GPS receiver performance enhancement via inertial velocity aiding

An integrated GPS/INS navigation system can employ inertial velocity inform ation to produce a more robust system. For a stand-alone GPS receiver, decr easing the receiver tracking loop bandwidth reduces the probability of losi ng lock in a jamming or interference environment if vehicle dynamics are lo w. However, reduced bandwidth increases tracking errors when dynamics are p resent. Beyond a certain limit, it causes a serious degradation in the dyna mic tracking loop performance. Providing inertial velocity aiding to the re ceiver tracking loops is an effective and popular treatment to help resolve this problem. In this paper, performance of the GPS receiver tracking loop s using inertial velocity aiding will be investigated. Different types of t racking loops, from 1st to 3rd order, are covered. Following the discussion of the system architecture and derivation of the related transfer function s for the tracking loops, both with and without aiding, the system performa nce, including transient response, steady-state error, and noise bandwidth is evaluated.