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Improving the underwater navigation performance of an IMU with acoustic long baseline calibration Satell. Navig. (IF 11.2) Pub Date : 2024-03-18 Paipai Wu, Wenfeng Nie, Yangfan Liu, Tianhe Xu
Underwater acoustic Long-Baseline System (LBL) is an important technique for submarine positioning and navigation. However, the high cost of the seafloor equipment and complex construction of a seafloor network restrict the distribution of the LBL within a small area, making an underwater vehicle difficult for long-distance and high-precision acoustic-based or inertial-based navigation. We therefore
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Accurate and efficient floor localization with scalable spiking graph neural networks Satell. Navig. (IF 11.2) Pub Date : 2024-03-11 Fuqiang Gu, Fangming Guo, Fangwen Yu, Xianlei Long, Chao Chen, Kai Liu, Xuke Hu, Jianga Shang, Songtao Guo
Floor localization is crucial for various applications such as emergency response and rescue, indoor positioning, and recommender systems. The existing floor localization systems have many drawbacks, like low accuracy, poor scalability, and high computational costs. In this paper, we first frame the problem of floor localization as one of learning node embeddings to predict the floor label of a subgraph
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Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS Satell. Navig. (IF 11.2) Pub Date : 2024-03-04 Yunhan Qi, Zheng Yao, Mingquan Lu
With the evolution of Global Navigation Satellite System (GNSS), new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques, which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal (WMS). Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency
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A rigorous real-time acoustic positioning method for ocean bottom seismic exploration Satell. Navig. (IF 11.2) Pub Date : 2024-02-19 Jinye Ma, Shouchuan Fang, Jianhu Zhao
The conventional technique for positioning seafloor geophones in ocean bottom seismic exploration encounters several challenges, including the significant impact of outliers on positioning results, underutilization of high-precision observations, and low efficiency in real-time data processing. These issues inevitably affect the quality of seismic exploration outcomes. To address these challenges and
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Underwater inertial error rectification with limited acoustic observations Satell. Navig. (IF 11.2) Pub Date : 2024-02-05 Hongqiong Tang, Hongyang He, Fangneng Li, Jiangning Xu
Underwater inertial navigation is particularly difficult for the long-durance operations as many navigation systems such global satellite navigation systems are unavailable. The acoustic signal is a marvelous choice for underwater inertial error rectification due to its underwater penetration capability. However, the traditional Acoustic Positioning Systems (APS) are expensive and incapable of positioning
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An initial investigation of the non-isotropic feature of GNSS tropospheric delay Satell. Navig. (IF 11.2) Pub Date : 2024-01-15 Ying Xu, Zaozao Yang, Hongzhan Zhou, Fangzhao Zhang
Tropospheric delay is a significant error source in Global Navigation Satellite Systems (GNSS) positioning. Slant Path Delay (SPD) is commonly derived by multiplying Zenith Tropospheric Delay (ZTD) with a mapping function. However, mapping functions, assuming atmospheric isotropy, restrict the accuracy of derived SPDs. To improve the accuracy, a horizontal gradient correction is introduced to account
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Characterizing extreme drought and wetness in Guangdong, China using global navigation satellite system and precipitation data Satell. Navig. (IF 11.2) Pub Date : 2024-01-01 Hai Zhu, Kejie Chen, Haishan Chai, Yuanbin Ye, Wenjian Liu
As global temperature rises, the frequency of extreme climate events, e.g., severe droughts and floods, has increased significantly and caused severe damage over the past years. To this regard, precipitation efficiency, a crucial meteorological parameter, could provide valuable insights for a better understanding of the patterns and characteristics of these extreme events. In this study, taking Guangdong
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Centimeter-level-precision seafloor geodetic positioning model with self-structured empirical sound speed profile Satell. Navig. (IF 11.2) Pub Date : 2023-12-04 Shuqiang Xue, Baojin Li, Zhen Xiao, Yue Sun, Jingsen Li
In-field Sound Speed Profile (SSP) measurement is still indispensable for achieving centimeter-level-precision Global Navigation Satellite System (GNSS)-Acoustic (GNSS-A) positioning in current state of the art. However, in-field SSP measurement on the one hand causes a huge cost and on the other hand prevents GNSS-A from global seafloor geodesy especially for real-time applications. We propose an
