623 results about "Pseudorange" patented technology

The invention discloses a Doppler and pseudo-range fusion positioning method and system for low-orbit satellite conduction signals, and relates to satellite positioning. The method comprises the steps that a Doppler and pseudo-range observation equation is established; performing least square residual calculation on the calculated Doppler and pseudo-range theoretical values and the observed Doppler and pseudo-range measured values, and taking a grid center point coordinate corresponding to a two-norm minimum value as a receiver position initial value; performing Taylor series expansion on the Doppler and pseudo-range observation equation, and representing a state updating matrix by using the established state transition matrix and receiver position, clock error and frequency offset correction; the inverse matrix of the observation noise covariance is used as a weight matrix to be distributed to the state transition matrix; and iterating the initial position value of the receiver, updating the state updating matrix, and stopping iteration until the two-norm of the residual solution is smaller than a set threshold value, so as to obtain the position, clock error and frequency offset results of the receiver. According to the method, the low-orbit satellite positioning algorithm model can be optimized, the convergence time is shortened, and the positioning precision is improved.

The invention discloses a high-precision train locomotive positioning method and system based on a GNSS (Global Navigation Satellite System) and INS (Inertial Navigation Satellite System) loose combination mode, and the method realizes the precise positioning of a train by combining the data of an IMU (Inertial Measurement Unit) and a GNSS (Global Navigation Satellite System). The method comprises the following steps: firstly, acquiring IMU data, performing error correction, and outputting corrected acceleration and angular velocity; meanwhile, a GNSS signal is obtained and a pseudo-range measurement value is extracted. Then, inertial navigation calculation is carried out, including attitude calculation, position and speed calculation and sensor deviation updating; through Kalman filtering fusion, state estimation and error correction are carried out by using complementary characteristics of the INS and the GNSS, so that the positioning precision is improved. In the initialization stage, the normal work of the system is ensured through the installation and parameter setting of the IMU and the GNSS. Finally, through Kalman filtering processing, accurate train position, speed, attitude and sensor deviation data are output, and reliable data support is provided for a train control system.

The invention provides a dual-antenna attitude and orientation and robust self-adaption method based on integrated navigation, which comprises the following steps: combining an INS (inertial navigation system) and a dual-antenna GNSS (global navigation satellite system), and enabling the system to output continuous and stable high-precision carrier attitude information when a GNSS signal is interfered by using dual-antenna integrated navigation. According to the method, most of satellite end clock correction, ionosphere and troposphere errors and receiver end clock correction are eliminated by using double-antenna GNSS pseudo-range and carrier phase double difference, robust statistics are calculated through heading prediction residual vectors to obtain robust factors, an observation noise covariance matrix is expanded to reduce the influence of system noise and observation noise, and the system performance is improved. A Mahalanobis distance based on a prediction residual vector is introduced to detect whether a system is abnormal or not, a state prediction covariance matrix is adjusted through a self-adaptive factor, weight reduction of an abnormal INS dynamic model is achieved, and the stability and reliability of system attitude information are improved through a noise covariance self-adaptive control mechanism.

The invention discloses a multi-path suppression positioning method and system for a banded sparse single Beidou CORS network, and relates to the technical field of satellite navigation positioning. According to the multi-path suppression positioning method for the banded sparse single Beidou CORS network, initial pseudo-range time sequence data are acquired, the time sequence data and regional state data are received, the pseudo-range data are corrected and analyzed, then, filtering processing is performed by using a preset filtering rule, a virtual base station is established, data fusion is performed, and the multi-path suppression positioning method for the banded sparse single Beidou CORS network is obtained. According to the method, the pseudo-range time sequence data of each satellite is dynamically corrected, and particularly, through comprehensive analysis of the reflecting surface information, the environment data and the signal arrival time difference, the accurate position information of the receiver is obtained. Errors caused by reflecting surface and environment changes can be recognized and corrected in real time, and the stability and precision of a positioning system in a complex environment are remarkably improved.

