利用GNSS反射信号载波测量湖面高度变化

Lake height variation measurement utilizing GNSS reflected signal carrier phase

给出一种利用导航卫星反射信号的载波相位测量光滑湖面高度变化的方法.首先建立载波相位观测方程,通过在直射与反射信号的观测量之间求单差,再在历元间求双差的方法,消除了大量误差并得到了直射与反射信号的几何路径差;然后根据各颗卫星的观测值和高度角等信息计算出湖面高度变化,并把各卫星得到的湖面高度度变化值进行加权平均以提高测量系统的精度和可靠性.仿真验证了方法在-15 dB信噪比下达到了毫米级的测量精度.

A lake height variation measurement method utilizing global navigation satellite system （GNSS） reflected signal carrier phase was given. Carrier phase observation equations were built firstly. Then the single-differences between the carrier phase observation measurements for direct and reflected signal and the double-differences between epochs were calculated. A large amount of errors was eliminated by the differencing process. Also, the geometry path differences of direct and reflected signal were derived. The lake height variation was calculated using observation measurement and elevation information from separate satellite. The weighted average of the lake height variations from various satellites was derived to improve the precision and reliability of the measuring system. Simulation confirms that the precision of millimeter order is achieved with the method under -15 dB signal to noise ratio（SNR）.