New Advanced RAIM with Improved Availability for Detecting Constellation-wide Faults, Using Two Independent Constellations

ABSTRACT Recently there has been much interest in the feasibility of providing a robust LPV-200 service worldwide circa 2030 relying on RAIM. However, conventional RAIM methods that were developed for the en route through nonprecision approach phases of flight and assume up to a single fault are not adequate for LPV-200 applications. For these applications, constellation-wide faults may need to be considered. Among threats of this class, faults caused by erroneous earth orientation parameters (EOPs) have been identified to be of particular concern. Interconstellation comparison (ICC) methods were previously proposed to detect constellation-wide faults. However, these methods do not provide as high an LPV-200 availability as desired. This paper presents a new method that can detect constellation-wide faults using two independent constellations and examines its LPV-200 availability. This method has been shown to be very effective in detecting the EOP fault and provides significantly higher LPV-200 availability than the ICC methods