scholarly journals Characterisation of GNSS Carrier Phase Data on a Moving Zero-Baseline in Urban and Aerial Navigation

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4046 ◽  
Author(s):  
Fabian Ruwisch ◽  
Ankit Jain ◽  
Steffen Schön
Keyword(s):  
Global Navigation Satellite System ◽  
Carrier Phase ◽  
High Sensitivity ◽  
Satellite System ◽  
Double Difference ◽  
Navigation Satellite ◽  
Noise Levels ◽  
Global Navigation ◽  
Zero Baseline ◽  
Global Navigation Satellite

We present analyses of Global Navigation Satellite System (GNSS) carrier phase observations in multiple kinematic scenarios for different receiver types. Multi-GNSS observations are recorded on high sensitivity and geodetic-grade receivers operating on a moving zero-baseline by conducting terrestrial urban and aerial flight experiments. The captured data is post-processed; carrier phase residuals are computed using the double difference (DD) concept. The estimated noise levels of carrier phases are analysed with respect to different parameters. We find DD noise levels for L1 carrier phase observations in the range of 1.4–2 mm (GPS, Global Positioning System), 2.8–4.6 mm (GLONASS, Global Navigation Satellite System), and 1.5–1.7 mm (Galileo) for geodetic receiver pairs. The noise level for high sensitivity receivers is at least higher by a factor of 2. For satellites elevating above 30 ∘ , the dominant noise process is white phase noise. For the flight experiment, the elevation dependency of the noise is well described by the exponential model, while for the terrestrial urban experiment, multipath and diffraction effects overlay; hence no elevation dependency is found. For both experiments, a carrier-to-noise density ratio (C/N 0 ) dependency for carrier phase DDs of GPS and Galileo is clearly visible with geodetic-grade receivers. In addition, C/N 0 dependency is also visible for carrier phase DDs of GLONASS with geodetic-grade receivers for the terrestrial urban experiment.

Double-Difference Carrier-Phase Network Solution Using Nominal Gnss Constellations (Future Perception)

2008 ◽  
Vol 43 (2) ◽  
pp. 65-73
Author(s):  
A. Farah
Keyword(s):  
Carrier Phase ◽  
Satellite System ◽  
Global Navigation Satellite Systems ◽  
Double Difference ◽  
Navigation Satellite ◽  
Network Solution ◽  
Satellite Systems ◽  
Performance Improvements ◽  
Global Navigation ◽  
Global Navigation Satellite

Double-Difference Carrier-Phase Network Solution Using Nominal Gnss Constellations (Future Perception)Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning accuracy using different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, Glonass and Galileo) using different combinations. This study presents results of double-difference carrier-phase solution for five stations-network using the three constellations and different combinations.

scholarly journals Purwarupa Differential Global Navigation Satellite System dengan Metode Real Time Kinematik Berbasis Radio Link Type Htox

2021 ◽  
Vol 6 (1) ◽  
pp. 8-13
Author(s):  
Surono Surono ◽  
Adhi Kusuma Negara ◽  
Endro Sigit Kurniawan
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Carrier Phase ◽  
Satellite System ◽  
Radio Link ◽  
Navigation Satellite ◽  
Raw Data ◽  
Link Type ◽  
Global Navigation ◽  
Global Navigation Satellite

Purwarupa Differential Global Navigation Satellite System bertujuan untuk meningkatkan akurasi dari receiver GNSS, dengan menambahkan referensi stasiun lokal untuk menambah informasi yang diterima dari satelit. Differential Global Navigation Satellite System ini menggunakan metode real time kinematik yang berbasiskan pada carrier phase (besaran sudut) dalam penentuan posisi data secara relatif dengan tingkat ketelitian mencapai satuan milimeter. Sistem RTK menggunakan data pengamatan fase data atau koreksi fase dikirim secara seketika dari stasiun referensi ke receiver pengguna. Hasil dari purwarupa adalah resiver GNSS geodetik berbasis radio link yang bisa diprogram agar bisa menghasilkan raw data. Pemrograman menggunakan software RTKLIB seri b33 dengan aplikasi RTKnavi untuk logging data.

scholarly journals Performance of Multi-GNSS Real-Time UTC(NTSC) Time and Frequency Transfer Service Using Carrier Phase Observations

2021 ◽  
Vol 13 (20) ◽  
pp. 4184
Author(s):  
Pengfei Zhang ◽  
Rui Tu ◽  
Xiaochun Lu ◽  
Lihong Fan ◽  
Rui Zhang
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Carrier Phase ◽  
Satellite System ◽  
National Standard ◽  
Prototype System ◽  
Navigation Satellite ◽  
Frequency Transfer ◽  
Global Navigation ◽  
Global Navigation Satellite

