Abstract: An inertial measurement unit is provided in which an arrangement of linear accelerometers in fixed positions measure angular acceleration and other inertial characteristics. Only linear acceleration readings are required for measurement of angular acceleration, and both expensive angular sensors and cyclically driven linear accelerometers are eliminated. A processor receives the linear accelerometer signals and calculates output values related to both the angular and linear motion of the body. In the preferred embodiment, the inertial measurement unit includes at least nine linear accelerometers, three disposed with their respective sensitive axes in substantially mutually orthogonal relationship defining first, second and third axes intersecting at a single origin point, and a pair of linear accelerometers disposed along each axis spaced at fixed distances from the origin point with their sensitive axes in substantially orthogonal relationship with each other and the axis.