scholarly journals GLONASS–only FDMA+CDMA RTK: Performance and outlook

GPS Solutions ◽  
2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Safoora Zaminpardaz ◽  
Peter J. G. Teunissen ◽  
Amir Khodabandeh
Keyword(s):  
Success Rate ◽  
Ambiguity Resolution ◽  
Formal Analysis ◽  
Integer Ambiguity Resolution ◽  
Integer Ambiguity ◽  
Short Baseline ◽  
Positioning Precision ◽  
The World ◽  
The Future ◽  
Insight Into

AbstractAn assessment of standalone GLONASS RTK performance is provided using its FDMA and CDMA signals. The new integer-estimable GLONASS FDMA model (Teunissen 2019), which guarantees the integer-estimability of its ambiguities, is employed. We introduce the combined integer-estimable GLONASS FDMA+CDMA model and compare its strength against the FDMA model for instantaneous integer ambiguity resolution and positioning. Various combinations of GLONASS signals are considered including FDMA L1, FDMA+CDMA L1+L3, FDMA L1+L2 and FDMA+CDMA L1+L2+L3. To provide insight into the current RTK performance of GLONASS, we used observations of a short baseline to analyze the integer ambiguity resolution success rate and positioning precision, formally and empirically. To provide insight into the future RTK performance of GLONASS, we present a formal analysis of the integer ambiguity resolution success rate and ADOP, assuming that all the GLONASS satellites transmit FDMA L1, L2 and CDMA L3 signals. A formal analysis of standalone GLONASS ambiguity resolution based on current and future GLONASS constellation is then presented for different locations around the world.

scholarly journals A Multi-Frequency Galileo PPP-RTK Convergence Analysis with an Emphasis on the Role of Frequency Spacing

2021 ◽  
Vol 13 (16) ◽  
pp. 3077
Author(s):  
Dimitrios Psychas ◽  
Peter J. G. Teunissen ◽  
Sandra Verhagen
Keyword(s):  
Ambiguity Resolution ◽  
Formal Analysis ◽  
Integer Ambiguity Resolution ◽  
Global Navigation Satellite Systems ◽  
Integer Ambiguity ◽  
Convergence Time ◽  
Frequency Separation ◽  
Dual Frequency ◽  
Single Receiver

The single-receiver integer ambiguity resolution-enabled variant of precise point positioning (PPP), namely PPP-RTK, has proven to be crucial in reducing the long convergence time of PPP solutions through the recovery of the integerness of the user-ambiguities. The proliferation of global navigation satellite systems (GNSS) supports various improvements in this regard through the availability of more satellites and frequencies. The increased availability of the Galileo E6 signal from GNSS receivers paves the way for speeding up integer ambiguity resolution, as more frequencies provide for a stronger model. In this contribution, the Galileo-based PPP-RTK ambiguity resolution and positioning convergence capabilities are studied and numerically demonstrated as a function of the number and spacing of frequencies, aiming to shed light on which frequencies should be used to obtain optimal performance. Through a formal analysis, we provide insight into the pivotal role of frequency separation in ambiguity resolution. Using real Galileo data on up to five frequencies and our estimated PPP-RTK corrections, representative kinematic user convergence results with partial ambiguity resolution are presented and discussed. Compared to the achieved performance of dual-frequency fixed solutions, it is found that the contribution of multi-frequency observations is significant and largely driven by frequency separation. When using all five available frequencies, it is shown that the kinematic user can achieve a sub-decimeter level convergence in 15.0 min (90% percentile). In our analysis, we also show to what extent the provision of the estimable satellite code biases as standard PPP-RTK corrections accelerates convergence. Finally, we numerically demonstrate that, when integrated with GPS, the kinematic user solution achieves convergence in 3.0 and 5.0 min on average and at 90%, respectively, in the presence of ionospheric delays, thereby indicating the single-receiver user’s fast-convergence capabilities.

Role of stochastic model on GPS integer ambiguity resolution success rate

GPS Solutions ◽  
2015 ◽  
Vol 20 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Ali Reza Amiri-Simkooei ◽  
Shahram Jazaeri ◽  
Farzaneh Zangeneh-Nejad ◽  
Jamal Asgari
Keyword(s):  
Stochastic Model ◽  
Success Rate ◽  
Ambiguity Resolution ◽  
Integer Ambiguity Resolution ◽  
Integer Ambiguity

scholarly journals Single-epoch RTK performance assessment of tightly combined BDS-2 and newly complete BDS-3

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Wanke Liu ◽  
Mingkui Wu ◽  
Xiaohong Zhang ◽  
Wang Wang ◽  
Wei Ke ◽  
...  
Keyword(s):  
Performance Assessment ◽  
Success Rate ◽  
Ambiguity Resolution ◽  
Satellite System ◽  
Asia Pacific ◽  
Single Frequency ◽  
Navigation Satellite ◽  
Short Baseline ◽  
Positioning Accuracy ◽  
Single Epoch

AbstractThe BeiDou global navigation satellite system (BDS-3) constellation deployment has been completed on June 23, 2020, with a full constellation comprising 30 satellites. In this study, we present the performance assessment of single-epoch Real-Time Kinematic (RTK) positioning with tightly combined BeiDou regional navigation satellite system (BDS-2) and BDS-3. We first investigate whether code and phase Differential Inter-System Biases (DISBs) exist between the legacy B1I/B3I signals of BDS-3/BDS-2. It is discovered that the DISBs are in fact about zero for the baselines with the same or different receiver types at their endpoints. These results imply that BDS-3 and BDS-2 are fully interoperable and can be regarded as one constellation without additional DISBs when the legacy B1I/B3I signals are used for precise relative positioning. Then we preliminarily evaluate the single-epoch short baseline RTK performance of tightly combined BDS-2 and the newly completed BDS-3. The performance is evaluated through ambiguity resolution success rate, ambiguity dilution of precision, as well as positioning accuracy in kinematic and static modes using the datasets collected in Wuhan. Experimental results demonstrate that the current BDS-3 only solutions can deliver comparable ambiguity resolution performance and much better positioning accuracy with respect to BDS-2 only solutions. Moreover, the RTK performance is much improved with tightly combined BDS-3/BDS-2, particularly in challenging or harsh conditions. The single-frequency single-epoch tightly combined BDS-3/BDS-2 solution could deliver an ambiguity resolution success rate of 96.9% even with an elevation cut-off angle of 40°, indicating that the tightly combined BDS-3/BDS-2 could achieve superior RTK positioning performance in the Asia–Pacific region. Meanwhile, the three-dimensional (East/North/Up) positioning accuracy of BDS-3 only solution (0.52 cm/0.39 cm/2.14 cm) in the kinematic test is significantly better than that of the BDS-2 only solution (0.85 cm/1.02 cm/3.01 cm) due to the better geometry of the current BDS-3 constellation. The tightly combined BDS-3/BDS-2 solution can provide the positioning accuracy of 0.52 cm, 0.22 cm, and 1.80 cm, respectively.

Applied Interval Based Integer Ambiguity Resolution

Navigation ◽  
2009 ◽  
Vol 56 (3) ◽  
pp. 205-219 ◽  
Author(s):  
E. VAN KAMPEN ◽  
E. DE WEERDT ◽  
Q.P. CHU ◽  
J.A. MULDER
Keyword(s):  
Ambiguity Resolution ◽  
Integer Ambiguity Resolution ◽  
Integer Ambiguity
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