The technique of carrier phase (CP), based on the global navigation satellite system (GNSS), has proven to be a highly effective spatial tool in the field of time and frequency transfer with sub-nanosecond accuracy. The rapid development of real-time GNSS satellite orbit and clock determinations has enabled GNSS time and frequency transfer using the CP technique to be performed in real-time mode, without any issues associated with latency. In this contribution, we preliminarily built the prototype system of real-time multi-GNSS time and frequency transfer service in National Time Service Center (NTSC) of the Chinese Academy of Sciences (CAS), which undertakes the task to generate, maintains and transmits the national standard of time and frequency UTC(NTSC). The comprehensive assessment of the availability and quality of the service system were provided. First, we assessed the multi-GNSS state space representation (SSR) correction generated in real-time multi-GNSS prototype system by combining broadcast ephemeris through a comparison with the GeoForschungsZentrum (GFZ) final products. The statistical results showed that the orbit precision in three directions was smaller than 6 cm for global positioning system (GPS) and smaller than approximately 10 cm for BeiDou satellite system (BDS). The root mean square (RMS) values of clock differences for GPS were approximately 2.74 and 6.74 ns for the GEO constellation of BDS, 3.24 ns for IGSO, and 1.39 ns for MEO. The addition, the GLObal NAvigation Satellite System (GLONASS) and Galileo satellite navigation system (Galileo) were 4.34 and 1.32 ns, respectively. In order to assess the performance of real-time multi-GNSS time and frequency transfer in a prototype system, the four real-time time transfer links, which used UTC(NTSC) as the reference, were employed to evaluate the performance by comparing with the solution determined using the GFZ final products. The RMS could reach sub-nanosecond accuracy in the two solutions, either in the SSR or GFZ solution, or in GPS, BDS, GLONASS, and Galileo. The frequency stability within 10,000 s was 3.52 × 10−12 for SSR and 3.47 × 10−12 for GFZ and GPS, 3.63 × 10−12 for SSR and 3.53 × 10−12 for GFZ for BDS, 3.57 × 10−12 for SSR and 3.52 × 10−12 for GFZ for GLONASS, and 3.56 × 10−12 for SSR and 3.48 × 10−12 for GFZ for Galileo.

A semi-analytical solution to the global navigation satellite system attitude determination problem

2017 ◽  
Vol 233 (3) ◽  
pp. 1033-1046
Author(s):  
Shengquan Li ◽  
Jianjun Zhu ◽  
Long Fan ◽  
Guobin Chang ◽  
Kailiang Deng
Keyword(s):  
Analytical Solution ◽  
Global Navigation Satellite System ◽  
Carrier Phase ◽  
Attitude Determination ◽  
Optimal Solution ◽  
Satellite System ◽  
Navigation Satellite ◽  
Estimation Errors ◽  
Global Navigation ◽  
Global Navigation Satellite

Global navigation satellite system attitude determination based on carrier phase differencing technique is studied. A realistic stochastic model is followed to fully consider the correlations among different measurements in the least-squares problem formulation. A prior-free, computation-fixed, and averagely optimal solution is proposed suitable for real-time and high-dynamic situations. The prior-free property is achieved by developing an analytical sub-optimal solution. This solution follows first transforming the original problem into one with vector measurements and then further approximating it with a general Wahba’s problem. The fixed computation is guaranteed by performing only one or two rounds of correction of the analytical solution. Every single round follows a linearization-estimation-correction process. The process also provides an error or covariance analysis for the estimate. The average optimality in terms of the root mean squared errors is brought about by the relatively good quality of the analytical solution and the fast convergence of the correction processes. The numerical experiments, with three 4 m long baselines and 5 mm (standard deviation) carrier phase errors, show that the estimation errors (in magnitude) for all three channels are well below 0.4° for almost all epochs and within 0.2° for most epochs.

scholarly journals OutFin, a multi-device and multi-modal dataset for outdoor localization based on the fingerprinting approach

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fahad Alhomayani ◽  
Mohammad H. Mahoor
Keyword(s):  
Global Navigation Satellite System ◽  
Urban Areas ◽  
Satellite System ◽  
Reference Points ◽  
Navigation Satellite ◽  
Data Types ◽  
Entry Barrier ◽  
Promising Alternative ◽  
Global Navigation ◽  
Global Navigation Satellite

AbstractIn recent years, fingerprint-based positioning has gained researchers’ attention since it is a promising alternative to the Global Navigation Satellite System and cellular network-based localization in urban areas. Despite this, the lack of publicly available datasets that researchers can use to develop, evaluate, and compare fingerprint-based positioning solutions constitutes a high entry barrier for studies. As an effort to overcome this barrier and foster new research efforts, this paper presents OutFin, a novel dataset of outdoor location fingerprints that were collected using two different smartphones. OutFin is comprised of diverse data types such as WiFi, Bluetooth, and cellular signal strengths, in addition to measurements from various sensors including the magnetometer, accelerometer, gyroscope, barometer, and ambient light sensor. The collection area spanned four dispersed sites with a total of 122 reference points. Each site is different in terms of its visibility to the Global Navigation Satellite System and reference points’ number, arrangement, and spacing. Before OutFin was made available to the public, several experiments were conducted to validate its technical quality.

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