Xsens has developed what it claims is the world"s smallest attitude and heading reference system. The MTi is a matchbox sized inertial measuring unit with solid state inertial sensors and earth-magnetic field sensors. It provides drift-free, gyro enhanced attitude and heading output with 0.5 degree accuracy, computed internally on a low power DSP, as well as 3D acceleration, 3D rate of turn and 3D magnetic field data.