GNSS网络RTK算法模型及测试分析

Model of GNSS network RTK algorithm and test analysis

针对GNSS网络差分系统软件的特点,比较分析双频P码伪距法、双频线性组合法2种宽巷模糊度的解算方法,给出解算结果的约束条件.然后采用改进的无电离层组合并根据模糊度的约束条件计算L1,L2的双差模糊度ΔN1,ΔN2.由ΔN1和ΔN2计算出的参考站间大气误差以及主站、虚拟参考站、卫星之间的空间向量关系构造出虚拟参考站的虚拟观测值.测试结果表明:系统软件的各项技术指标满足规范要求,平均初始化时间为27s,平面外符合精度x方向为2.8cm,y方向为1.7cm,高程方向为7.9cm.算法模型准确可行,系统各组成部分可靠性、稳定性好,能保持24h连续运行.

According to the characteristic of global navigation satellite system （GNSS） network realtime kinematic （RTK） software, two methods of resolving wide-lane ambiguity, double frequency P code pseudo range and double frequency linear combination, are compared, and constrained conditions for results are given. Then, an improved non-ionosphere combination method and the constrained conditions are adopted to compute double difference ambiguities of L1 and L2, which are abbreviated asΔ↓ΔN1 and Δ↓Δ N2, respectively. Finally, virtual observation can be constructed based on atmosphere errors among two reference stations and the space vector relationship among main station, virtual reference and satellite. The results show that the qualifications meet criterion requirements. The average initialization time is 27 s; the out accuracies are 2. 8 cm in x direction, 1.7 cm in y direction, and 7.9 cm in H direction. The algorithm models are accurate and feasible. The reliability and stability of the system is good. Continuous operation can be maintained for 24 h.