Estimating Indoor Walking Velocity Profile Using a Software Radio-Based Radar

Radar is an attractive technology for long term monitoring of human movement as it operates remotely, can be placed behind walls and is able to monitor a large area depending on its operating parameters. A radar signal reflected off a moving person carries rich information on his or her activity pattern in the form of a set of Doppler frequency components produced by the specific combination of limbs and torso movements. Deploying radars in indoor environments poses however challenges for the interpretation of signals reflected off a moving object due to multipath propagation. Two strategies for the estimation of human walking velocity profile in indoor environments are suggested and discussed. The accuracy of the strategies are evaluated and compared in a field experiment using a flexible and low-cost software defined radar platform. The results obtained indicate that both methods are able to estimate the velocity profile of the person´s translational movement with less than 10% error.