Vessel tracking by landmark bases

This work continues exploratory research aimed at improving methods using isolines of key navigation parameters traditionally applied in coastal navigation. The previously proposed idea of combining isolines for a single landmark base based on measured bearings and distances has been extended to multiple landmark bases, with tracking of four landmarks considered the basic option. Assuming the presence of irregular and regular measurement errors, regular errors are first compensated by transitioning to differential isolines in a general form. Next, the isolines or position line equations are presented in a reduced standard form and then solved using the least squares method. To compare different solutions, the accuracy of the obtained fixed position is estimated by the radial error. It is shown that regular errors are compensated when position lines are presented in a reduced standard form, but their reduction also allows compensating residual effects caused by the computational procedure. The most important findings of the research are visualized, and the main expressions are practically applied in the software of modern navigation systems. Simulation has shown that the radial error of the fixed vessel position, calculated from 26 reduced position lines presented in the standard form for four landmarks, is nearly twice less than the requirement for GNSS systems. Formalization of the proposed methods in state-of-the-art navigation systems and autonomous vessels will allow solving navigation information processing problems in coastal navigation at a new qualitative level.