50 results about "Satellite altitude" patented technology

The invention discloses a multi-GNSS satellite signal power abnormity real-time monitoring method. The method comprises the following steps: acquiring real-time observation data of an observation station network which is uniformly distributed globally; when the linear relation between the carrier-to-noise ratios of different frequency signals of each satellite in each observation station and the dynamic monitoring threshold value related to the elevation angle of each satellite are determined, one signal is used for predicting another signal by using the linear coefficient, and the deviation between an actual value and a predicted value is calculated; calculating a satellite elevation angle of the real-time observation data, and determining a monitoring threshold value of the current satellite at the current moment according to the satellite elevation angle; and counting an average value of the deviations of all satellites monitored by all observation stations at the current moment, and marking that the power of the current satellite at the current moment is abnormal when the absolute deviation of the current satellite is greater than a monitoring threshold value. According to the invention, on the basis of the carrier-to-noise ratio linear relation of different frequency signals and the dynamic monitoring threshold, real-time monitoring of various power abnormal scenes including natural interference, man-made interference, satellite active power adjustment and the like is realized.

A GNSS-TEC projection function estimation method with additional azimuth angle parameters comprises the following steps: obtaining observation data of a plurality of GNSS monitoring stations, and then extracting STEC from the observation data; the IPP point position with the satellite elevation angle larger than 70 degrees and the IPP point position with the satellite elevation angle smaller than 40 degrees are obtained respectively, and then satellites with the satellite elevation angle larger than 70 degrees and satellites with the satellite elevation angle smaller than 40 degrees located at the same IPP point position at the same moment are matched; projecting the STEC of the IPP point position of which the satellite elevation angle is greater than 70 degrees to the zenith direction to obtain a VTEC, and then calculating the STEC projection function value MFV of the IPP point position of which the satellite elevation angle is less than 40 degrees according to the corresponding VTEC; and obtaining an ionosphere projection conversion model, and solving to obtain a to-be-estimated coefficient of the projection function model of the additional azimuth angle parameter. According to the method, the TEC projection conversion error of the ionized layer is relatively small under the condition of a low satellite elevation angle.

The invention relates to the technical field of GNSS high-precision positioning, and provides a BIE-based real-time dynamic positioning integer ambiguity resolving method and system, and the method comprises the steps: obtaining a preliminary ambiguity subset through the screening of a satellite elevation angle and a carrier-to-noise ratio, and carrying out the correlation reduction processing; a multi-level screening mechanism is adopted and comprises three stages of dynamic optimization of coarse screening, fine screening and candidate group generation; a weight distribution model is improved based on Laplacian distribution to calculate candidate solution weights and probability weighted fusion is carried out; in combination with an ILS and BIE mixed fixing strategy, BIE weighted averaging is adopted when ILS fixing fails; a positioning result is optimized through dynamic satellite screening and multi-system data fusion, and a jump detection threshold value is set to realize abnormal recalculation. The method improves the reliability of real-time dynamic positioning, and guarantees the continuous and stable operation of the system in a signal shielding or multi-path interference scene through a jump detection and recalculation mechanism.

The invention relates to the technical field of satellite communication, in particular to a dynamic beam adjustment system for medium and low orbit satellite communication. Comprising a beam demand sensing unit; the dynamic beam calculation unit counteracts the influence of a complex environment on beam coverage through a multi-factor cooperative compensation mechanism; the beam execution adjustment unit is used for realizing beam accurate pointing and interference suppression through an adaptive phase optimization algorithm; and a satellite-ground cooperation unit. Through a multi-factor cooperative compensation mechanism, a beam theory pointing angle is calculated based on a spherical geometrical relationship, compensation amounts are determined by combining satellite motion, user movement and atmospheric refraction, and a communication scene is determined according to a satellite elevation angle, a user terminal motion speed and a communication link signal-to-noise ratio. The weight of each compensation amount is dynamically adjusted and synthesized into the total compensation amount, and finally the actual beam pointing angle is obtained, so that the coupling influence of multiple factors on beam coverage in a complex environment is effectively counteracted, and the beam pointing precision is improved.

