北斗三频非差观测值的电离层周跳探测与修复

Ionospheric cycle slip detection and repair based on BDS triple-frequency undifferenced observations

针对历元间隔较大或电离层延迟较大的情况,采用两个无几何相位组合与一个最优无几何无电离层组合形成3个线性无关的探测量,将历元间高次差法引用到无几何相位组合探测量中,通过选取合适的探测阈值,使无几何相位组合能够正确探测到较大电离层影响情况下的不敏感周跳。此外,文中采用了一种特殊的无几何无电离组合观测量进行辅助修复,通过两次取整保证了周跳修复的准确性,避免了传统三频周处理中的搜索算法造成错误修复的问题,试验表明,文中算法可以正确探测与修复较大电离层影响情况下不同北斗卫星星座类型的所有小周跳组合以及不敏感周跳组合。

In the case of high ionospheric activity or long epoch interval, this paper uses two geometry-ree phase combinations and optimal geometry-free, ionospheric-free code-phase combination to form three nonlinear detections, and repair the cycle slip for compass triple-frequency phase data. The high difference geometry-flee phase combination by weakening ionospheric activity as well as the amplifying cycle slip can detect insensitive cycle slip under circumstance of high ionospheric activity or long epoch. In the other hand, this paper presents using one kind of special geometry-free and ionospheric-free code-phase combination aid repairing cycle slip, which ensure correct reparation rate of cycle slip by means of double- rounding and avoids incorrect results caused by traditional search method. At last the observation data of long epoch interval under circumstance of high ionospheric activity are used to conduct the experiment, The result shows that the method presented can detect and repair small cycle slip in the case of high ionospheric activity or long epoch interval for different satellites of compass.