JOINT TIME-FREQUENCY TRANSFORM FOR RADAR RANGE DOPPLER IMAGING

Conventional radar imaging uses the Fourier transform to retrieve Dopp ler information. However, due to the complex motion of a target, the D oppler frequency shifts are actually time-varying. By using the Fourie r transform, the Doppler spectrum becomes smeared and the image is blu rred. Without resorting to sophisticated motion compensation algorithm s, the image blurring problem can be resolved with the joint time-freq uency transform. High-resolution time-frequency transforms are investi gated, and examples of applications to radar imaging of single and mul tiple targets with complex motion are given.