The invention discloses a multi-frequency multi-mode signal multi-path error weakening method, and relates to the technical field of precision positioning, and the method comprises the steps: constructing a multi-frequency multi-mode non-combination precision single-point positioning observation equation, separating multi-path errors in pseudo-range and phase observation values through the equation, and forming residual data; performing quality control on the residual error, and eliminating an abnormal value; feature extraction and judgment are carried out based on residual data, wherein time repeatability features, spatial distribution features and trend complexity features are extracted; selecting a correction model according to a feature judgment result, wherein the correction model comprises a fixed star daily filtering model, a multi-path hemispherical graph model and a trend surface analysis multi-path hemispherical graph model; and generating a multi-path error correction amount through a selected model, correcting an original observation value, and outputting a positioning result. The method solves the problem that the positioning precision is reduced due to multi-path errors, can effectively weaken the multi-path errors, improves the positioning precision and stability, adapts to a complex environment, and reduces data processing redundancy.

The invention discloses a GNSS (Global Navigation Satellite System) / inertial navigation tightly integrated navigation method and system based on robust auto-velocity constraint factor graph optimization, and the method specifically comprises the following steps: extracting pseudo-range and Doppler observation data from original observation information of a GNSS satellite, and obtaining accelerometer and gyroscope data from an INS (Inertial Navigation System); constructing a pseudo-range residual block, a Doppler residual block, an inertial navigation pre-integration residual block and a speed constraint factor, and integrating into a sliding window estimator based on factor graph optimization; according to the size of a set sliding window, adding all residual blocks in the window to form an optimized objective function; performing a first round of factor graph optimization to obtain a preliminary state estimation result, and endowing the observed quantity containing gross error with a relatively low weight; and updating the prior weight matrix, and carrying out second round of optimization to obtain a joint optimal estimation result of a plurality of moment states in the current time window. According to the method, the influence of gross error-containing observation information on weight estimation and state estimation is suppressed, the positioning precision is high, the robustness is strong, and the reliability is high.

The invention belongs to the technical field of time service, and relates to a Beidou time service delay processing method and device based on PPP-B2b. The method comprises the following steps: acquiring a navigation signal of a current epoch to obtain an observation value, a broadcast ephemeris and precise point positioning service information; obtaining a precision satellite position and a precision satellite clock error according to the broadcast ephemeris and the precision single-point positioning service information; forecasting to obtain a forecast value; calculating a difference value between the forecast value and the observation value, when the difference value does not exceed a preset threshold value, establishing a satellite pseudo-range and carrier phase ionosphere-free combination observation equation, establishing an antenna position constraint virtual observation equation, and performing resolving according to the combination observation equation and the virtual observation equation to obtain a receiver clock error result; and correcting the pulse per second according to a clock error result of the receiver so as to carry out delay time service. According to the invention, accurate time service can be realized, interference and environmental influence are avoided, and the convergence speed is high.

In estimating a position of a vehicle utilizing a global navigation satellite system (GNSS), it is desirable to exclude outliner GNSS measurements due to navigation signals via non-light-of-sight paths from the GNSS to the vehicle, but it leads to a distorted satellite geometry distribution. Complementariness between low-lying visual landmarks and healthy but high-elevation satellite measurements is explored to improve the geometry constraint. Measurements of an inertial measurement unit, low-lying visual landmarks captured by a forward-looking camera onboard the vehicle, and healthy but high-elevation satellite measurements are tightly-coupled integrated via sliding window optimization of system states used in a factor graph. To improve estimation performance, good initial guesses of system states are important. As such, initial guesses of velocity set and position set inside a sliding window are estimated simultaneously based on data of Doppler measurement, double-differenced (DD) pseudorange measurement and DD carrier-phase measurement as obtained in GNSS measurements.