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Stability analysis of reference station and compensation for monitoring stations in GNSS landslide monitoring Satell. Navig. (IF 11.2) Pub Date : 2023-11-13 Duo Wang, Guanwen Huang, Yuan Du, Qin Zhang, Zhengwei Bai, Jing Tian
The Real-Time Kinematic (RTK) positioning method of the Global Navigation Satellite System (GNSS) has been widely used for landslide monitoring. The stability of its reference station is crucial to obtain accurate and reliable monitoring results. Unstable reference stations due to the geological environment and human activities are difficult to detect and in practical applications often ignored. As
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Precise orbit determination of Haiyang-2D using onboard BDS-3 B1C/B2a observations with ambiguity resolution Satell. Navig. (IF 11.2) Pub Date : 2023-11-06 Kecai Jiang, Wenwen Li, Min Li, Jianghui Geng, Haixia Lyu, Qile Zhao, Jingnan Liu
The Haiyang-2D altimetry mission of China is one of the first Low Earth Orbit (LEO) satellites that can receive new B1C/B2a signals from the BeiDou-3 Navigation Satellite System (BDS-3) for Precise Orbit Determination (POD). In this work, the achievable accuracy of the single-receiver ambiguity resolution for onboard LEO satellites is studied based on the real measurements of new BDS-3 frequencies
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A double sideband combined tracking method for Galileo E5 AltBOC signals Satell. Navig. (IF 11.2) Pub Date : 2023-10-16 Tongwen Fan, Tisheng Zhang, Hongping Zhang, Jun Mo, Xiaoji Niu
The Galileo navigation satellite system (Galileo) E5 Alternative Binary Offset Carrier (AltBOC) signal brings various challenges due to its complex modulation, wide bandwidth, and multi-peaked auto-correlation function. While wideband tracking needs to solve the ambiguity problem and design dedicated baseband channels, the single-sideband cannot have the outstanding performance of the AltBOC signal
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Performance analysis of frequency-mixed PPP-RTK using low-cost GNSS chipset with different antenna configurations Satell. Navig. (IF 11.2) Pub Date : 2023-10-09 Xingxing Li, Hailong Gou, Xin Li, Zhiheng Shen, Hongbo Lyu, Yuxuan Zhou, Hao Wang, Qian Zhang
Low-cost Global Navigation Satellite System (GNSS) devices offer a cost-effective alternative to traditional GNSS systems, making GNSS technology accessible to a wider range of applications. Nevertheless, low-cost GNSS devices often face the challenges in effectively capturing and tracking satellite signals, which leads to losing the observations at certain frequencies. Moreover, the observation peculiarities
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Resilient timekeeping algorithm with multi-observation fusion Kalman filter Satell. Navig. (IF 11.2) Pub Date : 2023-09-18 Xiaobin Wang, Yuanxi Yang, Bo Wang, Yuting Lin, Chunhao Han
The timescales incorporated into the Primary Frequency Standard (PFS) exhibit excellent stability and accuracy. However, during the dead time of PFS, the reliability of the timescale can be compromised. To address this issue, a resilient timekeeping algorithm with a Multi-observation Fusion Kalman Filter (MFKF) is proposed. This algorithm fuses the frequency measurements from hydrogen masers with various
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Real-time service performances of BDS-3 and Galileo constellations with a linear satellite clock correction models Satell. Navig. (IF 11.2) Pub Date : 2023-09-04 Haojun Li, Danzeng Luojie, Huimin Ding
In order to facilitate high-precision and real-time Precise Point Positioning (PPP), the International GNSS (Global Navigation Satellite System) Service (IGS), BDS-3 (BeiDou-3 Navigation Satellite System), and Galileo navigation satellite system (Galileo) have provided real-time satellite clock correction, which is updated at a high-frequency. However, the frequent updates pose the challenges of increasing
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A new inter-system double-difference RTK model applicable to both overlapping and non-overlapping signal frequencies Satell. Navig. (IF 11.2) Pub Date : 2023-08-14 Wenhao Zhao, Genyou Liu, Ming Gao, Bo Zhang, Shengjun Hu, Minghui Lyu
Aiming at the problem that the traditional inter-system double-difference model is not suitable for non-overlapping signal frequencies, we propose a new inter-system double-difference model with single difference ambiguity estimation, which can be applied for both overlapping and non-overlapping signal frequencies. The single difference ambiguities of all satellites and Differential Inter-System Biases
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Multi-level autonomous integrity monitoring method for multi-source PNT resilient fusion navigation Satell. Navig. (IF 11.2) Pub Date : 2023-08-07 Rui Chen, Long Zhao
