Real-time PLKF= Predictive PLKF= max(PLKF,nom, PLKF,meas, Real-time PLKF,state) max(PLKF,nom, PLKF,meas, Predictive PLKF,state) Integrity algorithm against all sensor fault hypotheses can be applied for multi-sensor navigation system both prior to operation and in real-time operation.