73 results about "Cycle slip" patented technology

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 factor graph RTK positioning method based on ambiguity detection, recognition and repair, which comprises the following steps: detecting an unreliable solution by using an ambiguity domain and a state domain, recognizing possible cycle slip through forward and backward repair of window information, and finally adding a cycle slip repair factor to adjust a factor graph so as to ensure reliable and correct fixation of ambiguity. And therefore, the RTK positioning robustness in a complex environment is improved. In a complex urban environment, the method can basically realize continuous position estimation with centimeter-level precision. Besides, when the available satellites are few, the ambiguity fixing and positioning effects of the method are far better than those of the existing method, which shows that the method has better robust robust capability, and the RTK positioning capability in a complex environment is effectively improved.

The invention relates to a TDCP enhanced visual inertial odometer and a navigation positioning method thereof, the method aims at multi-sensor fusion positioning, uses an extended Kalman filter (EKF) to integrate visual features, IMU data and TDCP observation values, improves local pose estimation precision, and suppresses VIO error accumulation through absolute scale and course constraint provided by TDCP; meanwhile, the local estimation result and the global position of the GNSS are optimized and fused through a global pose map, and high-precision pose estimation which is globally consistent and within a global range is achieved. According to the method, optimization can be completed only through intermittent global positions, the problem of positioning failure of a traditional scheme in a GNSS challenge environment is solved, the problems of cycle slip accumulation and gross error interference when TDCP is independently used are effectively solved, and the method is suitable for automatic driving, unmanned aerial vehicles and other scenes with high real-time performance requirements.

The invention relates to the technical field of satellite navigation, in particular to a cycle slip detection method, device and equipment for a low-orbit navigation enhanced carrier observation value, and the method comprises the steps: constructing a first target cycle slip detection quantity and a second target cycle slip detection quantity based on a low-orbit satellite carrier phase observation value, and determining a cycle slip detection threshold value according to a low-orbit satellite high angle, and performing cycle slip detection on the low-orbit satellite carrier phase observation value according to the first target cycle slip detection quantity, the second target cycle slip detection quantity and a cycle slip detection threshold value to obtain a cycle slip detection result, and performing cycle slip marking on the low-orbit satellite carrier phase observation value according to the cycle slip detection result to obtain a cycle slip detection condition. Therefore, the problems of a large amount of misjudgment on the cycle slip of the low-orbit carrier observation value caused by the change of the ionosphere error in the carrier observation value in a short time and the like are solved, two cycle slip detection quantities are given based on the characteristic of rapid change of the ionosphere error, and the cycle slip detection threshold is determined in combination with the satellite height angle. Therefore, the low-orbit carrier cycle slip phenomenon can be accurately detected.

The invention discloses a global ionosphere modeling method based on a spherical radial basis function, and the method comprises the steps: laying Reuter grid points at an interval of 10 degrees on an ionosphere thin layer, and converting the Reuter grid points into a daily fixed geomagnetic coordinate system for modeling. Cycle slip monitoring and abnormal value identification and elimination are carried out on obtained satellite observation data (O file), then a precise satellite orbit position is obtained through interpolation in combination with a precise ephemeris file (SP3), hardware deviation is corrected through differential code deviation (DCB file), an AbBPoisson spherical surface radial basis function is adopted and converted into a 15-order truncated AbBPoisson spherical surface radial basis function, and finally, a precise satellite orbit position is obtained. The bandwidth is set to be 0.25, L2 regularization optimization is used, parameters of a radial basis function are solved through a least square method, and therefore global ionosphere modeling is carried out. Different from a traditional spherical harmonic function method, the abbeposon spherical radial basis function controls the control range of a radial base point by adjusting the bandwidth, higher precision can be provided in a data-intensive area, and the adaptability is higher.

