BDS三频非差观测数据周跳探测与修复方法

随着三频技术的出现,多频观测量及其丰富的线性组合特性为周跳的探测与修复提供了新的契机。因此提出三频非差观测量线性组合对载波相位观测数据中周跳进行实时探测及修复的方法。该方法构造无几何无电离层的码相组合,并通过对历元间的电离层延迟变化量进行实时估计与消除,构造出第三组线性无关的周跳探测量。用30 s采样间隔的北斗三频实测数据对算法性能进行验证,试验结果表明:该方法可以有效地对各频点的周跳实现探测与修复,即使在电离层活跃的应用场景中,该方法依然具有较好的性能。

Detection and repair of cycle slips for undifferenced BDS triple-frequency observations

Cycle-slip detection and correction are important issues in high-precision Global Navigation Satellite System (GNSS) data processing. The presence of the new frequency introduces more observations and degrees of freedom in data combination, which is beneficial for cycle-slip detection and repair. We proposed a novel real time cycle-slip detection and repair method based on undifferenced triple-frequency observations. This method employs two groups of geometry-free and ionosphere-free combinations of code and carrier phase observables, and constructs the third linearly independent detector for cycle-slip by eliminating the ionospheric delay variation between two consecutive epochs. The performance of the proposed method is validated with BeiDou triple-frequency observations with 30-s sampling interval. Results show that this method can effectively detects and corrects the cycle slips on each frequency, even under high ionospheric activity condition.