Disclosed in the present invention are a method and apparatus for constructing an ionospheric mapping function model, a device, and a storage medium. The method comprises: acquiring historical slant total electron content data of an ionosphere; in the historical slant total electron content data, taking, as a corresponding historical vertical total electron content value, a historical slant total electron content value corresponding to a satellite elevation angle greater than a preset angle, and calculating a corresponding historical mapping function value; acquiring a corresponding Modified Julian Day, local time, satellite elevation angle and azimuth angle of an ionospheric pierce point; and on the basis of the historical mapping function value, the Modified Julian Day, the local time, the satellite elevation angle, and the azimuth angle of the ionospheric pierce point, training a preset LSTM model by taking the Modified Julian Day, the local time, the satellite elevation angle and the azimuth angle of the ionospheric pierce point as inputs and taking the historical mapping function value as an output, so as to obtain an ionospheric mapping function model. The present invention can improve the accuracy of ionospheric mapping functions.

The invention discloses a method for constructing a regional polynomial ionosphere oblique delay model, which belongs to the field of ionosphere delay error correction of a global satellite navigation system, and comprises the following steps of: calculating a signal puncture point coordinate through a reference station latitude and longitude coordinate, and calculating a signal puncture point coordinate by taking the signal puncture point coordinate, observation time and a satellite elevation angle as joint independent variables; sTEC constructs a polynomial function model for dependent variables; the spatial-temporal dynamic characteristics and the geometric characteristics of the sight line of the satellite are synchronously incorporated into modeling, and the spatial-temporal change rule of the ionosphere region is accurately captured; by utilizing polynomial analysis characteristics, model parameters can be quickly output, a user can directly calculate the required STEC only by inputting own coordinates, time, a satellite elevation angle and a satellite azimuth angle, the process is remarkably simplified, and the real-time performance is improved. According to the invention, the defects of precision and efficiency in a complex regional scene in the prior art are overcome, and a more reliable ionosphere error correction scheme is provided for regional GNSS high-precision positioning.

The invention provides a ground GNSS differential data correction method and device, and the method comprises the steps: obtaining a pseudo range and a carrier phase, calculating a whole cycle jump value of the carrier phase through employing an M-W combination function and an ionosphere delay change rate, and correcting a carrier phase value through employing the calculated whole cycle jump value of the carrier phase. The influence of station-satellite geometric distance is eliminated, the influence of ionosphere change is considered, and the method is suitable for cycle slip detection in a dynamic environment; according to the method, a self-adaptive threshold model is constructed on the basis of Turbo Edit cycle slip detection in a flight dynamic observation environment, cycle slip misjudgment at a low satellite elevation angle is reduced, and the influence of too low sampling rate on GF combined cycle slip detection performance is weakened to a certain extent; and a technical guarantee is provided for applying the GNSS differential data to the flight test.

The invention provides a troposphere anisotropy-considered real-time PPP positioning method, and relates to the technical field of satellite navigation and positioning, and the method comprises the following steps: S01, receiving real-time GNSS observation data, broadcast ephemeris data and precision correction data, carrying out detection and restoration of clock slip and cycle slip, data quality control and preprocessing of antenna phase correlation errors on the data to obtain a preprocessed data set; s02, calculating the solar altitude after atmospheric refraction correction according to each preprocessed data set and the geographic position and observation time of the observation station corresponding to each data set; and S03, based on the solar altitude and the satellite altitude. According to the method, solar altitude parameters are introduced, the troposphere anisotropy effect caused by solar radiation is effectively modeled, and the precision and convergence speed of real-time precise single-point positioning are remarkably improved.

The invention provides a radar satellite three-dimensional attitude guiding method and system, and the method comprises the steps: calculating the geocentric distance and geocentric latitude and longitude of a satellite according to satellite orbit parameter information, calculating the height of the satellite and the geodetic latitude and longitude of a droop point through a WGS-84 reference ellipsoid model, and further obtaining the geocentric latitude and the earth radius of the droop point. The position vectors of the droop point and the satellite in a WGS-84 earth-fixed coordinate system are obtained respectively, the position vectors of the droop point and the satellite are compared to obtain the position vector from the satellite to the droop point, then the position vector is converted into a satellite orbit coordinate system, and rolling and pitching guide angles are calculated. Doppler frequency deviation caused by earth rotation is compensated by adjusting the yaw guide angle. According to the method, the problem that loads such as a spaceborne radar altimeter vertically point to the earth surface of the earth reference ellipsoid model is successfully solved, meanwhile, Doppler frequency deviation generated by earth rotation is compensated, and important technical support can be provided for a subsequent radar satellite earth observation task.