The invention discloses a carrier phase cycle slip real-time detection and repair method of an airborne GNSS receiver, and relates to the technical field of satellite navigation and positioning. The method comprises the following steps: acquiring GNSS signal data; calculating the phase variation of adjacent epochs, and constructing a cycle slip detection model; a multi-dimensional filtering method is adopted to carry out smoothing processing on carrier phase data, and measurement noise is reduced; correcting errors by using a non-difference method and a double-difference method in combination with satellite geometric information; repairing the detected cycle slip data by adopting a prediction method based on Kalman filtering or an autoregression model; and finally, recalculating a baseline solution result, and performing quality control to ensure that the repaired GNSS data meets the high-precision positioning requirement. The method can effectively improve the positioning precision of the airborne GNSS receiver in a high dynamic environment, enhances the integrity and reliability of data, and has important engineering application value.

The invention belongs to the field of global navigation satellite system (GNSS) data processing, and particularly relates to a real-time cycle slip detection method based on ionosphere variation trend constraint, which comprises the following steps of: firstly, fitting an ionosphere variation trend by using all observation satellite data at the current moment, and selecting a non-geometric combination observation value according to a sliding window; then ionosphere variation trend constraint is applied on the basis of a polynomial function, geomagnetic latitude is used as an independent variable to fit a polynomial coefficient, the ionosphere variation of each satellite observed value at the current moment is forecasted, and then the ionosphere variation and the non-geometric combination are differentiated to obtain ambiguity variation; and finally, a detection threshold is determined through the adaptive expansion factor changing along with latitude, and the ambiguity variation is detected to judge whether cycle slip occurs or not. The method is convenient to calculate, fully considers the change trend of the ionosphere, is suitable for real-time cycle slip detection application, and is more suitable for cycle slip detection application in the ionosphere disturbance period.

The invention relates to a cycle slip detection method for observation data of a single-frequency global navigation satellite system. The cycle slip detection method comprises the following steps: acquiring the observation data of the single-frequency global navigation satellite system; calculating the phase increment of the carrier phase accumulation observation value of each satellite between adjacent epochs based on the carrier phase accumulation observation value of each satellite under the epoch sequence; based on the Doppler observation value of each satellite under the epoch sequence, performing time domain integration on the Doppler observation value of each satellite between adjacent epochs to obtain a time domain integration result; subtracting the phase increment of the carrier phase accumulation observation value of the current satellite between the current epoch and the previous epoch from the time domain integral result of the Doppler observation value of the current satellite between the current epoch and the previous epoch to obtain a deviation detection quantity; and setting a deviation detection quantity threshold, and if the deviation detection quantity of the current satellite in the current epoch is greater than the deviation detection quantity threshold, judging that the current satellite has cycle slip in the current epoch.

The invention discloses an airborne Beidou positioning method and device suitable for an extra-high voltage converter station. The method comprises the following steps: acquiring original observation data of a base station and a moving station in an extra-high voltage converter station scene, and preprocessing the original observation data to obtain preprocessed observation values; performing cycle slip detection on a carrier phase in the observation value according to a preset criterion to obtain cycle slip information; constructing a factor graph optimization model according to the preprocessed observation value and the cycle slip information; performing floating point solution on the factor graph optimization model to obtain an ambiguity floating point solution; and carrying out ambiguity fixation on the ambiguity floating point solution to obtain a high-precision ambiguity fixed solution.

The invention discloses a PPP observation quality control method fusing inter-system mutual verification and residual feedback, and belongs to the technical field of satellite navigation high-precision positioning. The method comprises the following steps: firstly, acquiring current epoch multi-system multi-frequency original observation data and corresponding prior state information; secondly, performing gross error detection and elimination on the pseudo-range observation value by adopting an RANSAC method, and constructing a pseudo-range healthy satellite subset; then, carrier phase anomaly detection and cycle slip repair are carried out based on the subset, and an inter-system mutual verification mechanism and a dynamic weight adjustment strategy are introduced to further improve the reliability of an observation value; and finally, performing PPP calculation by using the high-quality observation data subjected to multi-level verification, and outputting a steady positioning result. According to the method, the problems that in a traditional method, due to pseudo-range gross error interference, carrier phase cycle slip misjudgment or missing detection is caused, and the anomaly detection capacity is insufficient in a multi-satellite simultaneous fault scene are effectively solved, the robustness and positioning precision of PPP in a complex environment are enhanced, and technical support is provided for high-reliability GNSS application.

