Assistance requirements definition for GNSS receivers in hostile environments

Increasing sensitivity and robustness of navigation receivers in hostile environments has become a central topic for the GNSS community. The paper investigates the use of assistance information allowing GNSS receivers' operations even in denied environments, characterized by high dynamics and low C/N0. The main assistance information will be discussed and, for each of them, a set of requirements definition will be presented, allowing weak GNSS signal acquisition and trackin