The invention belongs to the technical field of intelligent robot navigation and positioning, and discloses an intelligent robot autonomous mapping method in a GNSS rejection environment, which comprises the following steps of: monitoring a GNSS signal state in real time, and switching to pure laser SLAM mapping when detecting that the number of available satellites, PDOP or pseudo-range residual exceeds a threshold; the method comprises the following steps: acquiring three-dimensional point cloud data, filtering and denoising, obtaining a filtered and denoised current frame point cloud, performing laser radar mapping and positioning registration, selecting a key frame point cloud, constructing lightweight neural implicit scene representation, and training an MLP network; loopback detection is carried out, a sparse factor graph is constructed, key frame poses are corrected, then the key frame poses are applied to original three-dimensional point cloud data, and a two-dimensional grid map is generated. According to the invention, under the condition that the GNSS signal is blocked or fails, the environment map with high precision and low drift is continuously generated, and the real-time performance and robustness of autonomous mapping are remarkably improved.

The invention provides a regional interference signal detection method and device based on a Beidou router, and the method comprises the steps: obtaining reference broadcast ephemeris data of a network platform and local ephemeris data received by the Beidou router, carrying out the data integrity calculation, and judging whether the local ephemeris data are missing or not; performing same-epoch data comparison on the reference broadcast ephemeris data and the local ephemeris data, and judging whether the local ephemeris data has deception signals or not; calculating a visible satellite integrity rate in a fixed time window based on the observation data of the Beidou router, and judging whether interference signals exist in the observation data or not; analyzing by utilizing the cycle slip ratio and the carrier-to-noise ratio of the observation data, and judging whether interference signals exist in the observation data or not; under the condition that local ephemeris data do not have missing and deception signals and the observation data do not have interference, whether the observation data have the deception signals or not is judged based on pseudo-range single-point positioning and inter-epoch carrier phase difference velocity measurement, and the method can improve the reliability of Beidou signal interference detection.

The invention discloses a positioning method and device based on fusion of single Beidou navigation and a high-precision RTK technology, a medium and equipment in the technical field of satellite positioning. The positioning method comprises the following steps: determining single Beidou navigation information generated by a target receiver based on a single Beidou positioning device; extracting a pseudo-range observation value and a carrier phase observation value of the B1 / B2 frequency point; extracting a satellite number, epoch time, an ionosphere delay coefficient and a troposphere delay coefficient; determining delay deviation correction data of the Beidou satellite signal; total delay deviation in the signal transmission process is measured, and whether delay deviation correction is carried out or not is judged based on the dynamic delay threshold value model and the total delay deviation in the signal transmission process; and fusing the pseudo-range observation value of the receiver and the delay deviation correction data of the Beidou satellite signal, executing double-difference carrier phase calculation, and outputting a centimeter-level positioning result. According to the method, various transmission errors can be effectively eliminated, the positioning precision is remarkably improved, and the positioning continuity and stability are ensured.

The invention discloses a high-precision positioning method based on combination of a Beidou satellite and 5G-Mesh, and relates to the technical field of satellite positioning, and the method comprises the steps: receiving a navigation signal of the Beidou satellite and a communication signal of a 5G-Mesh network in real time; the topological structure change of the 5G-Mesh network is monitored in real time, and the connection relation between the nodes is dynamically adjusted in combination with network performance indexes; the receiver performs pseudo-range measurement on the signals of the visible satellites; a navigation message is demodulated from the received satellite signal, and the accurate position of each satellite at the current moment is calculated by using a satellite orbit calculation model; constructing a signal intensity fingerprint database; outputting a reference position having the highest similarity with the current signal strength characteristic to carry out error modeling on the Beidou satellite signal and the 5G-Mesh network signal; and fusing the two kinds of position information by adopting a weighted fusion algorithm. By fusing the technical advantages of the two positioning technologies, the positioning precision and reliability are improved, and the requirement for high-precision positioning in a complex scene is met.