For the integrity monitoring of a multi-source PNT (Positioning, Navigation, and Timing) resilient fusion navigation system, a theoretical framework of multi-level autonomous integrity monitoring is proposed. According to the mode of multi-source fusion navigation, the framework adopts the top-down logic structure and establishes the navigation source fault detection model based on the multi-combination
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Geodetic study on earth surface loading with GNSS and GRACE Satell. Navig. (IF 11.2) Pub Date : 2023-07-24 Kosuke Heki, Shuanggen Jin
Ice, snow, and liquid water on the surface of the Earth exert downward force onto the solid earth and deform the lithosphere typically in seasonal timescale. Space techniques, such as Global Navigation Satellite System (GNSS), made it possible to directly measure subtle displacements caused by loading. We can also observe such loads with time-variable gravity using gravity recovery and climate experiment
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GSTAR: an innovative software platform for processing space geodetic data at the observation level Satell. Navig. (IF 11.2) Pub Date : 2023-07-17 Chuang Shi, Shiwei Guo, Lei Fan, Shengfeng Gu, Xinqi Fang, Linghao Zhou, Tao Zhang, Zhen Li, Min Li, Wenwen Li, Cheng Wang, Yidong Lou
To meet the demands for the data combination with multiple space geodetic techniques at the observation level, we developed a new software platform with high extensibility and computation efficiency, named space Geodetic SpatioTemporal data Analysis and Research software (GSTAR). Most of the modules in the GSTAR are coded in C++ with object-oriented programming. The layered modular theory is adopted
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A state-domain robust autonomous integrity monitoring with an extrapolation method for single receiver positioning in the presence of slowly growing fault Satell. Navig. (IF 11.2) Pub Date : 2023-07-05 Zhangjun Yu, Qiuzhao Zhang, Shubi Zhang, Nanshan Zheng, Keqiang Liu
Single receiver positioning has been widely used as a standard and standalone positioning technique for about 25 years. To detect the slowly growing faults caused by satellite and receiver clocks in single receiver positioning, the Autonomous Integrity Monitoring with an Extrapolation method (AIME) was proposed based on the Kalman filter measurement domain. However, AIME was designed with the assumption
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Properties of multi-GNSS uncalibrated phase delays with considering satellite systems, receiver types, and network scales Satell. Navig. (IF 11.2) Pub Date : 2023-06-26 Ping Zeng, Zhetao Zhang, Yuanlan Wen, Xiufeng He, Lina He, Muzi Li, Wu Chen
The Wide-Lane (WL) and Narrow-Lane (NL) Uncalibrated Phase Delays (UPDs) are the prerequisites in the traditional Precise Point Positioning (PPP) Ambiguity Resolution (AR). As the generation mechanism of various biases becomes more complex, we systematically studied the impact factors of four satellite systems WL and NL UPDs from the perspective of parameter estimation. Approximately 100 stations in
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Estimation of BDS pseudorange biases with high temporal resolution: feasibility, affecting factors, and necessity Satell. Navig. (IF 11.2) Pub Date : 2023-06-19 Ke Su, Guoqiang Jiao
A common practice adopted for the pseudorange bias estimation and calibration assumes that Global Navigation Satellite System satellite-dependent pseudorange biases vary gently over time. Whereupon satellite pseudorange biases are routinely estimated and provided as the products with low temporal resolution, e.g., hourly or daily, by the agencies. The story sounds unquestionably perfect under the acquainted
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Study on systematic errors of BDS-3 broadcast ephemeris and their effects with Helmert transformation Satell. Navig. (IF 11.2) Pub Date : 2023-06-12 Min Li, Jiangnan Zhang, Guo Chen, Liang Chen, Qile Zhao
Previous studies have not evaluated the systematic errors implied in the third generation of BeiDou-3 Navigation Satellite System (BDS-3) broadcast ephemeris. In this paper we evaluate the systematic pattern described by the Helmert transformation parameters, including translations, rotations, and scale. BDS-3 broadcast and precise ephemerides from December 2019 to 2022 are collected, and the characteristics
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A joint InSAR-GNSS workflow for correction and selection of interferograms to estimate high-resolution interseismic deformations Satell. Navig. (IF 11.2) Pub Date : 2023-06-05 Hongzhi Liu, Lei Xie, Guoqiang Zhao, Eslam Ali, Wenbin Xu
