The dual-frequency carrier phase observation equation is built and ionosphere-free predigested, the estimate formula of zenith wet delay is deduced with least square method.
建立了双频载波相位观测模型，并将其进行无电离层延迟化简，用最小二乘原理推导了天顶湿延迟的估值公式。
2
The machine adopts dual-frequency conversion timing technology and Japan panasonic transducer, assuring every part drives synchronously.
采用双变频调速技术，日本松下变频器，保证机器各部位运行同步。
3
However, slightly different paths of carrier L1 and L2 will bring errors to estimations of the dual-frequency method.