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(IMUs) has allowed for the implementation of one sensor that will be able to measureorientation, acceleration and angular rate.An inertial measurement unit (IMU) is a versatile electrical sensor that combines theoutput from accelerometers, gyroscopes and magnetometers to give the three-dimensional(3D) orientation of an object. Thus, it is classified as a six degree of freedom motionsensor. There are different algorithms and mathematical relationships that have beenreported in literature that will fuse the sensor signals together in order to achieve the mostaccurate orientation estimation. Complementary and Kalman filters are two examples thathave been used in the research literature [Bachman, 2000; Luinge, & Veltink, 2005]. Thealgorithm used is highly dependent on the type of components used and in whatcombination the manufacturer has deemed necessary to achieve their desired output. Thusthe mathematical relationships and fusion algorithms will vary depending in the IMUdesign. The applications of orientation data is widespread amongst several industries,including: biomechanics, robotics, aerospace, underwater vehicles, automotive andvirtual reality [Bachman, 2000; Bachman, Yun, McKinney, McGhee, & Zyda, 2003;Brodie, Walmsley, & Page, 2008; Luinge, & Veltink, 2005; Waegli, & Skaloud 2007a,2007b].GPS is a well known technology that has been widely used to track the position andspeed of an object over land. It often is criticized for the accuracy of the position data,which can be up to ±20 m, and low update rates, which are typically in range of 1-5 Hz[Meyer, 2002]. The increasing availability of higher update rates is making it more28