Interactive Multiple Model-Based High-Resolution Tracking in Polar Form for Millimeter-Wave Radars

In this paper, we present an interactive multiple model (IMM) framework for high-resolution target tracking in millimeter-wave radars, using polar coordinates. Commonly, the motion models are formulated in Cartesian coordinates. However, the radar measurements originate in sensor-specific coordinates, which are often in polar form. We derive the Kalman prediction and update equations in polar coordinates for two motion models, viz., the constant velocity (CV) and the constant acceleration (CA) models. Further, we consider a combination of CV and CA models and derive the updates on the Markovian state transition probabilities for IMM. We derive state estimates using the IMM and quantify its computational complexity. We validate the proposed analysis using experiments based on Monte Carlo simulations and real-world radar data, in terms of target trajectories and root mean squared error.