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Whenever energy is exerted due to the mechanical movement of a moving subject, the energy can be measured and used for localization in indoor environments. As an example, a “Smart Floor” [23] was proposed with metallic plates that were instrumented with load cells, which used mechanical coupling between a moving person and the load cells. The plates were laid on the floor, and the signal captured via the load cell was processed in order to identify the person walking over a plate and the path they were taking. A more common example of exploiting mechanical energy for localization is via accelerometer (to measure acceleration) and gyroscope (to measure angular rotation) sensors. Such “inertial” sensors that are part of IMUs commonly found in smartphones can be used to estimate the trajectory of motion for a moving person or object, which can help with their localization in indoor environments [24]. In particular, such sensors are very useful to estimate the stride length and step counts for a person in motion, to determine their displacement over time. Techniques that use inertial sensors for localization are often referred to as “dead reckoning” techniques, as the location estimates provided by the sensors depend on previous measurements to estimate the absolute position or orientation of the object being tracked at any given instant. A challenge with using inertial measurements for localization is that the inertial sensors are susceptible to drift due to thermal changes in the circuitry of the sensors, calibration issues, and inherent noise [25].