Knowledge of the spatial distribution of interseismic deformations is essential to better understand earthquake cycles. The existing methods for improving the reliability of the obtained deformations often rely on visual inspection and prior model corrections that are time-consuming, labor-intensive, and do not consider the spatial distribution of interseismic deformations. Interferometric Synthetic
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Assessment of GNSS zenith tropospheric delay responses to atmospheric variables derived from ERA5 data over Nigeria Satell. Navig. (IF 11.2) Pub Date : 2023-05-29 Ifechukwu Ugochukwu Nzelibe, Herbert Tata, Timothy Oluwadare Idowu
Tropospheric delay is a major error caused by atmospheric refraction in Global Navigation Satellite System (GNSS) positioning. The study evaluates the potential of the European Centre for Medium-range Weather Forecast (ECMWF) Reanalysis 5 (ERA5) atmospheric variables in estimating the Zenith Tropospheric Delay (ZTD). Linear regression models (LRM) are applied to estimate ZTD with the ERA5 atmospheric
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M2C-GVIO: motion manifold constraint aided GNSS-visual-inertial odometry for ground vehicles Satell. Navig. (IF 11.2) Pub Date : 2023-05-18 Tong Hua, Ling Pei, Tao Li, Jie Yin, Guoqing Liu, Wenxian Yu
Visual-Inertial Odometry (VIO) has been developed from Simultaneous Localization and Mapping (SLAM) as a low-cost and versatile sensor fusion approach and attracted increasing attention in ground vehicle positioning. However, VIOs usually have the degraded performance in challenging environments and degenerated motion scenarios. In this paper, we propose a ground vehicle-based VIO algorithm based on
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Machine learning based GNSS signal classification and weighting scheme design in the built environment: a comparative experiment Satell. Navig. (IF 11.2) Pub Date : 2023-05-10 Lintong Li, Mireille Elhajj, Yuxiang Feng, Washington Yotto Ochieng
None-Line-of-Sight (NLOS) signals denote Global Navigation Satellite System (GNSS) signals received indirectly from satellites and could result in unacceptable positioning errors. To meet the high mission-critical transportation and logistics demand, NLOS signals received in the built environment should be detected, corrected, and excluded. This paper proposes a cost-effective NLOS impact mitigation
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GNSS rapid precise point positioning enhanced by low Earth orbit satellites Satell. Navig. (IF 11.2) Pub Date : 2023-04-11 Ju Hong, Rui Tu, Pengfei Zhang, Rui Zhang, Junqiang Han, Lihong Fan, Siyao Wang, Xiaochun Lu
The Low Earth Orbit (LEO) satellites can be used to effectively speed up Precise Point Positioning (PPP) convergence. In this study, 180 LEO satellites with a global distribution are simulated to evaluate their contribution to the PPP convergence. LEO satellites can give more redundant observations and improve satellite geometric distributions, particularly for a single Global Navigation Satellite
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Integrity monitoring scheme for single-epoch GNSS PPP-RTK positioning Satell. Navig. (IF 11.2) Pub Date : 2023-04-03 Wenhao Zhang, Jinling Wang
Integrity monitoring for precise point positioning is critical for safety-related applications. With the increasing demands of high-accuracy autonomous navigation for unmanned ground and aerial vehicles, the integrity monitoring method of high-precision positioning has become an essential requirement. While high precision Global Navigation Satellite Systems (GNSS) positioning is widely used in such
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Instantaneous velocity determination and positioning using Doppler shift from a LEO constellation Satell. Navig. (IF 11.2) Pub Date : 2023-03-20 Fei Guo, Yan Yang, Fujian Ma, Yifan Zhu, Hang Liu, Xiaohong Zhang
To provide backup and supplementation for the Global Navigation Satellite System (GNSS), Doppler shift from Low Earth Orbit (LEO) satellites can be used as signals of opportunity to provide positioning, navigation, and timing service. In this contribution, we first investigate the model and performance of instantaneous velocity determination and positioning with LEO satellites. Given a LEO constellation
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A new receiver clock model to enhance BDS-3 real-time PPP time transfer with the PPP-B2b service Satell. Navig. (IF 11.2) Pub Date : 2023-03-06 Yulong Ge, Qing Wang, Yong Wang, Daqian Lyu, Xinyun Cao, Fei Shen, Xiaolin Meng
A new Precise Point Positioning (PPP) service, called the PPP-B2b service, has been implemented in the BeiDou-3 Navigation Satellite System (BDS-3), which brings new opportunities for time transfer. However, the solution using the traditional PPP method with the PPP-B2b correction still absorbs some unknown errors and needs reconverging when there exist abnormal data. We developed a new receiver clock
