AbstractAs China's BeiDou Navigation Satellite System (BDS) has become operational in the Asia-Pacific region, it is important to demonstrate capabilities that a combination of GPS, BDS and GLONASS high-precision positioning. Multi-constellation increases available satellites thus improves positioning reliability. However at same time, will bring some challenges high-dimension ambiguity resolution (AR). In this contribution, GPS/BDS/GLONASS combined real time kinematic (RTK) method for...

Due to the massive multipath effects and non-line-of-sight (NLOS) signal receptions, accuracy reliability of GNSS positioning solution can be severely degraded in a highly urbanized area, which has negative impact on performance GNSS/INS integrated navigation. Therefore, this paper proposes multipath/NLOS detection method based K-means clustering algorithm for vehicle positioning. It comprehensively considers different feature parameters derived from raw observations, such as...

Currently, the integration of Global Navigation Satellite System (GNSS), Ultra-Wideband (UWB), and Inertial (INS) has become a reliable positioning method for outdoor dynamic vehicular airborne applications, enabling high-precision continuous in complex environments. However, environmental interference limitations single sources pose challenges. Especially areas with limited access to satellites UWB base stations, loosely coupled frameworks GNSS/INS UWB/INS are insufficient support robust...

An inter-system differencing model between two Global Navigation Satellite Systems (GNSS) enables only one reference satellite for all observations. If the associated differential biases (DISBs) are priori known, double-differenced (DD) ambiguities overlapping frequencies from different GNSS constellations can also be fixed to integers. This provide more redundancies observation model, and thus will beneficial ambiguity resolution (AR) real-time kinematic (RTK) positioning. However,...

The regional constellation of the BeiDou navigation satellite system (BDS) has been providing continuous positioning, and timing services since 27 December 2012, covering China surrounding area. Real-time kinematic (RTK) positioning with combined BDS GPS observations is feasible. Besides, all satellites can transmit triple-frequency signals. Using advantages multi-pseudorange carrier from multi-systems multi-frequencies expected to be much benefit for ambiguity resolution (AR). We propose an...

The distribution of total electron content (TEC) in the ionosphere is irregular and complex, it hard to model accurately. polynomial (POLY) used extensively for regional modeling two-dimensional space. However, active period ionosphere, POLY difficult reflect variation TEC. Aiming at limitation model, this paper proposes a new method with combining support vector machine (SVM) regression model. Firstly, established using observations continuously operating reference stations (CORS). Then SVM...

Real-time dynamic displacement and spectral response on the midspan of Jiangyin Bridge were calculated using Global Navigation Satellite System (GNSS) a speedometer for purpose understanding behavior temporal evolution bridge structure. Considering that GNSS measurement noise is large velocity/acceleration sensors cannot measure low-frequency displacement, Variational Mode Decomposition (VMD) algorithm was used to extract GNSS. Then, extracted from time series high-frequency vibration by...

Traditional Simultaneous Localization and Mapping (SLAM) (with loop closure detection), or Visual Odometry (VO) (without are based on the static environment assumption. When working in dynamic environments, they perform poorly whether using direct methods indirect (feature points methods). In this paper, Dynamic-DSO which is a semantic monocular visual odometry DSO (Direct Sparse Odometry) proposed. The proposed system completely implemented with method, different from most current systems...

This study presents a LiDAR-Visual-Inertial Odometry (LVIO) based on optimized visual point-line features, which can effectively compensate for the limitations of single sensor in real-time localization and mapping. Firstly, an improved line feature extraction scale space constraint matching strategy, using least square method, is proposed to provide richer front-end LVIO. Secondly, multi-frame LiDAR point clouds were projected into frame depth correlation. Thirdly, initial estimation...

Precise and reliable pose estimation is a critical requirement for autonomous system. In recent years, light detection range (LiDAR)-inertial odometry (LIO) has made significant advancements, especially in challenging environments with varying illumination other complexities. However, LIO systems known to local navigation, there can be problem of error accumulation over time, particularly global navigation satellite system (GNSS)-denied or the absence prior maps. Therefore, integrating...

Pseudo-satellite technology has excellent compatibility with the BDS satellite navigation system in terms of signal systems. It can serve as a stable and reliable positioning source signal-blocking environments. User terminals achieve continuous high-precision both indoors outdoors without any modification to module. As result, pseudo-satellite indoor gradually emerged research hotspot field. However, due complex variable radio propagation environment, is interfered by noise, multipath,...

In the conventional PPP-RTK mode, platform and users act only as generator utilizer of ionospheric corrections, respectively. sparse reference station networks or regions with an active ionosphere, high-precision modeling still faces challenges. This study utilizes concept crowdsourcing treats dynamic stations. By continuously feeding back information to platform, high-spatial-resolution is achieved. Additionally, weight factors related user positions are incorporated into polynomial models...

Light detection and ranging (LiDAR) has the advantage of simultaneous localization mapping with high precision, making it one important sensors for intelligent robotics navigation, positioning, perception. It is common knowledge that random measurement error global navigation satellite system (GNSS) observations usually considered to be closely related elevation angle factor. However, in LiDAR point cloud feature matching positioning model, analysis factors affecting unsophisticated, which...

The Beidou Navigation Satellite System (BDS), also known as Beidou, is an independently developed global satellite navigation system by China, and it the third mature following GPS GLONASS. BDS, along with GPS, GLONASS, GALILEO, recognized United Nations Committee on Global Systems a supplier. Comprising of space, ground, user segments, provides all-weather, all-time, high-precision positioning, navigation, timing services to users worldwide, unique short message communication capabilities....

<title>Abstract</title> <bold>OBJECTIVE </bold>To compare the clinical efficacy and safety of two posterior minimally invasive surgeries using percutaneous interlaminar approach: Delta large-channel endoscopic discectomy(DLED) versus Unilateral biportal discectomy(UBED) in treatment lumbar disc herniation(LDH). <bold>METHODS </bold>A retrospective analysis was conducted on 74 LDH patients treated with DLED(39 cases) UBED(35 from January 2023 to 2024. Observe operation time, number...

To address the challenge of optimizing layout pseudolite anchor points in complex indoor environments with significant occlusions, this paper proposes a multi-objective particle swarm optimization algorithm (MG-MOPSO). The leverages minimum geometric dilution precision (GDOP) configuration to optimize deployment, aiming meet high-precision requirements positioning systems. Experimental results show that compared standard MOPSO, MG-MOPSO improves convergence speed two objective functions by...