A system for estimating a receiver position with high integrity can include a reference station observation monitor configured to: receive a set of reference station observations associated with a set of reference stations, detect a predetermined event, and mitigate an effect of the predetermined event; a modeling engine configured to generate corrections; a reliability engine configured to validate the corrections; an observation monitor configured to: receive a set of satellite observations from a set of global navigation satellites corresponding to at least one satellite constellation; detect a predetermined event; and mitigate an effect of the predetermined event; a carrier phase determination module configured to determine a carrier phase ambiguity of the set of satellite observations; and a position filter configured to estimate a position of the receiver.