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

Yao, Yanjie; Gao, Jingxiang; Wang, J.; Hu, Hong; Li, Z.-K.

doi:10.1080/00396265.2015.1133518

Cited by 20 publications

(25 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The observables of EWL and WL were still suffered from the ionospheric delay. Yao et al (2016) proposed to take the mean value of the residual ionospheric delay from several previous epochs to compensate for the current epoch; however, this was not applicable to severe ionospheric disturbances conditions between adjacent epochs. (Li et al (2018), Chang et al (2019) and Li et al (2019) put forward the method in which polynomial interpolation fitting was applied to the residual ionospheric delay of the previous epochs, and a prediction was made using extrapolation to compensate for the current epoch, but Runge phenomenon is easily generated at polynomial interpolation node.…”

Section: Basic Observable Equationsmentioning

confidence: 99%

“…This sparsity makes it possible for FNN to fit for ionospheric delay of the neighboring epochs. Another problem exists in cycle slip processing is that the standard deviation of the code and carrier phase observables noise are usually set to 0.3 m and 0.003 m, respectively, so as to calculate the fixed detection thresholds (Wu et al, 2010;Yao et al, 2016), which may generate misjudgments or leakage judgments as measurement surroundings change. Therefore, to reduce the effect of extrapolation error and to adapt to other measurement noise including stochastic noise, multipath and so on, a reliable but simple detection threshold is promising.…”

Section: Basic Observable Equationsmentioning

confidence: 99%

“…According to triple-frequency theory, the STD forms of triple-frequency code combination and carrier phase combination can be expressed by Eqs. 5and 6 (Yao et al, 2016…”

Section: Code-phase Combinationmentioning

confidence: 99%

See 2 more Smart Citations

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

Qian¹

2020

Acta Geodynamica Et Geomaterialia

View full text Add to dashboard Cite

A refined triple-frequency cycle slip detection and repair algorithm for GPS/BDS undifferenced observables under high ionospheric disturbances is proposed. In this method, three linearindependent optimal observables combinations for GPS/BDS are selected. The residual ionospheric delay estimated from a "calculation-prediction mechanism", namely flexibly determine whether to calculate delay by observables themselves or to predict delay by a feedforward neural network (FNN), is used to compensate for the detection values. Additionally, we devise an adaptive detection threshold based on actual noise level to detect the cycle slip, and adopt the modified least-square decorrelation adjustment (MLAMBDA) to fix integer cycle slip. The performance of the proposed algorithm was tested with observables at 30 s sampling rate in a 2-day geomagnetic storm period. Results showed that the proposed algorithm can detect and repair all kinds of cycle slips as small as one cycle in the case of high ionospheric disturbances. No false repairs are generated despite the occurrence of very few misjudgments.

show abstract

Section: Basic Observable Equationsmentioning

confidence: 99%

Section: Basic Observable Equationsmentioning

confidence: 99%

See 1 more Smart Citation

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

Qian¹

2020

Acta Geodynamica Et Geomaterialia

View full text Add to dashboard Cite

show abstract

“…This assumption cannot be valid under high ionospheric activities, e.g., strong ionospheric scintillation, or for the observations with low sampling rate, e.g., 30 s. Besides that, the method to eliminate the ionospheric bias may lead to the measured value being inaccurate and thus losing sensitivity to cycle slips with one cycle magnitude. A similar ionospheric prediction method was also applied by Yao et al [25], in which several previous carrier-phase observations without cycle slips are required to correct the ionospheric bias. This prediction method can only effectively predict the time-differenced ionospheric delay when the data epoch interval is no larger than 5 s [26].…”

Section: Literature Reviewmentioning

confidence: 99%

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

et al. 2019

View full text Add to dashboard Cite

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.

show abstract

“…In processing data, cycle-slip greater than 10 cycles will be easily discovered, whereas it is difficult to discover cycle-slip smaller than 10 cycles, particularly the small cycle-slip with 1 to 5 cycles. Polynomial fitting, high-order finite-difference, ionized layer remnant and wavelet analysis are routine methods for detecting cycle-slip [2][3][4][5][6]. Among these methods, polynomial fitting is inapplicable because it requires phase change rate and such measurement isn't accessible in some receivers, failing to detect small cycle-slip with one to five cycles [7].…”

Section: Introductionmentioning

confidence: 99%

Small cycle-slip detection of single-frequency in BDS based on SVD

Gao

Huang

Zhang

et al. 2015

The 27th Chinese Control and Decision Conference (2015 CCDC)

View full text Add to dashboard Cite

To accurately detect and position small cycle slip is critical for high-precision BeiDou Navigation Satellite System (BDS) data processing. Thus, a method based on singular value decomposition (SVD) was proposed in this paper for detecting single-frequency small cycle-slip. First of all, detectable quantity of cycle-slip was measured according to observations of pseudo-range and carrier-phase. Then, a track matrix of attractors was constructed with Hankel matrix and processed with SVD to determine the singular value that reflected abrupt information. At last, signal components were reconstructed by inverse operations and transformation of reflexive space through SVD to detect cycle-slip pursuant to the position of signals in case of the maximum value. The experimental results suggested that the method put forward in this paper was effective for precisely detecting small cycle-slip within one to five cycles based on observations of single-frequency carrier-phase.

show abstract

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

Cited by 20 publications

References 21 publications

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

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

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

Small cycle-slip detection of single-frequency in BDS based on SVD

Contact Info

Product

Resources

About