring robot and a GNSS (Global Navigation Satellite System). The method comprises the following steps: performing signal synchronization and delay correction on a dual-mode observation pillar of a GNSS and a prism target of a measurement robot, and constructing a space-time reference network; controlling the measurement robot to emit an anti-interference laser pulse, counteracting environment vibration, and outputting a vibration compensation coordinate set; obtaining a dam slope displacement field through variable weight adaptive fusion processing; performing encryption scanning on an abnormal area exceeding a first deformation threshold in the displacement field to generate a polarization interferometric phase diagram, forming an adaptive data stream through three-stage dynamic classification coding, calculating a reference point drift component in combination with a dual-mode observation pillar, and extracting a net deformation set; and finally, mapping the net deformation set to a BIM model, constructing a color temperature gradient three-dimensional deformation situation map, triggering early warning for an area exceeding a second deformation threshold value, and generating a three-dimensional early warning map. According to the method, high-precision space-time unification of multi-source data can be realized, and the monitoring consistency and the anti-interference capability in a complex environment are remarkably improved.

The invention provides a three-dimensional flow velocity field inversion method and system based on coherence-assisted SAR adaptive offset tracking, and a storage medium, so as to improve the problem of decoherence caused by time heterogeneity in a synthetic aperture radar interferometry (InSAR) technology, and relates to the technical field of electric power engineering geological disaster monitoring. The method comprises the following steps: establishing a space-time baseline network between SAR images; obtaining coherence data after geocoding; selecting a pair of SAR images from the space-time baseline network as a reference unit, calculating an offset result through a pixel offset tracking technology for the reference unit, and determining an optimal matching window parameter of the reference unit; establishing a mapping function between coherence and optimal matching window parameters; according to the established mapping function, calculating an optimal matching window parameter of each remaining SAR image pair; and in combination with the line-of-sight average deformation rate fields of the ascending and descending rails, inverting a surface three-dimensional flow velocity deformation field of the target area through a geometric vector decomposition model.

The invention relates to the technical field of deep foundation pit monitoring, and discloses a deep foundation pit micro-deformation InSAR remote sensing method and system and a storage medium. The method comprises the following steps: synchronously acquiring data through a ground radar and an InSAR satellite, and obtaining a point target set and an original scattering characteristic sequence; obtaining a net deformation phase sequence without influence through registration residual correction, phase deduction and weighted fusion processing, and carrying out phase consistency quality control and unwrapping processing to obtain an accumulated deformation quantity sequence; constructing a deformation mechanism correlation characteristic matrix based on correlation analysis of the cumulative deformation quantity sequence and radar reflection intensity amplitude attenuation characteristics; and fusing the deformation mechanism correlation feature matrix and the real-time differential interference image group, extracting deformation rate and phase gradient change, and further generating a deep foundation pit local micro-deformation risk early warning index set. According to the invention, the tiny deformation of the surrounding area of the foundation pit can be effectively detected, potential risks are warned in advance, and the safety and monitoring efficiency in the construction process are improved.

The invention discloses an accurate monitoring system for linear deformation of a loess tunnel portal side upward slope, and relates to the technical field of geotechnical engineering and surveying and mapping. The system comprises a sensing network layer, a data acquisition and transmission layer, a cloud platform and data analysis layer and an application display layer, displacement data of discrete monitoring points are reconstructed into continuous full-field displacement and strain distribution through Kriging interpolation, then a displacement vector field is regarded as a whole to be analyzed, the maximum shear strain field of the displacement vector field is calculated, an abnormal area with the deformation gradient abrupt change is accurately positioned, and the deformation gradient abrupt change accuracy is improved. The abnormal point sets are merged into independent clusters according to spatial proximity and deformation consistency, and the geometric trajectory of a potential slip crack surface or crack is accurately outlined through curve fitting, so that the technical path fundamentally changes the limitation of point-mode monitoring, and can automatically identify a hidden linear failure trend which is difficult to find by naked eyes in a non-contact manner, so as to improve the detection accuracy of the hidden linear failure trend. And refined data support is provided for slope stability evaluation.

The invention discloses a complex terrain communication method and device based on multiple satellites and a storage medium, and the method comprises the steps: determining a navigation path and a moving speed of terminal equipment, and determining the track information of the terminal equipment in a preset time period relative to a current moment in real time; determining three-dimensional terrain information in the coverage area corresponding to the trajectory information based on the trajectory information corresponding to the terminal equipment; determining satellite docking information corresponding to each spatio-temporal trajectory point based on trajectory information corresponding to the terminal equipment, ephemeris information of a plurality of satellites and three-dimensional terrain information; determining a docking switching point according to the satellite docking information corresponding to each spatio-temporal trajectory point, and determining a switching vector based on the docking switching point; and determining a target switching strategy by using a particle swarm optimization algorithm according to a preset target function and the switching vector, and performing satellite switching according to the target switching strategy.

