GNSS-I/MR 河流边界及水位测量理论与仿真

This paper explored the feasibility of extracting the river boundary and measuring the river level using global navigation satellite system-interferometric/multipath reflectometry (GNSS-I/MR) from its geometry and theoretical models. Based on the difference in the dielectric constant between the bank and river and the fact that the bank has a slope relative to the river, two observational variables sensitive to river boundary, namely the reflected-to-direct ratio and the delay rate were defined. According to the estimated envelope and phase of carrier-to-noise ratio using Hilbert transform, this paper proposed the estimation method of the reflected-to-direct ratio based on a univariate quadratic equation and that of the delay rate based on linear fitting, as well as a 3-threshold maximum interclass variance-based algorithm to recognize river/bank and a looped fitting-based algorithm to extract the river boundary. The river level was measured based on the delay rate of the river surface. By setting up a simulation platform and designing two river scenarios, the effectiveness of the proposed method was verified through simulation.