Outliers and multipath effects significantly affect the positioning accuracy reliability of global navigation satellite system (GNSS), which must be handled properly in real-time kinematic (RTK) positioning, especially for low-cost devices. In this study, an extended robust estimation method (EIGG3) considering is proposed RTK positioning. The carrier-to-noise power density ratio (C/N0) template function introduced, then shrinking factor bifactor equivalent weight proposed, where one...

Abstract The Wide-Lane (WL) and Narrow-Lane (NL) Uncalibrated Phase Delays (UPDs) are the prerequisites in traditional Precise Point Positioning (PPP) Ambiguity Resolution (AR). As generation mechanism of various biases becomes more complex, we systematically studied impact factors four satellite systems WL NL UPDs from perspective parameter estimation. Approximately 100 stations a global network used to generate UPDs. results different show that estimation method, update frequency, solution...

Multipath is a major source of unmodeled errors that will hinder high-precision and high-reliability positioning, navigation, timing (PNT) in the global navigation satellite system (GNSS). Traditional methods mainly focus on how well to model multipath effects; little attention has been paid reliability corrections, which may have abnormal values, especially under complex observation conditions. In this article, robust pseudorange carrier phase hemispherical map (MHM) considering uncertainty...

The satellite clock prediction is crucial to support real-time global precise positioning services. Currently, the for Chinese BeiDou navigation system (BDS) still challenging satisfy applications. Based on exploration of existing models, an improved model combing spectrum analysis (SAM) and least-squares support-vector machine (LS-SVM) proposed especially BDS-2/3 satellites. Considering satellite-specific characteristics, parameters LS-SVM method are optimized by satellite, including input...

Although there are already several real-time precise positioning service providers, unfortunately, not all users can use the correction information due to either cost of and limitation their equipment or out coverage. An alternative way is enhance accuracy predicted satellite clocks for positioning. Based on study existing prediction models, an improved model combing spectrum analysis (SA) generalized regression neural network (GRNN) proposed especially BeiDou navigation system (BDS)-2...

To keep the global navigation satellite system functional during extreme conditions, it is a trend to employ autonomous technology with inter-satellite link. As in newly built BeiDou (BDS-3) equipped Ka-band links, every individual has ability of communicating and measuring distances among each other. The also less dependence on ground stations improved performance. Because huge amount measurement data, centralized data processing algorithm for orbit determination suggested be replaced by...

The BeiDou Global Navigation Satellite System (BDS), including the second generation (BDS-2) and third (BDS-3), has been widely used in areas of positioning, navigation, timing (PNT). One essential prerequisites for accurate PNT service is precise satellite orbits multi-frequency multi-constellation BDS-2 BDS-3 satellites. As usual, orbit products can be obtained from analysis centers (ACs) international GNSS Service (IGS). also downloaded Monitoring Assessment (iGMAS). Compared with IGS...

Global Navigation Satellite System-Acoustic (GNSS-A) technology has been widely used in ocean engineering and environmental science. Accurate sound travel time modeling is essential for GNSS-A seafloor positioning. Currently, half of the two-way (TWTT) as an approximation one-way (OWTT). In this work, error approximate OWTT investigated under different survey configurations, a sequential positioning method using extended Kalman filter (EKF) developed to investigate impact modeling....

Abstract In complex environments, signals are inevitably subject to phenomena such as reflection, refraction, diffraction, and obstruction, which result in significant unmodeled errors like colored noise, residual systematic errors, other special outliers. Consequently, the achievement of high-precise high-reliable Global Navigation Satellite Systems (GNSS) Precise Point Positioning (PPP) is not a readily solvable problem especially varying terrain topography. This paper proposed resilient...

The traditional satellite orbit determination system, which depends on ground stations and estimates every satellitepsilas states separately, can not meet the requirement of autonomous navigation system. To solve this problem, method semi-autonomous for whole constellation by using intersatellite crosslink a few activated stochastically was proposed. After establishing dynamic state equation, observations equation filtering model, flow simulation designed. And result verified that reduce...

For the purpose of further improving solution accuracies orbital and geodetic parameters for BDS (BeiDou Navigation Satellite System) precise applications, this paper focuses on enhancements antenna phase center offsets (PCOs) BDS-2 IGSOs (Inclined Geosynchronous Orbits) MEOs (Medium Earth through processing observations from a global tracking network. The daily estimated horizontal vertical PCO time series nearly three years DOY (Day Year) 001 in 2018 to 180 2020 are obtained using PANDA...

The tracking accuracy of a traditional Frequency Lock Loop (FLL) decreases significantly in complex environment, thus reducing the overall performance satellite receiver. In order to ensure high receiver this paper proposes new loop combining vector FLL (VFLL) with robust least squares method, which accurately matches weights received signals different qualities positioning accuracy. are selected at signal level, not observation level. paper, ranges strong and weak determined according...

The construction of underwater geodetic networks (UGN) is crucial in marine geodesy. To provide high-precision kinematic positioning for submersibles, an acoustic network configuration three seafloor base stations, one subsurface buoy, and sea surface buoy proposed. simulation results show that, a 3 km-deep sea, based on the proposed UGN, submersible range accuracy are primarily affected by size station array, while height has greater impact than range. Considering current ranging...

To keep the global navigation satellite system functional during extreme conditions, it is a trend to employ autonomous technology with inter-satellite link. As in newly built BeiDou (BDS-3) equipped Ka-band links, every individual has ability of communicating and measuring distances among each other. The also less dependence on ground stations improved performance. Because huge amount measurement data, centralized data processing algorithm for orbit determination suggested be replaced by...

Sea level monitoring is particularly important in coastal areas that are vulnerable to marine disasters. It was recently demonstrated the global navigation satellite system multipath reflectometry (GNSS-MR) technique, which uses signals reflected from sea, can be applied determine sea level. However, this approach does not provide sufficient accuracy or equally spaced sampling meet actual requirements for certain stations. To solve deficiency of traditional GNSS-MR least squares method,...