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 relates to a cycle slip processing method, device, equipment and medium, and the method comprises the steps: obtaining the observation error data of each satellite according to the difference between the double-difference carrier observation data of each satellite in a plurality of satellites of a target carrier frequency and the double-difference satellite-to-earth distance data of each satellite based on a current epoch and a previous epoch for a reference station and a monitoring station; the receiver clock drift deviation between the base station and the monitoring station is estimated based on the observation error data of the two first satellites, clock drift deviation data is obtained, and the two first satellites are the two satellites with the minimum observation error data difference value in the multiple satellites; and on the basis of the double-difference carrier observation data of a second satellite in the plurality of satellites, subtracting the double-difference satellite-ground distance data and the clock drift deviation data of the second satellite, and determining single-difference ambiguity incremental data so as to perform single-frequency cycle slip processing on the target carrier frequency of the current epoch on the base station and the monitoring station. According to the invention, single-frequency cycle slip processing can be efficiently and jointly carried out on double stations without the help of an external sensor.

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.

This application discloses an adaptive carrier phase smoothing pseudorange method and apparatus, which smooths the pseudorange of all frequency points in a simple and practical way. As long as there is a continuous carrier without cycle slip at any frequency point, pseudorange smoothing can continue without resetting the filter, so that the pseudorange before and after the positioning frequency point switching is smoothed, improving the smoothing accuracy. Furthermore, using a carrier of any frequency point to smooth the pseudorange of all frequency points reduces the large error caused by the positioning frequency point switching.

The invention belongs to the technical field of GNSS precise point positioning cycle slip detection, and discloses a DI-based adaptive GF cycle slip detection threshold model method, and the method comprises the steps: obtaining IGS tracking station data during an extra-large magnetic storm; preprocessing the data, and calculating an inter-epoch difference GF value and a DI value; obtaining 99.7 percentile in each interval section according to a 3 sigma criterion by using distribution of a time domain difference GF value and a DI value; performing quadratic polynomial fitting on the percentile to obtain a final threshold model; the GF adaptive threshold model based on the DI avoids the limitation that the ROTI is influenced by cycle slip, and effectively solves the problem of false detection.

The application provides a phase difference data processing method and system based on dual-polarized GNSS occultation, comprising: obtaining a low-orbit satellite orbit through precise orbit determination of LEO observation data and positioning auxiliary data; calculating atmospheric additional phase data of H channel and V channel based on the low-orbit satellite orbit and time-registered phase data, and performing geometric co-registration to determine the space-time position of the occultation event; constructing polarized phase difference according to the geometric co-registered phase data to obtain phase difference data, and repairing phase difference cycle slip according to the phase difference data; and performing data processing on the cycle slip repaired differential phase sequence to output phase difference products. The application can suppress clock and geometric residual, eliminate phase breaks caused by half / integer cycle slip and open / closed loop conversion, and correct phase difference, thereby outputting stable and consistent differential phase observable.

The application discloses a water surface elevation inversion method based on Beidou TDCP difference, and particularly relates to the field of satellite navigation and positioning, and is used for solving the discontinuity of water surface elevation inversion chain caused by the coupling of cycle slip and attitude distortion under high sea conditions of a mobile platform; through synchronous acquisition of direct carrier phase observation data, reflected carrier phase observation data and inertial high-frequency attitude data and construction of a multi-source synchronous observation data set, cycle slip detection is performed on the carrier phase observation data, and the ambiguity at the breakpoint is reserved as a brand-new unknown parameter in the observation equation, then the structure harmonic deformation kinetic energy equivalent, non-line-of-sight multipath phase divergence rate and rigid-flexible physical fidelity coefficient are jointly generated to obtain vertical displacement feedforward compensation, and finally, the time delay difference observation equation is constructed and the real-time water surface elevation is solved.

An embodiment of the present invention relates to a method and device for filtering pseudorange observations. The method includes: for any frequency point, when it is determined that there is no cycle slip phenomenon at epoch t, determining an initial ionospheric residual at epoch t and a first error of the initial ionospheric residual at epoch t; obtaining n fitted ionospheric residuals according to the n initial ionospheric residuals at n epochs and the time difference between any epoch and the first epoch among the n epochs; determining a second error of the fitted ionospheric residual at epoch t according to the n initial ionospheric residuals and the n fitted ionospheric residuals; judging whether the relationship between the second error and the first error satisfies a first preset condition, and if so, filtering the pseudorange observation at epoch t based on the fitted ionospheric residual at epoch t. Filtering the pseudorange observation at epoch t based on the more accurate fitted ionospheric residual at epoch t improves the accuracy of the pseudorange observation and the navigation and positioning accuracy.

