scholarly journals Assessment of Different Real Time Precise Point Positioning Correction Over the Sea Area

2019 ◽  
Author(s):  
Irwan Gumilar ◽  
Brian Bramanto ◽  
Teguh P Sidiq ◽  
Poerbandono . ◽  
Budi Mulyadi

In a global scale, the accuracy of Real Time Precise Point Positioning (RT-PPP) method in Global Navigation Satellite System (GNSS) point positioning is within cm to dm level. Unlike other conventional method in GNSS point positioning which used differential data to minimize the error sources, RT-PPP used additional orbit correction, clock correction and other atmospheric correction to minimize the error since RT-PPP is an absolute point positioning method. Currently, there are several providers who give the orbit correction and clock correction in real-time. Not only in the land area, this service can be also used in sea area. Thus, this research aims to analyse the differences in point determination derived from RT-PPP method by using several service providers in sea area. The RT-PPP data acquisition used three different receivers with unique service correction, namely RTX correction from Trimble Net R9 receiver, ATLAS correction from Hemisphere receiver and Veripos correction from Hemisphere receiver. All these antennas were set up on the ship with a controlled distance and the point coordinates were estimated from Seribu Island to Ancol, Jakarta with a different time interval for each receiver due to the technical limitations. To assess the point positioning stability, the distance between each antenna derived from point positioning then evaluated by comparing to its controlled distance. The results indicate that a time lag is found in Trimble Net R9 compared with the others, and it should be corrected first before applying the further analysis. In general, after removing the outliers, the distance and the precision between each antenna between Veripos-ATLAS is 4.472 ± 0.040 m, RTX-ATLAS is 2.054 ± 0.077 m and RTX-Veripos is 3.947 ± 0.060 m. Therefore, RT-PPP method can be used as an alternative in precise point positioning in sea area.

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2762 ◽  
Author(s):  
Lina He ◽  
Hairui Zhou ◽  
Yuanlan Wen ◽  
Xiufeng He

Although there are already several real-time precise positioning service providers, unfortunately, not all users can use the correction information due to either cost of the service and limitation of their equipment or out of the service coverage. An alternative way is to enhance the accuracy of the predicted satellite clocks for precise real-time positioning. Based on the study of existing prediction models, an improved model combing the spectrum analysis (SA) and the generalized regression neural network (GRNN) model is proposed especially for BeiDou satellite navigation system (BDS)-2 satellites. The periodic terms and GRNN-related parameters including length and interval of sample data, as well as a smooth factor, are optimized satellite by satellite to consider satellite-specific characteristics for all the fourteen BDS-2 satellites. The improved model is validated by comparing the predicted clocks of existing models and the improved model with precisely estimated ones. The bias of the predicted clock is within ±0.5 ns over three hours and better than that of the other models and can be used for several real-time precise applications. The clock prediction is further evaluated by applying clock corrections to precise point positioning (PPP) in both static and kinematic mode for eight IGS (International GNSS Service) MGEX (Multi-GNSS Experiment) stations in the Asia-Pacific region. In the static PPP, the improved model is validated to be effective, and position accuracies of some IGS MGEX stations achieve more than 30.0% improvements on average for each component, which enables us to obtain sub-decimeter positioning. In the kinematic PPP, the improved model performs much better than the others in terms of both the convergence time and the position accuracy. The convergence time can be shortened from 1–2 h to 0.5–1 h, while the position accuracy is enhanced by 15.4%, 21.6% and 19.3% on average in east, north and up component, respectively.


2016 ◽  
Vol 7 (6) ◽  
pp. 1856-1873 ◽  
Author(s):  
Raquel M. Capilla ◽  
José Luis Berné ◽  
Angel Martín ◽  
Raul Rodrigo

2014 ◽  
Vol 67 (3) ◽  
pp. 523-537 ◽  
Author(s):  
Aigong Xu ◽  
Zongqiu Xu ◽  
Xinchao Xu ◽  
Huizhong Zhu ◽  
Xin Sui ◽  
...  

On 27 December 2012 it was announced officially that the Chinese Navigation Satellite System BeiDou (BDS) was able to provide operational services over the Asia-Pacific region. The quality of BDS observations was confirmed as comparable with those of GPS, and relative positioning in static and kinematic modes were also demonstrated to be very promising. As Precise Point Positioning (PPP) technology is widely recognized as a method of precise positioning service, especially in real-time, in this contribution we concentrate on the PPP performance using BDS data only. BDS PPP in static, kinematic and simulated real-time kinematic mode is carried out for a regional network with six stations equipped with GPS- and BDS-capable receivers, using precise satellite orbits and clocks estimated from a global BDS tracking network. To validate the derived positions and trajectories, they are compared to the daily PPP solution using GPS data. The assessment confirms that the performance of BDS PPP is very comparable with GPS in terms of both convergence time and accuracy.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tamer Baybura ◽  
İbrahim Tiryakioğlu ◽  
Mehmet Ali Uğur ◽  
Halil İbrahim Solak ◽  
Şeyma Şafak

