Integer Satellite Clock Combination for Precise Point Positioning with Ambiguity Resolution

2016 ◽  
Author(s):  
Garrett Seepersad ◽  
Simon Banville ◽  
Paul Collins ◽  
Sunil Bisnath ◽  
Fran�ois Lahaye
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Satellite Clock ◽  
Point Positioning ◽  
Clock Combination

scholarly journals Ambiguity Resolution In Precise Point Positioning Technique: A Case Study

2015 ◽  
Vol 5 (1) ◽  
pp. 53-60 ◽  
Author(s):  
S. Nistor ◽  
A. S. Buda
Keyword(s):  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Precise Point Positioning ◽  
Main Idea ◽  
Convergence Time ◽  
Powerful Method ◽  
Satellite Clock ◽  
Positioning Technique ◽  
Point Positioning

Abstract Because of the dynamics of the GPS technique used in different domains like geodesy, near real-time GPS meteorology, geodynamics, the precise point positioning (PPP) becomes more than a powerful method for determining the position, or the delay caused by the atmosphere. The main idea of this method is that we need only one receiver – preferably that have dual frequencies pseudorange and carrier-phase capabilities – to obtain the position. Because we are using only one receiver the majority of the residuals that are eliminated in double differencing method, we have to estimate them in PPP. The development of the PPP method allows us, to use precise satellite clock estimates, and precise orbits, resulting in a much more efficient way to deal with the disadvantages of this technique, like slow convergence time, or ambiguity resolution. Because this two problem are correlated, to achieve fast convergence we need to resolve the problem of ambiguity resolution. But the accuracy of the PPP results are directly influenced by presence of the uncalibrated phase delays (UPD) originating in the receivers and satellites. In this article we present the GPS errors and biases, the zenith wet delay and the necessary time for obtaining the convergence. The necessary correction are downloaded by using the IGS service.

scholarly journals Receiver Widelane Analysis and Its Effect on Precise Point Positioning

2014 ◽  
Vol XL-2 ◽  
pp. 133-136
Author(s):  
M. Elsobeiey
Keyword(s):  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Precise Point Positioning ◽  
The Other ◽  
Satellite Clock ◽  
Phase Measurements ◽  
Other Hand ◽  
Differential Methods ◽  
Point Positioning ◽  
Over Time

Typically, differential carrier-phase-based methods have been used in positioning applications that require high accuracy. The main advantage of differential methods is solving the carrier-phase ambiguities and obtain millimetre-level accuracy carrier-phase measurements. Recent studies showed that it is possible to fix the un-differenced carrier-phase ambiguities into integers which is well-known as un-differenced carrier-phase ambiguity resolution. Unfortunately, the IGS neglects satellite hardware delay during satellite clock corrections estimation process. In case of differential methods, however, this will not affect the user as all common errors between the reference and rover receivers will be cancelled out by. Point positioning, on the other hand, will be affected by neglecting satellite hardware delays as those hardware delays will be lumped into the carrier-phase ambiguities destroying its integer nature. To solve this problem, satellite clock corrections must be estimated based on clock correction for each observable bases. The user, on the other hand, can form the ionosphere-free linear combination and divide and fix its two components, namely widelane and narrowlane. If both ambiguities are successfully fixed, few millimetres level of accuracy measurements are then obtained. In this paper, one month (December, 2013) of GPS data is used to study the receiver widelane bias, its behaviour over time, and receiver dependency are provided. It is shown that the receiver widelane bias is receiver dependent, stable over time for high-grade geodetic receivers. These results are expected to have a great impact on precise point positioning (PPP) conversion time and PPP carrierphase ambiguity resolution.

scholarly journals GPS + Galileo + BeiDou precise point positioning with triple-frequency ambiguity resolution

GPS Solutions ◽  
2020 ◽  
Vol 24 (3) ◽  
Author(s):  
Pan Li ◽  
Xinyuan Jiang ◽  
Xiaohong Zhang ◽  
Maorong Ge ◽  
Harald Schuh
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Triple Frequency ◽  
Point Positioning

scholarly journals Galileo millimeter-level kinematic precise point positioning with ambiguity resolution

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Georgia Katsigianni ◽  
Felix Perosanz ◽  
Sylvain Loyer ◽  
Mini Gupta
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Point Positioning

scholarly journals GPS/BDS-2/Galileo Precise Point Positioning Ambiguity Resolution Based on the Uncombined Model

2020 ◽  
Vol 12 (11) ◽  
pp. 1853
Author(s):  
Jin Wang ◽  
Guanwen Huang ◽  
Qin Zhang ◽  
Yang Gao ◽  
Yuting Gao ◽  
...  
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Three Dimensional ◽  
Convergence Time ◽  
Wide Lane ◽  
3D Positioning ◽  
System Bias ◽  
Point Positioning ◽  
Raw Observations ◽  
Gps Observations