The invention discloses a high-precision positioning method and system based on a multi-band single Beidou signal, and the method comprises the steps: receiving a multi-band signal from a single Beidou satellite, the multi-band signal comprises three bands B1I, B1C and B2a, extracting a pseudo-range measurement value and a carrier phase measurement value of the signal of each band, and calculating the pseudo-range measurement value and the carrier phase measurement value of the signal of each band according to the pseudo-range measurement value and the carrier phase measurement value; constructing an observation value model containing multi-path errors and ionosphere delay; performing wavelet transform decomposition on the multi-band observation value sequence to obtain signal characteristics on different frequency scales, and constructing a multi-path-ionosphere coupling separation discriminator using pseudo-range and carrier phase observation value characteristic difference and a frequency dependency relationship based on a wavelet decomposition result; the error dominant type is determined according to the size of the discriminant value output by the separation discriminator, the observation value is corrected by applying a corresponding error correction strategy, the corrected observation value is used for position calculation, and a high-precision positioning result is obtained.

The invention discloses a high-precision Beidou satellite navigation and positioning data acquisition method and system, particularly relates to the technical field of satellite navigation and positioning processing, and is used for solving the problem of positioning error increase caused by receiver hardware delay drift in the prior art. Inverting the first dynamic reference value by using carrier phase integral displacement, and extracting a third-order intermodulation component through coherent demodulation to generate a second dynamic reference value; adopting mutual information entropy analysis to select an effective reference value to calculate a residual error; fitting a theoretical value according to the carrier phase change rate to calculate deviation; marking a hardware drift error when the time domain correlation continuously exceeds a threshold value; finally, the ionosphere residual error is dynamically compensated to generate a corrected observation value, effective separation of the hardware drift error and the ionosphere residual error is realized, and the precision and reliability of long-time observation in a dynamic environment are improved.

The invention relates to the technical field of radar information, in particular to a satellite clock performance evaluation method for constructing a reference time benchmark based on an inter-satellite link, which comprises the following steps of: 1, collecting GNSS inter-satellite bidirectional pseudo-range observation data, establishing a bidirectional pseudo-range observation equation, reducing to the same target moment to obtain an inter-satellite relative clock error, and calculating the inter-satellite relative clock error; reducing to a main clock on a selected main satellite to obtain a clock difference of each clock relative to the initial time reference; step 2, fitting a polynomial clock error parameter by using the accumulated satellite clock error data with a certain arc length, deducting the clock error parameter from the satellite clock error epochwise, and calculating to obtain a clock error residual error; step 3, the alron variance of each satellite clock is calculated by using the clock error residual error, the stability of each clock is evaluated, and then the weight of each satellite clock is determined; 4, constructing a space-based time reference based on the clock error residual error obtained in the step 2 and the satellite clock weight determined in the step 3; and step 5, evaluating the performance of the satellite clocks based on the clock difference of each satellite clock under the space-based time reference.

The invention discloses a satellite navigation positioning method and device based on scene recognition, electronic equipment and a storage medium, and belongs to the technical field of satellite navigation positioning, and the method comprises the steps: determining the geometric space characteristics of each satellite according to the observation time, the satellite number of each satellite and preset satellite ephemeris information; according to the observation time, the satellite pseudo-range of each satellite and the satellite distance change rate of each satellite, determining the signal quality characteristics of each satellite; determining a satellite observation feature set based on the geometric space features of the satellites and the signal quality features of the satellites; inputting the satellite observation feature set and the satellite signal-to-noise ratio of each satellite into a preset scene recognition model to generate a scene category; and determining the positioning coordinate of the satellite navigation receiver according to the scene category in combination with the satellite signal-to-noise ratio of each satellite and the satellite pseudo-range of each satellite. According to the invention, the problem that satellite navigation positioning is not accurate enough in the prior art can be solved.

Machine learning techniques are used, in one embodiment, to mitigate multipath in an L5 GNSS receiver. In one embodiment, training data is generated to provide ground truth data for excess path length (EPL) corrections for a set of received GNSS signals. A system extracts features from the set of received GNSS signals and uses the extracted features and the ground truth data to train a set of one or more neural networks that can produce EPL corrections for pseudorange measurements. The trained set of one or more neural networks can be deployed in GNSS receivers and used in the GNSS receivers to correct pseudorange measurements using EPL corrections provided by the trained set of neural networks.