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Assessment of tomographic window and sampling rate effects on GNSS water vapor tomography Satell. Navig. (IF 11.2) Pub Date : 2023-02-20 Fei Yang, Yilin Sun, Xiaolin Meng, Jiming Guo, Xu Gong
The ground-based Global Navigation Satellite System (GNSS) water vapor tomography is increasingly important in GNSS meteorology. As the multi-GNSS and more ground-based GNSS sites can be incorporated into the regional water vapor tomographic model, determining the tomographic window and sampling rate is crucial for the modelling of the water vapor tomography. These two factors affect not only the number
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GNSS techniques for real-time monitoring of landslides: a review Satell. Navig. (IF 11.2) Pub Date : 2023-02-20 Guanwen Huang, Shi Du, Duo Wang
Currently, Global Navigation Satellite System (GNSS) Real-Time Kinematic positioning (RTK) and Precise Point Positioning (PPP) techniques are widely employed for real-time monitoring of landslides. However, both RTK and PPP monitoring techniques have their limitations, such as limited service coverage or long convergence times. PPP-RTK technique which integrates RTK and PPP is a novel approach for
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Authenticating GNSS civilian signals: a survey Satell. Navig. (IF 11.2) Pub Date : 2023-02-13 Muzi Yuan, Xiaomei Tang, Gang Ou
Civilian services of Global Navigation Satellite System are threatened by spoofing attacks since it is hard to determine the authenticity of a navigation signal with a detailed structure open to the public. Signal authentication effectively protects the security of the signal by attaching unforgeable information to one or several elements of the signal. Receivers can verify the authenticity of the
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Wind speed retrieval using GNSS-R technique with geographic partitioning Satell. Navig. (IF 11.2) Pub Date : 2023-02-06 Zheng Li, Fei Guo, Fade Chen, Zhiyu Zhang, Xiaohong Zhang
In this paper, the effect of geographical location on Cyclone Global Navigation Satellite System (CYGNSS) observables is demonstrated for the first time. It is found that the observables corresponding to the same wind speed vary with geographic location regularly. Although latitude and longitude information is included in the conventional method, it cannot effectively reduce the errors caused by geographic
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A FIR filter assisted with the predictive model and ELM integrated for UWB-based quadrotor aircraft localization Satell. Navig. (IF 11.2) Pub Date : 2023-01-16 Xu, Yuan, Wan, Dong, Bi, Shuhui, Guo, Hang, Zhuang, Yuan
To improve the accuracy of the Ultra-Wide Band (UWB) based quadrotor aircraft localization, a Finite Impulse Response (FIR) filter aided with an integration of the predictive model and Extreme Learning Machine (ELM) is proposed in this work. The FIR filter estimates the quad-rotor aircraft ’s position by fusing the positions measured with the UWB and Inertial Navigation System respectively. When the
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Performance of LiDAR-SLAM-based PNT with initial poses based on NDT scan matching algorithm Satell. Navig. (IF 11.2) Pub Date : 2023-01-12 Chiang, Kaiwei, Chiu, Yuting, Srinara, Surachet, Tsai, Menglun
To achieve higher automation level of vehicles defined by the Society of Automotive Engineers, safety is a key requirement affecting navigation accuracy. We apply Light Detection and Ranging (LiDAR) as a main auxiliary sensor and propose LiDAR-based Simultaneously Localization and Mapping (SLAM) approach for Positioning, Navigation, and Timing. Furthermore, point cloud registration is handled with
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A cluster positioning architecture and relative positioning algorithm based on pigeon flock bionics Satell. Navig. (IF 11.2) Pub Date : 2023-01-02 Deng, Zhongliang, Qi, Hang, Wu, Chengfeng, Hu, Enwen, Wang, Runmin
Unmanned clusters can realize collaborative work, flexible configuration, and efficient operation, which has become an important development trend of unmanned platforms. Cluster positioning is important for ensuring the normal operation of unmanned clusters. The existing solutions have some problems such as requiring external system assistance, high system complexity, poor architecture scalability
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Review of PPP–RTK: achievements, challenges, and opportunities Satell. Navig. (IF 11.2) Pub Date : 2022-12-06 Li, Xingxing, Huang, Jiaxin, Li, Xin, Shen, Zhiheng, Han, Junjie, Li, Linyang, Wang, Bo
