Investigation on Reference Frames and Time Systems in Multi-GNSS

Nicolini, Luca

doi:10.3390/rs10010080

Cited by 21 publications

(14 citation statements)

References 13 publications

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“…There were only nine GALILEO satellites available (April 2016) in Reference [21], but in our study 15 GALILEO satellites were available during our testing period (September 2017). Additionally, the results reported in Reference [37] show that the orbit and clock accuracies of GPS and GALILEO satellites are better than those of GLONASS and BDS satellites. The evaluation results in our study show, similarly, that the current accuracies of the real-time precise products of GPS and GALILEO satellites are better than those of GLONASS and BDS.…”

Section: Discussionmentioning

confidence: 97%

Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service

Wang

et al. 2018

Remote Sensing

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Precise Point Positioning (PPP) is a popular technology for precise applications based on the Global Navigation Satellite System (GNSS). Multi-GNSS combined PPP has become a hot topic in recent years with the development of multiple GNSSs. Meanwhile, with the operation of the real-time service (RTS) of the International GNSS Service (IGS) agency that provides satellite orbit and clock corrections to broadcast ephemeris, it is possible to obtain the real-time precise products of satellite orbits and clocks and to conduct real-time PPP. In this contribution, the real-time multi-GNSS orbit and clock corrections of the CLK93 product are applied for real-time multi-GNSS PPP processing, and its orbit and clock qualities are investigated, first with a seven-day experiment by comparing them with the final multi-GNSS precise product 'GBM' from GFZ. Then, an experiment involving real-time PPP processing for three stations in the Multi-GNSS Experiment (MGEX) network with a testing period of two weeks is conducted in order to evaluate the convergence performance of real-time PPP in a simulated kinematic mode. The experimental result shows that real-time PPP can achieve a convergence performance of less than 15 min for an accuracy level of 20 cm. Finally, the real-time data streams from 12 globally distributed IGS/MGEX stations for one month are used to assess and validate the positioning accuracy of real-time multi-GNSS PPP. The results show that the simulated kinematic positioning accuracy achieved by real-time PPP on different stations is about 3.0 to 4.0 cm for the horizontal direction and 5.0 to 7.0 cm for the three-dimensional (3D) direction.

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Section: Discussionmentioning

confidence: 97%

Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service

Wang

et al. 2018

Remote Sensing

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“…The results obtained indicated that the issue to overcame for the inclusion of the two satellites was related to the quality of their broadcast ephemerides. This drawback did not occur if sp3 precise orbits were used, whose goodness was verified by Sosnica et al [14] and by Nicolini and Caporali [21]. Figures 16 and 17 show the differences between the satellites' coordinates calculated by using the precise ephemerides and those calculated by using broadcast ones for the Milena (E14) and Doresa (E18) satellite.…”

Section: Resultsmentioning

confidence: 76%

Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits

Robustelli

Pugliano

2019

Remote Sensing

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On August 2016, the Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. As the Galileo constellation is not yet complete. It is very important to have two more satellites available since the position accuracy increases as the number of visible satellites increases. In this article, we examine how the inclusion of the Milena (E14) and Doresa (E18) satellites impacts the position accuracy. The analysis was carried out on 20 days of 1-Hz observations collected by a receiver placed in YEL2IGS (International GNSS service) station. Two different scenarios are considered: the first excludes the measurements coming from the analyzed satellites, while the second one includes them. The analysis was conducted by using a suitable software tool developed in the MATLAB® environment able to compute satellites position from both the broadcast and precise ephemerides, to assess DOP (Dilution Of Precision) parameters and to compute single-point positioning for all Galileo frequencies. The analyses are conducted by using both broadcast and precise ephemeris. The inclusion of the two satellites improves the system availability, varying it from 94.1–97.94%, the DOP parameters, and the percentages of achieved positioning solutions by about 5% regardless of the frequency used. Nevertheless, in the positioning domain, when the broadcast ephemerides are used, the inclusion of the satellites worsens both the horizontal and vertical accuracy of the solution. The deterioration of the horizontal accuracy goes from 0.17 m with E5a frequency measurements to 0.74 m with E1 measurements. The reduction of vertical accuracy goes from 0.68 m for E5a to 1.2 m for E1 measurements. However, if precise ephemerides are used, both the horizontal and the vertical accuracy remain stable, actually for the E5b frequency, the DRMS (Distance Root Mean Squared) improves by almost 0.5 m. The results achieved show that the real drawback to overcome is related to the quality of broadcast ephemeris as, when precise ephemeris are used, the number of solutions achieved is increased by about 5% with an accuracy similar to that obtained when the satellites are excluded.

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“…The superscript "ECI" indicates that the variable is expressed in the Earth Centered Inertial reference frame, whereas the subscript t 0 indicates the epoch the estimate refers to. The mean value of the estimateμ ECI t 0 is computed by propagating, for each object, its TLE to t = t 0 , computing its state vector in ECI reference frame x ECI t0 , computing the rotation matrix A ECI2RSW from ECI to radial, along-track, cross track (RSW) reference frame [22], and perturbing the state vector with a random vector ε ECI t 0…”

Section: Orbit Determination Refinementmentioning

confidence: 99%

Orbit Determination of Resident Space Objects Using the P-Band Mono-Beam Receiver of the Sardinia Radio Telescope

Losacco

Schirru

2019

Applied Sciences

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The population of space debris in near-Earth space is continuously growing and it represents a serious problem for active satellites and spacecraft. A performant ground-based and space-based network of sensors is necessary for space surveillance and consequently to prevent new collisions and monitoring atmospheric reentry of these objects. This paper illustrates the possible role of the Italian ground-based novel bi-static radar sensor, named BIRALET, for space monitoring and resident space objects tracking. The main characteristics of the receiver system, the Sardinia Radio Telescope with its P-band mono-beam receiver, are described in detail. Then, a preliminary analysis of the performance of the sensor is presented, and the results of numerical simulations are shown, providing a general overview on both observation capabilities and orbit determination accuracy achievable with the Sardinia Radio Telescope.

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Investigation on Reference Frames and Time Systems in Multi-GNSS

Cited by 21 publications

References 13 publications

Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service

Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service

Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits

Orbit Determination of Resident Space Objects Using the P-Band Mono-Beam Receiver of the Sardinia Radio Telescope

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