Two-Dimensional Absolute Velocity Estimation of Moving Targets by Real-Aperture Scanning Radar Using Multiorder Range Migration Fitting Method

Two-dimensional absolute velocity estimation of moving target is a key challenge for real-aperture scanning radar because 2-D velocity estimation methods suffer from low precision or heavy computation load. For example, the traditional Hough-transform-based method can only estimate the along-track velocity with one-order range migration. In this letter, a 2-D absolute velocity estimation method is proposed using the multiorder range migration information. The method extracts the multiorder range variation in adjacent echo sequences, and uses least-square linear fitting to estimate the along-track and cross-track velocity based on the relationship between the target echo and 2-D absolute velocity. Simulation experiments show that the velocity estimation error of the proposed method can be lower than 0.6 m/s, and the estimation time can be less than 1 s.