In this study, an uncombined precise point positioning (PPP) model was established and was used for estimating fractional cycle bias (FCB) products and for achieving ambiguity resolution (AR), using GPS, BDS-2, and Galileo raw observations. The uncombined PPP model is flexible and efficient for positioning services and generating FCB. The FCBs for GPS, BDS-2, and Galileo were estimated using the uncombined PPP model with observations from the Multi-GNSS Experiment (MGEX) stations. The root mean squares (RMSs) of the float ambiguity a posteriori residuals associated with all of the three GNSS constellations, i.e., GPS, BDS-2, and Galileo, are less than 0.1 cycles for both narrow-lane (NL) and wide-lane (WL) combinations. The standard deviation (STD) of the WL combination FCB series is 0.015, 0.013, and 0.006 cycles for GPS, BDS-2, and Galileo, respectively, and the counterpart for the NL combination FCB series is 0.030 and 0.0184 cycles for GPS and Galileo, respectively. For the BDS-2 NL combination FCB series, the STD of the inclined geosynchronous orbit (IGSO) satellites is 0.0156 cycles, while the value for the medium Earth orbit (MEO) satellites is 0.073 cycles. The AR solutions produced by the uncombined multi-GNSS PPP model were evaluated from the positioning biases and the success fixing rate of ambiguity. The experimental results demonstrate that the growth of the amount of available satellites significantly improves the PPP performance. The three-dimensional (3D) positioning accuracies associated with the PPP ambiguity-fixed solutions for the respective only-GPS, GPS/BDS-2, GPS/Galileo, and GPS/BDS-2/Galileo models are 1.34, 1.19, 1.21, and 1.14 cm, respectively, and more than a 30% improvement is achieved when compared to the results related to the ambiguity-float solutions. Additionally, the convergence time based on the GPS/BDS-2/Galileo observations is only 7.5 min for the ambiguity-fixed solutions, and the results exhibit a 53% improvement in comparison to the ambiguity-float solutions. The values of convergence time based on the only-GPS observations are estimated as 22 and 10.5 min for the ambiguity-float and ambiguity-fixed solutions, respectively. Lastly, the success fixing rate of ambiguity is also dramatically raised for the multi-GNSS PPP AR. For example, the percentage is approximately 99% for the GPS/BDS-2/Galileo solution over a 10 min processing period. In addition, the inter-system bias (ISB) between GPS, BDS-2, and Galileo, which is carefully considered in the uncombined multi-GNSS PPP method, is modeled as a white noise process. The differences of the ISB series between BDS-2 and Galileo indicate that the clock datum bias of the satellite clock offset estimation accounts for the variation of the ISB series.

scholarly journals Performance of Open Source Precise Point Positioning Software Using Single-Frequency GPS Data

2006 ◽  
Vol 41 (2) ◽  
pp. 79-86 ◽  
Author(s):  
Chalermchon Satirapod ◽  
Somchai Kriengkraiwasin
Keyword(s):  
Open Source ◽  
Precise Point Positioning ◽  
Main Tool ◽  
Single Frequency ◽  
Gps Data ◽  
Differential Gps ◽  
Satellite Clock ◽  
Positioning Accuracy ◽  
Point Positioning ◽  
Station Location

Performance of Open Source Precise Point Positioning Software Using Single-Frequency GPS Data This research aims to assess the performance of GPS Precise Point Positioning (PPP) with code and carrier phase observations from L1 signal collected from geodetic GPS receiver around the world. A simple PPP software developed for processing the single frequency GPS data is used as a main tool to assess a positioning accuracy. The precise orbit and precise satellite clock corrections were introduced into the software to reduce the orbit and satellite clock errors, while ionosphere-free code and phase observations were constructed to mitigate the ionospheric delay. The remaining errors (i.e. receiver clock error, ambiguity term) are estimated using Extended Kalman Filter technique. The data retrieved from 5 IGS stations located in different countries were used in this study. In addition, three different periods of data were downloaded for each station. The obtained data were then cut into 5-min, 10-min, 15-min and 30-min data segments, and each data segment was individually processed with the developed PPP software to produce final coordinates. Results indicate that the use of 5-min data span can provide a horizontal positioning accuracy at the same level as a pseudorange-based differential GPS technique. Furthermore, results confirm effects of station location and seasonal variation on obtainable accuracies.

Recent Developments in Precise Point Positioning

GEOMATICA ◽  
2012 ◽  
Vol 66 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S. Bisnath ◽  
P. Collins
Keyword(s):  
Real Time ◽  
Ambiguity Resolution ◽  
Carrier Phase ◽  
Precise Point Positioning ◽  
Solution Convergence ◽  
Similar Information ◽  
Recent Developments ◽  
Significant Step ◽  
Point Positioning ◽  
New Processing

In standard Precise Point Positioning (PPP), the carrier phase ambiguities are estimated as real-valued constants, so that the carrier-phases can provide similar information as the pseudoranges. As a consequence, it can take tens of minutes to several hours for the ambiguities to converge to suitably precise values. Recently, new processing methods have been identified that permit the ambiguities to be estimated more appropriately as integer-valued constants, as they are in relative Real-Time Kinematic (RTK) positioning. Under these conditions, standard ambiguity resolution techniques can be applied to strengthen the PPP solution. The result can be a greatly reduced solution convergence and re-convergence period, representing a significant step toward improving the performance of PPP with respect to that of RTK processing. This paper describes the underlying principles of the method, why the enhancements work, and presents some results.

An assessment of wide-lane ambiguity resolution methods for multi-frequency multi-GNSS precise point positioning

Survey Review ◽  
2019 ◽  
Vol 52 (374) ◽  
pp. 442-453 ◽  
Author(s):  
V. Duong ◽  
K. Harima ◽  
S. Choy ◽  
D. Laurichesse ◽  
C. Rizos
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Wide Lane ◽  
Point Positioning
Sign in / Sign up

Export Citation Format

Share Document