A5040505526- GNSS positioning and interference
- Advanced Frequency and Time Standards
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Atomic and Subatomic Physics Research
- Inertial Sensor and Navigation
- Network Time Synchronization Technologies
- Embedded Systems Design Techniques
- Target Tracking and Data Fusion in Sensor Networks
- Scientific Measurement and Uncertainty Evaluation
- Indoor and Outdoor Localization Technologies
- Advancements in PLL and VCO Technologies
- Astronomical Observations and Instrumentation
National University of Defense Technology
2019-2024
Abstract A new Precise Point Positioning (PPP) service, called the PPP-B2b has been implemented in BeiDou-3 Navigation Satellite System (BDS-3), which brings opportunities for time transfer. However, solution using traditional PPP method with correction still absorbs some unknown errors and needs reconverging when there exist abnormal data. We developed a receiver clock model to improve transfer correction. The transfers BDS-3, Global (GPS), BDS-3/GPS (Scheme1) are compared corresponding...
Abstract The third phase of BeiDou navigation satellite system (BDS-3) was officially commissioned on 31 July 2020. In this study, we make a comprehensive evaluation BDS-3 time transfer with the B1I, B3I, B1C and B2a measurements. multi-path (MP) errors noises different ranging signals are analyzed to illustrate characteristic code observations firstly. Then dual-frequency ionosphere-free linear combinations B1I&B3I B1C&B2a measurements used achieve transfer. Using Multi-GNSS...
2020 saw the official completion of BDS-3 and start PPP-B2b signal-based real-time precise point positioning (PPP) service to users in China neighboring areas. In this work, quality products is first evaluated compared with from CNES differential code bias (DCB) Chinese Academy Science (CAS). Then, a detailed performance evaluation PPP time transfer based on (B2b-RTPPP) conducted. Three solutions, namely, GPS-only (G), BDS-3-only (C), GPS + (GC) B2b-RTPPP are assessed. The results suggest...
The precise point positioning (PPP) technique has been widely used for remote time and frequency transfer. With the development of multiple global navigation satellite system (multi-GNSS), PPP with multi-GNSS studied in order to improve performance However, day boundary problem, model correction residuals, noise may affect clock estimation PPP. In this study, we refine receiver parameter using a stochastic an atomic solve these problems. First, modeling method is proposed reduce additional...
  The precise point positioning (PPP) timing service has been proposed in recent years and demonstrated to achieve sub-nanosecond accuracy. As an integral part of BDS-3, the PPP services via b2b signals (hereafter referred as PPP-B2b) are provided by BDS-3 GEO satellites with better than decimeter-level accuracy for users around China. In this research, a high-precision receiver based on PPP-B2b established, which obtains local clock offset respect Beidou Time (BDT) through time...
With the development of Real-Time Service (RTS) project, timing users can use real-time Precise Point Positioning (RT-PPP) technique for time transfer research. As a major participant RTS, Centre National d'Etudes Spatiales (CNES) conducts PPP-WIZARD (Precise with Integer and Zero-difference Ambiguity Resolution Demonstrator) project to assess PPP integer ambiguity resolution method, which is also called RT-IPPP. In this paper, we products broadcasted by CNES analysis center examine...
Single point positioning (SPP) can meet the requirements of majority real-time time transfer applications. Meanwhile, a single-frequency (SF) receiver is cheaper than dual-frequency receiver. However, SPP performance be greatly affected by large pseudorange observation noise. Phase smoothing an effective approach to reduce Since classical phase-smoothed algorithm does not account for effect ionosphere delay, we propose BDGIM-based eliminate ionospheric delay and apply it BeiDou Navigation...
These days, numerous organizations and Analysis Centers (AC) offer various Ambiguity Resolution (AR) products using methodologies. To use it for time-frequency transfer, there is no associated study. This paper chooses 16 MGEX stations with external high-precision atomic clocks to constitute 15 international time comparison links uses AR data from CNES, SGG, CODE, PRIDE laboratory, three ambiguity-fixed strategies, thoroughly evaluate the effects of strategies transfer. We reach following...
The PPP-B2b signal can provide users in China and its neighboring areas with real-time high-precision positioning service. Considering that single-frequency receivers have the advantages of low cost high-performance, broader market application potential, we propose a method based on extended Kalman filter (EKF). Experiments demonstrate that, first, accuracy reach several centimeters static mode, decimeter or meter level kinematic mode; second, GPS is worst, there will even be interruptions....
<p>Precise point positioning (PPP) technique is an effective tool for time and frequency applications. Using phase/code observations precise products, the PPP transfer allows accuracy of sub-nanoseconds within a latency several days. Although usually implemented in post-processing mode, using real-time (RT-PPP) with shorter remains attractive to community. In 2012, IGS (International GNSS Service) launched open-access service (RTS) project, broadcasting satellite orbit clock...
<p>In this paper, we focus on UAVs (Unmanned Aerial Vehicles) positioning in GPS-denied environments and proposes a navigation mode of “track reckoning + relative ranging heading constraint”. Internal sensors (gyros, accelerometer, barometer, etc.) measure the self-motion to obtain flight path attitude, external identify achieve peer-to-peer constraint for UAVs. In order guide swarm intended destination when GPS is denied, ground anchor nodes are set...
In 2020, users in and around China had access to a new real-time precise point positioning (RTPPP) service with the BeiDou global navigation satellite system (BDS-3) B2b (PPP-B2b) signal. this study, quality of PPP-B2b products is first assessed compared CNAV1 broadcast ephemeris. Then mode BDS-3 PPP time transfer (B2b-RTPPP) developed evaluated static kinematic modes. The results demonstrate that discontinuity orbit improved by applying PPP-B2b, its root mean square errors (RMSEs) are 0.081...
Numerous organizations and Analysis Centers (AC) currently offer various Ambiguity Resolution (AR) products using methodologies. However, there are no associated studies on their use for time-frequency transfer. This paper examines 16 Multi-GNSS Experiment (MGEX) stations with external high-precision atomic clocks to constitute 15 international time comparison links, uses AR data from CNES, SGG, CODE, PRIDE laboratories, three ambiguity-fixed strategies, thoroughly evaluate the effects of...