Cycle-Slip Processing Under High Ionospheric Activity Using GPS Triple-Frequency Data

2016 ◽  
pp. 411-423
Author(s):  
Lingling Chen ◽  
Lixin Zhang
Keyword(s):  
Cycle Slip ◽  
Frequency Data ◽  
Triple Frequency

scholarly journals Improved Cycle Slip Repair with GPS Triple-Frequency Measurements by Minifying the Influences of Ionospheric Variation and Pseudorange Errors

2021 ◽  
Vol 13 (4) ◽  
pp. 556
Author(s):  
Dehai Li ◽  
Yamin Dang ◽  
Yunbin Yuan ◽  
Jinzhong Mi
Keyword(s):  
Success Rate ◽  
Cycle Slip ◽  
Frequency Data ◽  
Success Rates ◽  
Precise Positioning ◽  
Ionospheric Effects ◽  
Triple Frequency ◽  
Basic Work ◽  
Cycle Slip Detection ◽  
Phase Data

In advance of precise positioning with phase data, cycle slip detection (CSD) is a basic work that should be implemented in phase data possessing. When the cycle slip occurred, cycle slip repair (CSR) can be taken to rebuild the continuity of phase data. Unfortunately, the large pseudorange errors can contaminate the combinations with the pseudoranges and phases such as the Hatch–Melbourne–Wubbena combination (HMW) and cause false CSD or wrong CSR results. On the other hand, the severe ionospheric time variation can deteriorate the epoch-difference geometry-free phase (GF), and tremendously interfere with the performances of CSD and CSR. To handle the aforementioned limitations, a global position system (GPS) triple-frequency CSR method (GTCSR) is proposed with two efficient treatments: (1) the significant ionospheric variations are corrected, and the influences from the residual ionospheric effects are minimized along with the observational noises; and (2) the impacts of large pseudorange errors are refrained by designing a discrimination function with a geometry-free and ionosphere-free phase to identify the correct cycle slip values. Consequently, CSR tests were conducted with three monitoring stations at different regions. First, during a strong geomagnetic storm, without correcting the ionospheric variation of CSR (WICSR) displayed obvious failures, and many epochs of cycle slip values from WICSR deviated from the known values. However, the results of the GTCSR were correct, and GTCSR presented a higher success rate than that of WICSR. Furthermore, for the real triple-frequency data, by adding gross errors of 2.5 m on all epoch-difference pseudoranges epoch by epoch, the conventional triple-frequency CSR with the optimized combinations (CTCSR) and the CSD with HMW (HMWCSD) showed many mistakes, where the results of CTCSR and HMWCSD on numerous epochs were inconsistent with the actual situations, but the success rate of GTCSR was significantly higher than those of CTCSR and HMWCSD. In summary, in the condition of the cutoff elevation being larger than 10 degrees, improved performances and higher success rates were achieved from GTCSR under environments of large pseudorange errors and severe ionospheric variations.

Accuracy Analysis of Ionospheric Prediction Models for Repairing Cycle Slips for BeiDou Triple-Frequency Observations

2019 ◽  
Vol 72 (06) ◽  
pp. 1565-1584 ◽  
Author(s):  
Yao Yifei ◽  
Cao Xinyun ◽  
Chang Guobin ◽  
Geng Hongsuo
Keyword(s):  
Prediction Models ◽  
Satellite Orbit ◽  
Ionospheric Delay ◽  
Earth Orbit ◽  
Cycle Slip ◽  
Step Method ◽  
Cycle Slips ◽  
Triple Frequency ◽  
Phase Combination ◽  
Repair Cycle

Both the code–phase combination and the Geometry-Free (GF) phase combination are widely employed to detect and repair cycle slips for BeiDou Navigation Satellite System (BDS) triple-frequency observations. However, the effect of residual ionospheric delay on Narrow-Lane (NL) or GF observations must be considered to avoid incorrect cycle–slip estimation. To improve the accuracy in repairing cycle slips, a corrective ionospheric delay value predicted from the previous ionosphere sequence is used to amend the NL or GF observations at the current epoch. The main purpose of the work reported here is to evaluate the efficacy of a three-step method proposed to detect and repair cycle slip using two extra-wide-lane code–phase and one GF phase combination observations. BDS triple-frequency data were processed in two stages: separate processing of geosynchronous Earth orbit satellites, and the division of inclined geosynchronous satellite orbit and medium Earth orbit satellites into two groups for processing at 30° elevation thresholds. Results revealed that using the prediction models to correct NL or GF observations could ensure a rounding success rate of cycle slip close to 100%, even under high ionospheric activity.

Real-time cycle-slip detection and repair for BeiDou triple-frequency undifferenced observations

Survey Review ◽  
2016 ◽  
Vol 48 (350) ◽  
pp. 367-375 ◽  
Author(s):  
Y.-F. Yao ◽  
J.-X. Gao ◽  
J. Wang ◽  
H. Hu ◽  
Z.-K. Li
Keyword(s):  
Real Time ◽  
Cycle Slip ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Time Cycle ◽  
Slip Detection

scholarly journals Instantaneous Triple-Frequency GPS Cycle-Slip Detection and Repair

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Zhen Dai ◽  
Stefan Knedlik ◽  
Otmar Loffeld
Keyword(s):  
Time Algorithm ◽  
Cycle Slip ◽  
High Data ◽  
Cycle Slips ◽  
Triple Frequency ◽  
Test Criteria ◽  
Cycle Slip Detection ◽  
Phase Data ◽  
Low Phase Noise ◽  
Slip Detection

A real-time algorithm to detect, determine, and validate the cycle-slips for triple-frequency GPS is proposed. The cycle-slip detection is implemented by simultaneously applying two geometry-free phase combinations in order to detect more insensitive cycle-slips, and it is applicable for high data rate applications. The cycle-slip determination adaptively uses the predicted phase data and the code data. LAMBDA technique is applied to search for the cycle-slip candidates. The cycle-slip validation provides strict test criteria to identify the cycle-slip candidates under low phase noise. The reliability of the proposed algorithms is tested in different simulated scenarios.

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