NIORAIM algorithm applied to a multiconstellation GNSS: Analysis of integrity monitoring performances in various phases of flight

Many studies have been conducted on RAIM to use GNSS navigation systems in those fields where very strict performances are required. In safety-of-life applications, such as aviation, in critical phases of flight such as approach and landing, integrity plays an extremely important role and integrity monitoring functions become necessary. To perform such task many algorithms have been proposed: NIORAIM is one of the most promising. NIORAIM uses non-uniform weights applied to the pseudo-range measurements of satellites involved in the position solution lowering the integrity levels, thus improving integrity availability at the cost of a very slight degradation of accuracy of the position solution.