An integrated GPS/INS navigation system can employ inertial velocity information to produce a more robust system. For a stand-alone GPS receiver, decreasing the receiver tracking loop bandwidth reduces the probability of losing lock in a jamming or interference environment if vehicle dynamics are low. However, reduced bandwidth increases tracking errors when dynamics are present. Beyond a certain limit, it causes a serious degradation in the dynamic tracking loop performance. Providing inertial velocity aiding to the receiver tracking loops is an effective and popular treatment to help resolve this problem. In this paper, performance of the GPS receiver tracking loops using inertial velocity aiding will be investigated. Different types of tracking loops, from 1st to 3rd order, are covered. Following the discussion of the system architecture and derivation of the related transfer functions for the tracking loops, both with and without aiding, the system performance, including transient response, steady-state error, and noise bandwidth is evaluated.

This paper presents an integrated INS (Inertial Navigation System) and camera-based navigation system. The camera-based navigation system provides position measurement aiding to the INS. This is an alternative to the more conventional GPS (Global Positioning System) aided INS. The system is intended for UAVs (Unmanned Aerial Vehicles) and long-range missiles. The basic principles of camera-based navigation are presented. The Kalman filter based integration of INS and camera-based navigation is discussed. Total system simulation results are shown together with INS simulations for comparison. Finally, a brief overview of factors that improve the navigation accuracy is presented.

Several military and commercial platforms are currently installing GPS and inertial navigation sensors concurrently with the introduction of high-quality visual capabilities and digital mapping/imagery databases. This enables autonomous geo-registration of sensor imagery using GPS/inertial position and attitude data, and also permits data from digital mapping products to be overlaid automatically on the sensor imagery. This paper describes the system architecture for a Navigation/Electro-Optic Sensor Integration Technology (NEOSIT) software application. The design is highly modular and based on commercial off-the-shelf (COTS) tools to facilitate integration with sensors, navigation and digital data sources already installed on different host platforms.