The PPP–RTK method, which combines the concepts of Precise of Point Positioning (PPP) and Real-Time Kinematic (RTK), is proposed to provide a centimeter-accuracy positioning service for an unlimited number of users. Recently, the PPP–RTK technique is becoming a promising tool for emerging applications such as autonomous vehicles and unmanned logistics as it has several advantages including high precision
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Refining the ERA5-based global model for vertical adjustment of zenith tropospheric delay Satell. Navig. (IF 11.2) Pub Date : 2022-11-28 Zhu, Ge, Huang, Liangke, Yang, Yunzhen, Li, Junyu, Zhou, Lv, Liu, Lilong
Tropospheric delay is an important factor affecting high precision Global Navigation Satellite System (GNSS) positioning and also the basic data for GNSS atmospheric research. However, the existing tropospheric delay models have some problems, such as only a single function used for the entire atmosphere. In this paper, an ERA5-based (the fifth generation of European Centre for Medium-Range Weather
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Analysis of GPS P(Y) signal power enhancement based on the observations with a semi-codeless receiver Satell. Navig. (IF 11.2) Pub Date : 2022-11-15 Tang, Xiaomei, Yuan, Muzi, Wang, Feixue
The Global Position System (GPS) satellites of Block IIR-M and later versions can turn on the signal power enhancement if needed. In recent years, this power enhancement has been triggered several times when the U.S force was involved in local conflicts, which was observed by the monitoring receivers at International GNSS Service (IGS)/international GNSS Monitoring and Assessment System (iGMAS) stations
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Supplementary open dataset for WiFi indoor localization based on received signal strength Satell. Navig. (IF 11.2) Pub Date : 2022-11-08 Bi, Jingxue, Wang, Yunjia, Yu, Baoguo, Cao, Hongji, Shi, Tongguang, Huang, Lu
Several Wireless Fidelity (WiFi) fingerprint datasets based on Received Signal Strength (RSS) have been shared for indoor localization. However, they can’t meet all the demands of WiFi RSS-based localization. A supplementary open dataset for WiFi indoor localization based on RSS, called as SODIndoorLoc, covering three buildings with multiple floors, is presented in this work. The dataset includes dense
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Quasi-4-dimension ionospheric modeling and its application in PPP Satell. Navig. (IF 11.2) Pub Date : 2022-11-02 Gu, Shengfeng, Gan, Chengkun, He, Chengpeng, Lyu, Haixia, Hernandez-Pajares, Manuel, Lou, Yidong, Geng, Jianghui, Zhao, Qile
Ionospheric delay modeling is not only important for Global Navigation Satellite System (GNSS) based space weather study and monitoring, but also an efficient tool to speed up the convergence time of Precise Point Positioning (PPP). In this study, a novel model, denoted as Quasi-4-Dimension Ionospheric Modeling (Q4DIM) is proposed for wide-area high precision ionospheric delay correction. In Q4DIM
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Precise orbit determination for a large LEO constellation with inter-satellite links and the measurements from different ground networks: a simulation study Satell. Navig. (IF 11.2) Pub Date : 2022-10-24 He, Xingchi, Hugentobler, Urs, Schlicht, Anja, Nie, Yufeng, Duan, Bingbing
Geodetic applications of Low Earth Orbit (LEO) satellites requires accurate satellite orbits. Instead of using onboard Global Navigation Satellite System observations, this contribution treats the LEO satellite constellation independently, using Inter-Satellite Links and the measurements of different ground networks. Due to geopolitical and geographical reasons, a ground station network cannot be well
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Observable-specific phase biases of Wuhan multi-GNSS experiment analysis center’s rapid satellite products Satell. Navig. (IF 11.2) Pub Date : 2022-10-17 Geng, Jianghui, Zhang, Qiyuan, Li, Guangcai, Liu, Jingnan, Liu, Donglie
Precise Point Positioning (PPP) with Ambiguity Resolution (AR) is an important high-precision positioning technique that is gaining popularity in geodetic and geophysical applications. The implementation of PPP-AR requires precise products such as orbits, clocks, code, and phase biases. As one of the analysis centers of the International Global Navigation Satellite System (GNSS) Service (IGS), the
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An efficient approach for anti-jamming in IRNSS receivers using improved PSO based parametric wavelet packet thresholding Satell. Navig. (IF 11.2) Pub Date : 2022-10-10 Kambham, Jacob Silva Lorraine, Ramarakula, Madhu
The Indian Regional Navigation Satellite System provides accurate positioning service to the users within and around India, extending up to 1500 km. However, when a receiver encounters a Continuous Wave Interference, its positioning accuracy degrades, or sometimes it even fails to work. Wavelet Packet Transform (WPT) is the most widely used technique for anti-jamming in Global Navigation Satellite
