Application of time-frequency analysis and Kalman filter to range estimation of targets in enclosed structures

Accurate range estimation and tracking of moving targets are important tasks in urban sensing. A dual-frequency radar, which estimate the range of a target based on the phase difference between two closely spaced frequencies, has been shown to be a cost-effective method to accomplish both tasks. When the data is processed using time-frequency analysis, phase difference and Doppler frequency signatures can be simultaneously obtained with noise resistance and target discrimination capability. In this paper, we consider robust range estimation based on Kalman filter that inherently fuses the phase difference and Doppler frequency information. Significant performance improvement is observed through simulation and real measurement examples.