The invention provides a ground positioning method and device fusing Doppler and pseudo-range of a low-orbit satellite, and the method comprises the steps: collecting pseudo-range observation values and Doppler frequency shift observation values of a plurality of epoch signals through a ground receiver in a transit time period of the low-orbit satellite by employing an enhanced link between the low-orbit satellite and the ground, and obtaining a Doppler frequency shift observation value of the multiple epoch signals; the orbital position, the running speed and the clock error of the low-orbit satellite corresponding to the epoch signal are collected; calculating the position, speed and clock error of the low-orbit satellite at the emission moment of each epoch signal; when the number of the accumulated observation equations reaches a preset threshold value, a fixed weight least square algorithm is adopted to fuse pseudo-range observation values and Doppler information to solve the position of a ground user receiving end; performing post-test residual error test on the calculation result; and if the after-test residual error test is passed, outputting a positioning result.

The invention discloses a BDS-based three-dimensional coordinate accurate positioning monitoring method and system, and belongs to the technical field of satellite navigation and positioning, and the method specifically comprises the steps: calculating a pseudo-range measurement value and a carrier phase observation value through receiving a navigation satellite signal; eliminating a multi-path effect by adopting a multi-path detection algorithm and a dynamic multi-path error model, and correcting a pseudo-range measurement value by utilizing an error source model; dynamic calibration parameters are calculated by combining real-time environment data and a preset calibration model, and the pseudo-range measurement value is recorrected; calculating the position by using a carrier phase difference algorithm, and outputting a three-dimensional coordinate and a displacement variation; according to the method, high-precision and real-time displacement monitoring is realized through comprehensive processing of a multi-path effect and dynamic calibration.

The invention provides a satellite signal transmitting method, device and equipment and a computer storage medium, and the method comprises the steps: determining a target first signal and a target satellite through signal quality evaluation parameters of a plurality of first signals received by first ground equipment, and then carrying out the transmission of a satellite signal based on a pseudo-range of the target first signal and an error correction parameter of the target satellite, calculating the downlink transmission time of the second signal, then obtaining the receiving moment when the first ground equipment receives the target first signal, calculating the theoretical emission moment of the second signal based on the receiving moment and the downlink transmission time of the second signal, and obtaining the superframe duration and the theoretical emission moment of the second signal; and calculating the first uplink transmission time delay when the second ground equipment transmits the third signal to the target satellite, and finally adjusting the actual transmission time of the third signal of the second ground equipment according to the first uplink transmission time delay, so that the actual transmission time of the third signal is aligned with the theoretical transmission time of the second signal, thereby improving the transmission success rate of the satellite signal.

The invention relates to the technical field of navigation positioning, and discloses a satellite positioning method and device based on deep learning and filter coupling driving, and a medium. Determining a coarse positioning result of the receiver based on a least square method by using an observation pseudo-range between the receiver and each satellite and a model pseudo-range between the receiver and each satellite obtained by modeling; extracting observation quality features based on a coarse positioning result; inputting the observation quality features into a noise estimation model obtained based on deep learning to obtain a measurement noise covariance matrix and a noise compensation value; determining a state vector of a filter at an initial moment based on the coarse positioning result, and updating the state vector of the filter step by step based on the measurement noise covariance matrix and the noise compensation value to obtain a state vector at a to-be-estimated moment, the state vector at the to-be-estimated moment comprising a positioning result of the receiver at the to-be-estimated moment; noise and errors in the environment can be effectively compensated, so that the influence of the noise and the errors is effectively reduced, and the accuracy of satellite positioning is improved.

