User localization using ultrasonic presence sensing systems

We consider an ultrasonic sensor system deployed for indoor presence detection. In such a presence sensing system, we are interested in the problem of user localization using time-difference-of-arrival (TDOA) measurements collected, due to transmission from sensors in different time slots, at a particular sensor. We present a tracking algorithm to improve estimation of TDOA values resulting from a user movement. Subsequently the localization algorithm to obtain user position from the estimated TDOA values is described. Validation of the algorithms is done using an experimental setup to demonstrate proof-of-concept in an office setup.