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Multi-GNSS products and services at iGMAS Wuhan Innovation Application Center: strategy and evaluation Satell. Navig. (IF 11.2) Pub Date : 2022-09-26 Li, Xingxing, Wang, Qingyun, Wu, Jiaqi, Yuan, Yongqiang, Xiong, Yun, Gong, Xuewen, Wu, Zhilu
Over the past years the International Global Navigation Satellite System (GNSS) Monitoring and Assessment System (iGMAS) Wuhan Innovation Application Center (IAC) dedicated to exploring the potential of multi-GNSS signals and providing a set of products and services. This contribution summarizes the strategies, achievements, and innovations of multi-GNSS orbit/clock/bias determination in iGMAS Wuhan
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Evaluation of the performance of GNSS-based velocity estimation algorithms Satell. Navig. (IF 11.2) Pub Date : 2022-09-19 Ji, Li, Sun, Rui, Cheng, Qi, Wang, Junhui
Global Navigation Satellite System (GNSS) based velocity estimation is one of the most cost-effective and widely used methods in determining velocity in geodesy and transport applications. Highly accurate and reliable velocity measurements can be obtained by exploiting the raw Doppler, carrier phase, and pseudorange measurements with a GNSS receiver. There are several approaches to GNSS-based velocity
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Performance improvement of 5G positioning utilizing multi-antenna angle measurements Satell. Navig. (IF 11.2) Pub Date : 2022-09-05 Guo, Wenfei, Deng, Yue, Guo, Chi, Qi, Shufeng, Wang, Jingrong
Time delay-based the 5th Generation Mobile Communication Technology (5G) positioning is a main method to perform high-precision positioning in Global Navigation Satellite System (GNSS) denied areas. However, in practical applications, the occlusion of signals in a complex environment results in few observable base stations, which affects the reliability and accuracy of positioning. The aim of this
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Real-time GNSS precise point positioning with smartphones for vehicle navigation Satell. Navig. (IF 11.2) Pub Date : 2022-08-22 Li, Zishen, Wang, Liang, Wang, Ningbo, Li, Ran, Liu, Ang
The availability of raw Global Navigation Satellite System (GNSS) measurements from Android smart devices gives new possibilities for precise positioning solutions, e.g., Precise Point Positioning (PPP). However, the accuracy of the PPP with smart devices currently is a few meters due to the poor quality of the raw GNSS measurements in a kinematic scenario and in urban environments, particularly when
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A resilient adjustment method to weigh pseudorange observation in precise point positioning Satell. Navig. (IF 11.2) Pub Date : 2022-08-08 Zhang, Qieqie, Zhao, Long, Zhou, Jianhua
The accurate weighting of pseudorange observations is important to improve the convergence time and positioning quality of Precise Point Positioning (PPP). Currently, the weight of a pseudorange observation is mainly determined with empirical stochastic models. However, in a complex environment, due to the inability to adapt for the dynamic changes of the user environment, the empirical stochastic
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A review of real-time multi-GNSS precise orbit determination based on the filter method Satell. Navig. (IF 11.2) Pub Date : 2022-07-25 Lou, Yidong, Dai, Xiaolei, Gong, Xiaopeng, Li, Chenglong, Qing, Yun, Liu, Yang, Peng, Yaquan, Gu, Shengfeng
Stable and reliable high-precision satellite orbit products are the prerequisites for the positioning services with high performance. In general, the positioning accuracy depends strongly on the quality of satellite orbit and clock products, especially for absolute positioning modes, such as Precise Point Positioning (PPP). With the development of real-time services, real-time Precise Orbit Determination
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A multipath mitigation algorithm for GNSS signals based on the steepest descent approach Satell. Navig. (IF 11.2) Pub Date : 2022-07-13 Qiu, Wenqi, Zeng, Qinghua, Xu, Rui, Liu, Jianye, Shi, Jinheng, Meng, Qian
Multipath interference seriously degrades the performance of Global Navigation Satellite System (GNSS) positioning in an urban canyon. Most current multipath mitigation algorithms suffer from heavy computational load or need external assistance. We propose a multipath mitigation algorithm based on the steepest descent approach, which has the merits of less computational load and no need for external
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An indoor fusion navigation algorithm using HV-derivative dynamic time warping and the chicken particle filter Satell. Navig. (IF 11.2) Pub Date : 2022-06-27 Chen, Jian, Song, Shaojing, Gong, Yumei, Zhang, Shanxin