The invention is suitable for the field of satellite navigation signal processing, and provides a low-orbit satellite satellite-borne GPS cycle slip detection method, which comprises the following steps: acquiring observation value data of a low-orbit satellite satellite-borne GPS, and calculating an MW combination wide lane ambiguity value of the satellite-borne GPS; an IAO algorithm is adopted to optimize the set average number of times and the noise standard deviation of the ICEEMDAN algorithm; decomposing the wide lane ambiguity value into a plurality of intrinsic mode function (IMF) components and a residual component by adopting an optimized ICEEMDAN algorithm; a permutation entropy algorithm is adopted to calculate permutation entropy values of all the IMF components, the IMF components needing to be denoised are screened out, and the IMF components needing to be denoised are denoised in combination with a wavelet threshold denoising method; and performing signal reconstruction on the IMF component which is denoised by the wavelet threshold denoising method and the IMF component which does not need to be denoised to obtain denoised wide lane ambiguity, calculating the difference value of the denoised wide lane ambiguity between the current epoch and the adjacent epoch, and judging whether cycle slip exists or not according to a preset threshold. According to the method, the cycle slip detection accuracy and reliability of the low-orbit satellite in a high-dynamic and strong-noise environment are remarkably improved, and the misjudgment rate and the missed judgment rate are reduced.

This invention discloses a method for extracting ionospheric scintillation factors based on DORIS dual-frequency observations, belonging to the field of space weather monitoring and satellite navigation technology. By constructing a cycle slip detection and low elevation angle control method suitable for the DORIS system, the RODTI (Rate of Change in Total Electron Content) factor of the ionosphere is extracted. A two-dimensional grid background field of ROTI is constructed using GPS observation data from IGS stations, achieving spatiotemporal matching between DORIS and GPS scintillation factors. Furthermore, a support vector regression method considering latitudinal constraints is introduced to normalize and correct the RODTI amplitude, solving the problem of inconsistent scintillation factor amplitudes between different observation systems. This yields a more accurate RODTI with amplitudes consistent with ROTI, thus forming a complete method for extracting ionospheric scintillation factors based on DORIS dual-frequency observations. This method can reliably reflect the spatiotemporal distribution characteristics of ionospheric scintillation on a global scale, providing a new data source for constructing a multi-source ionospheric scintillation dense monitoring network covering oceans, polar regions, and other areas, and has broad applicability.

The invention relates to the technical field of global navigation satellite system data processing, and discloses a GARCH-based GNSS cycle slip detection threshold real-time determination method, which comprises the following steps: acquiring GNSS double-frequency observation data, constructing a Morse-Wiberner and geometric distance-free combination observation value, and carrying out differential processing to obtain a noise time sequence. Secondly, traversal calculation is carried out based on an akaike information criterion, and the optimal order and the sliding window length of the GARCH model are determined; then, a current epoch condition standard deviation is predicted using the model, and a multiple factor is adjusted in combination with an environmental state to construct a dynamic detection threshold. And finally, comparing an absolute value of the noise sequence with a threshold value to judge a cycle slip, and calculating an integer solution by constructing an observation equation to complete repair. According to the method, the heterovariance characteristic of the observation noise is modeled by using the GARCH model, so that the adaptive adjustment of the detection threshold along with the environmental noise level is realized, the misjudgment rate in a complex environment is effectively reduced, and the detection accuracy is improved.