The embodiment of the invention provides a method and a system for processing ocean multi-parameter wide-width imaging data of a Beidou interference altimeter, and relates to the technical field of GNSS-R. The method comprises the following steps: constructing a set of complete and strict data processing chain; through precise calculation of a GNSS-R direct signal and reflection signal delay inequality interference geometric model and correction of actual measurement delay inequality errors, systematic errors in the process of converting original signals into geophysical parameters are remarkably reduced, and the precision and reliability of parameters obtained through final inversion are improved. And on the basis of a self-adaptive data collection strategy of parameter space-time transformation characteristics and a spatial interpolation reconstruction process, discrete strip data is intelligently'woven 'into a continuously-covered wide-swath imaging type data product, so that the data format better meets the analysis requirements in the fields of oceanography, climatics and the like, and the intuition and usability of the product are improved.

The invention belongs to the technical field of geophysical exploration, and particularly relates to a method and a system for quantitatively measuring intrinsic parameters of bedrock fractures based on all-angle domain amplitude and phase joint inversion. The method comprises the following steps: acquiring geological radar reflection data of a target fracture at a plurality of incident angles; synchronously extracting data sequences of amplitude change along with angles and phase change along with angles; establishing a fracture reflection theoretical model; constructing a target function jointly constrained by the amplitude residual and the phase residual; and adopting a global optimization algorithm to minimize the target function, and synchronously inverting to obtain the fracture opening, the filler dielectric constant and the occurrence parameter. According to the invention, through the combined constraint of the amplitude and the phase, the inversion multiplicity is effectively inhibited; accurate system effect correction is adopted, so that the reliability of large-angle data is ensured; according to the method, multi-parameter synchronous inversion without prior hypothesis is realized, the inversion precision is small in relative error, the method is obviously superior to a traditional method, and the method has important engineering application value.

The application provides a differential interferometric SAR satellite deformation rate measurement precision analysis calculation method and system. The implementation steps of the application are as follows: (1) establishing a differential interferometric SAR satellite long-time sequence deformation rate measurement equation, and determining various error sources affecting the system deformation rate measurement precision; (2) deducing an error transfer function of each error source of the differential interferometric SAR long-time sequence deformation rate measurement on the target long-time sequence deformation rate measurement precision; (3) designing satellite system parameters; (4) calculating the influence degree of each error source on the differential interferometric SAR long-time sequence deformation rate measurement precision of the satellite system; and (5) solidifying the calculation process, and quickly responding when the satellite system design parameters change. The application can be used for the overall design of a differential interferometric SAR long-time sequence deformation rate measurement satellite system.

The invention belongs to the technical field of physical ocean and remote sensing application, and particularly relates to a sub-mesoscale signal extraction method based on Ku / Ka dual-frequency SAR (Synthetic Aperture Radar) height measurement, which comprises the following steps of: acquiring a Ku / Ka dual-frequency sea surface height observation original data set and IMU (Inertial Measurement Unit) attitude and trajectory data; registering the average sea surface and tide height to a space-time sampling position of Ku / Ka synchronous observation and deducting from the original height to obtain an initial sea surface height anomaly sequence of the two channels, and processing the initial sea surface height anomaly data of the two channels to obtain a fused height anomaly sequence; performing attitude coupling mode extraction on the fused height anomaly sequence to obtain a height anomaly sequence after platform error elimination; meanwhile, smoothing processing is carried out to obtain a smoothed sequence; and interpolating the smoothed sequence into a two-dimensional regular grid, performing small-scale secondary smoothing denoising on grid data, interpolating a mesoscale background field at the same time into the same grid, and deducting the mesoscale background field to obtain a sea surface height anomaly data system with sub-mesoscale as a main part.

The invention belongs to the technical field of gravity and magnetic method exploration data processing, and relates to a source body positioning method based on intelligent gravity and magnetic field separation and Euler deconvolution, which comprises the following steps: setting gravity and magnetic abnormal field modeling parameters according to geological and physical property data of a research area; generating an initial seed point in the underground three-dimensional grid and expanding and growing the initial seed point to generate Q independent abnormal field models; mapping the position of the model to a real coordinate, and calculating to obtain a forward modeling abnormal field data set; extracting the maximum value of the global absolute value of the data set and sorting in an ascending order, superposing the first p absolute values to generate a composite field, and constructing a field separation data set by taking the p absolute value as a target field and the composite field; using the field separation data set to train the field separation network until convergence; inputting measured data score departure field and residual field data, and selecting data for iterative separation according to requirements to obtain a field separation result; and obtaining a preliminary positioning result by using a field separation result and combining with an Euler deconvolution method, and determining final source body positioning after screening. The method has the beneficial effects that multi-scale geological target field separation can be realized, and source body positioning can be determined.

