基于VRS的GPS网络RTK差分改正方法

GPS NRTK correction method based on virtual reference station

为实现网络差分系统的高精度差分定位,利用虚拟参考站技术提出一种网络RTK差分改正信息的生成方法。利用VRS技术建模生成了虚拟参考站的双频伪距观测值、双频载波相位观测值,重点推导了关键的载波相位数据项参数的算法公式,遵循RTCM2.3国际标准协议编码生成了RTCM3、RTCM18、RTCM19号差分改正电文,通过同步实验的方法与标准RTCM相应的主要参数进行了数值对比。实验表明,该方法生成的差分改正信息主要数据项与标准值的误差小于0.04cycle,当被用于GPS网络差分定位时,移动站的平面精度优于5cm.

In order to realize precision positioning based on network difference, an method for calculating difference correction message of NRTK was proposed by virtual reference station technique. The double frequency pseudorange and carrier phase observation were simulated by VRS technique. The formula to calculate carrier phase, which is the crucial parameter of RTCM message, was derived in detail. The message for RTCM3, RTCM18 and RTCM19 is coded according to RTCM international protocol. The primary parameter of messages was compared with counterpoint of standard RTCM by isochronous observation experiment. The experiment results show that the error between the primary parameter and standard value is less than 0.04 cycle and the plane positioning precision error is less than 5 cm when the message is used to rover for network difference.