Real-time kinematic (RTK) technique is important for mapping applications requiring short measure time, the distance between rover and base station, and high accuracy. There are several RTK methods used today such as the traditional RTK, long base RTK (LBRTK), network RTK (NRTK), and precise point positioning RTK (PPP-RTK). NRTK and LBRTK are popular with the advantage of the distance, the time, and accuracy. In the present study, the NRTK and LBRTK measurements were compared in terms of accuracy and distance in a test network with 6 sites that was established between 5 and 60 km. Repetitive NRTK and LBRTK measurements were performed on 6 different days in 2015-2017-2018 and additionally 4 campaigns of repetitive static measurements were carried out in this test network. The results of NRTK and LBRTK methods were examined and compared with all relevant aspects by considering the results of the static measurements as real coordinates. The study results showed that the LBRTK and NRTK methods yielded similar results at base lengths up to 40 km with the differences less than 3 cm horizontally and 4 cm vertically.


GPS Solutions ◽  
2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Yulong Ge ◽  
Feng Zhou ◽  
Tianjun Liu ◽  
WeiJin Qin ◽  
Shengli Wang ◽  
...  

2013 ◽  
Vol 36 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Junping Chen ◽  
Haojun Li ◽  
Bin Wu ◽  
Yize Zhang ◽  
Jiexian Wang ◽  
...  

GPS Solutions ◽  
2018 ◽  
Vol 22 (3) ◽  
Author(s):  
Lin Pan ◽  
Xiaohong Zhang ◽  
Xingxing Li ◽  
Jingnan Liu ◽  
Fei Guo ◽  
...  

2018 ◽  
Vol 71 (4) ◽  
pp. 769-787 ◽  
Author(s):  
Ahmed El-Mowafy

Real-time Precise Point Positioning (PPP) relies on the use of accurate satellite orbit and clock corrections. If these corrections contain large errors or faults, either from the system or by meaconing, they will adversely affect positioning. Therefore, such faults have to be detected and excluded. In traditional PPP, measurements that have faulty corrections are typically excluded as they are merged together. In this contribution, a new PPP model that encompasses the orbit and clock corrections as quasi-observations is presented such that they undergo the fault detection and exclusion process separate from the observations. This enables the use of measurements that have faulty corrections along with predicted values of these corrections in place of the excluded ones. Moreover, the proposed approach allows for inclusion of the complete stochastic information of the corrections. To facilitate modelling of the orbit and clock corrections as quasi-observations, International Global Navigation Satellite System Service (IGS) real-time corrections were characterised over a six-month period. The proposed method is validated and its benefits are demonstrated at two sites using three days of data.


2019 ◽  
Vol 11 (3) ◽  
pp. 311 ◽  
Author(s):  
Wenju Fu ◽  
Guanwen Huang ◽  
Yuanxi Zhang ◽  
Qin Zhang ◽  
Bobin Cui ◽  
...  

The emergence of multiple global navigation satellite systems (multi-GNSS), including global positioning system (GPS), global navigation satellite system (GLONASS), Beidou navigation satellite system (BDS), and Galileo, brings not only great opportunities for real-time precise point positioning (PPP), but also challenges in quality control because of inevitable data anomalies. This research aims at achieving the real-time quality control of the multi-GNSS combined PPP using additional observations with opposite weight. A robust multiple-system combined PPP estimation is developed to simultaneously process observations from all the four GNSS systems as well as single, dual, or triple systems. The experiment indicates that the proposed quality control can effectively eliminate the influence of outliers on the single GPS and the multiple-system combined PPP. The analysis on the positioning accuracy and the convergence time of the proposed robust PPP is conducted based on one week’s data from 32 globally distributed stations. The positioning root mean square (RMS) error of the quad-system combined PPP is 1.2 cm, 1.0 cm, and 3.0 cm in the east, north, and upward components, respectively, with the improvements of 62.5%, 63.0%, and 55.2% compared to those of single GPS. The average convergence time of the quad-system combined PPP in the horizontal and vertical components is 12.8 min and 12.2 min, respectively, while it is 26.5 min and 23.7 min when only using single-GPS PPP. The positioning performance of the GPS, GLONASS, and BDS (GRC) combination and the GPS, GLONASS, and Galileo (GRE) combination is comparable to the GPS, GLONASS, BDS and Galileo (GRCE) combination and it is better than that of the GPS, BDS, and Galileo (GCE) combination. Compared to GPS, the improvements of the positioning accuracy of the GPS and GLONASS (GR) combination, the GPS and Galileo (GE) combination, the GPS and BDS (GC) combination in the east component are 53.1%, 43.8%, and 40.6%, respectively, while they are 55.6%, 48.1%, and 40.7% in the north component, and 47.8%, 40.3%, and 34.3% in the upward component.


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