scholarly journals GPS/BDS triple-frequency cycle slip detection and repair algorithm based on adaptive detection threshold and FNN-derived ionospheric delay compensation

2020 ◽  
pp. 141-156
Author(s):  
Nijia Qian
Keyword(s):  
Detection Threshold ◽  
Ionospheric Delay ◽  
Cycle Slip ◽  
Adaptive Detection ◽  
Delay Compensation ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Slip Detection

scholarly journals Ionosphere-Constrained Triple-Frequency Cycle Slip Fixing Method for the Rapid Re-Initialization of PPP

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 117 ◽  
Author(s):  
Fuxin Yang ◽  
Lin Zhao ◽  
Liang Li ◽  
Jianhua Cheng ◽  
Jie Zhang
Keyword(s):  
Ionospheric Delay ◽  
Cycle Slip ◽  
Frequency Diversity ◽  
Cycle Slips ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Wide Lane ◽  
Data Gap ◽  
The Impact ◽  
Slip Detection

The re-initialization of precise point positioning (PPP) can be avoided by cycle slip detection and correction. Ionospheric delay is critical for cycle slip detection and correction, especially for a long data gap. The frequency diversity from GNSS modernization provides the potential for mitigating the impact of ionospheric delay on cycle slip detection and correction. The proposed method constructs the extra-wide lane (EWL), the wide lane (WL), and the narrow lane (NL) epoch-differenced linear combinations based on the ionosphere constrain criterion, so as to determine the undifferenced cycle slips from the cascading ambiguity resolution. The experiment results show that the cycle slips can be fixed correctly even though cycle slips occur in all the available carrier phase observations, and the 3 min data gaps can be merged without high precision positioning continuity loss. The kinematic experiment shows that the instantaneous re-initialization can be achieved with the proposed method.

Reliable real-time triple-frequency cycle slip detection and recovery with adaptive detection thresholds

2019 ◽  
Vol 30 (5) ◽  
pp. 055007 ◽  
Author(s):  
Chenlong Deng ◽  
Jianhui Cui ◽  
Weiming Tang ◽  
Xuan Zou ◽  
Liang Shu
Keyword(s):  
Real Time ◽  
Cycle Slip ◽  
Adaptive Detection ◽  
Detection Thresholds ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Slip Detection

scholarly journals Cycle Slip Detection during High Ionospheric Activities Based on Combined Triple-Frequency GNSS Signals

2019 ◽  
Vol 11 (3) ◽  
pp. 250 ◽  
Author(s):  
Dongsheng Zhao ◽  
Craig Hancock ◽  
Gethin Roberts ◽  
Shuanggen Jin
Keyword(s):  
Global Navigation Satellite System ◽  
Satellite System ◽  
Ionospheric Delay ◽  
Navigation Satellite ◽  
Cycle Slip ◽  
Cycle Slips ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Global Navigation Satellite ◽  
Slip Detection

The current cycle slip detection methods of Global Navigation Satellite System (GNSS) were mostly proposed on the basis of assuming the ionospheric delay varying smoothly over time. However, these methods can be invalid during active ionospheric periods, e.g., high Kp index value and scintillations, due to the significant increase of the ionospheric delay. In order to detect cycle slips during high ionospheric activities successfully, this paper proposes a method based on two modified Hatch–Melbourne–Wübbena combinations. The measurement noise in the Hatch–Melbourne–Wübbena combination is minimized by employing the optimally selected combined signals, while the ionospheric delay is detrended using a smoothing technique. The difference between the time-differenced ambiguity of the combined signal and this estimated ionospheric trend is adopted as the detection value, which can be free from ionospheric effect and hold the high precision of the combined signal. Five threshold determination methods are proposed and compared to decide the cycle slip from the magnitude aspect. This proposed method is tested with triple-frequency Global Navigation Satellite System observations collected under high ionospheric activities. Results show that the proposed method can correctly detect and fix cycle slips under disturbed ionosphere.

scholarly journals A Cycle Slip Repair Method Against Ionospheric Effects and Observational Noises for BDS Triple-Frequency Undifferenced Phases

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2819
Author(s):  
Dehai Li ◽  
Jinzhong Mi ◽  
Pengfei Cheng ◽  
Yunbin Yuan ◽  
Xingli Gan
Keyword(s):  
Detection Method ◽  
Satellite System ◽  
Ionospheric Delay ◽  
Observation Data ◽  
Cycle Slip ◽  
Cycle Slips ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Observational Noise ◽  
Slip Detection

The cycle slip detection (CSD) and cycle slip repair (CSR) are easily affected by ionospheric delay and observational noise. Aiming at mitigating the above disadvantage, a new BeiDou navigation satellite system (BDS) triple-frequency CSR method (BTCSR) is proposed for the undifferenced phase. BTCSR learns from the classic triple-frequency CSR (CTCSR), with combinations of phases and pseudoranges in correcting ionospheric delay and optimizing observational noise. Different from CTCSR, though, BTCSR has made the following improvements: (1) An optimal model of calculating cycle slip combination is established, which further takes into account the minimization of the effect of residual ionospheric error after the correction. The calculation of cycle slip combination is obtained with the root mean squared errors (0.0646, 0.1261, 0.1069) of cycles, resulting in CSR success rate of 99.9927%, and the wavelengths (4.8842,3.5738,8.1403) of m. (2) A discriminant function is added to guarantee the CSR correctness. This function utilizes epoch-difference value of the ionosphere-free and geometry-free phase to select the correct cycle slip value, which eliminates the interference of large pseudorange errors in determining the final cycle slip. Consequently, the performances of BTCSR and CTCSR have been compared. For the real BDS pseudorange observation with additional 1.5 m errors, which can cover situations of 99.96% pseudorange noise, results of CTCSR show failure, but results of BTCSR keep correct. Moreover, BTCSR has made the following improvements relative to the geometry-free cycle slip detection method (GFCSD) and Melboune–Wubbena cycle slip combination detection method (MWCSD): (1) During a moderate magnetic storm of level 6, CSR testing, with the BDS monitoring station in a low latitude region, showed that some failures occur in GFCSD because of severe ionospheric variation, but BTCSR could correctly identify and fix cycle slips. (2) For the BDS observation data with an additional 1.5 m error on the actual pseudoranges, MWCSD exhibited failures, but the repair results of BTCSR were correct and reliable. (3) For the special slips of (0,59,62) cycles, and equal slips of (1,1,1) cycles on (B1,B2,B3), that are hard to detect by GFCSD and MWCSD, respectively, BTCSR could repair these correctly. Finally, BTCSR obtains reliable repair results under large pseudorange errors and severe ionospheric variations, and the cut-off elevation larger than 10 degrees is the suggested background.

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.

A triple-frequency cycle slip detection and correction method based on modified HMW combinations applied on GPS and BDS

GPS Solutions ◽  
2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Dongsheng Zhao ◽  
Gethin Wyn Roberts ◽  
Craig M. Hancock ◽  
Lawrence Lau ◽  
Ruibin Bai
Keyword(s):  
Correction Method ◽  
Cycle Slip ◽  
Triple Frequency ◽  
Cycle Slip Detection ◽  
Slip Detection
Sign in / Sign up

Export Citation Format

Share Document