The invention discloses a troposphere delay multi-layer grid modeling method fusing GNSS and ray tracing, which comprises the following steps of: performing ambiguity fixing processing on non-difference and non-combination PPP positioning data from GNSS reference stations, and estimating per-epoch parameters of each reference station, including troposphere delay, a satellite elevation angle and an azimuth angle; the longitude, the latitude and the altitude of the receiver are measured; the estimation parameters except for the troposphere delay are combined with meteorological data to serve as input of ray tracing calculation, so that the troposphere delay profile of the position of each receiver is determined to serve as ray tracing troposphere delay; and according to the troposphere delay estimated by the GNSS at the height of the reference station and the ray tracing troposphere delay, combining the ray tracing troposphere delays calculated at different height layers to obtain GNSS troposphere delays at different height layers, and forming a multi-layer GNSS troposphere delay product.

The invention provides a PPP-RTK random model construction method and system for weakening ionospheric scintillation influence, and belongs to the technical field of navigation positioning, the PPP-RTK random model is applied to an observation equation of a PPP-RTK rapid precision positioning model to carry out PPP-RTK positioning, and the method comprises the following steps: when the carrier-to-noise ratio of satellite observation data is higher than a preset threshold value, determining that the PPP-RTK random model is a PPP-RTK random model; determining weight factors of the pseudo-range and the phase observation value based on the satellite elevation angle so as to set random noise distribution obeyed by the pseudo-range and the phase observation value in the observation equation; and when the carrier-to-noise ratio of the satellite observation data is lower than a preset threshold value, determining weight factors of the pseudo-range and phase observation values according to the carrier-to-noise ratio intensity and the satellite elevation angle so as to set random noise distribution obeyed by the pseudo-range and phase observation values in the observation equation. According to the invention, the influence of ionospheric scintillation on PPP-RTK positioning is effectively weakened, and rapid, accurate, continuous and steady PPP-RTK positioning in a scintillation environment is realized.

The invention discloses a broadcast ionosphere model adaptive selection method for a GNSS (Global Navigation Satellite System) terminal, which comprises the following steps: receiving navigation message information broadcasted by each GNSS system in real time, and obtaining various broadcast ionosphere model parameters; calculating the geographic latitude corresponding to the ionospheric puncture point according to the current position coordinate of the user, the satellite elevation angle and the azimuth angle; according to the geographic latitude and the time period of the current calculation time, selecting an optimal broadcast ionosphere model under the current space-time condition; and according to the optimal broadcast ionosphere model and the broadcast ionosphere model parameters, calculating to obtain a correction value of the ionosphere delay amount. According to the invention, by selecting the optimal broadcast ionosphere model in the current environment, the positioning precision is improved, the error of a certain model is prevented from being amplified, the advantages of each broadcast ionosphere model are exerted, and the stability and consistency of system positioning are improved; dynamic environment change is supported, and good space-time adaptive capacity is achieved; and model selection is realized only at a user side without modifying the broadcasting format of the existing satellite message.

The invention relates to an ionosphere pseudo observation random model construction method considering time-varying characteristics and baseline trend, which comprises the following steps: extracting a single-difference ionosphere delay estimated value as a sample, counting the random characteristics of the sample through a sub-window, and converting the absolute value expectation of the sample in the sub-window into an estimated value of a single-difference ionosphere delay standard deviation; the method comprises the following steps: selecting a satellite elevation angle, a baseline length, local time and a baseline azimuth angle as influence factors, expressing the standard deviation of single-difference ionosphere pseudo observation as a product form of each influence factor, and introducing logarithmic transformation into the standard deviation of single-difference ionosphere pseudo observation; and converting the product form into a linear regression form taking a satellite elevation angle, a baseline length, local time and a baseline azimuth angle as independent variables, and performing exponentiation on the linear regression form to obtain a single-difference ionosphere pseudo observation random model. The interpretation capability of the random model constructed by the method on the uncertainty of the ionosphere is remarkably enhanced, and the RTK resolving performance is remarkably improved under the condition of a low-latitude complex ionosphere.

