Determination of optimal satellite phase bias combinations for BeiDou triple-frequency PPP-RTK
Determination of optimal satellite phase bias combinations for BeiDou triple-frequency PPP-RTK
复制标题
北斗三频PPP-RTK最佳卫星相位偏差组合的确定
DOI：
10.1088/1361-6501/ab30fb
复制
发表时间：
2019
影响因子：
2.4
通讯作者：
Yuan Yunbin
中科院分区：
文献类型：
--
作者：
Chen Yongchang;Zhang Baocheng;Yuan Yunbin
实时动态精密单点定位（PPP-RTK）技术主要依靠基于卫星相位偏差（SPB）信息的整周模糊度解算，实现单台接收机的高精度实时定位服务。对于基于非组合观测的PPP-RTK技术，由于相关性强，基频SPB的精度较低，需要经常更新。因此，必须确定用于向用户传输的具有低更新率的北斗三频SPB的最适当线性组合。为了获得北斗三频SPB的组合，我们使用Z变换来处理SPB估计对应的协方差矩阵，以生成去相关的SPB组合。针对不同的情况，分别采用无几何、几何固定和几何加卫星钟的PPP-RTK方案对区域网数据进行处理。计算结果表明，B_1、B_2和B_3频率的初级稳定、次级稳定和三级稳定SPB组合分别为（0，−1，1），（1，2，-3），和（−33，−129，163）对于无几何变量，（0，−1，1），（1，2，−3）和（−21，−95，117）用于几何固定变体，（0，−1，1），（1，3，−4）和（−18，−84，103）用于几何加卫星时钟固定变体。此外，SPB序列的统计结果提供了大于7 d的主要稳定组合的稳定期。对于二级和三级稳定组合，无几何变量的稳定周期为12 h和5 h，几何固定变量的稳定周期为12 h和8 h，几何加卫星钟偏移变量的稳定周期为12 h和10 h。这些稳定期表明SPB信息应该多久更新一次，并为PPP-RTK服务器的计算资源分配提供有意义的见解。
The precise point positioning real-time kinematic (PPP-RTK) technique enables a single receiver to achieve high-precision and real-time positioning services, mainly relying on integer ambiguity resolution based on satellite phase bias (SPB) information. For the PPP-RTK technique based on uncombined observations, the SPBs of basic frequencies are available only at low precision because of high correlation and therefore need to be updated frequently. Thus, the most appropriate linear combinations of BeiDou triple-frequency SPBs with low update rates for transmission to users must be identified. To acquire combinations of BeiDou triple-frequency SPBs, we use the Z-transformation to process the covariance matrixes corresponding to SPB estimates to generate decorrelated SPB combinations. To meet different circumstances, geometry-free, geometry-fixed and geometry-plus-satellite-clock-fixed variants of PPP-RTK are applied to process data from the regional network. The computed results indicate that the primary stable, secondary and tertiary stable SPB combinations of B1, B2 and B3 frequencies are (0, −1, 1), (1, 2, −3), and (−33, −129, 163) for the geometry-free variant, (0, −1, 1), (1, 2, −3), and (−21, −95, 117) for the geometry-fixed variant, and (0, −1, 1), (1, 3, −4), and (−18, −84, 103) for the geometry-plus-satellite-clock-fixed variant. Furthermore, the statistical results of the SPB series provide stable periods of the primary stable combinations of longer than 7 d. For the secondary and tertiary stable combinations, the stable periods for the geometry-free variant are 12 h and 5 h, for the geometry-fixed variant 12 h and 8 h, and for geometry-plus-satellite-clock-offset variant 12 h and 10 h. These stable periods suggest how often the SPB information should be updated and provide meaningful insight for the allocation of the computing resources of the PPP-RTK server.