Compact Sensor System for Target Localization
Stian Tafjord Hovde · NORA - Norwegian Open Research Archives · 2017
The main topic of this thesis is to design a compact sensor system that provides target localization functionality.The system should be low cost, small and lightweight, so it can be mounted on a standard assault rifle.To localize a given target, the system has to both determine its own position, and the distance and direction to the target.The most challenging part of this is to determine the heading.To find this heading, our system uses a dual antenna Global Navigation Satellite System (GNSS) receiver.Because of the risk of GNSS signals being jammed, our proposed system also includes a stereo camera and an inertial measurement unit (IMU).Together these are able to maintain heading reference for a period of time after the loss of GNSS signals.The data from our sensors are fused in an error state Kalman filter implemented in Navigation Laboratory (NavLab).Test results show that with the short antenna baseline available in this system, the GNSS receiver still gives a good heading estimate, if we compensate for receiver bias.Results also show that addition of the stereo camera reduces the heading drift by a factor of at least 2. In the worst case scenario, an acceptable heading is maintained for up to 5 minutes without GNSS, with some assumptions.It is concluded that the designed sensor system is a viable device to extract target coordinates in the field.The results achieved in this thesis provide a good foundation for further work on this subject.