The invention discloses a GNSS diffraction error detection method based on signal-to-noise ratio change rate estimation. The method comprises the following steps: placing a receiver in an open environment, observing multi-day data, reading observation files obtained by Beidou / GNSS receivers of a base station and a monitoring station, performing pseudo-range single-point positioning calculation, obtaining elevation angles of satellites, and outputting signal-to-noise ratio sequences of the satellites; counting the change of the signal-to-noise ratio of each satellite along with the elevation angle of the satellite in an open environment; building a function model of the change of the satellite signal-to-noise ratio along with the satellite elevation angle; in an actual shielding environment, constructing a signal-to-noise ratio rate estimation model based on Kalman filtering; during real-time positioning, the calculated signal-to-noise ratio predicted value and the change rate thereof are compared with a result in an open environment, and whether a current observation value is a diffraction error is judged; according to the invention, the method achieves the real-time detection of the diffraction error of the carrier phase observation value during the Beidou / GNSS data processing, facilitates the accurate control of the data quality of the observation value, and improves the positioning precision of Beidou / GNSS.

The invention provides a GNSS (Global Navigation Satellite System) differential positioning data quality control method, device, equipment and medium. The method comprises the following steps: acquiring a mean error rms and an ambiguity check rate RATIO after baseline calculation in a GNSS differential positioning process; determining a discrete discourse domain value nrms of the rms according to the discrete discourse domain Nrms of the median error, and determining a discrete discourse domain value nRATIO of the RATIO according to the discrete discourse domain NRATIO of the ambiguity check rate; according to the nrms and the nRATIO, adjusting the elevation angle of the satellite; and carrying out baseline solution again based on the adjusted satellite elevation angle. According to the method provided by the invention, after baseline calculation is carried out, the satellite elevation angle is adjusted according to the median error rms and the ambiguity check rate RATIO, calculation precision control is carried out, baseline calculation is carried out again based on the adjusted satellite elevation angle, and GNSS differential positioning precision is ensured.

The invention discloses a method for constructing a high temporal-spatial resolution ionosphere model for a dense GNSS deformation observation station. The method comprises the following steps: collecting double-frequency observation data and broadcast ephemeris of a dense GNSS deformation monitoring station in a modeling area; calculating a multi-path effect, a cycle slip ratio and a data effective rate, and screening out data meeting quality requirements; respectively acquiring a satellite end DCB and a receiver end DCB; using the screened double-frequency observation data to calculate a non-geometric distance combination, and combining a satellite end DCB and a receiver end DCB to obtain an oblique path TEC; based on thin layer hypothesis, calculating a puncture point position of a satellite signal in a thin layer and a satellite elevation angle and an azimuth angle at the puncture point, and converting an oblique path TEC into a vertical TEC by using a projection function; and constructing a TEC grid model, and averaging the vertical TECs of all puncture points falling on each grid to obtain a TEC value and a system. According to the invention, calculation is carried out by using the data of the existing large-scale dense GNSS deformation network monitoring stations, and the value-added effect of the data is realized on the premise that the construction cost is not increased.

The invention provides a GNSS diffraction error elimination method based on a regular hexagon grid, and the method comprises the steps: obtaining observation data and broadcast ephemeris of a GNSS reference station and a monitoring station, carrying out the calculation, obtaining an observation residual sequence of each satellite, and obtaining the corresponding elevation angle and azimuth angle of the satellite; a regular hexagon grid model covering the observation hemispherical surface is constructed, the regular hexagon grid model comprises a plurality of regular hexagon units which are equal in area and have isotropy, the observation residual error sequence is mapped into the corresponding regular hexagon units according to the elevation angle and the azimuth angle of the satellite, and a grid residual error set is formed; performing statistical distribution analysis on the grid residual error set in each regular hexagon unit, and calculating statistical characteristic parameters of residual errors; when the statistical characteristic parameters exceed a preset threshold value, it is judged that the corresponding regular hexagon units are polluted by diffraction errors, a data quality control grid mask is generated, and observation values in the regular hexagon units which are judged to be polluted by the diffraction errors are removed in subsequent positioning calculation.

