Abstract: The INERTIAL SENSOR TRACKING SYSTEM is an overall system installation consisting of wireless body pack transmitters, broadband telemetry transceivers, computer and monitoring equipment, and emergency power generation for tracking personnel in an underground mine environment. The system is designed to function with normal primary power and on battery operation in the event of an emergency. In the past inertial sensors have been large spinning mass gyroscopes and large mass-based accelerometers. These inertial sensors have required high voltage three phase electrical supplies. The “wearable” body pack must be battery operated and the sensors must be small and lightweight. Micro-Electro-Mechanical (MEM) sensors fulfill both the requirements of low weight and low power consumption. The accuracy of the MEM sensor has been developed sufficiently to incorporate, with de-noising algorithms, an accurate position-sensing device.