The invention relates to the technical field of satellite navigation signal processing, in particular to an LSTM-GF combined adaptive threshold cycle slip detection method, which comprises the following steps: firstly, constructing a GF combined sequence through GNSS carrier phase observation data, and carrying out first-order difference on the sequence to obtain a GF combined cycle slip detection threshold delta GF; then, a predicted TEC fluctuation intensity coefficient value TECVariation is obtained by using an LSTM (Long Short Term Memory) prediction model and inputting a historical TEC sequence value; and finally, constraining a TEC fluctuation intensity coefficient value by using an adjustment coefficient alpha, carrying out weighted average on the GF combination detection threshold value and the TEC fluctuation coefficient value to obtain an adaptive threshold value LGFt of the LSTM-GF combination, if delta GFt is greater than LGFt, determining that cycle slip occurs, and otherwise, determining that cycle slip does not exist. According to the invention, the accuracy of GNSS cycle slip detection of the GF combination under the condition that the ionosphere is active can be improved, and the false detection rate is reduced.

The application provides an ionosphere model parameter and differential code bias estimation method and device, comprising: reading observation files and ephemeris files for single point positioning, marking complete arc segments according to observation value continuity and cycle slip detection, performing carrier phase smoothing pseudo-range on continuous observation values in the complete arc segments, and calculating ionosphere slant delay; projecting the ionosphere slant delay to ionosphere vertical delay through a projection function; fitting the regional ionosphere through an ionosphere polynomial model; establishing an error equation according to the projected ionosphere vertical delay and the estimated ionosphere vertical delay value obtained through fitting, obtaining initial ionosphere model parameters and differential code bias; and obtaining robust estimation ionosphere model parameter estimation and differential code bias estimation through a robust estimation algorithm. The application improves the detection and control of observation data quality, reduces the interference of abnormal values on the results, and ensures the stability and accuracy of ionosphere estimation.

The invention relates to a fast convergence satellite clock error resolving method under regional station distribution, which belongs to the field of satellite navigation, and comprises the following steps: in a regional monitoring network, constructing a normal equation by using an ionosphere-free combination pseudo range and a carrier phase by using a known precise orbit and a station coordinate; in the Kalman filtering stage, covariance forecasting is carried out on satellite clock correction, receiver clock correction and troposphere delay, cycle slip detection and covariance forecasting are carried out on ambiguity, when the ambiguity has no cycle slip and converges, the forecasting covariance is reset to be a minimum value so as to apply reinforced constraint, and the reinitialization time is remarkably compressed; performing parameter estimation to obtain an optimal value and a pseudo-range post-test residual error; the satellite clock error constant deviation is calculated through multi-station multi-epoch residual errors in a combined mode, and the satellite clock error constant deviation is fused into the original code deviation to form extended code deviation parameter broadcasting; the user side only needs to add the extension correction in the pseudo-range observation value to realize instantaneous centimeter-level positioning. According to the invention, high-precision and high-availability real-time precise single-point positioning service under the regional network condition is realized.

The present invention belongs to the technical field of ocean surveying, and discloses a method and system for attitude correction of an ocean buoy observation carrier based on multi-antenna Beidou. The method includes obtaining Beidou observation data of four Beidou receiver antennas on the buoy; after data preprocessing, eliminating gross errors and detecting cycle slips, adopting the kinematic differential mode to perform high-precision dynamic baseline vector solution to obtain the baseline vector values between the four Beidou receiver antennas; through prior constraint of baseline length and dynamic unconstrained network adjustment solution, detecting and weakening the gross error results in the baseline vectors to obtain the independent baseline vector results of the four Beidou receiver antennas; using the baseline vectors calculated in real time to obtain the current real-time attitude results; after performing buoy attitude correction based on the physical parameters of the buoy, obtaining precise buoy geodetic height observation results. The present invention improves the applicability and accuracy of ocean buoys under harsh sea conditions.

This invention discloses a satellite navigation enhancement method and system based on inertial navigation data. To address the problems of slow convergence, frequent cycle slips, easy loss of fixed solutions, and discontinuous or abrupt navigation outputs in real-time dynamic differential positioning and precise single-point positioning under highly dynamic and complex obstruction environments, this invention aligns the inertial measurement unit data with carrier phase and Doppler observation data in time, constructs a continuous-time state trajectory, establishes a Gaussian process prior, and performs tight-coupled joint estimation of trajectory state and carrier phase integer ambiguity within a sliding time window. Based on the carrier phase residual, it performs change point detection to determine cycle slips, triggers ambiguity reset, and performs re-initialization constraints based on inertial prediction state and uncertainty to complete the update estimation. This achieves the technical effects of robust cycle slip detection and rapid recovery, improved fixed solution preservation capability and switching smoothness, and enhanced continuity and stability of navigation solutions.