The application discloses a kind of multi-path ghost suppression method of millimeter wave radar tunnel scene, it is applied to millimeter wave radar target detection field, for the poor multi-path ghost suppression effect in tunnel scene of prior art;The application first constructs confidence criterion using the multidimensional information point cloud data generated by radar original echo, and carries out density-based clustering to point cloud data;Then linear fitting is carried out to zero doppler point cloud to obtain the slope information of tunnel wall, simultaneously, the median line slope of dynamic point cloud pair is matched with the slope set, and the target pair associated successfully is judged as multi-path ghost with lower confidence;Finally, considering the motion characteristics of target in tunnel, as well as multi-path reflection geometric model, the double rectangular region division of transverse and longitudinal is carried out to dynamic point cloud, and the point cloud data in region is subjected to Doppler information constraint, and the target satisfying the condition and with lower confidence is screened out and judged as multi-path ghost.The application can detect vehicle target in semi-closed environment, while retaining real target, can effectively identify and suppress the multi-path ghost generated by reflection of tunnel wall and railing etc..

The invention discloses a load saturation prediction method and device for satellite communication, and the method is applied to a gateway station, and comprises the steps: constructing a first data set corresponding to each sampling time period, and carrying out the fitting of each first data set, and generating a corresponding reference distribution curve; constructing a second data set corresponding to the current time period, and fitting the second data set to generate a corresponding first actual distribution curve; pre-determining the channel capacity between each satellite and the corresponding coverage area, and broadcasting the first actual distribution curve, a first reference distribution curve corresponding to the current time period and the channel capacity to each satellite; determining a second reference distribution curve corresponding to the next time period, calculating a deformation parameter between the first reference distribution curve and the second reference distribution curve, and predicting a second actual distribution curve; and selecting a prediction point in the second actual distribution curve, and determining the load saturation of each satellite in the next time period according to the prediction point and the channel capacity.

The invention provides a satellite Ka wave band inter-satellite link antenna phase center change calibration method and system, and the method comprises the steps: collecting L wave band observation data and Ka wave band inter-satellite link observation data of a ground observation station, carrying out the gross error elimination, cycle slip detection, epoch normalization and combination, and generating a clock error-free and geometry-free observation quantity; analyzing the variation range of a nadir angle and an azimuth angle of the observation data, constructing a piecewise linear original PCV function model taking the nadir angle and the azimuth angle as independent variables, and synchronously resolving original PCV parameters of a satellite L / Ka wave band in a joint orbit determination process; decomposing the original PCV into a smooth PCV and a corresponding Z-direction PCO by adopting a least square separation technology, performing interpolation on a PCV value based on a discrete grid, and establishing a final PCV grid correction model; joint orbit determination error correction is introduced into the PCV correction model, a new round of joint orbit determination is carried out, the satellite L / Ka waveband PCO correction amount is calculated, and high-precision in-orbit calibration of the satellite Ka waveband inter-satellite link antenna phase center change is achieved.

The invention belongs to the technical field of wireless communication, and particularly relates to a positioning method based on low-orbit satellite opportunity signal Doppler measurement. The method solves the Doppler measurement positioning problem based on low orbit (LEO) satellite opportunity signals under the condition that GNSS signals are limited or unavailable. A positioning process is modeled as a non-linear state space framework, a joint estimation scheme combining a cubic Kalman smoother and an expectation maximization algorithm is provided, efficient estimation of a terminal position and Doppler frequency shift is realized, and noise covariance is adaptively optimized at the same time. The method provided by the invention theoretically ensures the optimal performance in statistical significance. A simulation result shows that compared with a traditional nonlinear least square method, the scheme provided by the invention can remarkably improve the positioning precision, and the calculation overhead is kept reasonable and balanced.

The invention relates to the technical field of road surface monitoring, in particular to a sensor-based road surface quality detection system, which comprises a disturbance extraction module, a trajectory analysis module, a consistency identification module, a sudden change sorting module and a crack confirmation module. According to the invention, through the time sequence correlation analysis of the vertical structure vibration acceleration, the GPS direction vector and the transverse angular velocity signal in the vehicle driving process, the disturbance behavior and the trajectory deviation trend change in the vehicle and road surface contact process can be identified, and after the structure disturbance and the trajectory variation are correlated and compared, the stability of the vehicle is improved. Further screening real disturbance response from change consistency, constructing a space transfer model of crack mutation in combination with a joint state structure of disturbance intensity and offset amplitude, identifying a joint abnormal interval of structural damage and trajectory deviation in time and space, and determining a joint abnormal interval of structural damage and trajectory deviation in time and space through a multi-dimensional index distribution density and time continuity discrimination standard. And accurate judgment and spatial calibration of the crack area are realized.

