Hybrid fault detection technique in assisted GNSS

High sensitivity GNSS receivers tracking weak signals have been developed for indoor applications and to operate in urban canyons. They allow tracking GNSS satellites when the signal is strongly attenuated by structures, walls and buildings. The signal at receiver level is distorted by many reflected components. A coherent error model depending on receiver C/N0 measurement for indoor and deep urban scenarios may take into account errors components due to thermal noise, short and medium multipath and it may be exploited in the navigation algorithms (i.e. WLS, kalman filter).