The use of dead reckoning and fingerprint matching for navigation is a widespread technical method. However, fingerprint mismatching and low fusion accuracy are prevalent issues in indoor navigation systems. This work presents an improved dynamic time warping and a chicken particle filter to handle these two challenges. To generate the Horizontal and Vertical (HV) fingerprint, the pitch and roll are
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Comprehensive assessment of real-time precise products from IGS analysis centers Satell. Navig. (IF 11.2) Pub Date : 2022-06-24 Li, Bofeng, Ge, Haibo, Bu, Yuhang, Zheng, Yanning, Yuan, Leitong
Real-Time Precise Point Positioning (RT-PPP) has been one of the research hotspots in GNSS (Global Navigation Satellite System) community for decades. Real-time precise products of satellite orbits and clocks are the prerequisite for RT-PPP. Thus, it is of great importance to investigate the current multi-GNSS real-time precise products in State Space Representation (SSR) from different analysis centers
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Improving BDS broadcast ephemeris accuracy using ground-satellite-link observations Satell. Navig. (IF 11.2) Pub Date : 2022-06-13 Chen, Junping, Wang, Jungang, Yu, Chao, Zhang, Yize, Wang, Bin
The BeiDou Navigation Satellite System (BDS) employs a hybrid constellation including GEO (Geosynchronous Earth Orbit), IGSO (Inclined Geosynchronous Orbit), and MEO (Medium Earth Orbit) satellites, where the GEO and IGSO satellites are critical to providing continuous and reliable Positioning, Navigation, and Timing (PNT) services in the Asia–Pacific region. To handle the inconsistency between the
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PPP-RTK considering the ionosphere uncertainty with cross-validation Satell. Navig. (IF 11.2) Pub Date : 2022-05-26 Li, Pan, Cui, Bobin, Hu, Jiahuan, Liu, Xuexi, Zhang, Xiaohong, Ge, Maorong, Schuh, Harald
With the high-precision products of satellite orbit and clock, uncalibrated phase delay, and the atmosphere delay corrections, Precise Point Positioning (PPP) based on a Real-Time Kinematic (RTK) network is possible to rapidly achieve centimeter-level positioning accuracy. In the ionosphere-weighted PPP–RTK model, not only the a priori value of ionosphere but also its precision affect the convergence
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Satellite integrity monitoring for satellite-based augmentation system: an improved covariance-based method Satell. Navig. (IF 11.2) Pub Date : 2022-05-09 Zheng, Shuaiyong, Gao, Mengzhi, Huang, Zhigang, Jin, Xiaoqin, Li, Kun
Satellite integrity monitoring is vital to satellite-based augmentation systems, and can provide the confidence of the differential corrections for each monitored satellite satisfying the stringent safety-of-life requirements. Satellite integrity information includes the user differential range error and the clock-ephemeris covariance which are used to deduce integrity probability. However, the existing
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Modeling and assessment of five-frequency BDS precise point positioning Satell. Navig. (IF 11.2) Pub Date : 2022-05-01 Wu, Zhiyuan, Wang, Qianxin, Hu, Chao, Yu, Zhihao, Wu, Wei
Since its full operation in 2020, BeiDou Satellite Navigation System (BDS) has provided global services with highly precise Positioning, Navigation, and Timing (PNT) as well as unique short-message communication. More and more academics focus on multi-frequency Precise Point Positioning (PPP) models, but few on BDS five-frequency PPP models. Therefore, this study using the uncombined and Ionospheric-Free
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Principle and performance of multi-frequency and multi-GNSS PPP-RTK Satell. Navig. (IF 11.2) Pub Date : 2022-04-11 Li, Xingxing, Wang, Bo, Li, Xin, Huang, Jiaxin, Lyu, Hongbo, Han, Xinjuan
PPP-RTK which takes full advantages of both Real-Time Kinematic (RTK) and Precise Point Positioning (PPP), is able to provide centimeter-level positioning accuracy with rapid integer Ambiguity Resolution (AR). In recent years, with the development of BeiDou Navigation Satellite System (BDS) and Galileo navigation satellite system (Galileo) as well as the modernization of Global Positioning System (GPS)
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Investigating GNSS PPP–RTK with external ionospheric constraints Satell. Navig. (IF 11.2) Pub Date : 2022-03-28 Zhang, Xiaohong, Ren, Xiaodong, Chen, Jun, Zuo, Xiang, Mei, Dengkui, Liu, Wanke
Real-Time Kinematic Precise Point Positioning (PPP–RTK) is inextricably linked to external ionospheric information. The PPP–RTK performances vary much with the accuracy of ionospheric information, which is derived from different network scales, given different prior variances, and obtained under different disturbed ionospheric conditions. This study investigates the relationships between the PPP–RTK