Fast and reliable ambiguity resolution (AR) has been a continuing challenge for real-time precise positioning based on dual-frequency Global Navigation Satellite Systems (GNSS) carrier phase observation. New GNSS systems (i.e., GPS modernization, BDS (BeiDou Navigation Satellite System), GLONASS (Global Navigation Satellite System), and Galileo) will provide multiple-frequency signals. The GNSS...

The code-phase divergences, which are minimal for GPS, GLONASS, and Galileo satellites, are commonly found in BeiDou Navigation Satellite System (BDS) Geostationary Orbit (GEO), Inclined GeoSynchronous Orbit (IGSO) and Medium Earth Orbit (MEO) satellites. Several precise positioning applications which use code observations are severely affected by these code biases. We present an analysis of co...

Abstract In order to solve the problem of insufficient accuracy and reliability ship position display in AIS(Automatic Identification System) system, a federated Kalman filter is designed, an open algorithm architecture built, AIS BDS positioning information sources are selected for fusion, fusion part framework improved by IMMF covariance crossover obtain more accurate reliable target motion s...

Abstract With the networking completion of Beidou navigation satellite system (BDS-3), BDS-3 was opened in whole world on July 31, 2020. It is important practical significance to analyze performance and GPS terms common view timing comparison. In order accuracy comparison for BDS-3/GPS global time, experimental with medium long baseline carried out based algorithm by using National Metrology be...

Currently, the space segment of all five satellite systems capable providing precise time transfer services, namely BDS (including BDS-3 and BDS-2), GPS, GLONASS, Galileo, Quasi-Zenith Satellite System (QZSS), has almost been fully deployed, which will definitely benefit with satellite-based point positioning (PPP) technology. This study focuses on latest performance BDS/GPS/GLONASS/Galileo/QZS...

The linear combination of multi-frequency carrier-phase and pseudorange observations can form the combined with special properties. type number frequencies will directly affect characteristics observations. BDS-2 BDS-3 broadcast three five signals, respectively, study their is great significance for precision positioning. In this contribution, in cycles meters sorted out. Seven frequency modes ...

In this work, we consider the problem of modeling the dynamic structure of human activities in the attributes space. A video sequence is first represented in a semantic feature space, where each feature encodes the probability of occurrence of an activity attribute at a given time. A generative model, denoted the binary dynamic system (BDS), is proposed to learn both the distribution and dynami...

Defensins are generally implicated in the quick resistance of epithelial surfaces to microbials; however, recent reports have indicated that defensins also have unknown purposes in relation to noninfectious diseases. In this study, the localization patterns of anti-microbial peptides, β defensins (BDs), in the tracheal epithelium of male C3H mice under exposure to toluene were analyzed by immun...