The invention relates to an ephemeris broadcast and time synchronization method for Beidou pseudolite deformation monitoring, and belongs to the technical field of satellite positioning. The method comprises the following steps: constructing a linearization error equation based on a pseudo-range observation value, and solving a clock error correction amount in combination with a robust iterative algorithm to improve the time synchronization precision; analyzing ephemeris parameters of the Beidou GEO satellite, calculating earth-fixed coordinates of the Beidou GEO satellite, and rotating and adapting the earth-fixed coordinates; establishing an affine transformation relationship between the pseudo-satellite coordinates and GEO ephemeris, and generating optimized pseudo-satellite ephemeris data; and a time synchronization protocol is designed, and clock skew is compensated through bidirectional timestamp interaction of the main base station and the pseudo satellite. According to the method, nanosecond synchronization of the pseudo-satellite and the real satellite is realized, the ephemeris parameter redundancy problem of the static pseudo-satellite is optimized, multi-system cooperative work is supported, and the deformation monitoring reliability and precision under the complex terrain are remarkably improved.

The invention discloses an underwater navigation positioning method and system based on supercontinuum laser intensity correlation. The system comprises a master control system, a transmitting end underwater base station and a receiving end underwater carrier. The method comprises the following steps: firstly, a main control system generates a super-continuum laser signal with pseudo-random code information, the super-continuum laser signal is separated into optical signals of different wavelength channels through a light splitting module, and the optical signals are respectively sent to underwater base stations uniquely corresponding to the wavelength channels and are emitted; then the underwater carrier receives optical signals from a plurality of base stations, identifies a signal source base station according to wavelength identification, performs correlation operation with a locally copied pseudo-random code sequence, determines signal arrival time TOA and calculates a pseudo-range; and finally, resolving the three-dimensional coordinate and local clock error result of the underwater carrier by combining the pseudo-ranges, absolute positions and transmission delays of the underwater carrier and the at least four base stations. According to the invention, high-precision and high-robustness absolute positioning of the underwater environment is realized, and the reliability of long-time positioning and navigation of the underwater robot is enhanced.

The invention discloses a multi-vehicle cooperative positioning method based on progressive non-convex factor graph optimization, and the method comprises the steps: firstly calculating a GNSS pseudo-range error factor, an inter-vehicle distance measurement error factor and an inter-epoch constraint factor according to the collection data of a vehicle-mounted terminal GNSS sensor and a UWB distance measurement sensor; then a progressive non-convex welsch cost function is constructed, and an equivalent objective function is constructed in combination with a GNSS pseudo-range error factor, a workshop distance measurement error factor and an inter-epoch constraint factor; and finally, carrying out factor graph optimization on the equivalent objective function, solving an optimal weight and state, and outputting a global state and final weights of a GNSS pseudo-range error factor, a workshop distance measurement error factor and an inter-epoch constraint factor. According to the method, abnormal measurement values in cooperative positioning are suppressed by constructing a progressive non-convex welsch cost function, and meanwhile, multi-epoch and multi-node measurement information is fully fused by adopting a factor graph optimization architecture, so that the reliability of cooperative positioning is improved.

The invention discloses an adaptive filtering Beidou navigation and inertial navigation positioning and attitude determination method and device, and the method comprises the steps: constructing a short-baseline carrier phase and pseudo-range double-difference observation equation through BDS satellite second pulse signals received by a first BDS receiver and a second BDS receiver, and solving the short-baseline carrier phase and pseudo-range double-difference observation equation to obtain the positioning information of a carrier where a second antenna is located; assigning the positioning information of the carrier to the inertial navigation system as an initial positioning value, carrying out positioning and attitude determination on the carrier through the inertial navigation system based on the initial positioning value, and outputting the latest positioning and attitude determination information of the carrier; carrying out Kalman filtering processing on the positioning information of the carrier and the latest positioning and attitude determination information of the carrier, and outputting the optimal attitude and positioning information of the carrier; the Kalman filtering is used for adaptively adjusting noise by using a carrier state vector through innovation analysis; the state vector is constructed by using the positioning information of the carrier and the latest positioning and attitude determination information of the carrier. The problem of error accumulation in the navigation process can be effectively solved, and the positioning precision is improved.

