High-accuracy heading determination

In a system of systems context, a variety of applications are dependent on the knowledge of location and attitude of individual agents in order to collaborate. For example, a soldier on the battle field observing a potential target transmits this information to a base station which then is shared with an unmanned air vehicle for surveillance. Without precise knowledge of the soldier's position and azimuth angle to the target, the handoff to the UAV would not carry much merit. The availability of low-cost MEMS inertial measurement units (IMU) increases the feasibility of realizing a compact inertial navigation systems (INS) capable of operating in a variety of environments, including GPS degraded or denied scenarios. Due to errors in the IMU, it is very challenging to self-initialize the attitude of the device in a reasonable time frame. In this paper, we present a novel approach that utilizes a unique magnetohydrodynamic (MHD) angular rate sensor (ARS) in a carouseling configuration in order to perform attitude self-initialization to within 4-milli radians in less than a minute. Further more, real environmental issues, such as platform vibration and base motion (e.g. sinking) are also addressed.