The application discloses a kind of construction methods of regional polynomial ionospheric oblique delay model, belong to the ionospheric delay error correction field of global satellite navigation system, comprising: the signal piercing point coordinates are calculated by the longitude and latitude coordinates of reference station, then signal piercing point coordinates, observation time and satellite elevation angle are jointed as independent variable, and STEC is as dependent variable to construct polynomial function model;By synchronously including the space-time dynamic characteristics and satellite line-of-sight geometric characteristics into modeling, the space-time variation law of ionosphere is accurately captured;Using the analytical properties of polynomial, the model parameters can be quickly output, users only need to input their own coordinates, time, satellite elevation angle and satellite azimuth angle to directly calculate the required STEC, significantly simplify the process and improve real-time performance.The present application fills the accuracy and efficiency gap of the prior art in the complex scene, and provides a more reliable ionospheric error correction scheme for regional GNSS high-precision positioning.

The invention discloses a self-adaptive modulation and coding method and a self-adaptive modulation and coding system for a space-air-ground integrated Internet of Vehicles, and provides a non-feedback high-reliability transmission scheme for a vehicle low earth orbit (LEO) communication scene. According to the scheme, aiming at the problems of complexity and time-varying characteristics of a link between a vehicle and an LEO satellite in space-air-ground integrated vehicle networking communication, according to different satellite parameters including satellite height, communication frequency band, satellite elevation angle to ground, communication packet length and the like, and a bit error rate curve obtained by simulation, the communication efficiency of the vehicle and the LEO satellite is improved. A non-feedback adaptive modulation coding scheme based on deep learning is designed, and non-feedback high-reliability transmission between the vehicle and the LEO satellite is realized. A simulation experiment shows that the adaptive modulation coding scheme can realize reliable data transmission when the link redundancy budget is 1.5 dB; meanwhile, the deep learning method adaptively selects a modulation coding scheme under the conditions of different orbit heights, carrier frequencies and data packet lengths, so that the reliability of vehicle LEO satellite channel communication is remarkably improved.

The invention relates to an amplitude flicker index aggregation method and device based on elevation angle weighting, and belongs to the field of satellite navigation and ionosphere monitoring. Comprising the following steps: acquiring amplitude flicker indexes and elevation angle data of GNSS satellite signals at multiple moments; the data are cleaned, and effective signals meeting the locking time, the elevation angle threshold value and the requirements of a specific satellite system are reserved; for the kth satellite signal at the moment t, calculating the weight based on the proportion of the elevation angle sine value of the kth satellite signal to the sum of the elevation angle sine values of all satellites at the moment t; and weighting and aggregating the flicker indexes of all satellites according to the weights, and generating a comprehensive flicker index reflecting the influence of the positioning performance. In order to verify the effect, correlation analysis is carried out on the weighted aggregation result and the precision single-point positioning error of the receiver, and the correlation analysis is compared with a traditional aggregation method. According to the method, the relevance between the scintillation index and the positioning error is remarkably enhanced, and more effective technical support can be provided for ionosphere scintillation monitoring, positioning risk early warning and anti-interference design.

This invention relates to the field of navigation satellite application technology, and particularly to a method and apparatus for inverting the multipath reflection coefficient of a water surface in a global navigation satellite system. Specifically, it includes the following steps: S1, releasing wave-damping material: releasing a linear damping medium onto the sea surface; S2, acquiring observation parameters: during the effective time of wave suppression, using a GNSS geodesic receiver to acquire observation data files and calculate the signal incident angle information; receiving a standard format RENIX file from the satellite using the GNSS geodesic receiver; calculating the satellite elevation angle information, obtaining the specific navigation satellite signal incident angle value P, and calculating the phase difference of the reflected signal; S3, inverting the water surface reflection coefficient α: inverting the water surface reflection coefficient α using a machine learning method. This invention achieves suppression of multipath errors in a water surface environment, improves the stability of monitoring point coordinates, and solves the problem of high false alarm frequency in large water areas.