The present application relates to the technical field of satellite navigation signal processing, and particularly relates to a non-continuous epoch cycle slip detection method, comprising collecting observation data; judging whether the observation data produces an inter-epoch cycle slip, if the observation data produces an inter-epoch cycle slip, then executing the next step, otherwise performing sampling separation; interrupting the counting of the epochs of the observation data losing lock to obtain the lock loss time; using a data processing software to perform sampling separation on the observation data to obtain a sampling interval; judging whether the inter-epoch interval of the observation data or the lock loss time is greater than 1s, if the inter-epoch interval of the observation data or the lock loss time is greater than 1s, then executing the next step, otherwise performing multiple difference detection; using the sampling interval to use the Lagrange interpolation method to perform interpolation on the observation data to construct high sampling rate data; using the high difference method to perform multiple difference detection on the observation data or the high sampling rate data to judge whether there is a non-continuous epoch cycle slip, and obtaining a detection result, thereby solving the problem that the existing cycle slip processing method cannot detect non-continuous epoch cycle slip.

The invention discloses a pseudo-range multipath error processing method, which comprises the following steps: receiving an observation sequence sent by a satellite navigation system, carrying out cycle slip detection on an original carrier phase observation value sequence in the observation sequence, obtaining a cycle slip detection result, obtaining a carrier phase sequence and a pseudo-range sequence from the observation sequence based on the cycle slip detection result, and sending the pseudo-range multipath error to the satellite navigation system. The method comprises the following steps: acquiring a carrier phase sequence and a pseudo-range sequence, acquiring a CMCD sequence based on the carrier phase sequence and the pseudo-range sequence, acquiring a pseudo-range multi-path error estimator sequence, constructing a pseudo-range multi-path error measurement coefficient and a pseudo-range multi-path error significant detection quantity based on the CMCD sequence and the pseudo-range multi-path error estimator sequence, and determining the pseudo-range multi-path error according to the pseudo-range multi-path error significant detection quantity. And when it is detected that the pseudo-range multi-path effect is significant, dynamically adjusting the variance of the pseudo-range observation value in the pseudo-range sequence based on the pseudo-range multi-path error measurement coefficient so as to suppress the pseudo-range multi-path error. According to the method, pseudo-range multipath errors can be suppressed, the method can adapt to low-cost chip sets and dynamic positioning requirements, and the cost-benefit ratio is relatively high.

This invention belongs to the field of multi-source fusion navigation, specifically designing a combined navigation method of precise single-point positioning and lidar, further enhancing the stability and reliability of navigation and positioning. The method utilizes the high-precision positioning results of lidar to construct a cycle slip detection model, assisting in correcting cycle slips caused by precise single-point positioning observations after satellite signal interruption, thus achieving rapid convergence and improving the reliability of positioning in autonomous driving systems. Addressing the problem of map overlap and positioning drift caused by lidar tracking failures in similar scenarios such as tunnels and long corridors, the method employs topological road network information to establish backend constraints and a relocation method based on point cloud SC description to achieve map repair and positioning correction functions, respectively. For the error accumulation phenomenon of lidar SLAM in large outdoor scenes, the method uses PPP calculation results to provide an initial position for lidar scanning and matching to correct accumulated errors.

The invention relates to a time sequence RTK / INS (Real Time Kinematic / Inertial Navigation System) integrated navigation method based on double differences between GNSS epochs, and belongs to the technical field of navigation positioning and integrated navigation. The method comprises the following steps: performing single-point positioning and error correction on GNSS original observation data, and constructing an inter-epoch double-difference observation value; carrying out Lie group / manifold space pre-integration on IMU data, estimating a carrier state and assisting cycle slip detection; and finally, based on a factor graph optimization framework, fusing various constraint factors for modeling and solving, checking fixed integer ambiguity through an LAMBDA method and Ratio, and performing feedback optimization. According to the invention, centimeter-level high-precision relative positioning can be realized, and the continuity, robustness and calculation precision of positioning in a complex environment can be improved.