A simple position estimator that improves advanced RAIM performance

We describe a simple method to determine a Global Navigation Satellite System (GNSS) position estimator for advanced receiver autonomous integrity monitoring (RAIM) that improves availability upon the commonly used least squares estimator. The idea consists in searching the estimator among all affine combinations of the all-in-view least squares estimator and a fault-tolerant estimator - the one corresponding to the most difficult fault to mitigate. Availability simulations show a significant improvement in vertical guidance coverage levels for a dual constellation scenario.