基于贝叶斯压缩感知的周跳探测与修复方法

Cycle slip detection and repair based on Bayesian compressive sensing

针对观测噪声对周跳探测与修复性能的影响,提出了一种新的利用贝叶斯压缩感知技术进行周跳探测与修复的方法.在历元间-站间载波相位双差观测模型的基础上,通过挖掘周跳信号的稀疏特性,获取感知矩阵,推导并建立稀疏周跳探测模型,利用稀疏贝叶斯学习中的相关向量机原理,结合周跳相关数据的先验信息,基于主动相关决策理论,进行回归估计获得周跳预测值的分布,进而实现周跳的探测与修复.实验表明,新方法在仅利用单频或双频载波相位观测量的情况下能有效探测并修复周跳,性能优于正交匹配追踪法及l_1范数法.

The presence of cycle slips corrupts the carrier phase measurement which is critical for high precision global navigation satellite system static or kinematic positioning.The process of cycle slips is comprised of detecting the slips,estimating its exact integer and making a repair.In this paper,a novel approach to cycle slip detection and repair based on Bayesian compressive sensing is proposed,in order to reduce the noise effects on the performances of cycle slip detection and repair.Unlike traditional cycle slip detection and repair methods,we exploit the sparse property of the cycle slip signal,aiming to obtain the perception matrix and establish the sparse cycle slip detection model.Then in order to estimate and repair the value of cycle slips,the residuals of carrier phase double difference and the interference noise between multiple satellites,when more than one satellite has cycle slips,are taken into consideration,which is used as prior information to obtain the likelihood expression for cycle slip signal.Finally,we use the prior information about signals based on relevance vector machine principle derived from sparse Bayesian learning to predict cycle slip distribution and then estimate the value of cycle slips.The novel approach is tested with the actual collection of satellite data in the experiment.It is shown that the novel approach proposed in this paper can effectively estimate cycle slips and achieve better performance than orthogonal matching pursuit and l1 norm based algorithm when the redundancy of carrier phase is large enough.In the case of single frequency carrier phase observation,when redundancy is not less than 7,the novel approach can completely detect and repair cycle slips;in the case of dual-frequency carrier phase observation,when cycle slips happen in four of the eight satellites,97.6% probability of accuracy is accomplished by the new approach.