The invention discloses a PPP / INS / vision / LIDAR tight coupling navigation method based on multi-system real-time precision service, and belongs to the technical field of navigation and positioning. In order to solve the problem of insufficient real-time positioning precision and reliability in a complex urban environment, the invention provides a hierarchical fusion architecture: firstly, by using original data of an inertial navigation system, a visual sensor and a laser radar, high-precision and high-frequency local pose estimation is generated through tight coupling factor graph optimization; the accumulative error of inertial navigation is effectively inhibited; then, taking the local attitude as observation information, and performing tight coupling factor graph optimization on the observation information, a precise orbit obtained by PPP enhanced service decoding and a GNSS original observation value after clock correction, namely a pseudo range and a carrier phase; multi-source information is deeply fused on the observation value level, the complementary advantages of the sensors are fully played, and finally continuous and reliable centimeter-level high-precision positioning in the urban complex environment is achieved.

A GNSS receiver, a method of estimating position, and an associated computer program are provided. An example method includes calculating a first (full) position solution based on pseudorange measurements made at a first time. One or more position updates are then calculated based on the first position solution, using delta carrier range measurements which compare first carrier range measurements, made at the first time, with second carrier range measurements, made at a second time. When calculating the one or more position updates, the delta carrier range measurements may be corrected to compensate for satellite motion between the first time and the second time. Corrections may also be made to compensate for changes in ionospheric delay.

The invention relates to the technical field of navigation positioning, and discloses an INS-assisted positioning system and method under a GNSS / INS positioning system, and a medium, and the system comprises a prediction pseudo-range confirmation module, a floating point solution calculation module, a first optimal fixed solution calculation module, a second optimal fixed solution calculation module, and a fusion solution module. According to the scheme, the floating point ambiguity resolving and fixing process is optimized by correcting inertial information in real time, specifically, inertial prior information is corrected by using a combined positioning high-precision result, a traditional GNSS pseudo-range estimation method is replaced, an improved partial ambiguity fixing strategy is introduced, the fixing efficiency of non-optimal subset ambiguity is improved, and the positioning accuracy of the GNSS pseudo-range estimation method is improved. According to the method, the positioning precision, the stability and the real-time performance can be remarkably improved in a complex urban environment.

The invention relates to the technical field of computers, and particularly provides a time service method and device of a low-orbit satellite, electronic equipment and a storage medium. The method comprises the following steps: acquiring a digital navigation signal, and suppressing an interference spectral line of the digital navigation signal to obtain a suppressed digital navigation signal; performing amplitude-frequency compensation on the suppressed digital navigation signal to obtain a target navigation signal; correcting the pseudo-range observation model and the carrier phase observation model of the low-orbit satellite based on an error model of precise point positioning to obtain a corrected pseudo-range observation model and a corrected carrier phase observation model; and carrying out precise point positioning calculation on the corrected pseudo-range observation model, the corrected carrier phase observation model and the navigation message of the target navigation signal to obtain clock error data of the target navigation signal, and carrying out time service on a local clock according to the clock error data.

The invention discloses a low-altitude aircraft accurate positioning method based on Beidou satellite data, and the method comprises the following steps: collecting the multi-source data of Beidou positioning, IMU, barometer and altimeter in the flight process, and generating an original positioning data set; after multi-source data are aligned, a fusion data sequence is constructed; carrying out error modeling by adopting zero offset correction, drift compensation and scale normalization, and outputting a calibrated data sequence; an improved FGO algorithm is input, factors such as Beidou satellite pseudo-range, IMU integration and process prior are processed in a combined mode, track combined optimization is executed, and a preliminary positioning result is output; performing error correction by combining a ground differential base station and satellite-based enhanced data, and outputting a high-precision positioning result sequence; and abnormal point elimination and trajectory smoothing are realized through consistency discrimination and confidence evaluation, and a final positioning result is obtained. The method improves the positioning precision and robustness of the low-altitude aircraft, and is suitable for high-precision positioning application in a complex environment.