中文摘要：

分析了未能探测到的小周跳或粗差对GPS精密单点定位的影响,提出了一种改进的抗差Kalman滤波方法。该方法通过相位观测值验后残差分析,对传统抗差方案中等价权为0的情况进行周跳处理,能同时兼顾相位观测值中的粗差和小周跳问题。利用实测数据和模拟数据进行实验,结果表明,该方法不但可以显著改善未能探测的周跳对于定位结果的影响,同时避免了传统抗差方案中出现的后续历元相位残差持续增大的情况。

英文摘要：

The impact of small undetected cycle slip or outliers on precise point positioning is discussed and an improved robust Kalman filtering is proposed.The new method can deal with both small cycle slip and outliers well through analyzing the posteriori phase residuals.For phase observations with zero weight in traditional robust scheme,we reinitialize its ambiguity and keep its original weight.And for those may be contaminated by gross error,we lower its weight and enlarge the variance of its ambiguity.Both observed data and simulated data tests show that the new method can not only improve the positioning results significantly,but also avoid the bad influence of small undetected cycle slip,which may cause the continually increasement of phase observation residuals in subsequent epochs.