Carrier phase cycle slips can be an important source of error in precise Global Navigation Satellite System (GNSS) positioning. In such cases, cycle slips can seriously compromise the positioning accuracy and reliability, especially for single-frequency receivers, which do not provide simultaneous measurements at different frequencies to generate effective linear combinations for cycle slip detection. We introduce a high-rate Doppler-aided cycle slips detection and repair (DACS-DR) method to detect and repair cycle slips in single-frequency low-cost GNSS receivers, which benefit from the availability of high-rate Doppler measurements. The distributions of the residuals of the time-differenced carrier phase minus the carrier phase change derived from Doppler observations are analyzed systematically under different sampling rates. A comparison is further performed between the low-cost and high-end receivers. Considering that the loss of lock indicator (LLI) output by receivers can also reflect the condition of cycle slips, the reliability of the LLI is also discussed based on our experimental receiver. Based on these analyses, the DACS-DR method is used in a float-PPP experiment with a data set collected under a difficult situation: a high-latitude urban canyon (Akureyry, northern Iceland, Dec. 2017) with intense ionospheric scintillation. The results demonstrate that the convergence time, positioning errors, and the number of re-convergence events are all significantly reduced with the proposed method. Furthermore, the RMS values of the positioning errors in the horizontal and vertical directions are improved by 44.2% and 21.2%, respectively.

中文翻译：

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低成本单频接收机的高速率多普勒辅助周跳检测与修复方法

载波相位周跳可能是精确定位全球导航卫星系统（GNSS）的重要误差来源。在这种情况下，周跳会严重影响定位精度和可靠性，特别是对于单频接收器而言，单频接收器无法同时提供不同频率的测量结果以生成有效的线性组合以进行周跳检测。我们引入了一种高速率多普勒辅助周跳检测和修复（DACS-DR）方法来检测和修复单频低成本GNSS接收机中的周跳，这得益于高速率多普勒测量的可用性。在不同的采样率下，系统地分析了时差载波相位减去从多普勒观测得到的载波相位变化的残差分布。进一步在低成本和高端接收机之间进行比较。考虑到接收器输出的锁定指示器（LLI）的丢失也可以反映周期滑移的情况，我们还基于实验接收器讨论了LLI的可靠性。基于这些分析，DACS-DR方法用于浮点PPP实验，其数据集是在困难的情况下收集的：高纬度城市峡谷（冰岛北部阿克雷里，2017年12月），电离层强烈闪烁。结果表明，所提出的方法显着减少了收敛时间，定位误差和重新收敛事件的数量。此外，水平和垂直方向上的定位误差的RMS值分别提高了44.2％和21.2％。