12 results about "Cycle slip" patented technology

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 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.

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.

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.

A method for GNSS cycle slip repair and navigation accuracy improvement under ionospheric inhomogeneity conditions includes: acquiring and preprocessing GNSS observation data to obtain an observation sequence; calculating, based on the observation sequence, observations including wide-lane (MW) combined observations, geometrically neutral (GF) combined observations, total electron content along the slant path, and the rate of change of total ionospheric electron content; using a static parameter transfer method, making a preliminary determination of cycle slips by comparing the difference between the MW combined observations of the current epoch and the previous epoch with a preset MW threshold; constructing a GF combined cycle slip detection and repair model based on the GF geometrically neutral (GF) combined observations, their difference components, and the rate of change of total ionospheric electron content; dynamically planning the GF cycle slip detection threshold using the GF combined cycle slip detection and repair model; and performing cycle slip detection and repair based on the preliminary determination and the GF cycle slip detection threshold. This invention reduces the false alarm cycle slip incidence under strong ionospheric disturbance conditions.

This invention belongs to the interdisciplinary field of wireless positioning and deep learning, and discloses a UWB and BeiDou fusion positioning method and system based on deep learning. The method includes: a dual-source signal preprocessing step, which performs non-line-of-sight error detection and compensation on the UWB ranging signal and multipath suppression and cycle slip repair on the BeiDou pseudorange signal; a graph attention network base station topology modeling step, which constructs the base station as a graph structure and outputs the confidence weights of each ranging link through the graph attention network; an attention mechanism-driven adaptive fusion step, which uses a multi-head attention network to dynamically calculate the fusion weights of the dual-source signals; a long short-term memory network trajectory prediction and backtracking smoothing step, which maintains positioning continuity when the signal fails and corrects the accumulated error after recovery; and a closed-loop optimization step, which updates the model parameters based on the positioning residual feedback.

This invention relates to the field of satellite navigation and positioning technology, specifically to a generalized multi-combination cycle slip detection method for ionospheric preprocessing in LEO enhanced GNSS-PPP. It utilizes STK software to establish a GPS / BDS / LEO hybrid constellation and generates simulated observations of dual-frequency pseudorange and carrier phase by importing precise IGS products. A non-integral spherical harmonic function model is used for ionospheric delay correction. The corrected multi-frequency observations are then linearly combined, and geometric and clock error terms are eliminated through constraints. The optimal combination coefficients are solved using the least squares method, and a system of equations is constructed using two sets of different coefficients. The dual-frequency cycle slip values ​​are calculated through epoch-time difference decomposition. Finally, cycle slips are detected and carrier phase observations are corrected based on threshold criteria. This invention effectively solves the problem of missed detections and false alarms caused by the strong coupling between ionospheric errors and cycle slips in high-dynamic LEO scenarios using traditional methods, significantly improving the reliability of cycle slip detection and positioning accuracy.

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.

The application provides a kind of integrated navigation deep coupling carrier phase quality control and adaptive robustness method, comprising: for the complex situation of frequent discontinuous scene download wave phase precision difference, tracking discontinuous, and carrier phase tracking unstable cycle slip, respectively through carrier phase prediction and cycle slip detection method, effectively improve the carrier phase observation value quality of deep integrated receiver.For the observation quality of GNSS is susceptible to interference and the error divergence performance of INS, using improved adaptive robustness Kalman filtering algorithm, effectively improve the integrated navigation positioning precision.The application effectively weakens the influence of abnormal model deviation and abnormal value, improves the positioning precision of integrated navigation system.

This invention provides a method and system for adaptive RAIM (Rapid Interference Detection and Interference Assist) for low-Earth orbit (LEO) GNSS satellites. It requires no hardware modification and acquires data synchronously via a primary and backup dual-machine setup. It employs incremental statistical algorithms to achieve multi-feature dynamic threshold early warning; performs fine-grained detection of cycle slips, multi-frequency variations, and Doppler consistency in the observation domain; isolates faulty satellites using sliding window adaptive RAIM; introduces rigid constraints on orbital dynamics to ensure solution integrity; performs tiered handling based on comprehensive interference confidence; and autonomously switches to orbit extrapolation mode for seamless overflight in the event of severe interference, while also possessing global baseline adaptive calibration capabilities. The advantages of this invention include low resource consumption, rapid response, long-term stable operation, and onboard autonomous closed-loop handling capabilities, effectively ensuring the navigation safety of LEO satellites in complex electromagnetic environments.

A method and device for reducing cycle slip misjudgment during ionospheric scintillation in high latitude regions are proposed, which belongs to the field of space weather monitoring and satellite navigation technology. By analyzing the variation law between the total electron content rate of change index and the cycle slip detection value, it is found that the fluctuation range of the detection value increases with the increase of ROTI within a certain range. Based on this finding, a regional threshold model is proposed, which selects a fixed threshold under low scintillation conditions and constructs an adaptive cycle slip threshold detection model by quadratic fitting according to the relationship between ROTI and detection value under strong scintillation conditions. Then the model is verified by using continuous annual GNSS data of multiple high latitude stations. The proposed regional adaptive threshold model shows good stability and applicability under different intensity of ionospheric disturbances, effectively improving the accuracy and reliability of precise point positioning in high latitude regions.