The present disclosure relates to an indoor-outdoor discrimination and positioning method and device, a storage medium and an electronic device. The method comprises: obtaining wireless signal strength information of a base station; when the wireless signal strength information is less than a first preset threshold, obtaining a satellite elevation angle and a signal-to-noise ratio; obtaining determination index data according to the satellite elevation angle and the signal-to-noise ratio; when the determination index data is greater than a second preset threshold, determining that a person corresponding to a terminal device is located outdoors; and determining position information of the person outdoors according to motion sensor data collected by the terminal device and satellite positioning data. The method can be applied to a factory building or a complex equipment area, and indoor-outdoor discrimination and high-precision positioning outdoors can be achieved.

The application relates to the technical field of satellite communication, in particular to a dynamic beam adjustment system for medium and low orbit satellite communication. The system comprises a beam demand perception unit, a dynamic beam calculation unit, a beam execution adjustment unit and a satellite-ground coordination unit. The dynamic beam calculation unit offsets the influence of complex environment on beam coverage through a multi-factor collaborative compensation mechanism. The beam execution adjustment unit realizes accurate beam pointing and interference suppression through an adaptive phase optimization algorithm. The application calculates the theoretical pointing angle of the beam based on spherical geometry, determines the compensation amount in combination with satellite movement, user movement and atmospheric refraction, dynamically adjusts the weight of each compensation amount and combines the compensation amounts into a total compensation amount according to the satellite elevation angle, user terminal movement speed and communication link signal-to-noise ratio, and finally obtains the actual beam pointing angle, so that the coupling influence of multi-factors on beam coverage in complex environment is effectively offset, and the beam pointing precision is improved.

The invention discloses an RTK random model refining method based on pseudo-range error distribution prediction. The method comprises the following steps: extracting a pseudo-range double-difference observation value residual error, and independently segmenting a residual error sequence of each satellite based on a variance point change detection method; performing layered parameterized model fitting and parameter estimation on the segmented residual error sequence; extracting a satellite elevation angle, an azimuth angle, a signal-to-noise ratio, a signal lock loss identifier and pseudo-range information from GNSS original observation data as features; a composite loss function combining a Huber function and priori knowledge constraints is constructed to suppress the influence of extreme abnormal values, and an intra-batch sample weight reduction strategy is introduced to improve the training stability; predicting a mean value and a standard deviation parameter of pseudo-range error distribution in real time by adopting a space-time diagram neural network architecture fusing LSTM and a diagram attention network; the predicted distribution parameters are used for refining the RTK random model in Kalman filtering; and finally, ambiguity fixation is carried out through an LAMBDA method, and a fixed solution or a floating solution is output.

The invention relates to a fast open-loop GNSS-R height measurement method and system based on space-time frequency combination, and the method comprises the steps: collecting multi-frequency GNSS signals, carrying out the coarse time delay and coarse Doppler frequency offset estimation of each multi-frequency GNSS signal, and carrying out the compensation of the multi-frequency GNSS signals through coarse Doppler frequency offset; based on the coarse time delay and the compensated multi-frequency GNSS signal, carrying out forming processing on a wave beam in a time domain direction, and constructing a space-time-frequency joint vector; through a spatial domain smoothing technology, rank increasing is carried out on the autocorrelation matrix of the space-time-frequency joint vector, and the problem of rank deficiency of the autocorrelation matrix is solved; performing feature analysis on the autocorrelation matrix according to a subspace decomposition method, and estimating direct view path time delay, specular reflection path time delay and a direct view path incoming angle; and deducing a satellite elevation angle according to the direct-view path incoming angle, and inverting the height from the receiver to the ground surface through the delay inequality of the direct-view path and the mirror reflection path and the satellite elevation angle. According to the technical scheme of the invention, high-precision effective estimation of the height of the receiver can be realized quickly with low complexity.

The present invention discloses a non-line-of-sight signal recognition method, system, computer equipment and storage medium. The method comprises: obtaining the GNSS raw data in the receiver and performing a solution to obtain satellite signal characteristics, wherein the satellite signal characteristics include Doppler frequency shift measurement value, carrier-to-noise ratio, satellite altitude angle and satellite azimuth angle; marking the satellite type according to the raw data to construct a satellite type label; counting the number of line-of-sight satellite labels at the same time to obtain the actual number of observable satellites, and according to the preset satellite cutoff altitude angle, obtaining the theoretical number of visible satellites, and using the ratio of the two as a custom feature; using the satellite signal characteristics and the custom characteristics as feature values ​​to form a feature vector; inputting the feature vector into a deep neural network for training to obtain a non-line-of-sight signal recognition result. The present invention improves the accuracy and stability of classification recognition by implicitly increasing the amount of information of the spatial factors of the recognition task environment.

