Auto-focusing UWB array radar imaging of a target in unknown motion using Muller and Buffington metrics and cross-range blurriness

We propose two target speed estimation methods for an ultra-wideband radar imaging system. The system consists of array antennas scanning while a target is moving. The proposed methods use the Muller and Buffington sharpness metric and cross-range blurriness of radar images to estimate the target speed, and compensate for the estimated motion to generate focused images automatically. The proposed methods are applied to the measurement of a knife, handgun and mannequin on an electrically-controlled moving stage. Measurement results showed that both the proposed methods can estimate target speeds, but with different accuracies. It was also confirmed that the proposed methods can generate high-quality images for moving targets with unknown speeds.