The invention discloses a three-dimensional elastic block-fault motion deformation coupling model construction method and system. Comprising the following steps: acquiring geodetic survey data of earth crust movement between earthquakes and an active fault distribution map, and dividing different active blocks; the movable blocks are associated with geodetic measurement data through spatial position attributes, and motion features of different blocks are distinguished; adjacent boundaries are extracted to serve as modeling boundary faults, and discretization processing is carried out; constructing a three-dimensional elastic block-fault motion deformation coupling model including block rotation, internal strain, fault normal velocity discontinuity counteracting, inclined fault positive slippage and negative dislocation response; inverting parameters of the three-dimensional elastic block-fault motion deformation coupling model by adopting a constrained least square method; and according to the coupling coefficient, identifying the potential pregnancy and earthquake concave-convex body on the fault. According to the method, a more complete inter-earthquake three-dimensional elastic model is established, and support is provided for accurate research of active fault coupling characteristics, recognition of gestational earthquake concave-convex bodies and judgment of major earthquake dangerous areas.

The invention relates to a polarization navigation course angle estimation method based on a neural network, an end-to-end classification neural network is constructed, the input of the classification neural network is an urban sky scene polarization image, and the output of the classification neural network is a sun meridian angle. According to the network, a plurality of steps of polarization mode segmentation, restoration and the like are omitted, the sun meridian angle is directly estimated from an urban polarization image with a sheltered area, and the course angle estimation process is greatly simplified. Besides, polarization modes of different scenes, different shielding degrees, different weather and illumination conditions and different shielding types are adopted as a data set to train the network, the generalization ability of the neural network can also be improved, the effect of the neural network in the scenes of different shielding degrees is ensured, and the robustness of the neural network is improved. And particularly, the course angle estimation precision in an urban environment with dense shielding is improved.

The invention discloses a satellite group collaborative prediction method based on Lie group differential manifold and covariant optimization, and mainly solves the problems of inaccurate disturbance modeling, poor physical interpretation and large prediction error in the prior art. According to the scheme, the method comprises the following steps: mapping the position and attitude of a satellite to an SE (3) manifold, and describing the movement speed of the satellite by using Lie algebra; establishing a multi-level Lie algebra disturbance decomposition mechanism including absolute perturbation, relative coupling and observation noise; constructing a Riemannian loss function by using the orbit state after Lie group manifold embedding and the orbit state deviation obtained by disturbance decomposition; defining an orbital state updating rule by using a covariant derivative of the function, and iteratively solving the orbital state updating rule on the SE (3) manifold to output an orbital state prediction result of the satellite; for an abnormal state of inter-satellite link interruption, a differential geometric connection form is defined, and virtual relative position observation of an integral generation orbit state is carried out. According to the method, the physical interpretability and long-term prediction stability of orbit prediction can be improved, prediction errors are reduced, and the method can be used for low orbit communication constellation deployment of frequency band inter-satellite links.

The invention provides a low earth orbit satellite communication initial time frequency offset estimation method, and belongs to the technical field of satellite communication. When satellite communication initial time-frequency offset estimation is carried out, initial time-frequency offset coarse estimation is firstly completed based on a first auxiliary synchronization signal, time-frequency offset coarse compensation is carried out on a received signal by using an estimation result, then initial time-frequency offset fine estimation is further completed based on a second synchronization signal, and the compensated signal is sent to a demodulation module for demodulation. The two-step time-frequency offset estimation method provided by the invention combines the advantages of the symmetric Chirp reference signal and the pseudo code sequence for time-frequency offset estimation, can realize rapid and accurate time-frequency offset estimation in a large-frequency offset scene, and improves the performance of a low-orbit satellite communication system.

The invention provides a stratigraphic structure and ground pressure distribution detection method based on wave velocity tomography, and relates to the technical field of wave velocity tomography. The method comprises the following steps: firstly, arranging dense linear detector arrays in a monitoring area at an interval of 5m, and collecting the distribution condition of an aquifer, a lithology detection result and a drill core diagram of the monitoring area; recording seismic wave data, carrying out noise reduction processing on the seismic wave data, picking up arrival time, and associating the arrival time with a waveform event; performing path tracking on an observation result by adopting a wave velocity inversion algorithm, generating a wave velocity tomography image and substituting the wave velocity tomography image into the wave velocity-ground pressure evaluation model; and finally generating a ground pressure distribution diagram.