The invention provides an orthogonal signal demodulation method with a Doppler frequency shift correction function for reducing the bit error rate, which is characterized in that when a satellite moves to a terminal for transmitting a data packet, the carrier frequency observed by a transmitter is increased, and the carrier frequency is reduced; the observed carrier frequency is reduced along with the distance between the satellite and the terminal, the change of the observed frequency is caused by Doppler frequency shift and is equal to v * f / c, v is the relative speed from the satellite to the terminal, f is the carrier frequency, c is the light velocity, and the Doppler frequency shift of the satellite is displayed; the position of the satellite changes between-600 kilometers and 600 kilometers relative to the position of the terminal in the advancing direction, for 2.4 GHz carrier frequency, when the height of the satellite is 600 kilometers and the speed of the satellite is 7.6 kilometers per second, Doppler frequency shift ranges from-35 kilometers to 35 kilometers, and the problem of frequency synchronization caused by Doppler frequency shift in satellite communication is solved.

This invention discloses a dual-antenna GNSS-IR water level monitoring method, apparatus, device, and storage medium, relating to the field of water level measurement technology. The method involves placing a first antenna below a second antenna and using a dual-antenna receiver to receive the signal-to-noise ratio (SNR) sequences of both the first and second antennas. Based on the antenna spacing, the antenna interference phase difference is calculated. Based on the antenna interference phase difference, the interference phase of the target antenna is calculated. Based on the oscillation frequency and wavelength of the SNR sequences, the interference phase, the GNSS satellite elevation angle, and the absolute antenna altitude, the absolute altitude of the target water surface is calculated. Compared to existing technologies, this invention solves the problem of low sampling rate in traditional single-antenna GNSS-IR altimeter measurement. Furthermore, compared to dual-antenna GNSS-IR, this invention offers more stable signal tracking and lower hardware costs.

This invention discloses a method for constructing a high spatiotemporal resolution ionospheric model using dense GNSS deformation monitoring stations. The method includes: collecting dual-frequency observation data and broadcast ephemeris data from dense GNSS deformation monitoring stations within the modeling area; calculating multipath effects, cycle slip ratio, and data effectiveness, and selecting data that meets quality requirements; acquiring satellite-end DCB and receiver-end DCB respectively; calculating geometrically insensitive distance combinations using the selected dual-frequency observation data, and combining the satellite-end DCB and receiver-end DCB to obtain the oblique path TEC; based on the thin-layer assumption, calculating the puncture point location of the satellite signal in the thin layer, the satellite elevation angle, and azimuth angle at the puncture point, and converting the oblique path TEC to vertical TEC using a projection function; constructing a TEC grid model, and averaging the vertical TEC of all puncture points falling in each grid to obtain the TEC value and system. This invention utilizes data from existing large-scale dense GNSS deformation network monitoring stations for calculation, achieving data value enhancement without increasing construction costs.

The application provides a GNSS diffraction error elimination method based on a regular hexagon grid, comprising: acquiring observation data and broadcast ephemeris of GNSS reference stations and monitoring stations, calculating observation residual sequences of each satellite, and acquiring corresponding satellite elevation angles and azimuth angles; constructing a regular hexagon grid model covering an observation hemisphere, the regular hexagon grid model comprising a plurality of regular hexagon units with equal areas and isotropy, mapping the observation residual sequences into corresponding regular hexagon units according to the satellite elevation angles and azimuth angles, and forming a grid residual set; statistically analyzing the grid residual set in each regular hexagon unit, and calculating statistical characteristic parameters of the residuals; when the statistical characteristic parameters exceed a preset threshold, determining that the corresponding regular hexagon unit is contaminated by diffraction errors, generating a data quality control grid mask, and eliminating the observation values in the regular hexagon unit determined to be contaminated by diffraction errors in subsequent positioning calculation.